Recent Ph.D. Theses
| Name | Title | Year | Research Group |
|---|---|---|---|
| Mohammad Motaharifar | Control Structure Design and Implementation for Eye Surgery Training Dual Master Haptic System Abstract Surgery training have always been one of the most important challenges for the surgeons. Owing to the higher accuracy required in eye surgery than in other surgeries, any mistake made by the trainee might lead to undesired complications for the patient. Recently, dual-user haptic systems consisting of two haptic consoles, one for the trainer and one for the trainee, has been developed as an assistive tool to facilitate surgery training. In these systems, the trainer and the trainee collaboratively perform surgical tasks through their haptic consoles. In the proposed surgery training haptic system, the environment is directly manipulated by one surgeon and the other surgeon is indirectly involved in the procedure through the haptic system. This makes a special training framework which is applicable to not only virtual environment but also real environments such as physical phantoms, cadavers and patients with special focus on the vitrectomy surgery. Initially, the surgery is directly performed by the trainer and the position of the trainer is transformed to the trainee’s hands through the haptic system. Utilizing this step, the trainee can increase his/her expertise in different tasks by learning the true movements. After obtaining the required level of surgical skills, the trainee can perform the surgery directly on the environment with trainer’s supervision. To avoid undesired complications, the trainer is able to interfere into the procedure in the case of sudden mistakes happens by the trainee. Due to the interaction between the users in the dual user haptic systems, the decision of each user is affected by the other user. Hence, new application-based control structures are required to be further investigated. The majority of the previously proposed control methodologies for this system have not simultaneously considered special requirements of surgery training and stability analysis of the nonlinear closed-loop system which is the objective of this thesis. In order to describe the objectives and facilitate controller design for dual user haptic systems, this thesis introduces two training approaches including Expert Continual Action (ECA) and Expert Supervision & Intervention (ES&I). The ECA training approach is based on the trainer to perform all details of surgical operation, while the trainee freely experiences the task and receives the haptic guidance signals from the trainer. The control schemes based on ECA are appropriate for the most primary level of training in which the trainee does not have sufficient experience to perform the operation. On the other hand, the ES&I training approach is based on giving the trainee the chance to conduct the surgical operations and be supervised and corrected as needed, while the trainer is provided with the facilities to interfere in the operation and correct probable mistakes made by the trainee. In this approach, the trainer is not required to be involved at every stage of surgical procedures. Thus, the trainer is just given a supervisory role to interfere with the procedure only when a mistake is performed by the trainee. Notably, a unique feature of the proposed training structure is its application to remote training with real environment. In this case, one surgeon holds the surgical instrument and directly performs the surgical procedure, whereas the other surgeon is indirectly involved in the surgical operation through the haptic system. This requires a specially designed haptic system for each surgical task to provides the necessary movements required for that surgery. This issue is specially studied for the vitrectomy surgery and the designed haptic system is presented. In brief, the main contribution of this thesis is to introduce the above training approaches and develop some control schemes based on each training approach. Each control scheme is developed based on its respective training approach by utilizing the necessary mathematical tools of control theory. The stability of the closed-loop system for each control scheme is studied using input-to-state stability (ISS) analysis. Besides, some simulation and experimental results are presented to support the proposed methodologies. Finally, the specially designed haptic system for facilitating vitrectomy surgery training is presented. | 2019 | Surgical Robotics |
| Seyed Ahmad Khalilpour | Robust Control and Stability Evaluation of a Suspended Cable Robot considering the cable Dynamics Abstract Known for their lower costs and numerous applications, cable robots are attractive research fields in the robotic community. However, considering the fact that they require an accurate installation procedure and calibration routine, they have not yet found their true place in real-world applications. This thesis aims to propose a new control strategy that requires no meticulous calibration and installation procedures and can handle the uncertainties induced as a result of that. It should be noted that cable-driven robots generally cover a large-scale workspace. As such, the cable dynamics can not be ignored and phenomena such as cable flexibility may cause undesirable vibration. Therefore, in large cable-driven robots, the challenge of kinematic uncertainty is not the only problem to be solved and in addition to it, the cable dynamics should also be considered during the design procedure of the controller. The problem becomes more complicated when we consider the fact that in a deployable robot, accurate and expensive measurement tools are not generally available. In the field of robotics, most of the common control systems are based on a cascade structure in which the inner controller is assumed to be a fast high-bandwidth controller, and the outer controller (a user-specified control loop) is responsible for the robot’s main objective: trajectory tracking. The effectiveness of such an approach depends on the assumption that the inner loop controller is fast enough, and thus its dynamics may be ignored. In practice, such an assumption generally does not hold. Therefore, In chapter 2 of this thesis, we analyze the whole structure of the cascade controller and investigate the effect of selected structures and coefficients for the inner loop controller. In addition to this, an inner loop controller is designed to mitigate the adverse effects of dynamic uncertainties (of the actuators and power transmission systems, i.e. pulleys) on force tracking. These effects are more notable when the cables are directly driven by the motors. Chapter 3 extends the study presented in the previous chapter by deriving a model for a spatial cable-driven robot with flexible cables and employing the singularity perturbation theory for analyzing it. In this chapter, assuming a flexible dynamic model for cables, we propose a robust cascade control method and investigate the effects of inner-loop force controllers on the robot’s performance. In chapter 4, the cable model is extended and the effects of both cable mass and flexibility are investigated simultaneously. In this chapter, we employ the passivity theorem to propose a new control law which exploits an information fusion method. Finally, in order to illustrate the performance of the proposed controller, we present the results of an experiment on a deployable suspended cable-driven robot, which shows the effectiveness of the proposed controller in the presence of the uncertainties. | 2019 | Parallel and Cable Robotics |
| Alireza Norouzzadeh Ravari | Efficient representation of outdoor environment in mobile robotic simultaneous localization and mapping problem based on the information complexity Abstract Several algorithms are proposed for solving the Simultaneous Localization And Mapping (SLAM) problem for mobile robots. An efficient representation is required for large scale environment exploration and long term navigation, which is the main concern of this thesis. For this purpose, observations of sensors such as stereo camera or Microsoft Kinect are represented as a linear combination of atoms of a parametric dictionary by sparse modeling technique. The parametric dictionary is composed of Gaussian functions. In order to perform loop closure detection, the Normalized Compression Distance (NCD) is employed from information theory. The performance of this technique is analyzed in some indoor and outdoor environments. In addition, it has been proved that the developed environment representation is transformation invariant in the sense of Kolmogorov complexity. Furthermore, another environment is developed based on the Non Uniform Rational B-Spline (NURBS) for more accurate environment representation, simpler obstacle detection and smooth path planning. The NURBS-based environment representation is equipped with all of the sparse model benefits such as lower dimensionality, representation of information complexity, transformation invariance, parametric representation and uniqueness. Also, in contrast to the conventional environment representation methods, discrete sensor observation can be expressed in a continuous parametric space. This makes the obstacle detection simple and parametric representation of robot's path possible. The applicability of the proposed method is shown by several experiments on indoor and outdoor data-sets. | 2016 | Autonomous Robotics |
| Azadeh Zarif Loloei | Workspace Optimization of Spatial Cable-Driven Redundant Parallel Manipulators Abstract Since late 1980s, the study of cable driven parallel robots has received increasing attention. Using cables instead of rigid links in parallel robots makes them a suitable choice to remedy some of the traditional shortcomings of conventional robots. Replacing rigid links by the cables, however, introduces new challenges in the study of cable driven robots, of which design and workspace analysis are the most critical ones. One of the most important challenges propounded in cable mechanisms area is their workspace analysis. Researches ever done in this regard suffer from some deficiencies such as too much calculation in the numerical methods and complexity of the analytic methods and their weakness in analyzing the workspace of spatial robots with more than one degree of redundancy. Fundamental wrench introduced in this study is a new horizon in workspace analysis. Fundamental wrenches not only have presented an interesting insight in workspace analysis area, they have been also effective in calculating the optimal cable force in the presence of the external forces. One of the assessments done on workspace is that of robot performance which is practicable through kinematic criteria. In this thesis, with due attention to the absence of a comprehensive criterion in cable mechanisms area and considering the attributes of the fundamental wrench, force sensitivity criterion has been proposed. Aside from expressing the ratio of cable force variations to the external forces, this index also analyses the robot singularity and controllability in the workspace. Controllability is one of the essential insights in cable robots workspace. The performance of Nasir spatial cable driven redundant parallel schemes has been further studied considering the proposed method in workspace analysis and force sensitivity criterion. Mani conceptual design has been proposed with the purpose of optimizing the previous designs. Then with the usage of multipurpose optimizing methods such as genetic algorithm, Pareto-optimal solution has been obtained in a way that the end functions have been optimized simultaneously. The results obtained from simulations confirm the practicability of the proposed methods in workspace analysis, cable kinematic criterion, conceptual designing and its optimization. | 2014 | Parallel and Cable Robotics |
| Mohammad A.Khosravi | Modeling and Robust Control of Redundant Parallel Cable Robots Considering Longitudinal Flexibility in Cables Abstract Since late 1980s, the study of cable driven parallel robots has received increasing attention. Using cables instead of rigid links in parallel robots, makes them a suitable choice to remedy some of the traditional shortcomings of conventional robots. Replacing rigid links by the cables, however, introduces new challenges in the study of cable driven robots, of which control and the dynamic behavior of the cables are the most critical ones. Cables are usually elastic elements and may encounter elongation and vibration. Therefore, elasticity in cables may cause position and orientation errors for the moving platform. This problem is a critical concern in applications where high bandwidth or high stiffness is a stringent requirement. It should be noted that modeling the dynamic effects of elastic cables is an extremely comprehensive task. Furthermore, it is also important to note that the obtained models must not only be sufficiently accurate, they must be usable for controller synthesis, as well. Therefore, in practice it is proposed to include only the dominant effects in the dynamic analysis. According to this approach, In this thesis axial spring is used to model dominant dynamics of the cable and a new and more precise model of the cable-driven robot with elastic cables is derived and being used in the control design and stability analysis. Using obtained model, three control algorithms are proposed to cope with vibrations due to inevitable elasticity of the cables. The first algorithm is formed in the cable length space and the stability of the closed-loop system is analysed through Lyapunov’s second method. Next, dynamics of the cable robot with elastic cables is rewritten to the standard form of singular perturbation theory. Using results of this theory, second and third control algorithms are proposed in the task space for this class of robots. Then, by separation of slow and fast variables stability analysis of the closed-loop system with proposed algorithms are performed. The third control algorithm uses popular PID control in its structure. Although it has simple structure which is a benefit in the implementation process, it can robustly stabilize the system. Simulation and experimental results verify the effectiveness of the proposed control algorithms and show that these algorithms can stabilize the system and efficiently cope with vibrations due to elasticity in the cables. | 2013 | Parallel and Cable Robotics |
| Ala Shariati Dehaghan | H∞ Control of Input delay systems with Derivative Feedback Abstract This thesis presents H∞ controller design for input delay systems with derivative feedback in presence of both constant and time-varying delay. By this control law, the resulting closed-loop system turns into a specific time-delay system of neutral type with both delayed-term coefficients depending on the control law parameters. proportional-derivative state feedback and output derivative feedback are two examples of this control law. In this thesis, these two examples are fully investigated. In some practical problems such as active vibration suppression systems the state-derivative signals are easier to access than the state variables. To this aim, an H ∞ -based state-derivative feedback control problem for input-delayed systems has been considered in this thesis, as an special case of proportional-derivative state feedback. Moreover, we have addressed an H ∞ PD controller for input-delayed systems, which leads to the aforementioned special closed-loop system of neutral type. It can be easily shown that designing a PD controller for an augmented plant model with an integrator, is equivalent to the design of a PI controller for the original plant model. Considering this fact and widespread application of PI controller in industrial plants, the significance of the developed theory will be better appreciated. Lyapunov-Krasovskii functional has been used for the design of both H ∞ proportional-derivative state feedback and H ∞ PD/PI controller for input delay systems. Consequently, new delay-dependent sufficient conditions for the existence of both H ∞ proportional-derivative state feedback and H ∞ state-derivative feedback in presence of uncertain delay are derived in terms of some matrix inequalities. Furthermore, descriptor model transformation is used to derive delay-dependent sufficient conditions for the existence of H ∞ PD/PI controller in terms of some matrix inequalities as well. The resulting H ∞ controllers stabilize the closed-loop neutral system and assure that the H ∞ -norm to be less than a prescribed level. Some application examples are presented to illustrate the effectiveness of the proposed methods. | 2012 | Dynamical Systems Analysis and Control |
| Hooman Sadjadian | Kinematic Modeling, Dynamic Analysis and Position Control of a Redundant Hydraulic Shoulder Manipulator with Proper Force Distribution Abstract | 2006 | Parallel and Cable Robotics |
| Sadjaad Ozgoli | Design and Implementation of Position Controller for Flexible Joint Robot Subject to Actuator Saturation Abstract The desire for higher performance from the structure and mechanical specifications of robot manipulators has spurred designers to come up with flexible joint robots (FJR). Several new applications such as space manipulators and articulated hands necessitate using FJRs. This necessity has emerged new control strategies required, since the traditional controllers implemented on FJRs have failed in performance. Since 1980's many attempts have been made to encounter this problem and now, several methods have been proposed including various linear, nonlinear, robust, adaptive and intelligent controllers. Among these, only a few researchers have considered practical limitations such as actuator saturation in the controller synthesis, although it is a real practical drawback to achieve good performance. On the other hand actuator saturation has been considered by the control community from early achievements of control engineering. During 50's and 60's at the beginning era of optimal control, researchers have been working on saturation, introducing bang-bang control methods. Over the last decade the control research community has shown a new interest in the study of the effects of saturation on the performance of systems. In fact it can be said that in the past, researchers were encountered actuator saturation as a drawback and they had developed methods to avoid it, while now researchers develop methods to achieve a desirable performance in the presence of actuator saturation encountered as a limitation. A common classical remedy for systems with bounded control is to reduce the bandwidth of the control system such that saturation seldom occurs. This is a trivial weak solution, since even for small reference commands and disturbances the possible performance of the system is significantly degraded. This idea (reduction in bandwidth by reduction in the closed loop gain) is practical and "easy", hence it motivates some researchers to propose an "adaptive" reduction in bandwidth consistent with the actuation levels. The "adaptation" process is done under supervision of a supervisory loop, and as proposed in a paper, it can be accomplished through complex computations, which seem not to be practically implementable. In order to come up with an online implementable controller in presence of saturation, we have proposed a fuzzy logic supervisory control in this work. In this topology, the fuzzy logic is set to be "out of the main loop", at a supervisory level, at the aim of preserving the essential properties of the main controller. This idea is then modified to use with composite controller for FJRs. It is observed in various simulations that by including this supervisory loop to the controller structure, the steady state performance of the system is preserved, and moreover, the stability of the overall system which may be affected by addition of a saturation block, will retain. In other words the supervisor can remove instability due to saturation. The stability analysis of the overall system, however, is essential for the closed loop structure for susceptible applications of the FJRs such as space robots. Robust stability proof for the "composite + supervisor" method has been also given in detail in this thesis. A second approach has been also proposed in this thesis. The robust methods proposed in this approach are simpler than the previous method (composite + supervisor) in structure, and moreover, they need only the feedback of the link position. In this approach using a frequency weighted penalty function of the control action is recommended in the mixed sensitivity minimization. Furthermore, in order to decrease the amplitude of the control action while keeping the desired bandwidth, a mixed minimization method has been also proposed. Numerical controller design has obtained using LMI method. Simulations verify the superior performance of the mixed method compared to that of the composite PID+PD controller and the mixed sensitivity controller. In this thesis, practical implementations of the proposed methods have also accomplished to verify the theoretical results. These implementations illustrate the effectiveness of the proposed methods in practice. | 2005 | Flexible Robotics |
Recent M.Sc. Theses
| Name | Title | Year | Research Group |
|---|---|---|---|
| Negar Hojati | Presentation and implementation of performance evaluation procedure ARAS Haptic System for eye Surgery Training (ARASH:ASiST) Abstract These days, with the advancement of robotic science, the use of haptic systems has become commonplace in surgical training. ARASH:ASiST Eye Surgery Training System can provide a suitable framework for vitrectomy surgery training and surgeon skill assessment. In this study, after reviewing the existing methods of evaluating surgeon’s skills, we present the proposed method and finally apply it on the dataset from the ARASH:ASiST experiments and analyze the results. The traditional method of training and evaluating a surgeon is solely based on seeing, doing, and learning, which has many disadvantages, including inaccurate surgeon evaluation, outcome-based assessment, the possibility of harm to the patient, and the need for a specialist physician at each stage of training and evaluation. Various methods have been suggested so far to automate the training and evaluation process for novice surgeons. Recent algorithms have received increasing attention to machine learning methods, which has also been addressed in this study. In this study, by extracting key features of tool movements, it has been attempted to categorize surgeons with high accuracy into two or three levels, novice, intermediate and expert surgeons. | 2020 | Surgical Robotics |
| Amirhossein Safari | Torque Distribution Optimization in Two-wheel-drive Electric Motorcycle Abstract Extensive advances in the electric motorcycle industry have made it possible to build and control two-wheel-drive motorcycles, which is studied in this thesis. The effect of torque distribution on the handling and energy consumption of such motorcycles are investigated in details. For this purpose, various motorcycle models are reviewed. In general, the motorcycle models investigated show the oscillating, unstable, and non-minimum phase modes for such system. Using these models and using the neural network approach to obtain one of the main parameters (roll) for the system, a specific model is developed. Variant handling indexes are analyzed in different maneuvers, and according to form of maneuver and by presenting a supervisory control system, the operational framework of optimal torque distribution is determined. Finally, the simulation of the motorcycle has been performed in the powerful BikeSim software, and variant maneuvers were considered. In this study the system performance with and without active torque distribution is evaluated based on handling and energy indices. The results of the simulations show that the total steer torque required by the rider is reduced by 12%, which results in the comfort of riding control. Furthermore, the relation of total steer torque with different handling indexes has been investigated and the direct relationship between them are reported. In addition, in direct paths with different acceleration and braking scenarios, it is shown that the use of this algorithm reduces the energy consumption of the motorcycle by about 10%. | 2020 | --- |
| Reza Heidari | Design and Implementation of Impedance Control on Dual-user System for Eye Surgery Training Abstract Haptic devices can be used to set the motor skills of a novice surgeons in order to train them on how to perform cataract or vitrectomy eye surgeries. The ARASH:ASiST haptic system facilitates the procedure of surgery training by involving the expert and novice physicians in the process and providing the appropriate haptic feedback. The proposed framework for training is composed of two sections. First, the surgery is directly conducted by the expert surgeon. At the same time, the novice surgeon receives these correct movements through the haptic system. It helps the novice surgeon by increasing his/her level of competence in different tasks by learning the expert’s maneuvers. Second, the novice surgeon performs the surgery with the supervision of the expert. The proposed training framework allows the expert surgeon to intervene immediately into the process as many times as needed in order to avoid undesired complications. This intervention is due to the sudden mistakes happens by the trainee. Due to the interaction between two users and the environment and because of the exerted forces importance, a novel robust impedance scheme is proposed for utilizing in its control system. The stability analysis is presented by considering the closed-loop stability of the nonlinear system. The experimental results are implemented on the ARASH:ASiST haptic device, which is specially designed for vitrectomy surgery. Altogether, the main contribution of this thesis is to design a robust switching gain impedance controller for medical training purposes with a mechanical pedal mechanism to switch the dominant user during the procedure. The simulation and experimental results confirm the effectiveness of the proposed control algorithm in enhancing surgery training quality level. | 2020 | Surgical Robotics |
| Rooholla Khorrambakht | Sensor Fusion For Calibration and Control of ARAS Suspended Cable-Driven Robot Abstract Owing to their simple structures and low costs, cable-driven parallel manipulators are strong candidates for many industrial and civil applications. In this family of manipulators, the deployable cable-driven robots hold a special place. These robots may be quickly installed at a new location, which makes a big array of applications possible. However, deployability imposes challenges in terms of implementation, calibration, and control of the robot. For implementation, the system components must be modular and easy to install. Furthermore, the utilized embedded systems must be light-weight and power-efficient while being powerful enough to handle the computations in real-time. For calibration, the algorithms must be accurate and simple to perform while requiring no specialized sensors. Finally, a suitable control system requires high-quality feedback from the end-effector’s pose, which for a deployable robot, has to be achieved using low-cost sensors. This thesis proposes a unified framework for fusion and kinematic calibration, based on factor graphs and the GTSAM library, which is flexible and easy to expand. Furthermore, the required sensors and embedded systems for the robot have been developed such that they satisfy the deployability criteria. This research is comprised of three phases. In the first phase, the suitable sensors and embedded systems for the ARAS-CAM robot have been investigated and developed. Next, throughout the second phase, the kinematic calibration has been addressed, and its importance for proper fusion and state estimation has been investigated. Finally, in the third phase, the potential fusion scenarios for the ARAS-CAM robot have been analyzed, and a unified fusion and calibration framework has been proposed. The implementation results show the suitability of proposed algorithms for accurate calibration and localization of the robot not requiring any expensive sensors and complicated procedures, which a prerequisite for deployability. | 2020 | Parallel and Cable Robotics |
| Mohammad Amin Kashi | Predicting Depth from Semantic Segmentation using Game Engine Dataset Abstract Depth perception is fundamental for robots to understand the surrounding environment. As the view of cognitive neuroscience, visual depth perception methods are divided into three categories, namely binocular, active, and pictorial. The first two categories have been studied for decades in detail. However, research for the exploration of the third category is still in its infancy and has got momentum by the advent of deep learning methods in recent years. In cognitive neuroscience, it is known that pictorial depth perception mechanisms are dependent on the perception of seen objects. Inspired by this fact, in this thesis, we investigated the relation of perception of objects and depth estimation convolutional neural networks. For this purpose, we developed new network structures based on a simple depth estimation network that only used a single image at its input. Our proposed structures use both an image and a semantic label of the image as their input. We used semantic labels as the output of object perception. The obtained results of performance comparison between the developed network and original network showed that our novel structures can improve the performance of depth estimation by 52% of relative error of distance in the examined cases. Most of the experimental studies were carried out on synthetic datasets that were generated by game engines to isolate the performance comparison from the effect of inaccurate depth and semantic labels of non-synthetic datasets. It is shown that particular synthetic datasets may be used for training of depth networks in cases that an appropriate dataset is not available. Furthermore, we showed that in these cases, usage of semantic labels improves the robustness of the network against domain shift from synthetic training data to non-synthetic test data. | 2020 | Autonomous Robotics |
| Mohammad Isaac Hosseini | Design and implementation of a high speed ploter cable-driven robot and its control system Abstract The art of drawing and painting has long been associated with human life. The application and importance of this issue have caused in recent decades to see robots called painter robots in various industrial and non-industrial applications. Therefore, in this thesis, using the structure of cable robots, the design, construction, and control of painting robots are discussed, which not only have low implementation costs but also by having high speed and acceleration can convey the concept of the desired drawing to the audience in a finite time. To achieve this, first, a new cable structure has been proposed for this group of robots that can improve the oscillations and unwanted rotations of the system as much as possible without the need for additional actuators. Also, to free the robot from external sensors, the proposed controllers in the joint space have been designed. Although this significantly reduces implementation costs, if proper controllers are not adopted in this space, due to the challenges mentioned for cables, the optimal tracking, and even system stability will be overshadowed. Therefore, in the continuation of this research, a robust nonlinear controller and a robust adaptive controller have proposed in such a way that they ensure the cables are in tension and the resulting fluctuations are damped. furthermore, thanks to using the time-delay estimation technique in the scheme of proposed controllers, the dynamics model of the robot is not also needed. Also, the stability of the closed-loop system will be analyzed and proven through Lyapunov’s direct method. Finally, the Kamal-ol-Molk painter robot is introduced and built as an example of the proposed structure, and the results of the implementation of the proposed controllers on it show the effciency of these methods in practical applications. | 2020 | Parallel and Cable Robotics |
| Amirhossein Samii | Design of Regenerative–Friction Braking System an Electric Motorcycle to Optimize Battery Life a Brake-to-Battery Charging Abstract In this approach, a regenerative friction braking system is designed to optimize battery lifetime and recurrent charge. Regenerating energy of braking is of high importance when it comes to electric motorcycles and electric machines. The recurrent energy produced by braking directly affects the battery lifetime which is a challenging issue to be considered. The recovered energy may be returned to the battery properly by utilizing fuzzy control approaches. Furthermore, to optimize the controller, intelligent optimization algorithms are employed. The goal of this optimization is to minimize the adverse effect of the return current on the battery and also to absorb the most energy during braking with a safe braking. In order to properly control the amount of return current, it is necessary to properly monitor the battery charge level. Unfortunately, it is not possible to measure this quantity and it is necessary to use appropriate methods for estimating the battery charge level. Fortunately, a suitable method has been proposed in connection with this topic, which is used in this dissertation. With the successful implementation of these two parts, in the proposed system, the amount of braking force required for safe braking on the motorcycle is extracted and modeled using the Bike-Sim simulator. Then, the optimal ratio of force distribution in the two parts of reducing-friction is formulated using nonlinear optimization methods, and its solution is done online. After designing the controller and intelligent optimization, the motorcycle model has been made in both theoretical and practical modes, and the model has been tested and evaluated in a hypothetical way with the conditions of turning and slope. According to the results, this method can improve energy recovery from the brake by 10% more than the traditional method of brake distribution. | 2020 | --- |
| Mohammad Savadzadeh | Time Optimal and Online Trajectory planning for cable robot ARAS-CAM Abstract در این پایان نامه، به طراحی مسیر برخط بهینه زمانی برای ربات های کابلی افزونه پرداخته شده است. در تعیین مسیر حرکتی ربات های کابلی چالش هایی وجود دارد از قبیل اینکه کابل¬ها همواره باید کشیده باشند و تنها می توانند نیروی کششی به جسم اعمال کنند. قیود ناشی از بهینگی، مانند بهینه بودن زمان حرکت مجری نهایی و یا انرژی مصرفی عملگرها یکی دیگر مسائلی است که در طراحی مسیر حرکتی ربات در نظر گرفته شود. با وجود اینکه افزونگی در تعداد عملگر های ربات این امکان را به ما می دهد که به نتایج مطلوب تری برسیم، اما در عین حال حل این مسائل در ربات های افزونه به مراتب دشوارتر است، چراکه بیشمار حالت برای توزیع گشتاور میان عملگرهای ربات برای اعمال یک نیرو مشخص وجود دارد. معیارهای مخلتفی برای دسته بندی روش های ارائه شده برای طراحی مسیر ربات ها می توان برشمرد، یکی از این دسته بندی ها بر اساس برون خط یا برخط بودن روش ارائه شده است. مشخصا برای طراحی مسیر برخط نسبت به برون خط کار دشوارتری پیشرو است، و باید الگوریتم بهینه ای از منظر حجم محاسباتی ارائه گردد. در این پایان نامه ابتدا مقدمه ای در خصوص ربات های کابلی و روش های طراحی مسیر بیان شده است، در ادامه با تشریح مسئله ی طراحی مسیر برخط و بررسی چالش¬های آن، با استفاده از معادلات سینماتیکی و دینامیکی ربات، روشی برخط بهینه زمانی برای حل چالش های مطرح شده ارائه شده است. در نهایت الگوریتم پیشنهادی بر روی ربات ARAS-CAM پیاده سازی شده و نتایج آن بیان می گردد. | 2019 | Parallel and Cable Robotics |
| Vahid Ajallooeian | Detection and tracking of moving cars in city roads using deep learning methods Abstract The ultimate goal in developing autonomous vehicles is to remove the driver function, and the whole process of driving will be done by control unit. Therefore, it is essential that the decision-making system has the most environmental awareness. Being aware of the map of the environment and the obstacles that the vehicle faces during its mission, is one of the most important factors affecting the decisions of the central system. If a self-driving car wants to do a mission in a dynamic environment (e.g. reaching a destination), knowing the status of the various obstacles and having a proper estimate of the location, speed and direction of the obstacles will be essential. Different approaches have been proposed to solve this problem using various tools such as LIDAR and ultrasonic sensors. Although these methods have had some success so far, their reliability has not yet been widely accepted in the automotive industry. In this research, moving objects are detected and tracked using a combination of deep learning and classical methods. The data required for the process is provided by a camera mounted on a moving vehicle. If the object becomes occluded, the function of the detector is disrupted and its location is provided by the proposed method. Different movement patterns have been learnt to a recurrent neural network and a mechanism for correction of detector and tracker is developed. Finally, The algorithm has been evaluated by captured videos from Tehran university and the result is presented. | 2019 | Autonomous Robotics |
| Arash Iranfar | Design and implementation of a cooprative adaptive control structure for ARAS haptic eye surgery training system. Abstract امروزه با پیشرفت علم رباتیک، استفاده از سامانههای هپتیکی در امر آموزش جراحی مرسوم شده است. سامانهی آموزش جراحی چشم ARASH:ASiST میتواند چهارچوب مناسبی جهت آموزش جراحی ویترکتومی و آب مروارید فراهم کند. در این پژوهش پس از بررسی روال پیادهسازی الکترونیکی و نرمافزاری این سامانه، به معرفی سه ساختار مشارکتی مناسب امر آموزش پرداخته شده است. اساس کار این ساختارها استفاده از قید مجازی برای مشخص کردن میزان اختیار عمل جراح تازهکار است. در رویکرد اول از یک قید کشسان که میزان سختی آن با میزان خطای تعقیب موقعیت جراح ماهر توسط جراح ماهر در یک پنجرهی زمانی تنظیم میشود استفاده شده است. در رویکرد دوم یک قید مجازی بدون ذخیرهی انرژی استفاده شده است که اجازهی خطای کمتری به جراح تازهکار میدهد و در عین حال مشخصهی فنری از خود نشان نمیدهد. در رویکرد سوم یک کنترلکنندهی تطبیقی طراحی شده است که ایرادهای دو روش قبل را برطرف میکند. برای تحلیل پایداری این ساختارها، در دو مورد اول رویکرد ناکنشوری و در مورد سوم رویکرد پایداری ورودی به حالت استفاده شده است. برای بررسی کارایی این ساختارها، در دو مورد اول به شبیهسازی اکتفا شده ولی مورد سوم در عمل مورد استفاده قرار گرفته و نتایج پیادهسازی آن ارائه شده است | 2019 | Surgical Robotics |
| Alireza Bourbour | Implementation of suspended cable robot calibration and control Abstract Enabling many applications to be possible and affordable, the introduction and development of cable driven robots has opened many doors to the field of serial and parallel robots. Utilization of cables instead of rigid links leads to remarkable properties such as agility and speed, large workspace, and heavy payload capabilities. But, all this comes with the price of facing challenges induced by the very nature of the cable, the problem of elasticity, being limited to positive forces, vibrations, and difficulties of measuring the accurate length. However, by implementing wise topologies and controllers, these robots could be advantageous in many industries. As a step toward this goal and in order to be used easily and effectively, the concept of easy deployable cable driven robots is introduced in which the robot anchors are easily movable. The consequence of this ease is that by changing the configuration and position of the robot, all the pervious calibrations are distorted and a repeated calibration has to be executed. In this thesis, adequate methods for calibration of the robot is investigated and practical approaches toward this problem are introduced. In addition, an appropriate design for controlling the robot, considering its very nature of being easily deployable, is suggested. In the field of calibration, methods for jacobian, Kinematic and dynamic calibration are investigated and the corresponding implementations are done. For the controller, based on the working condition of the robot, PID and Adaptive controllers are utilized. Finally, implementing these methods, suitable performance was achieved. | 2018 | Parallel and Cable Robotics |
| Mohammad Hossein Salehpour | Distributed control system design and implementation of multi-robotic dome monitoring system Abstract Dome-shaped structures are one of the most attractive parts in important ancient architectures, including beautiful and internationally admired domes. Similar to all other buildings, the cleaning, inspection, and repair tasks are necessary for these structures. Dome’s surfaces are not easily reachable and they are hard and dangerous to climb. These tasks involve high level of expertise and experience which are not easy to find and very costly. Due to these difficulties and issues there has been a robotic platform designed and implemented to climb steep surfaces such as domes. This multi-robotic platform includes N similar robots connected to each other through cables and arranging a robotic loop around the dome shaped structure. This robotic platform works on the dome based on cooperation between robots.
In this thesis, we represent a distributed method to control the prescribed robotic platform to obtain desired performance. In the proposed method, we develop a path for climbing the dome surface in a faster speed than the centralized methods. Another goal for this planning problem is to minimize the tension of the connecting cables. Minimizing this tension leads to a minimum pressure to the dome’s surface during the climbing phase, assuming there is an ideal controller on each single robot that can perform moving commands regardless to other robots status and behavior in the robotic loop. In this thesis, we present the prescribed controller. To obtain desired performance in different situations on the dome, robust control approaches. Firs a dynamic model of robot’s behavior on the dome is derived based on Lagrangian equations and then based on different situations that the robot can face during the action on the dome we obtain uncertainty and design a robust controller in presence of this uncertainty. In a sentence, it is said that here in this thesis, we represent a distributed controller for multi-robotic dome climbing platform and the novelty is that we solved the self-stability, which is an important issue in distributed problems. | 2018 | Dynamical Systems Analysis and Control |
| Pouria Mehrabi | Probabilisitc Framework for Dynamic Object Recognition and Tracking in 3D Environment Abstract Probabilisitc Framework for Dynamic Object Recognition and Tracking in 3D Environment | 2018 | Autonomous Robotics |
| Faraz Lotfi | Design and implementation of robust SDRE filter on Charge estimation of Lithium-Ion battery Abstract Nowadays recognition of the importance of clean fuel has led to increased use of electric vehicles. Despite the researchers’ efforts in this field, still the limitation of the range per battery charge remains as a critical challenge which avoids these vehicles from being extensively used. Furthermore, the battery charge shall be usedwithin a definite amount in order to protect the battery life. Since direct measurement of the battery state of charge is not possible, usually estimation of this quantity is being performed. In this thesis, an efficient filter is designed to estimate the remaining battery charge through a suitable model. Due to the necessity of high energy density in electric vehicles, the lithium ion batteries are used. The model used for such batteries is the reduced order of an electrochemical model called single particle model, in which the output voltage of the battery is a non-linear function of the battery state of charge.Taking into account the importance of the uncertainty of the model, in this thesis it is proposed to combine the switching method with an SDRE non-linear filter structure. For this purpose, first the theoretical development of this filter and its robustness analysis is reviewed and then its implementation on the non-defined lithium ion battery is taken into consideration.The simulation results verifies the efficiency of the recommended filter in comparison to the conventional filters which is quite promising in practical implementations. Furthermore, in order to demonstrate the applicability, performance and effectiveness of the purposed filter, real implementation is reported. | 2017 | Dynamical Systems Analysis and Control |
| Ali Noormohammadi Asl | Mobile Robot Motion Planning for Search and Exploration Under Uncertainty Abstract The main contribution of this thesis is motion planning for specific goals such as environment exploration, search and coverage. However, the presence of uncertainties makes them challenging tasks. In order to achieve a reliable plan and decision, these uncertainties should be considered in the robot’s planning and decision making. Therefore, the path planning for the exploration and search is modeled as an asymmetric Traveling Salesman Problem (aTSP) in the belief space in which the robot should search a series of goal points. Toward reducing the complexity of the aforementioned problem, the Feedback-based Information Roadmap (FIRM) is exploited. Using FIRM, the intractable traveling salesman optimization problem in the continuous belief space is changed to a simpler optimization problem on the TSP-FIRM graph. The optimal policy of the robot is obtained by finding the optimal path between each two goal points and solving the aTSP and then the policy is executed online. Also, some algorithms are proposed to overcome the deviation from the path, kidnapping, finding new obstacles and becoming highly uncertain about the position which are possible situations in the online execution of the policy. Consequently, the robot should update its graph, map and policy online. The generic proposed algorithms are extended to the nonholonomic robots. In the online and offline phase, switching and LQG controllers as well as a Kalman filter for localization, are adopted. In order to show the applicability, performance and effectiveness of the proposed algorithms, a simulation and a real implementation are done in webots software using the e-Puck robot and in a floor of Electrical Engineering faculty on Melon robot, respectively. | 2017 | Autonomous Robotics |
| Sara Abkhofteh | Design and Implementation of a Robust Adaptive Control Structure for Cooperative Teleoperation Systems with Dual Masters Abstract In this research, an adaptive nonlinear structure for dual user teleoperation systems for the application of surgery training is presented. The proposed adaptive controller is designed to eliminate undesired effects of existing uncertainties in each robotic manipulator. This robust control structure is also investigated the effects of the dynamics of the users' hands and the environment, as one of the control loop components. In this control scheme a force feedback has been used to convey the proper sense of interaction between environment and the robot. In addition to that, an impedance reference model is designed to control force and position simultaneously. As it is necessary to measure forces to reach the desired impedance and considering the fact that installation of force sensors is challenging and expensive, especially in the slave, a high-gain observer is utilized in order to estimate the velocities and the forces. The general stability analysis of the system has been proved by means of the input-to-state stability concept and the small gain theorem. Finally, by considering several different scenarios and implementing the control structure on two haptic devices and a virtual surgeon robot, the performance and the efficiency of the system has been evaluated. | 2017 | Surgical Robotics |
| Omid Esrafilian | Simultaneous localization and mapping and autonomous flight of a quad rotor robot using a monocular camera Abstract It goes without saying that in such a sophisticated world the prominent role of the robots cannot be eliminated. When it comes to the Robots, controversy surrounds the issue how to construct an autonomous robot. The aim of this thesis is the indoor autonomous flight and exploration of a Quad-Rotor robot by a monocular SLAM. In general, this study consists of two parts, namely estimating the 3D robot position and reconstructing the environment map, and determining the unseen areas and generating an appropriate path to explore such areas. The former part encompasses some methods for scale correction, information filtering, and map enrichment. To estimate the robot position and reconstruct the environment map in this thesis ORB-SLAM 2 has been used which works based on detecting corner features of image sequence and preduces sparse map. Morover, filtering and linear fiiting methods have been utilized for the sake of scaling factor correction and data compensation as well the new method has been presented for map enrichment. The latter part consists of unexplored area detection, goal determination, and path generation parts. The suitable and new method has been proposed for distinguishing the accessible and unaccessible localities and obstacles for exploring the environments as far as possible. Furthurmore, the new aproch for generating appropriate path has been proposed which includes some various path planning methods. All of the presented algorithms have been implemented using low cost commercial Quad-Rotor called AR.Drone and in the Robot Operating System (ROS). Moreover, experimental verifications of the proposed algorithms are reported. | 2017 | Autonomous Robotics |
| Pedram Agand | Design Control Architecture based on Environment Impedance Properties in Teleoperation Systems: a Bayesian Approach Abstract Nowadays, regarding spread wide use of Teleoperation systems in medical applications like invasive surgeries, researchers are looking for a way to enhance two contradicting factor namely stability and transparency in the presence of uncertainty in models, medium and environment. Firstly, a decentralized $H_\infty$ robust controller is proposed with global stability criterion. On the other hand, based on nonlinearity and Non Gaussianity of environment, randomized algorithms are proposed for identification and control. In this thesis, a generalization of Bayesian approaches to online estimation and identification of environment dynamic is proposed. Finally, this generalization will lead to a full probability distribution which wrap up whole information exist in the system. Then, a decision making paradigm is utilized to employ control signals which stabilized nominal system and perturbation in a probability robust approaches. The systematic way to utilized information in the decision making process is described in the proposed algorithm. Therefore, firstly particle filter is proposed as a robust suboptimal solution of Bayesian problem. In another approach, MCMC is used to identify whole parameter uncertainty online. Then by utilizing MMT structure to transfer model parameters rather than signals, adaptive probabilistic robust rule is proposed to derive control law. | 2017 | Surgical Robotics |
| Nahid Khajeh Ahmadi | Design and Implementation of a 2R-1T 3-DOF Haptic Device Abstract Recently, haptic devices and virtual reality simulators has attracted a large amount of attention in surgery training applications. Because of complexity and sensitivity of eye surgery, design and implementation of a training system for this type of surgery is very challenging. In this thesis, design and fabrication of a three degrees-of-freedom haptic device for the use in a dual haptic eye surgery training system is presented. This haptic device has two rotational and one translational degrees of freedom corresponding to the required movements in the eye surgery. Remote center of motion, which is necessary for this type of surgery, is satisfied using the parallelogram mechanism in the haptic device structure. The mass and inertia of device is significantly reduced by applying strict considerations. Fully static balancing is applied using counterweight, and hence, the operator does not feel gravitational force at all. All the three degrees of freedom of the haptic device is actuated using capstan-drive transmission systems. The cable routings and cable transmission systems, in addition to the suitable transmission ratio with no backlash, caused the two main motors of the device be grounded, and to reduce the device mass noticeably. Suitable performance of the haptic device is evaluated by some practical experiments. | 2017 | Surgical Robotics |
| Fatemeh Akrami | BCI Control of a Robotic Arm Based on Pattern Recognition of Neuro-Motion Signals Abstract Brain-computer interface (BCI) establish a connection between the brain activities and robotic systems through converting the brain signals into perceptible control signals for machines. Such a system has been a specific area of interest in order to provide interaction of people with disabilities with the surrounding environment. Using the system, the brain patterns for a certain type of behavior is obtained and the related control commands is produced. This control signal represents a specific neuro-behavior of the brain and can be used in BCI systems. SSVEP is a specific type of such a control signal which is produced at the occipital lobe of the brain in response to an external oscillating stimulus. The frequency of this signal is matched with the frequency of the input stimuli that can be identified using EEG test, which is the focus of the current research. As the brain signals are the neurological reaction of the individuals to stimulus signals it is crucial to design a suitable stimulus system as well as investigation of its effectiveness. In this research, after the required study and investigation a suitable visual stimulus is designed and implemented, and its effectiveness is proved through experiments. Secondly, various statistical and pattern identification methods such as CCA, MSI and MEC are proposed for coding the main characteristics of the SSVEP signals and the methods are implemented in practice by recording data of several individuals. Finally for having a physical perception of the BCI system a robotic arm is used. After extraction of the governing equations and modeling the simulator, an integrated system comprising the robotic arm and EEG machine is developed in Simulink and the final implementation is performed on the robotic arm. | 2017 | Dynamical Systems Analysis and Control |
| Iman Safari | EEG Signal Identification Approach to Robotic Arm Control by Enhancement of Hand Position and Velocity Estimation Abstract The use of brain signals in the control context drew a lot of attention nowadays. Unlike the absurd notion exist in this context that by considering specific features of brain activities, classifying them is possible, there exists a lot of difficulties. The aim of this study is to declare control commands using brain signals. In this work, Emotiv Epoc+ Device, which is 14 channel headsets, is used. We first tried to distinguish between the left and right hand movements. Then, four main directions of right hand swipe(movement) are identified by brain signals. But accurate recognition of hand gestures is not occurring. Existence of muscular signals with higher amplitude than brain signals, cause brain signal extraction and analysis problems. Accurate measurement of brain signals is impossible without appropriate sensor sensitivity. In this work, different approaches have been made for estimating hand movement. Finally, in order to achieve adequate accuracy for control objectives, by inspiring P300 approach and using face muscles signals, more than 95 percent prosperity achieved in specifying movement command. Moreover, Intention to movement in P300 approach is being replaced by eye blinking detection at the time of observing specific stimulus for movement. Therefore, movement can be detected in four directions and three different speeds. Besides, this method could be extended for other movements. By extracting signal features like maximum and minimum amplitude, exact blinking moment specified for each person and by comparing this with stimulus appearance time, intended command determined. In comparison with brain signals, using blinking signal which is muscular signal, cause fewer difficulties in analyzing and extraction. | 2017 | Dynamical Systems Analysis and Control |
| Abbas Bataleblu | Design and Implementation of a 2RT parallel robot for eye telesurgery Abstract Vitreoretinal eye surgery is considered as minimally invasive surgery. In such surgery, the surgeon removes only a small part of the body gap that causes less scarring and reduced recovery time of the patient. To make full advantage of the minimally invasive surgery on the eye and to avoid expansion of scarring, no force must be applied during surgery at the span of the sclera which shows the importance of using remote center of motion (RCM) mechanisms. Design and building of the 2RT robot for eye telesurgery registered in ARES group based on the achievement of accuracy is the purpose of this thesis. In addition, implementation of a control structure for controlling robot’s position is the other aim. In this regard, design and building of the 2RT spherical parallel mechanism for eye surgery is done in this Project. Besides, based on the need of the power transfer system, analysis, design and building of the Capstan drive system (Cable driven sectorial rotary actuator) as the actuators of the robot and also, the element causing pretension force in the cable ,due to using cable power transfer system, are the alternate achievements in this thesis. Furthermore, precise designing of the robot's links and its end effector in order to build the robot is done and the position control is implemented on the built 2RT eye surgery robot. Beyond shadow of doubt, this robot is capable of being used in clinical approaches in near future. | 2017 | Parallel and Cable Robotics |
| Soheil Gholami | Design and Implementation of a Robust Nonlinear Control Scheme in Teleoperation with Time Varying Delay in Eye Surgery Application Abstract In this work, an adaptive output-feedback controller is proposed in order to achieve a desired impedance behavior in robotic tasks in the presence of various uncertainties in their dynamics. A high-gain observer is also utilized in the proposed control structure which makes it possible to achieve this goal using only position feedback of robots joints, which in turn, reduces implementation costs by eliminating additional sensor requirements. It also improves controllers gain margins by cancelling noises in velocity feedbacks. The proposed controller is designed to be used in haptic and tele-operation systems and due to the fact that the high-gain observer is utilized the force and velocity sensors are not needed. The stability analysis of this method is proved via the input to state stability concept. Finally, to evaluate the presented structure several scenarios is considered and the effectiveness of this scheme is shown. | 2016 | Surgical Robotics |
| Parisa Masnadi | Implementation of Image-based visual servoing of featureless objects by nonlinear control schemes Abstract In this study, the nonlinear control of image-moment based visual servoing has been considered. The combination of image-moments has been utilized as image features for tracking appropriate image of the target object. The control signal was calculated by comparison between the current and target image features. Visual servoing is utilized widely in industry and medicine. Therefore, increasing domain of attraction, robustness, and accuracy of the tracking are the main issues in this field. To achieve these purposes, combination of sliding mode control with image moments has been proposed. Based on the selected image features and modeling, proportional integral type sliding surface has been suggested, and due to nature of the system, the control signal type is velocity. The proposed method has been implemented on a five dof industrial robot, and the performance of this method has been compared to the nonlinear control of kernel based visual servoing. The results display an increase in the domain of attraction, velocity, and accuracy with respect to kernel based visual servoing. In situations, where some part of the object image is out of camera field of view, unmodeled distortion is imposed to the system. The conventional controller could not cope with distortion and failed to convergence. The nonlinear kernel based visual servoing controls each dof separately, as a result, it cannot converge the system to target point in this special case. However, the proposed method in this study is robust to uncertainty and controls four dof of camera motion simultaneously; therefore it can manage this situation. The stability of the controller is analyzed by the Lyapunov theory. | 2016 | Visual Robotics |
| Amin Khorasani | Optimal Design and Implementation of Delta Parallel Robot for Rapid Pick and Place Application Abstract Delta Robot is considered as one of the well-known high speed robotic platform in industry. An agile robot which is mainly used for pick and place application in production lines. The unique characteristic of Delta robot such as parallelogram structure, having high stiffness in a confined structural volume and suitable dynamic performance with high acceleration and speed make Delta Robot as one of the best choice for small pick and place applications. In this thesis a three DoFs Delta Robot with pure translational motion has designed and implemented. After introducing the mathematical model of geometrical structure and jacobian analysis, the dynamic model of the robot is extracted using Lagrangian method which has been verified using Msc ADAMS dynamic simulation software. Based on the previous research in ARAS upon kinematic optimization, dynamic optimization is performed to determine the exact dimensional parameters of the robot and according to dynamic analysis suitable actuators are chosen for the implementation of robot. Using the available facilities in ARAS lab a prototype of the robot for pick and place application is made. | 2016 | Parallel and Cable Robotics |
| Zahra Marvi | Implementation of ARES Parallel Spherical Robot for Eye Telesurgery and Applying Impedance Control on it Abstract In this thesis, the technology of using a parallel spherical structure in eye surgery is examined and impedance control for insersion of surgical instrument is implemented. This thesis consists of “analysis and design” and “implementation” sections. In the first part, after the study of requirements of an adequate robot for most popular eye surgeries in the world, kinematic and jacoban analysis of propsed robot in ARAS group named ARES is done based on spherical trigonometry which is much simpler that other conventional methods. ARES is a 3 DOF robot, whose arms constitute a 2 DOF rotational mechanism and the end-effector provides a linear motion for insertion of surgical instrument. Mechanical and electrical design of the end-effector of robot is elaborated in detail. The “Implementation” part consists of simulation and implementation of control schemes on fabricated robot. In simulation, an inverse dynamics impedance controller with sliding mode observer, as well as an adaptive impedance controller with high gain observer is applied on the robot SimMechanics model. Finally, position control of the arms of the robot and impedance control on fabricated end-effector is applied. The presented results are very promising to use the achievenments of this thesis in eye surgery. | 2016 | Surgical Robotics |
| Yaser Shahriari | Robust Optimization for Online simultaneous localization and 3D mapping on Quadrotor Abstract Localization and mapping are fundamental requirements to enable mobile robots to operate robustly in their environments. In this thesis, we have created novel simultaneous localization and mapping (SLAM) benchmark which are more robust to place recognition and sensor errors. The first part of the overall problem is to create a graph, by identifying nodes and factors between the nodes based on sensor data. Such a system is often referred to as the front-end. The second part entails finding the configuration of the nodes that best explains the factors. This step corresponds to computing the maximum-likelihood map and a system solving it is typically referred to as a back-end. Converging to the correct solution is challenging if outliers are present or the initial guess is far away from the global minimum. Therefore we investigated four robust algorithms and evaluated its robustness against outliers. with consideration a trade-off between processing time and accuracy, we have emphasized on dynamic covariance scaling (DCS).This thesis has reviewed variety methods to using each published algorithms in diff erent parts of the SLAM and ultimately we have designed a dynamic and user-friendly software package with Robot Operating System (ROS) that called KNTU-SLAM. In this benchmark, The latest algorithms in different parts of the system has aggregated together. by appropriate recommendations, efficiency of feature extraction and image descriptors algorithms were improved the results since compared that with the previous powerful benchmark like RGBD- SLAM which created at University of Freiburg. The superiority of this project has shown when implemented on a variety of mobile robots at ARAS Lab in K.N. Toosi University of Technology. Also for the first time, creating a three-dimensional map and localizaton in real time on quadrotor with using Kinect camera by wifi that transfered data to another computer for processing. it has been with a new proposed node in ROS. To display the produced map has used OctoMap and point cloud that has given required components for Autonomous aims to the user. | 2016 | Autonomous Robotics |
| Kamran Taran | Implementation and Control of Agile Eye Robot Abstract Nature has always been the main guide for human on the path of development and progress; because existing systems in nature had designed and deployed in the highest efficiency and optimality. One wonders is how to moving human's eye and its' structure. In this research, is tried to design and implement a parallel robot by mimicking structure of human's eye. To use in variety of applications similar to eye's application, like high speed orientation of end effector. Of course, this requires some considerations and some optimizations of the structure, fit to intended target, so this requirements has been considered in designing process. agile eye is a spherical parallel robot that had made of connecting kinematic chains to an end effector. The chains each consisting of two curved links and two rotary joints, provide three degrees of freedom for end effector. All components of robot move with a fixed distance to the center of the robot and on the concentric spheres with different radius. By installing various tools on the end effector the robot can be used in a wide variety of applications like military, industrial, medical, hobby and so on. Intended application or robot in this research is tracking visual purposes. A high speed camera is installed on the end effector that received images processed by real time algorithm implemented by Opencv and python. After determining target location, the proper path is designed in the task space and by implemented control algorithms, the robot moves in order to track the target. According to the motion of robot, it can be installed on mobile platforms with shaking such as mobile robots, cars and boats. there is no need to stabilizer plate for camera because shakes applied to robot compensated by gyro and accelerometer sensors installed on end effector. In the process of designing the robot, direct and inverse kinematics relations discussed and mechanism to achieve an unique solution for robot kinematics and positioning the robot in a work situation has been introduced. In the following, robots dynamic relations at the task space by Lagrange method for using in robot control is obtained. Parameters such as agility, and being away from singularity, is intended to design the structure of robot. That with discussion in the task space and also utilizes intelligent optimization methods including genetic algorithm. Optimal structure for the robot is presented. Details of the design of mechanical and electronic components of robot expressed and finally some control methods including the classic, model based and robust controllers in the joint and task space on the robot are implemented and their performance were compared. | 2016 | Parallel and Cable Robotics |
| Ahmad Sharifi | Formulation and Optimal Trajectory Planning in Controllable Workspace of Cable Suspended Robots Abstract In this thesis, a method for online time-optimal trajectory planning in controllable workspace of cable suspended robots is proposed. First, kinematics and dynamics formulation of cable suspended robots specifically three cable robot and RoboCrane are derived. After- wards, by defining the online trajectory planning problem and investigating its challenges, a procedure to overcome the challenges is presented. In this procedure, the direction of the acceleration vector of platform is in direction of the unit vector resulted from the vector difference of desired and instantaneous velocities and its magnitude is calculated with respect to cable forces limitation and dynamic formulation. Furthermore, an auxiliary function is used to spot actuator speed limitation. To prove time optimality of the method, Pontryagin’s minimum principle is applied. Simulations certify the success of the considered method in online trajectory generation of cable suspended robots. | 2015 | Parallel and Cable Robotics |
| Fatemeh Mahdavi | Analysis and design consensus controller in delayed multi-agent systems Abstract In multi-agent systems, while agents, under interaction topology, achieve a convergence in state variables, then state consensus has been occurred. In this thesis, first, consensus problem in singular multi-agent systems in presence of exogenous disturbances and under delayed directed interaction graph has been redefined and analyzed. Then, by application of transforming for sepration of differential and algebraic parts, appropriate control protocol is proposed. Multi-agent system consensus problem is converted to N subsystems stability problem, by eigenvalue decomposition. Later, by conversion of differential part of these subsystems to descriptor ones, an idea for gain matrices design is provided. These gain matrices are achieved by linear matrix inequality with H_∞ control approach. Finally by different simulations, represented features in this thesis compared to other references will be discussed and analyzed their results. | 2015 | Dynamical Systems Analysis and Control |
| Samim Khosravi | Extension and implementation of control methods to increase transparency in minimal invasive telesurgery systems Abstract This thesis studies the problem of minimal invasive telesurgery. In this research fidelity criteria is introduced, since slave robot interacts with soft tissues in telesurgery. Impedance control and sliding impedance control is used for master and slave robot, respectively. Impedance control parameters of master side are determined by small gain method to maintain the stability of the total closed loop system in the case of spring- damper environment on slave side and constant delay in communication channel is also considered. Parameters of slave controller are obtained from the optimization problem with fidelity cost function and robust constraint against uncertain environment. Also, Stability of the closed loop system with proposed control stucture is guaranteed by input to state stability method when the delay in communication channel is time varying. Finally, proposed control structure is implemented on haptic omni and virtual reality SMOS robot as master and slave robot, respectively and the results of the different scenarios such as free motion and constraint motion with constant and variable time delay time in the communication channel is presented. Also Stability and performance of the closed loop system with the proposed control structure is examined and satisfactory results are obtained. | 2015 | Surgical Robotics |
| Reza Baba ghasabha | Design and Implementation of Vision Based Robust Nonlinear Controller on KNTU CDRPM Abstract Cable driven parallel robots (CDPRs) remedy some shortcomings of the conventional serial and parallel robots. Using cables instead of rigid links in the robot structure has some positive features such as large workspace, high speed manipulation and high payload to robot weight ratio. However, using cables introduces new challenges in the study of cable-driven parallel robots. Cables are able to apply only tensile forces and due to the inherent flexibility of the cables, measuring cable length is not reliable in applications with high accuracy. Furthermore, due to the axial vibrations in cables, the moving platform may experience unwanted vibrations. Moreover, it shall be noted that in practice the kinematic and dynamic models of CDPRs possess structured and parametric uncertainties and precise knowledge of the models is unavailable. For these reasons, control of the cable driven parallel robots is more challenging than that of the conventional robots. In this thesis, new approaches is proposed in order to overcome these challenges and improve the performance of the CDPRs in tracking the desired trajectories. Due to the inaccuracy of the cable length measurement, a vision-based pose measurement is designed and implemented as a suitable and economical solution. An appropriate marker is designed for fast and accurate tracking and the pose of the end-effector is measured by extracting marker features in real-time. Then, an adaptive controller is designed in task space coordinates and adaptation is performed on both the dynamic and kinematic parameters. It is shown that the performance of the proposed adaptive controller is significantly improved by the correction of the internal forces. Then, In order to reduce the effect of both structured and parametric uncertainties and external disturbances, an adaptive robust controller is designed based on the adaptation of the uncertainties upper bound. The main feature of this approach is that the result is not in debt of finding a linear regression form for kinematic and dynamic models, and furthermore, it does not require a priori knowledge on the uncertainties upper bound. Then, in order to damp the longitudinal vibration of cables, a composite controller is proposed. By using the result of singular perturbation approach, the stability of the overall closed-loop system is analyzed through Lyapunov second method. Finally, the effectiveness of the proposed controllers is examined through some experiments on a planar cable driven parallel robot with four actuated cable driven limbs and it is shown that the proposed controllers is able to provide suitable tracking performance in practice. | 2014 | Parallel and Cable Robotics |
| Amir Molaei | Dynamic Modeling of Cables in Cable Robots Abstract یکی از پرکاربردترین ابزارهایی که توسط انسان در بخشهای مختلفی از زندگی مورد استفاده قرار میگیرد اجزای انعطافپذیر، چون طناب میباشند. اختراع طناب به عنوان هفتمین اختراع بشر در دوران باستان به شمار میرود. مهمترین کاربرد این ابزار در آن دوران جابجایی اجسام سنگین بوده که با گسترش جوامع بشری و توسعه صنایع کاربردهای گستردهتری برای آن ایجاد شده که متناسب با این کاربردها این ابزار نیز خود، دستخوش تحولات اساسی شده است به طوریکه امروزه شاهد به کارگیری انواع مختلف کابلهای فولادی و مصنوعی در زندگی روزمره میباشیم . یکی از بخشهای رو به رشد تکنولوژی در دنیای مدرن صنعت رباتیک میباشد که استفاده از این عضو رباتهایی با ساختاری متفاوت را وارد دنیای رباتیک نموده است که از آن جمله میتوان به رباتهای کابلی اشاره نمود. رباتهای کابلی دستهای از رباتهای موازی میباشند که در آنها به جای استفاده از بازوهای صلب، کابلهایی که توسط قرقره باز و بسته میشوند وظیفه جابجایی مجری نهایی را بر عهده دارند. ساختار موازی این ربات و استفاده از کابل در آنها موجب پیچیدگی دینامیک حاکم بر این رباتها شده است. در این پروژه هدف اصلی به دست آوردن یک مدل دینامیکی مناسب برای کابل در این دسته از رباتها میباشد که در ابتدا مدلی از کابل بدون صرف نظر کردن از نیروهای برشی و خمشی به دست آمده یک دستگاه معادلات دیفرانسیل پارهای میباشد که با استفاده از روش اختلاف محدود حل این معادلات صورت گرفته است. با توجه به اینکه معادلات به دست آمده غیرخطی بوده و نیز کوپلینگ بین معادلات زیاد میباشد استفاده از این معادلات برای کاربردهای کنترلی امر مناسبی نمیباشد که بدین منظور یک مدل دینامیکی مناسب که برای کاربردهای کنترلی مناسب میباشد برای دینامیک کابل ارائه شده که میزان اختلاف مدل ارائه شده با مدل اصلی مورد بحث قرار میگیرد. | 2014 | Parallel and Cable Robotics |
| Leila Mehri | "Development of 3D Visual Odometry in mobile robots and its implementation on iSAM2 " Abstract The aim of this thesis is to estimate the path navigated by a mobile robot using stereo camera images. In order to do so, an egomotion estimation algorithm, which is called visual odometry, is presented and the result of its implementation is shown. In the visual odometry algorithms, the current position of the camera is obtained by the sum of the previous position with the current egomotion of camera. Thus, the error is accumulated at each step and causes the drift in estimated path from ground truth. In this research we present solutions to reduce the effects of the accumulated error in the estimated camera path. It is assumed that the camera moves with constant acceleration, then its velocity is corrected in each step by a standard Kalman filter. The proposed solution leads to significient reduction in the estimated path drift from ground truth. Finally the proposed algorithm is implemented on SLAM using isam method and its result is carefully investigated. | 2014 | Autonomous Robotics |
| Hamed Khajehvand | Conceptual Design and Robust Control of a Parallel Robot for High Speed Pick and Place Applications Abstract Parallelogram structure, high strength within limited structural volume and good dynamic behavior as well as high speed and high acceleration has made parallel Delta robot as one of the best choices in applications which involve handling small objects. In this thesis, the robot is used in its simplest structure, namely three degrees of freedom. After introducing the mathematical model and the Jacobian analysis, robot dynamics are derived based on Lagrange method. Modeling reliability is verified via a simulation of the robot in ADAMS software. Kinematic parameters of the robot are optimized according to three kinematic indices representing robot’s speed and skill, via a multi-objective optimization by NSGAII and a Pareto front of optimal parameters are provided. Moreover, trajectory of the robot’s end effecter is planned with the aim of reaching its maximum speed. By solving the inverse kinematics and dynamics and obtaining joint space restrictions on speed, acceleration and torque of actuated joints, specifications of appropriate motors are determined. Finally, a robust control algorithm is introduced to suppress parametric uncertainties in both kinematics and dynamics of the robot and the global stability of closed loop system is verified using Lyapunov second method. Simulation results demonstrate that the optimization method while used along with appropriate path and trajectory planning and proposed control algorithm leads to the largest number of robot displacements within a specified time interval, complying with the expected minimum cost and practical implementation perspectives. | 2014 | Parallel and Cable Robotics |
| Ebrahim Abedloo | Development of The Dynamics Identification Methods for Parallel Manipulators Using Gibbs-Appell Formulation, and Calibration of KNTU CDRPM Abstract Parallel robots are dominating industry, aerospace and medicine due to the low inertia, high acceleration and accuracy with respect to serial robots. Robot calibration is a major concern in practical application of robotic systems for identifying the performance characteristics of robotic platforms, decreasing the cost with an increase in robot performance. Robot calibration consist of three main steps, modelling, measurement and identification and it’s output model have a broad range of appalications in model based control theories and fault detection schemes. The closed kinematic chains of parallel robots leads to a challenging modeling procedures using conventional methods and this research aims at providing a promising solution to the dynamic modelling with a novel approach. At first, we introduce a systematic approach, based on the Gibbs-Appell formulation, for the modelling of robots, including serial robotic arms, parallel robots and cable driven robots. Providing the closed form and linear regression models are of the main results of this research applicable in robot control and identifications, which are verified through simulations and experiments. Due to motion constraints, all the dynamic parameters are not involved in motion behavior of the robot, using and representing the optimal regression model, we have obtained the motion behavior of the robots with the minimum number of parameters. Due to motion constraints, all the dynamic parameters are not involved in motion behavior of the parallel robots. One consequence of our study is utilizing the Gram-Shmidth theorem and singular values and obtaining of optimal regression model which represents the motion behavior of the parallel robots with the minimum number of parameters. In the following the identification is performed using a suitable excitation signal and using KF, BLS and LS methods. Based on the simulations and experimental results this method has a better performance comparing the popular identification schemes such as OLS. Improving the identification methods we aim at using the identified models in control schemes .In this regard we have developed the existing control schemes for the direct (explicit) use of optimal regression model and the performance is investigated in tracking problem. Covering the existing uncertainty like friction and flexibility a nonlinear model NARX, NARMAX,NOE are used as a hybrid model accompanying regression model. The other consequence of our study is introducing a linear-local method, based on optimal regression model, which has shown a suitable performance to overcome unmodeled dynamics, preserving the useful properties of linear model. Finally for the verification of the proposed method, experimental implementation is done on the Nasir Cable Driven Parallel Robot. | 2014 | Parallel and Cable Robotics |
| Mojgan Rostami | Region of convergence expansion for model predictive control of non-linear discrete time systems by linear matrix inequalities Abstract In this thesis a gain scheduling method is proposed for robust model predictive control of nonlinear discrete-time systems. The system is composed of a linear model perturbed by an additive state-dependent nonlinear term. A robust model predictive controller is designed in the literature to compensate for the uncertainty of the system. In order to enlarge the region of convergence it is proposed that several equilibrium points are considered, and several robust controllers are designed. By switching between the controllers it is verified that the region of convergence may be enlarged, while the overall stability of the system is preserved. The stability analysis is based on Lyapunov functions for each of level sets, while state feedback control law are designed by minimization of a desired cost function formed in linear matrix inequalities. | 2014 | Dynamical Systems Analysis and Control |
| Mir Alireza Athari | Online simultaneous localization and 3D mapping based on point cloud representation in mobile robots Abstract The main goal of this thesis is to design a simultaneous localization and 3D mapping based on points cloud representation system for a mobile robot. The sensor used in this system is a RGB-D camera. In the following thesis, Front-end & Back-end of this system is described and in front-end section FOVIS library is used for visual odometry and by adding depth information to feature matching section of FOVIS, the error of motion estimation is decreased. Next, a hash function called Radial Variance based hash is used for loop detection and for improving the accuracy, images are compared against the map. In the Back-end we have used iSAM2 framework alongside with switchable constraints robust loop closing method. In the robust method we have discussed about the effects of initial weights and an initialization method is provided which improves the results. Finally the whole SLAM system is implemented on a mobile robot from K.N.Toosi University called Avril and the verification results are provided. | 2014 | Autonomous Robotics |
| Maryam Salimifar | Improvement and implementation of Teleoperation control systems based on transparency Abstract In one branch of robotics, called telerobotics, control of robots in distant or inaccessible places is investigated. Human operator takes a manipulator and moves one robot (master), giving necessary commands to move another robot (slave) in another environment. For a sense of appreciation of that environment, information such as force or position is feedback to the operator. Transparency is a measure of how the operator feels the distant environment. In this thesis, we have expanded one of the methods in improving transparency to a robust control problem. Time delay in information transition is one of the hardships of control design, which is considered as uncertainty, augmented to a linear system. Robust performance is obtained by adding transparency function to the robust control structure. In force-position structure, a robust controller can be designed in a mixed sensitivity problem to optimize transparency, while guaranteeing stability. Robust control problem has been simulated on a master-slave system. Eventually, the proposed structure is implemented on a real system, with phantom omni haptic device as the master, and Cartesian robot as the slave parts. In order to correctly model the real system as a linear one, friction and un-modeled dynamics in the Cartesian robot have been compensated. Environment force has been estimated by Kalman filter and is feedback to the phantom. The results reveal robust stability, with an acceptable transparency | 2014 | Surgical Robotics |
| Mahsa Parsapour | Development and Implementation of Visual Servoing System for Featureless Object based on Image Kernel and Nonlinear Control Schemes Abstract One method to simplify interaction with robots is to use visual servoing system. In this thesis, we introduce a sliding mode controller design in kernel-based visual servoing. The main goal is to track a target object without any guiding features like lines, point, etc. In the kernel-based approach, a sum of weighted image signal, or Fourier transform of image signal, is used as a measurement for tracking purpose which is known as kernel-measurement. Tracking error is the difference between current and desired kernel-measurement and it is used as input variables to PI sliding mode controller. Through binding kernel-measurement to sliding mode control, our configured system will outperform conventional kernel-based visual servoing system. The proposed method is implemented on a 5 degrees of freedom industrial robot and is compared with conventional kernel-based visual servoing approach for different initial conditions. The stability of proposed algorithm is analyzed via Lyapunov theory. The uncertainties such as image noise, image blur, and camera calibration errors can affect the stability of system. And, the system will fail to track the target object partially or totally. Present thesis only investigates the effect of image noise. The controller parameters are tuned autonomously based on sliding condition to reduce the effect of boundness uncertainties. | 2013 | Visual Robotics |
| Mohammad Ali Ansari | Proposing a method for consensus in high-order networked multi-agent systems with time-delayed communications Abstract In This Thesis, at first the concept of consensus in multi agent systems is redefined and analyzed then considering the problems in this context, some solutions are proposed. Issues outlined in this thesis are divided in two parts, optimal structure design for network graph and stability analysis with the presence of delay in communication links. Up to now, by defining undirected graph structures for graphs and with utilization of the properties of Laplacian matrix for these structures, optimal structures have been designed using semi-definite programming. Design algorithms include neither diagraphs nor convergence to general minimum point. Furthermore, restrictions governing resolved issues, with the presence of delay in communication links are proposed. Analytical methods are presented to overcome these limitations as much as possible. Simulations show a good performance of the presented methods in this thesis. | 2013 | Dynamical Systems Analysis and Control |
| Arsalan Rahimabadi | Development of stability indices to determine the geometrical features of autonomous dynamical systems Abstract There are plenty of definitions about stability of a dynamic system. Also a nonlinear system response can be classified geometrically as equilibrium point, periodic solution, strange attractors, homoclinic orbits, etc. In this thesis firstly, sector stability has been defined and a theorem is presented to provide the stability conditions. By using sector stability a proper framework for the geometrical representation of equilibrium point in addition to stability analysis and also a classification for the equilibrium point of second order autonomous nonlinear systems is presented. Then, by defining rotational region concept some theorems about existence of periodic orbit and homoclinic orbit has been proved. Also, by using this concept through a theorem, asymptotic stability of the equilibrium point of a second order autonomous system is generalized to global asymptotic stability. Then, a new definition of algorithm in the stability problem is stated. In the sense presented in this thesis, an algorithm in stability problem in not limites just to result in a stable or unstable solution, but it may lead to functions that can be used to analyze dynamic response of the system. In this regard, a basic theorem about the use of such functions is introduced. This theorem is important in two aspects; firstly, in this method there is no need for positive definite functions in stability analysis and this greatly simplifies the operation. Secondly, in addition to stability it can assess instability of the equilibrium point. Furthermore, definition of the eigenfunction and its connection with analysis of dynamic behavior of an autonomous system through invariant sets is introduced. By using these concepts an eigenfunction for a linear system is presented which can be used to analyze stability condition of hyperbolic or non-hyperbolic linear systems. Finally, by using a different definition of eigenvalue problem comparing to other references, the eigenfunctions of a system is calculated. Along the thesis, different case studies and complex dynamic system, have been studied and analyzed by the proposed methods, in order to transfer the required expertise to use this theorem to the reader. | 2013 | Dynamical Systems Analysis and Control |
| Rana Talaei Shahir | Development of Optimization Methods in iSAM2 Algorithm and Its Implementation on a Mobile Robot Abstract موضوع این پایاننامه بررسی روش بهینهسازی در الگوریتم iSAM2 و توسعه آن به منظور افزایش دقت و کارایی است. با توجه به این موضوع، در این راستا، ابتدا به معرفی مفاهیم اولیه مربوط به SLAM بر اساس گراف و نقش مسأله کمترین مربعات در SLAM و همچنین توضیح کامل مفاهیم الگوریتم iSAM2 پرداخته شده است. بر مبنای این مقدمات، روشهای بهینهسازی استفاده شده بروز در مسأله هموارسازی در SLAM، بررسی شده و مزایا و معایب آنها ارایه شده است. سپس روش داگلگ، روشی که به تازگی مورد استفاده قرار گرفته است با الگوریتم iSAM2 تطبیق داده شده و به صورت بههنگام پیادهسازی شده است. نتایج بهدست آمده به طور کامل تجزیه و تحلیل شده و دلایل ناکارآمدی این روش ذکر شده است. در ادامه روشی جدید موسوم به داگلگ دوگانه به منظور بهبود نتایج بهدست آمده از روش داگلگ، به ویژه برای مجموعه دادههای با مقیاس بزرگ ارایه شده و برتری آن توسط پیادهسازی بههنگام در الگوریتم iSAM2 مورد بررسی و تجزیه و تحلیل قرار گرفته است. سپس، این روش جدید با اضافه کردن ماتریس پیششرط به آن، توسعه یافته و نتایج پیادهسازی آن در الگوریتم iSAM2، بررسی شده است. در ادامه، حساسیت الگوریتم به مقادیر انتخاب شده برای پارامترهای بروزرسانی شعاع در مسایل ناحیه اعتماد از جمله داگلگ و داگلگ دوگانه مورد توجه و بررسی قرار گرفته و با انتخاب مقادیر مناسب برای پارامترها، بهبود قابل توجهی در دقت الگوریتم بهدست آمده است. درنهایت، پیادهسازی عملی بر روی ربات آوریل گروه رباتیک ارس انجام شده و نتیجه آن ارایه شده است. | 2013 | Autonomous Robotics |
| Seyyed Ahmad Khalilpour | Multi Objective Optimal Design of Cable Robots Based on Kinematic Sensitivity and Controllable Workspace Indices Abstract Today robotic science poses as a powerful tool in industry and its progressive evaluation resolves industrial factories’ problems. Likewise cable robots were invented with the purpose of eliminating the difficulties of series and parallel robots which were used formerly. The use of cable robots was accepted for its low cost of manufacturing, low power consumption and at the same time, its large workspace and heavy payload handling. But cable robots too, have their own limitations, such that cables must always be in a tension mode, also collisions of cables with each other as well as with the end effector or environmental objects are important issues in the design of cable robots. The design of the robot must be such that the robot could have sufficient dexterity and could do any arbitrary task in all necessary directions. In this project, to qualify for the above constraints, volume of controllable workspace, translational and rotational kinematic sensitivity and global condition number indices are used. Also, combining and developing the mentioned criterions in the framework of interval analysis is another approach which has been used in order to achieve more useful and efficient indices. In
this thesis, the designs of the planar and spatial cable robots as the two major kinds of cable robots are investigated. By taking the advantages of multi-objective optimization methods such as genetic algorithm and particle swarm method, optimal pareto front for the design parameters of the cable robot is obtained such that, simultaneously all objective functions of the robot design are optimum. | 2013 | Parallel and Cable Robotics |
| Saeid Shakib | Development of Sliding Mode Controllers for Underactuated Systems Abstract standard sliding mode controllers are aclass of variable structure control systems which due to robustness have found their way to control societies .beside outstanding capacities of these controllers, some disadvantages arises that have been suppressed in new generations of these controllers.on the otherhand underactuated systems are systems with fewer inputs than their DOF's. for synthesis and control them, we need to transform them into normal forms.accordingto existing litrature, using partial feedback linearization and legandre transformation, two DOFs systems may transform into cascade form with two subsystes; internal dynamic and double integrator subsystems. in this thesis in order to regulate a class of two DOF underactuated systems, sliding mode controller is employed in a unusual manner, distinctively to change the structure of system. however to stabilize both subsystems successfully a variable based on the concept of differential flatness is introduced which can affect both DOFs. also the condition in which legandre transformation is a flat output is released and a feedback is developed which transforms the input. by this trick system is transformed into linear controlable canonical form. eventually sliding mode controller is applied. finally for this procedure an algorithm is generated and to examine the efficiency of algorithm, it is applied to RTAC benchmark and its robustness is inspected against parametric uncertainties and disturbance and finally is compared with a hybrid controller. | 2013 | Dynamical Systems Analysis and Control |
| Sadaf Fardad | Development of the Ordering and Elimination Method in iSAM2 Algorithm and Implementation on a Mobile Robot Abstract The simultaneous localization and mapping asks if it is possible for an autonomous robot to start in an unknown location in an unknown environment and then incrementally build a map of this environment while simultaneously using this map to compute absolute robot location. Finding the optimal and online solution, often called the maximum likelihood, is important and obtained by solving a sequence of least-squares minimization problems. In practice, the initial problem is nonlinear and it is usually addressed by repeatedly solving a sequence of linear systems. In an online SLAM application, updating and solving the nonlinear system in every step may become considerably expensive for large problems. While, iSAM2 is a completely novel approach to providing an efficient and exact solution to a sparse nonlinear optimization problem in an incremental setting. In this thesis, the above mentioned algorithm is studied and implemented in details and the efficiencies of different parts are evaluated. Many papers have indicated that variable elimination, instead of sparse matrix factorization, is the prevailing element in efficiency of this algorithm. Besides, it has been emphasized that delicate variable reordering over the graph, prior to the factorization, is essential for the decrease of implementation time. While herein it is illustrated that the most time-consuming part of this algorithm is to solve the linearized system at each iteration. Experiments demonstrate that reordering and elimination take merely 5.34 percent of implementation time. In addition, development of minimum-degree-based algorithms may not produce significant reduction in fill-in. | 2013 | Autonomous Robotics |
| Abbas Ali Rasouli | Dynamic Modeling and Robust Control Design for Control Loop of a Flying Object Abstract In this thesis a robust autopilot for a surface-to-air missile for different situation of flight is designed. The missile is tail control type. According to various altitudes and speeds of flight, different transfer functions for the system can be obtained as a designed invariant time controller can stabilize all models. On this purpose the transfer function of lateral acceleration to the input of finest deflection is separated to two transfer functions: first the transfer function of lateral acceleration to pitch angular velocity, second the transfer function of pitch angular velocity to finest deflection. It is shown that with this separation, having the transfer function of pitch angular velocity to controlled signal in hand, we can obtain the transfer function of lateral acceleration to command of proper acceleration. Since the system is time variant, the robustness of designed controller is proved theoretically and is confirmed with simulation. | 2013 | Dynamical Systems Analysis and Control |
| Leila Ghomi | تحلیل سینماتیکی، دینامیکی و کنترل ربات کابلی تصویربرداری فضایی Abstract در پایاننامهی حاضر به بررسی ربات کابلی معلق در فضا پرداخته شدهاست. پس از بررسی سینماتیک سه نوع ربات به منظور فیلمبرداری فضایی، رباتی با این ویژگی که در هر بازوی آن دو کابل به صورت موازی و همطول قرار دارد؛ انتخاب شده است. استفاده از ساختار متوازیالاضلاع باعث عدم دوران مجری نهایی میشود و در نتیجه ربات سه درجهی آزادی انتقالی خواهداشت. در صورت نیاز به چرخش دوربین، که بر روی مجری نهایی ربات سوار است؛ مکانیزمی که با دوربین روی مجری نهایی قرار میگیرد؛ حرکات مورد نظر را ایجاد میکند. پس از این طراحی ها، به تحلیل دینامیک و فضای کاری ربات با توجه به رویکرد کابل معادل برای هر بازو پرداختهشده است. از آنجاییکه فضای کاری ربات بسیار بزرگ است و جرم کابلها تأثیر زیادی در رفتار ربات خواهد داشت در این پایان نامه از جرم کابلها صرفنظر نشدهاست و تحلیل کاملی در این خصوص ارائه شده است. در پایان به طراحی کنترلکنندهای مناسب که علاوه بر ایجاد ردیابی مناسب، توانایی غلبه بر نویز و اغتشاش را داشتهباشد، پرداخته شده است و عملکرد آن در شبیه سازیهای متنوع مورد آزمون و تحلیل قرار گرفته است. | 2012 | Parallel and Cable Robotics |
| Hannaneh Soltani | Development and implementation of visual navigation for Melon mobile robot using stereo camera Abstract In this thesis a stereo vision-based algorithm for mobile robots navigation and exploration in unknown outdoor environments is proposed. The algorithm is solely based on stereo images and implemented on a nonholonomic mobile robot. The first step for exploration in unknown environments is construction of the map of circumference in real-time. By getting disparity image from rectified stereo images and translating its data to 3D-space, point cloud model of environments is constructed. Then by projecting points to XZ plane and put local maps together based on visual odometry, global map of environment is constructed in real-time. A* algorithm is used for investigating optimal path and nonlinear back-stepping controller guides the robot to follow the identified path. Finally, the mobile robot explores for a desired object in an unknown environment through these steps. Experimental results verify the effectiveness of the proposed algorithm in real-time implementations | 2012 | Autonomous Robotics |
| Leila Ghosi | Modeling and Control of a Cable Robot in Rehabilitation Application Abstract Rehabilitation Science has shown that in most cases repeated movements of human limbs can help patients regain the functions of the disordered limb. In this regard, the use of robots can be very effective. Robotic systems for rehabilitation with logging information like position, trajectory, velocity and force play a role in recording the progress of patients’ therapy and provide a systematic approach to the adoption of those exercises. Cable robots have some characteristics like large workspace, low-cost, flexibility and being light weight which makes them suitable for rehabilitation purposes. In this thesis the design of a parallel cable robot for upper limb rehabilitation, is presented. Anatomy of shoulder and elbow joints and the range of their motions for physiotherapy purposes have determined and by considering them as the desired trajectory, the designing of robot has been accomplished. By choosing appropriate kinematic chains, rehabilitation robot follow desired trajectory properly and do not collide with patient and the patient can feel freedom and comfort. In addition to this, some other advantages of designed robot are: reducing the number of actuators and the number of parameters that should have changed in the control algorithm, for different patients. Next kinematic and singularity analysis of the proposed structure has been reported and isotropy of the robot has been confirmed. In the next step dynamic equations are derived by using the Lagrange method and finally, by using two methods of impedance and position control, stability and performance of robot is simulated. | 2012 | Parallel and Cable Robotics |
| Amir Mobarhani | Mobile Robot Task Planning using Semantic Map Abstract Home and service robotics is one of the many applications of intelligent robots. In this filed robots need to collect sufficient perceptional information from their environment in order to decide how to perform their tasks. The environment’s semantic map is one of the helpful bases for the robot decisions. In this Thesis, a system is proposed to generate semantic map of the environments. In this system, global and local features in the received images are extracted in order to classify the images into a set of predefined classes. When region of current place of robot is recognized, new information of the region are correlated to other its component in the semantic map. The global features of each region in the environment are represented by a high dimension histogram which is used to classify the region via the RVM method. Also, this region classification is performed according to its local features extracted by SIFT or SURF methods. This part of classification is accomplished with respect to likelihood between local feature in the image and several local feature bases. These bases are previously created from local features of each region. The generated semantic map is consisted of room shape model, metric and topological map and appearance model of each region. Also, the proposed system benefits from a low computational histogram based exploration method, which facilitate autonomous semantic map generation. Experimental results of the proposed method in the simulated and real environments show that the classification process is performed with 90% accuracy and exploration time is decreased in comparison to original method. The proposed system in semantic map generation increased the efficiency of robot’s decisions in searching special object problems. | 2012 | Autonomous Robotics |
| Bita Fallahi | Stability Analysis and development of telerobotics control schemes for flexible link manipulators Abstract In most of the teleoperation systems, the data traveling through comminucation channel encounters some amount of time delay which can destabilize the system. In wave based teleoperation, although passivity is ensured for any constant time delay, tracking performance is usually distorted due to the bias term introduced by wave transmission. To improve the position tracking error, one way is to augment the forward wave with a corrective term and achieve passivity by tuning the bandwidth of a low pass filter in the forward path. In this paper this method is analyzed and it is shown that this method fails to meet the passivity condition in contact to stiff environments, especially at steady state. In this paper a new method is proposed and an analytical solution for passivity at steady state and semianalytical solution for all other frequencies are represented and this analysis is extended to rigid multiple DoF systems. This method represents a simple structure which improves the position tracking performance and ensures passivity of the system in contact to stiff environments. Furthermore, due to the application of flexible robots in teleoperation systems, a method is considered to control the position of a one DoF flexible link and the proposed wave based method is studied for this flexible link. | 2011 | Parallel and Cable Robotics |
| Nina Marhamati | Development of SLAM Algorithms for Large Scale Environments Abstract Particle filters are widely used in mobile robot localization and mapping. Choosing an appropriate proposal distribution plays an important role in the success of particle filters. The proposal distribution, conditioned on the most recent observation, is known as the optimal proposal distribution. Sampling from this distribution, increases the number of effective particles and limits the degeneracy of filter. Conventionally, the optimal proposal distribution is approximated by a Gaussian distribution, which can lead to failure if the true distribution is non-Gaussian. In this thesis, we review and compare some methods of approximating the optimal proposal distribution. Also, we propose two novel solutions to the problem of feature-based SLAM, through Monte Carlo approximation of the optimal proposal distribution which show superior results in terms of MSE and number of effective particles. Simulation and experimental results show that the new algorithms outperform the aforementioned conventional methods. | 2011 | Autonomous Robotics |
| Farnaz Adib Yaghmaei | Developing Methods for SLAM in Dynamic Environment with Grid Based Map Abstract In this thesis two new methods for navigation in dynamic environment are introduced based on force field approach. In these approaches it is assumed that the unknown trajectory of dynamic obstacle is predicted by Kalman Filter. The mobile robot avoids colliding the moving object by using the two proposed methods of potential ban or escaping algorithm. In these methods, robot navigates through static and dynamic objects without any predefined information about their motion. The motion of each moving object is predicted by a Kalman filter, and the force field map is generated and updated for the robot to navigate among static and dynamic obstacles. Finally, a cost function based on minmax theory is defined to measure the performance of different methods, and it is shown through different experiments that the proposed method is out performing traditional approaches. | 2011 | Autonomous Robotics |
| Mohammad Hossein Saadatzi | Workspace and Singularity Analysis of 5–DOF Symmetrical Parallel Robots with Linear Actuators Abstract nth | 2011 | Parallel and Cable Robotics |
| Seyed Ali Salamati | Modeling and identification of Nekka power plant steam turbine and development of its control system Abstract In this thesis, at first, a precise and nonlinear model is developed for Nekka power plant turbine from its real data and documents. We proposed to use boiler-turbine coordinated control system to increase effective efficiency of the steam unit. Identification procedures have been performed to obtain continuous time models of Nekka steam turbine at various loads. After determining the upper bound for uncertainty and choosing a good performance weighting function, a robust controller was designed and implemented in closed loop for the turbine nonlinear model. However, the closed loop performance was not suitable. In the next stage, a cascade controller structure in which the turbine loop was closed by a PI controller is proposed in order to significantly reduce the uncertainty. By using this structure, a new controller was designed for the system. Simulation results demonstrate very suitable performance of closed loop system with this new controller in terms of tracking, speed of response, and damping of oscillations. | 2011 | Dynamical Systems Analysis and Control |
| Rashid Mokhtari | Improving Transparency of Teleportation Systems in the presence of flexibility in Slave Robot Abstract In teleoperation systems two robots (named as master and slave) is used to the indirect manipulation of an object. In certain application such as Minimal Invasive Surguery (MIS) or space, the desire is to use thin and lightweight manipulators. Surgical robots use thin links that reduce the size of the surgical incision. As a result of this technique, the size of trauma to tissues decreases and the patient will suffer less pain and will recover fast. However the space robots are designed to be lightweight and compact for minimum liftoff cost and energy consumption during robot control. One of the major problems while using a lightweight manipulator as slave robot is flexibility. A teleoperation system with reliable transparency can extend the application range of MIS or space robots to more complicated procedure. The Transparecy of teleoperation system will be affected by flexibility, while using lightweight manipulator as slave robot because of the bending and vibration of the flexible links during a maneuaverIn this thesis, the control and improving of transparency of the teleoperation system in the presence of the flexible link slave robot, is discussed. The flexible manipulator dynamic is derived on the basis of a Lagrangian-assumed mode method. A set of simulation results are provided to validate the theoretical model. The full order flexible dynamic model does not allow the determination of a nonlinear feedback control for flexible manipulators as for rigid ones, because there are not as many control inputs as output variables. This drawback is overcome by a model order reduction, based on a singular perturbation strategy, where the fast state variables are the elastic forces and their time derivatives. A composite control is adopted as follows: at First, a slow control is designed for the slow subsystem, which is shown to be the model of the equivalent rigid-link manipulator. Then a fast control is designed to stabilize the fast subsystem around the equilibrium trajectory set up by the slow subsystem under the effect of the slow control.
| 2010 | Surgical Robotics |
| Kian Dorr | Design and Implementation of Electrical Capacitance Tomography (ECT) System Abstract This thesis presents the design and implementation of an electrical capacitance tomography system. The electrical capacitance tomography aims to reconstruct the tomographic images of pipelines or vessels by estimating the permittivity of materials inside the region of interest. Estimating the permittivity of materials is done by measuring the capacitances on the surface of object and solving an inverse problem. Electrical tomography techniques for process imaging are very prominent for industrial applications due to their low cost, safety, high capture speed, and suitability for different vessel sizes. Among electrical tomography techniques, electrical capacitance tomography has been the subject of extensive recent research due to its non-invasive nature and capability of differentiating between different phases based on permittivity distribution on the cross-section of interest. Research in electrical capacitance tomography is inherently interdisciplinary, and its areas of research can be categorized as: (1) sensor design, (2) hardware electronics, (3) and image reconstruction. Since the work presented in this thesis is based on implementation of an ECT system, the basic concepts of ECT systems such as sensitivity matrix, forward problem and inverse problem are discussed. In this thesis, the forward problem is solved by the finite element method, and Gauss integral method and charge method for the computation of charges and capacitances are used. The results obtained for the capacitance for a coaxial cable are compared with an analytical solution. Two qualitative and quantitative approaches for calculating the sensitivity matrix are completely explained and compared. The traditional image reconstruction algorithms utilized in the inverse problem are used together with two methods of computation of capacitances and two approaches of calculation of sensitivity matrix. Simulation results show the charge method is more accurate than Guass integral method, and the quantitative approach is faster than qualitative approach although their responses are fairly similar. In hardware design, different configurations for implementing the sensor have been introduced. The presented ECT system has been implemented using charge-discharge circuit. The reconstructed images from a phantom are satisfying for the implemented prototype system. | 2010 | Dynamical Systems Analysis and Control |
| Omid Gerami | ِDesigning a robost controller for the telerobotic system in presence of variable time delay Abstract One of the ways to confront the time delay, which is modeled as uncertainty, in the telerobotic systems is sliding mode control. In this method which is developed for linear and 1-DOF telerobotic systems, constant delay is considered as an unknown function in which upper bound is known, and by using sliding mode controller the system is stabilized in presence of stated delay. In practice robots have several DOF and their dynamic equation is nonlinear. In this thesis the mentioned method is developed for several DOF robots with nonlinear dynamics. According to the fact that in industrial applications time delay in the communication channel is time-varying and these variations can cause unstability in the telerobotic system, there is a need for a method to stabilize the system in presence of such delays. The most important innovation of this thesis is development of a sliding mode controller in telerobotic systems with variable time delay. At first, by assuming that both delay and its derivative are bounded in the first theorem of chapter 4 stability of the system in presence of assumed delay is proved. Then, by using this theorem a proper control law to stabilize the telerobotic system is presented. Different simulations show the stability and proper performance of this system. | 2010 | Surgical Robotics |
| Mohammad Ali Mohammadkhani | مدل سازی و کنترل ربات شش درجه آزادی هیبرید Abstract با توجه به مزایای قابل توجهی که رباتهای هیبرید نسبت به رباتهای موازی و سری دارند، طراحی و ساخت این گونه رباتها، در دهه اخیر رو به افزایش است. تاکنون فعالیتهای جدی بر عملکرد رباتهای سری و موازی صورت گرفته است، اما رباتهای هیبرید با توجه به پیچیدگیهای آنها و عدم وجود استانداردهای طراحی نیازمند بررسی و تحلیلهای عمیقتری میباشند. اغلب طراحیهای رباتهای هیبرید بر اساس توسعه رباتهای موجود بوده است. ایده اصلی این پژوهش، ترکیب و توسعه مکانیزمهای سری و موازی موجود به منظور افزایش قابلیتها و ویژگیهای رباتهای هیبرید میباشد. در این پایاننامه نشان داده شدهاست ترکیب مکانیزمهای سری و موازی به گونهای که تداخل بین آنها وجود نداشته باشد، میتواند قابلیت و رفتار ربات را بهبود بخشد. در فصل اول این پژوهش، طرحهای سالهای اخیر برخی از محققین آورده شده و مروری بر اهداف و طرحهای آنها صورت گرفته است. معمولا محققین و پژوهشگران علم رباتیک، عملکرد طرحها و ساختارهای جدید رباتها را بر اساس مشخصه های رباتیکی می سنجند. مشخصه های رباتیکی متداول شامل سختی، مهارت و ابعاد فضای کاری میباشد. در فصل دوم، با استفاده از مشخصه های فنی رباتها، طرحهای ارائه شده بهینه سازی گردیده اند. در این پایان نامه، فرمولاسیون جدیدی برای رباتهای هیبرید ارائه شده و بر اساس آن برخی طرحهای ارائه شده در این پایان نامه، بهینه سازی شده است. در فصل سوم، معادلات دینامیکی ربات هیبرید بر اساس مراجع موجود استخراج شدهاست. تحلیلهای دینامیکی به ربات هیبرید 3UPU-Gimbaled محدود شده و نتایج آن با شبیه سازی ارزیابی گردیده است. فصل چهارم به طراحی جبرانساز ربات پرداخته است. ابتدا، جبرانساز IDC برای ربات هیبرید طراحی شده و سپس، برای شرایط با حضور نامعینی، جبران ساز کنترل مقاوم مد لغزشی مرتبه دوم طراحی گردیده است. | 2010 | Dynamical Systems Analysis and Control |
| Mehdi Ataollahi | Adaptive Robust Controller Design for Nonminimum Phase Systems: Applied to a Dual Stage Hard Disk Drive Abstract Improvement of the head positioning performance in hard disk drives is necessary for increasing storage density, and reducing data access time. The adaptive robust backstepping method has recently proposed for this problem, however, the developed method can be used only for minimum phase systems. Applying this method on hard disk drives, which is naturally modeled by a non-minimum phase system, is possible by considering the nom-minimum phase behavior of the system as uncertainty. However, performing such design procedure may significantly reduce the closed loop performance. In this thesis two methods are proposed to extend previously proposed backstepping method for non-minimum phase systems. In these methods the non-minimum phase model of the system is incorporated in the design scheme rather than considering it as uncertainty, in order to improve control effort and overall performance. In the first proposed method a zero placement routine is added to the design procedure to reclaim the controller. Next, the adaptive part of the controller is replaced by a totally new model reference control structure in order to enable the controller to include non-minimum phase models. Both methods are developed for dual stage hard disk drive systems and by performing some simulations the significance of each method on the performance improvement is studied and compared in detail. | 2010 | Flexible Robotics |
| Fatemeh Bakhshandeh | Development and implementation of visual servoing methods for unmarked objects Abstract Commonly Visual Servoing is separated into tracking and control parts. None of the previous methods attempt to optimize these two parts. In Kernel Base Visual Servoing method the main purpose is to combine and optimize whole control loop. By kernel definition a lyapanov candidate function is formed and control input is computed to proof the lyapanove stability. It is implemented in four degrees of freedom. In this thesis previous algorithm is implemented and also a new method in scale and rotation correction is presented. We propose Log-Polar Transform instead of Fourier Transform for 2 degrees of freedom. Besides we synthesize all four degrees of freedom to show visual tracking. Comparison between LPT and FFT shows advantages of our new method. | 2010 | Visual Robotics |
| Mohammad Mahdi Share Pasand | Extension of Robust Internal Model Control to Linear singular systems Abstract In this thesis, the problem of singular control systems is studied in detail. Singular systems arise naturally in process control as well as other fields. Existing control algorithms are discussed and their advantages and disadvantages are compared to each other. A new method in state space is presented for state observation and disturbance attenuation. A robust control scheme for uncertain singular systems is proposed in the frequency domain in order to yield to an offset free, robust, disturbance ejective closed loop system, whose performance is superior to that of conventional state space methods. The problem of algebraic loop and its relation to the regularity concept is illustrated and an algorithm to avoid algebraic loop is proposed. The proposed method for avoiding algebraic loops is incorporated in the control system. Moreover, it is shown that the internal model control scheme for singular systems is an extension of the internal model control algorithm for standard systems. Therefore, the thesis makes an extension of the internal model control into the singular systems. Several examples were provided and the results were simulated to show the effectiveness of proposed methods. | 2010 | Dynamical Systems Analysis and Control |
| Reza Oftadeh | Accurate Pose Estimation of KNTU CDRPM Moving Platform, from position and force sensing on Cables Abstract Cable driven redundant parallel manipulators (CDRPM) have prominent characteristics such as wide workspace, higher payload per moving mass and capacity to produce ultra-high accelerations. These abilities make these manipulators a sensible candidate for many industrial tasks. This thesis investigates the different aspects of these manipulators in both theoretical and practical approaches. First, a precise analysis is given for both planar and spatial models of these manipulators. Moreover a new analytical solution is developed for forward kinematic problem of the planar model by using force sensors data. It is shown that this solution is faster and more accurate compare to previous solutions presented for this problem. Next, a new method is developed to analysis the dynamics of general CDRPMs with rigid cable. This method eventuates to an explicit dynamic equation for these manipulators. In this analysis, dynamics of variable mass systems is used to meticulously model the translation of cable mass inside and outside of the workspace. Both Newton-Euler and Lagrange formulation is used to derive the dynamic model and it is shown that both formulations lead to an identical dynamic equation. Afterwards, a general dynamic model is derived for CDRPMs with elastic cables. This model can be used for different kinds of CDRPMs with diverse structures. In order to verify the developed model, it is shown that many elastic equations derived for cables in the literature are special cases of this generalized model. At last, in a practical approach, design and production of different mechanical systems of KNTU CDRPM is presented. In this part, based on project requirements, the selection procedure of the cables, frame and force sensors are stated. Moreover, a new design for robot winch system is demonstrated which preserves the position of the cable attachment points. Some views of the produced system along with production drafts of the parts are also presented. | 2010 | Parallel and Cable Robotics |
| Aida Farahani | پيادهسازی روش هدايت بصری بر روی بازوی رباتیک میتسوبیشی با استفاده از روشهای تخمين و دستهبندی همزمان اشياء Abstract امروزه، جایگاهی که علم روباتیک پس از حدود پنجاه سال در صنعت دنیا پیدا کرده بر کسی پوشیده نیست. هدایت بصری روبات، از جمله روشهای هوشمند سازی روباتها در عملکرد و مواجهه با شرایط از پیش تعیین نشده برای آنهاست. در هدایت بصری پیاده سازی شده در پروژۀ حاضر، به جای استفاده از مختصات از پیش تعیین شده، با استفاده از یک شبکه عصبی پرسپترون دو لایه، تصاویر دریافتی دوربین متصل به مچ روبات مورد پردازش قرار داده شده و مختصات شئ هدف را نسبت به آن بهدست آوردیم. سپس، موقعیت تخمین زده شده برای جسم، به سینماتیک معکوس روبات ارسال شده تا آن را در مختصات مطلوب و جهتگیری صحیح در مقابل جسم قرار دهد. برای قراردادن روبات در موقعیت مطلوب نسبت به شئ، از حل سینماتیک معکوس به روش screw استفاده شده است. همچنین برای افزایش قابلیت انعطاف سیستم، از چند کلاس مختلف اشیا استفاده کرده و با شبکۀ عصبی دیگری، دستهبندی اشیا را نیز انجام دادهایم. الگوریتمهای فوق بر روی روبات پنج درجه آزادی میتسوبیشی گروه روباتیک ارس که دوربینی بر روی عملگر نهایی آن نصب شده است، انجام شده و نتایج مورد قبولی از اجرای الگوریتم فوق را به نمایش میگذارد. | 2009 | Visual Robotics |
| Ehsan Mihankhah | Adding Autonomous Behavior to Resquake Robots Abstract This thesis focuses on adding basic autonomous behaviors to a tracked mobile robot called Silver. Silver was initially designed and manufactured by resquake to perform as a fully tele-operative platform in the real environments and especially to be used in the buildings that are heavily destructed by earthquake. After testing the successful platform in several standard environments such as International RoboCup Rescue Arenas and developing the platform since 2005, adding autonomous behavior is now the main research criteria in Resquake. We started by simplified indoor environments with mostly polygonal structures. Self localization and mapping based on a genuine line fitting algorithm that only processes LASER range finder distance data, is the first objective in this thesis. Providing vector information about the polygonal objects of the environment and the need of very low computing effort are the most important outcomes of this algorithm. Localization and mapping algorithm is then used to help robot in exploring the environment. To avoid touching the walls and objects at the same time staying close to them, covering the arena and realizing the end of exploration mission are the main goals of the navigation and exploration algorithm which is based on Fuzzy logic. The last objective of the thesis is autonomous staircase detection and autonomous staircase climbing. A smart sensor placement helps the robot find and climb the staircase fast, safely and smoothly. Successfulness of every part of the thesis is proven by doing several experiments. An experiment result is discussed at the end of each section of the thesis and to conclude the research, all results are provided and discussed again in the last section. | 2009 | Autonomous Robotics |
| Mohammad M. Aref | طراحی و تحلیل سینماتیکی و دینامیکی روبات موازی کابلی افزونه دانشگاه صنعتی خواجه نصیرالدین طوسی Abstract روبات موازي كابلي KNTU CDRPM پروژهاي است كه در گروه روباتیک ارس جهت تلفيق و كاربرد تكنولوژيهاي نوين و معرفي نسل جديدي از روباتهای صنعتی به جامعة علمي کشور تعريف شده است. یکی از کاربردهای اين روبات حمل و جابجایی دقیق تجهيزات اپتيكي مربوط به تابش اشعه ليزر است كه در جوشکاری دقیق سه بعدی قطعات فلزي استفاده می شود. در این پایاننامه، طراحی و تحلیل سینماتیکی و دینامیکی روبات موازی کابلی دانشگاه صنعتی خواجه نصیرالدین طوسی مورد مطالعه قرار گرفتهاست. همچنین توسعه روباتهاي موازي کابلی براي كاربردهاي دیگر نگاه كليتري است که در اين طراحي مورد تعقیب قرار گرفته است. بدین منظور نخست با معرفی روباتهای موازی موجود در مراکز صنعتی و تحقیقاتی، ادبیات موضوع مورد کنکاش قرار گرفته و سپس با معرفی و تحلیل معیارهای طراحی گامی در راه طراحی دقیق این نوع روباتها برداشته شدهاست. مبانی منطقی طرحهای اولیه بررسی شدهاست تا طرحی پایه برای KNTU CDRPM جهت بهینهسازی معرفی شود. در طراحی بهینه، روشی تحت عنوان بازبینی نظارتی پیشنهاد گردیدهاست. این روش همچنین جهت تعیین وزنهای توابع هزینه در تابع هزینهی کل مفید میباشد. مراحل یاد شده بر روی روبات بکاربسته شدهاست تا ابعاد و مشخصات بهینه برای این روبات کشف شود. نتايج حاصل از تحليل نشان ميدهد كه روبات KNTU CDRPM از فضاي كاري وسيعتر و ماهرتري نسبت به ساير انواع روباتهاي موازي و روباتهاي موازي كابلي بهره ميبرد. این مهم در نتیجهی تحلیلهای سینماتیکی و دینامیکی مرتبط، صحه گذاری میگردد. | 2009 | Parallel and Cable Robotics |
| Noushin Poursafar | Robust model predictive control of uncertain systems with unstructured uncertainty using LMI Abstract Although manufacturing processes are inherently nonlinear, the vast majority of MPC applications are based on linear dynamic models. By using a linear model and a quadratic objective, the nominal MPC algorithm takes the form of a highly structured convex quadratic program (QP), for which reliable solution algorithms can easily be found. This is important because the solution algorithm must converge reliably to the optimum. Nevertheless, there are cases where nonlinear effects are significant enough to justify the use of nonlinear model predictive control. Using a nonlinear model in model predictive control changes the control problem from a convex quadratic program to a non-convex nonlinear problem, which is much more challenging to solve. In this Thesis, we introduce a model predictive control algorithm for nonlinear discrete-time systems. The systems are composed of a linear constant part perturbed by an additive state-dependent nonlinearity term. The control objective is to design a state-feedback control law that minimizes an infinite horizon cost function within the framework of Linear Matrix Inequalities (LMI). In particular, it is shown that the solution of the optimization problem can stabilize the nonlinear plants. Three extensions, namely, application to systems with input delay, nonlinear output tracking, and output feedback, are followed naturally from the proposed formulation. As a natural extension of RMPC, robust state observation (RSO) is also covered in this thesis. The essential point that distinguishes RSO from conventional state observation is that RSO combines physical state nonlinearity with the robust observer formulation. Finally, in this thesis, several numerical examples are given to illustrate the performance of the controller | 2009 | Dynamical Systems Analysis and Control |
| Hadi Haji eghrari | Dynamic Adaptive Robust Control of a Dual-Stage HDD Servo System Abstract This dissertation focuses on the high performance adaptive robust control of linear systems in the presence of parametric uncertainties and uncertain nonlinearities (e.g., disturbances) and its application to the control of high precision mechanical systems like a Dual-Stage Hard Disk Drive servo systems. Here, an alternative algorithm for the synthesis of dynamical backstepping design procedure has been proposed to develop a new scheme for Dynamic ARC. This new strategy is more engaged with the dynamic of the system, and thus can perform more effectively than the static one which is based on the traditional backstepping design. The dynamic models of the VCM and PZT actuators, which are used in the read/write head of hard disk drive, are discussed, and a simple, but accurate, model is represented for each of the actuators. These two actuators are used in a dual stage servo control strategy to serve a pretty accurate performance. Beeing high order, apparently, these models are not so proper for backstepping strategy; then, they are reduced to lower order ones using proper reduction methods. Simulations are run for embedded control system of dual stage HDD. Results show the effectiveness of this structure in terms of transient performance, tracking errors, and disturbance rejection, in both track seeking and track following modes. | 2009 | Dynamical Systems Analysis and Control |
| Alaleh Vafaei | Dynamic Modeling and Control of KNTU CDRPM Considering the Elastic Cables Abstract Design and manufacturing of the cable driven parallel manipulators is emerging in the late decade due to numerous advantages of these robots compared to the other parallel manipulators and serial robots . One of the challenging problems in these robots is the accuracy of tracking, which is highly affected by the elasticity of the cables. In this project, dynamic modeling of the cable driven parallel manipulators, KNTU CDRPM as an instance, considering the elasticity of the cables and then proposing an effective controller based on the obtained model, is studied. At first, the stability analysis of the integrated controller for the rigid robot is proposed using the Lyapunov theory. Then, with a step toward the final goal of this research i.e. control of the flexible robot, a robust controller is designed considering the uncertainty of the Jacobian matrix. One of the problems arising from the elasticity of cable links is the change in the angle of attachment point of the cables to the end effector, and this causes uncertainty of the Jacobian matrix. Hence, a nonlinear robust controller is designed against uncertainty of the Jacobian and Gravity matrices and external
| 2009 | Parallel and Cable Robotics |
| Ehsan Aboosaeidan | کنترل موقعیت دهی مرکز جرم با استفاده از سیال برای افزایش قابلیت مانور ربات امدادگر ResQuake Abstract ربات پایه متحرک ، رباتیست که قابلیت حرکت در یک محیط مشخص را دارد و در جای مشخصی ثابت نشده است. از این رو دارای قدرت مانور و حرکت در جهتهای مختلف میباشد. ربات پایه متحرک مورد بررسی، ربات امدادگر ResQuake با سامانه حرکتی شنی میباشد. علاوه بر شنی اصلی، چهار شنی فرعی مستقل هرکدام با یک درجه آزادی، امکان پیکربندیهای مختلفی به این ربات میدهند. عملکرد ربات پایه متحرک به صورت خودکار ، نیمه خودکار یا غیر خودکار امکانپذیر میباشد. عملکرد خودکار در زمینههای مختلف کاری ربات نظیر عبور خودکار از مانع میتواند تعریف شود، که در کنار حفظ تعادل و افزایش قدرت مانور برای ربات پایه متحرک شنی موضوعاتی هستند که در این پایاننامه مورد بررسی قرار میگیرد. پایاننامه در دو بخش اصلی ارائه شده است؛ که عبارتند از: بهبود عملکرد ربات با تعیین مسیری بهینه برای عبور خودکار از مانع افزایش پایداری و قدرت مانور به کمک سامانه جابجایی مرکز جرم مبتنی بر سیال. در بخش اول، ابتدا به توصیف سینماتیک پیکربندی نظیر محاسبه محل مرکز جرم ربات با توجه به پیکربندیهای گوناگون ربات میپردازیم.. در ادامه، با توجه به قابلیتهای ربات ، مسیر بهینه و چگونگی حرکت آن برای عبور از مانعی با ارتفاع مشخص، در قالب الگوریتمی با 8 مرحله معرفی میشود. معیارهای اصلی انتخاب مسیر بر اساس افزایش پایداری، کاهش لغزش، جلوگیری از وارد آمدن ضربه، کاهش گشتاورهای مفصلی و موتورهای محرک و در نتیجه کاهش مصرف انرژی میباشند. در این بخش معیار پایداری مورد استفاده معیار MHS میباشد. شبیه سازی مسیر بر اساس نقاط تکیهگاهی، رئوس چند ضلعی حامی ، و تماس ربات با محیط میباشد که ضمن در نظر گرفتن موقعیت مانع با تعریف قیود هندسی حاکم بر محیط فرضی و سینماتیک ربات در هر مرحله بدست میآید. با استفاده از نتایج شبیه سازی به پیاده سازی مسیر با بازخور کردن زاویة رقص بدنة اصلی ربات میپردازیم که از حساسه ژیروسکوپی بدست میآید. از سوی دیگر، به عنوان عملکرد غیرخودکار، ربات همان مانع را در حالی که توسط کاربر ماهر کنترل میشود طی میکند. بدین ترتیب، نتایج حاصل از پیاده سازی عبور خودکار و غیرخودکار مقایسه شده و کاهش یا افزایش اندیسهای پایداری، لغزش، و مصرف انرژی در کنار سایر معیارهای فوق الذکر مورد بحث و بررسی قرار میگیرند. در بخش دوم، به ارائة طرح جابجایی و ایجاد تغییرات هدفمند در موقعیت مرکز جرم برای افزایش پایداری و قدرت مانور جهت عبور از موانع بلند میپردازیم. در این راستا، چگونگی طراحی سیستم جابجا کنندة مرکز جرم با استفاده از سیالی چگال نظیر جیوه معرفی میشود. طراحی، ساخت و پیاده سازی سامانه جابجایی مزبور به طور کامل ارائه و عملکرد آن تشریح میشود. در انتها به بررسی عملکرد واقعی سامانه مزبور بر روی ربات در الگوریتم بهینة موردنظر همراه با عبور از موانع بلند میپردازیم. معیارهای مورد نظر در طی مسیر مورد بررسی قرار گرفته و بهبود قاطع عملکرد با معیارهایی از قبیل افزایش قدرت مانور و پایداری مشخص میشود. | 2009 | Autonomous Robotics |
| Amirhossein Tamjidi | Developing Methods for Performance Improvement of EKF in SLAM problem and proposing an Algorithm for Single Source SLAM Abstract In this thesis the improvement of EKF based on modification in observation information handling is discussed. In addition, an estimation procedure is proposed for Single-Source SLAM which is an SLAM algorithm that uses a single source for both observation and motion model. Contents of this thesis are organized in four parts. General background about the uncertainty in robotics, definition of some used terminology and Recursive Bayesian Estimation is discussed in first chapter. In chapter two, theoretical foundations of two well known SLAM algorithms, namely FastSLAM and SEIF, are covered. In chapter three, the Consistency of EKF-SLAM is analyzed based on the role of observation model. It is proposed based on this analysis that for improved consistency the bearing-range observations of features are only used for feature initialization and after that only the bearing observation is used in estimation process. Proposed method proved to be efficient based on simulation results and implementation on real data. In chapter four an estimation framework is proposed for Single-Source SLAM. Correlations that emerge as a result of using a common source for both observation and motion model are calculated and appropriate modifications are made in conventional EKF-SLAM in order to take these correlations into account. | 2009 | Autonomous Robotics |
| Sedigheh Dehghani | Controller and Predictive Filter Design In Human Arm Motion Abstract motion control system uses the motion memory to accomplish an appropriate movement. It uses the past experience, learns and creates a precise or incident knowledge of the physical properties of the body and the external environment. In this thesis, since the interaction with the environment is one of the main characteristics of the human motion controller design, a dynamic impedance control model is considered. This model consists of two feedback loops, the internal force loop and the external position loop in the Cartesian space. By exploiting dynamic impedance control scheme, the controller identifies the mechanical impedance of the environment while interacting and adapting its required impedance coefficients. A neural network self tuning PID controller is used to determine the impedance control coefficients. By this means and through the adaptation properties of neural networks, the proportional, integral and differential coefficients of the impedance controller is obtained during the interaction with the environment. Finally, the results of proposed controller structure are compared with the same experiments and past researches, and the accuracy and precision of its performance is studied in detail. | 2009 | Cybernetic Robotics |
| Hossein Beikzadeh | Stability and Performance Analysis and Robust Synthesis of the Nonlinear SDRE Observer Abstract In recent years, the state dependent Riccati equation (SDRE) based design techniques are increasingly being used in a wide variety of nonlinear control and filtering applications. Remarkable theoretical advances have been made regarding the SDRE control and the asymptotic stability properties of the system with full state feedback. However, there are limited slight attempts concerning the theoretical aspects of the SDRE observer and there remain many unanswered questions, such as stability and convergence of the filter in a noisy environment and its robustness against uncertainties and disturbance inputs. This thesis analyzes stability and performance of the SDRE observer in both of the deterministic and stochastic settings. In addition to presenting a novel structure of this observer with guaranteed exponential stability in a continuous-time deterministic (noise free) framework, the convergence conditions of the discrete-time SDRE filter in a stochastic (noisy) framework have been also derived. The theoretical results are illustrated through some appropriate simulation examples. Moreover, we propose two effective methods which can increase the region of attraction of the SDRE observer. The first approach, which has been used in the formulation of the proposed exponential observer, is based on the guaranteed cost control and can be justified in deterministic settings. The other approach, which is a direct outcome from the robustification of the SDRE filter against unknown disturbances as well as model uncertainties, may be used in stochastic environments. In fact, in this method by developing a robust SDRE observer, that is one of the main innovations of this dissertation, we reduce the sensitivity to the initial estimation error. Simulation results demonstrate the performance improvement for each of these two methods in comparison with the usual SDRE techniques. Finally, combining the SDRE controller and observer, a nonlinear tracking system is designed and under certain conditions, the asymptotic stability of the closed loop system has been also ensured. Then, in order to examine the practical usefulness of the proposed method, it is applied to the sensorless speed/position control problem for permanent magnet synchronous motor (PMSM) derives. | 2009 | Dynamical Systems Analysis and Control |
| AliAkbar Aghamohammadi | Design and Implementation of SLAM Methods using the Information of a Range Finder and a Monocular Camera Abstract This thesis is a step towards solving SLAM problem practically. This thesis aims to design and develop new solutions for SLAM problem, which can be used to make mobile robots more intelligent. There exist two major contributions in this thesis: "Design and implementation of a solution for SLAM problem in the structured environments, using the information of a range finder as the only data source" and "augmenting the information of a monocular camera and a range finder to solve the SLAM problem in unstructured environments". Both of these methods is explained completely | 2008 | Autonomous Robotics |
| Yousef B. Bedoustani | مدلسازی، حل مساله افزونگی وکنترل بازوی رباتیک موازی کابلی Abstract دراین پایاننامه ابتدا سینماتيک بازوی رباتیک موازی پیشنهاد شده برای قسمت گیرنده رادیو تلسکوپ غولپیکر LAR به صورت تحلیلي بدست آمدهاست. سپس دینامیک بازوی رباتیک مورد نظر با فرض صلب بودن کابلها و با استفاده از روش نیوتن-اویلر مورد تحلیل قرار گرفته و همچنين روشی بهینه برای حل مساله افزونگی با در نظر گرفتن این حقیقت که نیرو انتقال یافته توسط کابلها همیشه باید کششی باشد، ارائه شدهاست. با استفاده از این توپولوژی نشان داده شده است که یک کنترلکننده تشکیل شده، از دو قسمت Inverse dynamic Control و PD حتی در حضور اغتشاشات بسیار بزرگ وارد شده توسط باد، به خوبی قادر به کنترل بازویرباتیک میباشد. سپس مدلی ساده و کارآمد برای كشساني و میرایی کابل ارائه شده و دینامیک حاصل از این مدلسازی به دینامک بازویرباتیک موازی اضافه شده است. در این حالت نشان داده شده است که کنترلکننده کلاسیک ارائه شده در حالت صلب دیگر قادر به کنترل بازوی رباتیک حتی بدون در نظر گرفتن اغتشاش باد نمیباشد. بدین منظور یک کنترلکننده ترکیبی که از دو قسمت کُند و تُند، با توجه به ساختار ترکیبی بازوی رباتیک کابلی پیشنهاد شده است. ساختار اين کنترلکننده ترکیبی (کُند وتُند) با استفاده از نظریه انحرافات تکین ارائه شده و مورد تحليل و بررسی قرار گرفته است. نتایج شبیه سازی شده عملکرد مطلوب کنترلکننده ترکیبی را حتی در حضور اغتشاشات شدید باد نشان میدهد. | 2008 | Parallel and Cable Robotics |
| Pooneh Gholami | Control & Redundancy Resolution of the Cable Driven Parallel Manipulator Abstract The challenging control problem of the cable driven redundant manipulators is dueto the complexity of its dynamic and the required stringent performance for the its promising applications. This paper presents an approach to the control of the KNTU CDRPM using an adaptive cascade control scheme. The goal in this approach is achieving accurate trajectory tracking while assuring positive tension in the cables. The cascade control topology uses two loops, namely the internal and external loops. The inherent nonlinear behavior of the cable manipulator is controlled by the internal loop, while the external loop can effectively reduce the target tracking errors of the end-effector in the presence of disturbance force/torques. The cascade strategy reduces the tracking error by 80% compared to that of a single loop controller in the KNTU CDRPM. Moreover, adaptation of the cascade controller gains can significantly improve the overall tracking performance. The closed–loop performance of various control topologies are analyzed by a simulation study that is performed on the KNTU CDRPM. Since, the dynamic equations of this parallel manipulator are implicit in its general form, special integration routines are used for integration. The simulation study verifies that the proposed controller is not only promising to be implemented on the KNTU CDRPM, but also being suitable for other cable driven manipulators. | 2008 | Parallel and Cable Robotics |
| Shirin Dadashi | Experimental Identification and H∞ Control of 2-link Flexible Joint Robot Abstract In this thesis, spectral identification and design and implementation of the controller for flexible joint robot (FJR) is presented and the capability of the controller to deal with actuator saturation is investigated in practice. The experimental procedures are introduced to regulate the frequency resolution of the spectral identification for both two links. The new procedure of design is introduced for the 2 link to avoid an instability caused by unmodeled phase behavior which cannot be encapsulated in multiplicative uncertainty. In order to avoid instability caused by unmodeled phase behavior, the robust controller design is divided into two stages: controller design and checking closed loop sensitivity function. Simulation results reveal the capability of the controller to stabilize the closed loop system and to reduce the tracking error in the presence of the actuator limitation. Finally, the effectiveness of Robust Decentralized control has been checked for motion control of the links at the same time. | 2007 | Flexible Robotics |
| Akram Bayat | Wavelet Based Algorithms for Tracking Moving Object By Mobile Robot Abstract In this thesis, we present various algorithms to track moving objects by a mobile robot. Our algorithms based on hypothesis that the object areas are not defined for the robot. To this end, we have desigened a new wavelet based algorithm and a color texture based algorithm for real time object tracking in a video sequence. This purpose have been achived using a special search method for finding best match among feature vector of object and feature vector of the search window. Finally suitable feature for the object have been formed. This feature is dispersion of detail coefficients in the wavelet based algorithm. This featue alonge with the size invariant property, makes it possible to successfully track a object in the images.We use Euclidean distance measure for finding the distance of two feature vectorThe algorithm has been implemented in a PC running widows XP operating system with Pentium IV 3GHz full cash processor and 1GB of RAM memory. considering 240 320 pixels search window. The results have shown that our algorithms is often superior to traditional template methods for object tracking applications. | 2006 | Autonomous Robotics |
| Peyman Sheykholeslami | Adaptive-Robust Control for Dual-Stage Hard Disks Abstract With the aim to increase storage capacity of magnetic hard-disc drive systems (HDD-systems) in particular the track-per-in value, dual-stage actuated HDD-systems have been of interest for many years. Dual-stage actuator systems, comprising a voice-coil-motor (VCM)-actuator for coarse actuation and a high bandwidth PZT-actuator, have been an attractive alternative to the commercially used single VCM-actuator system. Since they allow for higher servo bandwidth and more accurate positioning of the read/ write head. Designed as high bandwidth actuator with small displacement of less than 2 micrometers, different types of high bandwidth secondary actuators have been introduced, mounted on the VCM-actuator, either on the suspension, head or slider. Servo-control in HDD comprises three different tasks. One of the tasks is track following, during which data is written or read from one of the concentric tracks on a hard disk. For track following, linear control structures are usually used. The second task of HDD-servo control is track seeking for which often non-linear control methods or special control methods involving path planning are employed. The transition between the two control tasks, track seeking and track following, is usually achieved by the task of track settling to prevent large overshoots. In this research we first introduce structure of HDD-systems and need for increasing of accuracy for its control system. In chapter 2 we introduce various structures of micro actuators and their mathematical models. Then in chapter 3 we introduce various structures of control for this system. In chapter 4 and 5 we introduce ARC controller structure and design and simulate this structure on HDD Dual Stage systems with compensator prefilter respectively. | 2005 | Dynamical Systems Analysis and Control |
| Mahdi Noori | Generalized Predictive Control for Nonlinear Systems Combined with Feedback Linearization and Linear Uncertainty Compensator Abstract Model based predictive control originated in the late seventies and has been developed considerably since then. Predictive control is now widely regarded as one of the standard control algorithms for industrial processes. In this thesis a new approach to design generalized predictive controller for nonlinear systems with model uncertainty is proposed. The controller is based on a state-space model composed of generalized predictive control, uncertainty compensator and feedback linearization. The uncertainty compensator is proposed in this method to remedy the drawbacks of the model based algorithm used in both GPC and Feedback Linearization structure. Stability analysis of the method is elaborated and a comparison study with of the nonlinear predictive methods is performed using computer simulations. The efficiency of this method is illustrated through simulations. | 2005 | Dynamical Systems Analysis and Control |
| Amir haddadi | Designing Guidance and Control Methods for Unmanned Aerial Vehicles Abstract Nowadays, guidance and control methods have very important usage in various fields as agricultural applications, topography and surveying, hostilities and wars. A complete Autopilot system is composed of a path planner system, referring to the next point of the trajectory of the vehicle's motion, a guidance system, which represents commands to the control system using path planner information, and a control system generating control commands to the control surfaces. Navigation systems make feedback of the control loop. In this thesis after surveying on navigation and guidance methods used in aircraft autopilot systems, we completely model a real UAV with complete details and its real parameters in the MATLAB/Simulink environment. The complete generated 4x4 nonlinear model will be controlled, using robust control methods for each 2x2 plant separated from the large model, named Lateral and Longitudinal systems. | 2005 | Dynamical Systems Analysis and Control |
| Mohammad Reza Sabaghian | Multivariable Identification & Control of the Servo-Hydraulic Robot Shoulder Abstract Parallel mechanisms have been the subject of many researches in recent two decades. These mechanisms are more precise and powerful with respect to serial ones. The major point around these mechanisms is the singularity problem which can be overcome by smart designing. Hydraulic shoulder is a parallel mechanism using four actuators to achieve three degree of freedom. Identification and control of the shoulder is the subject of this research. This text can be divided in two major parts. In the first section, the hydraulic shoulder has been surveyed and identified as a 4x4 transfer function. Centralized control is the topic of the next section. Inverse Nyquist array is used to obtain diagonal dominance and four proportional-integral controllers are used to close the loop. However, sensitivity to noise and sensitivity to changes of the nominal model make this method unsuitable for the real world. To overcome the problem, a H∞ robust controller is designed which make the closed loop system robust and less sensitive to noise. At the end of this thesis, different methods of controlling the shoulder are compared. | 2005 | Parallel and Cable Robotics |
| Siavash Fakhimi Derakhshan | Identification and Robust Controller design for the Servo-Hydraulic Robot Shoulder Abstract In this thesis the ability of modern controllers on the hydraulic robot shoulder, a 3-Degree Of Freedom (3DOF) parallel mechanism with redundancy in actuators, is investigated. The cinematic and dynamic analyses of this mechanism are the subject of the previous works. In this work, with the aim of robust control of position and impedance, the linear identification is performed and in accordance with the estimated models, some appropriate controllers are designed. In each case with the consideration of different criteria in the performance of the system, the ability and effectiveness of each controller in tracking and rejection of disturbance, is investigated | 2005 | Parallel and Cable Robotics |
| Habib Rahimi | Nonlinear Quantitative Feedback Theory Controller Design for Flexible Joint Robot Abstract In this project, we will use Quantitative Feedback Theory (QFT) to design a for Flexible Joint Robot (FJR). During design procedure we will see the most important superiority of this method which is the possibility of having trade off between practically obtainable characteristics and desired specifications. Also QFT offers some efficient and facile unique techniques to encounter nonlinear systems which save us from complicated analytical methods for nonlinear systems or general identification methods in frequency domain (like, in ). In this project, first we attempt to design a holistic controller for FJR, but we realize that flexibility make it necessary using composite control idea to control fast and slow dynamics separately. Hence, after controlling fast dynamics by a corrective term, we design a QFT controller for the rest system which is equivalent to the rigid system. Due to the fact that the flexibility of the real system is much less than the benchmark system, QFT can design a suitable controller for it without using composite control idea. | 2004 | Flexible Robotics |
| Saeed Barghandan | Identification of the Global Control Logic of the Nekka Power Plant and the Design of a Multivariable Controller for its Boiler Abstract Persistent increase of power generation demand necessitates the use of modern
| 2004 | Dynamical Systems Analysis and Control |
| Saeed Mahyad | Control of Human Simulated Arm by Use of EMG Signals Abstract One of major disabilities that occur because of war or incidents is loss of limbs. Using of artificial prosthesis has a long history. After World War II, many researches have been accomplished to add movement abilities to artificial limbs. For this purpose, biological signals were considered as a media between man and prosthesis. One of these signals is electromyogram or EMG signal. This signal can only be used for control of the prosthesis, if it is already analyzed by pattern recognition methods to determine desired movement and produce proper control signals. In this research, biological generation of EMG signals, their properties, and different methods in pattern recognition for movement class extraction will be introduced. The main goal of this research is a realistic assessment of practical problems that exist in implementation of cybernetic hand. For this purpose, MLP classifier and IAV of signals are used for pattern recognition phase. One of the main problems that exist in current cybernetic hands is their control systems. In these methods, after determination of movement class, prosthesis starts to move with a predetermined and constant velocity. This makes the movements unnatural. Furthermore, we can not add combinational movements to prosthesis. To solve these problems, we closely observe the natural system behavior in order to find ideas that make them significantly perfect and efficient. For this purpose, we have modeled the musculoskeletal system of arm and simulate brain’s control on it. The results of this modeling lead us to introduce a new control topology to control arm movements more naturally than before. Finally, the proposed control method will be simulated and results are analyzed | 2004 | Cybernetic Robotics |
| Azad Ghaffari | End-point Control of a Flexible-link By Using a Sliding Mode Controller Abstract By ever increasing application fields wherein robots are being deployed the need for high speed performance, more precision, decreased the energy consumption, the researchers and manufacturers were both encouraged to design and implement lighter manipulators. Decreasing the weight of the manipulators caused flexibility while at the same time resulted in vibration problem. The flexible-link is an infinite dimension system. To design controller a reduced order model of system is employed. There are unmodeled dynamics, some other uncertainties and external disturbances, which affect the closed loop performance and must be eliminated. Sliding mode controller is a well-known nonlinear robust controller. The equivalent control method is a conventional way to design this controller, usually based on linear switching surface. The sliding surface equation has a great rule in controller performance. To eliminate high frequency oscillations a continuous approximation of hard switch will be used in boundary layer. In this case the equation of switching surface affects the controller performance directly in boundary layer. In the other hand increasing the number of nonlinear terms in dynamic equations causes higher order terms will be needed in sliding surface to reach a better performance. Increasing the sliding surface degree will affect some performance indices such as domain of attraction. At the first step neural networks will be used to adjust two main parameters of smooth switch, slow rate and amplitude. Because loss of stability prove and a few degrees of freedom, this method was not distributed. By assuming these important points and for modification of the sliding mode controller, a. general. approach to design nonlinear sliding surface for systems in regular form will be presented. To improve the stability conditions and optimize a conventional cost function, the nonlinear optimal approach was mixed with sliding mode method. To prove the stability of sliding phase the global asymptotic stability idea was used to design the equivalent control signal. All of previous steps were proved analytically. At last, the expansion of domain of attraction of closed loop system by increasing the order of the surface is verified by simulation results. The nonlinear surface decreases the level of cost function in all of simulation cases. To solve mathematics equations, the Maple software was used. Simulations was done in Matlab and Simulink environments. The thesis text is typed in FarsiTEX that is the Farsi version of the LATEX. The great parts of figures were plotted by LATEXcad. | 2004 | Dynamical Systems Analysis and Control |
| Mehdi shaterian | Nonlinear H ∞ Controller Synthesis For Flexible Joint Robots Abstract In this thesis, the synthesis of a nonlinear H ∞ controller for flexible joint robot (FJR) has been studied in detail, and the effectiveness of the presented control law is evaluated through simulations. The problem of disturbance attenuation and insensitivity of the performance to the parameter deviations is addressed, respectively by a systematic nonlinear H ∞ control synthesis, considering uncertain nonlinear model for the system. Simulation comparisons show that the nonlinear H ∞ controller yields to superior performance such as larger domain of attraction and smaller control effort, compared to that of the linear H ∞ controller. Moreover, with the proposed controller the total performance of the closed loop system is illustrated to be superior to that of previous controllers, despite smaller control effort needed in here. | 2004 | Flexible Robotics |
| Soleiman Gholampour | Position and Force Control for Hydraulic Parallel Robot Abstract Most of industrial robots work as an open chain that called serial robots. They have some problem in implementation such as accuracy, flexibility etc. In this case, we should use parallel robots. However, they have singularity problem in their workspace. To solve this problem, redundancy is a common solution. In this thesis, we benefit from a 3-DOF robot with a redundant actuator, which works like a human shoulder. At first, we derived a dynamic model of the hydraulic actuator in order to design a controller. To achieve a force control routine for actuators, a lag controller has designed. In order to achieve a good performance in position control, a control structure that consists of gravity compensation, H∞ robust controller, and controller that compensate error of parameter estimation, has proposed. Simulation result illustrates acceptable response in terms of accuracy and robustness. The proposed closed loop system has a significant tracking performance, despite the presence of disturbance and measurement noise. | 2003 | Parallel and Cable Robotics |
| Ehsan Jamei | Adaptive Robust Control for Hard Disk Servo Systems Abstract Adaptive robust controller is proposed for read/write head systems for hard disk drives (HDD). This structure can be applied to both track seeking and track following modes, and it makes the mode switching control algorithms found in conventional HDD servo system unnecessary. A discontinuous projection based on adaptive robust controller (ARC) is considered first. This controller theoretically guarantees a prescribed transient performance and tracking in presence of parametric uncertainties. An improved desired compensation ARC scheme is then presented, in which the regressor is calculated using reference trajectory information. This has been done by structural vibration minimized acceleration trajectory control method (SMART). The resulting controller has several implementation advantages such as less online computation time, less vibration, reduction of noise measurement effect, separation of robust control design from parameter adaptation, and a faster adaptation rate. The simulation and comparison results are presented to illustrate the effectiveness and the achievable control performance of the proposed controller algorithm. | 2003 | Dynamical Systems Analysis and Control |
| Ala Shariati | Robust H∞ Control Of Active Suspension Abstract In this research first an H∞, controller is designed for hydraulically actuated active suspension system of a quarter-modelled vehicle in a cascade feedback structure. Using the proposed structure, the nonlinear behavior of the actuator is reduced significantly. Therefore, in the controller synthesis, a proportional controller is used in the inner loop, and a robust H∞, controller forms the outer loop. By this means, the vehicle oscillations in the human sensitivity frequency range is reduced to a minimum. Optimal observer estimates the output of the quarter-car model of vehicle. The above strategy is also used for a half-car and full-car model of vehicle in decentralized control form. Statistical analysis of the simulation results using random input as road roughness, illustrates the effectiveness of the proposed control algorithm. | 2003 | Dynamical Systems Analysis and Control |
| Gholamreza Bakhshi | Composite Robust Control Design in Flexible Joint Robots Abstract In this thesis, the robust control of flexible joint robots with the emphasis on the performance and control effort limitation is analyzed in detail. First, a special control algorithm, named composite PID, is elaborated, and the main drawback of it to provide solutions for limited control effort is described. In order to remedy this drawback, with a new approach to control synthesis, an H. framework is proposed. In this framework, linear identification techniques are used to represent the open-loop system nonlinear dynamics as a linear model with multiplicative uncertainty. Then, an controller is designed for the system with the emphasis on robust performance and especially limited control effort. By this means, relatively suitable tracking performance is obtained with much smaller control effort. These desirable performances cannot be obtained if in the uncertainty representation, sharp peaks were not neglected. Despite the practical importance of this method, above assumption causes robust stability of the closed-loop system cannot be claimed rigorously. In order to remedy this theoretical draw back and have the benefits of composite control in addition to controller, it is proposed to combine these methods, in which the PID controller of the composite control algorithm is replaced with an controller, designed for performance. It is observed that on the contrary to composite PID control, the composite control is robustly stable, despite control effort limitations. Moreover, the proposed composite control law can provide similar tracking performance to composite PID, with much smaller control effort. | 2002 | Flexible Robotics |
| vahid Saeidi | Solar Field Modeling and Temperature Control of Yazd ISCC Power Plant Abstract Currently, Yazd ISCC power plant consist of two gas units and is planned to have one steam unit being in cooperation with one parabolic through solar collectors plant acting as an auxiliary power generator. Since the solar field is a distributed system it exhibits time delays in its dynamic characteristics. Because of the extension of the solar field and significant distance between the temperature sensors and control valves, the time delays are relatively long and also varying with respect to time, as a result of oil flow variation. The temperature of the outlet oil and the outlet steam water„ of solar boiler should be regulated with respect to the designed reference commands. In the meantime, the existence of long and variable time delays make the closed loop control strategies challenging. In this thesis, a GPC control scheme for the system is proposed using dynamical modeling and simulation of the solar field. First the derived models of the system components are verified through a simulation study. Then the closed loop response of the system using conventional PI controller and GPC controller are compared. The obtained results show the effectiveness of the proposed controller scheme and its performance robustness with respect to the variation of time delays and system parameters. On the other hand for closed loop system with short time delay, conventional PI controller is well performed, and is preferred due to its simplicity of implementation. | 2002 | Dynamical Systems Analysis and Control |
| Ahmad Goodarzian | طراحی مسیر پروازی یک موشک ضد کشتی در کانال سمت و تعیین زمان مناسب روشن شدن رادار | 2002 | Dynamical Systems Analysis and Control |
| Mohammad Reza Eskandari | مدلسازی و شناسایی خطای نشتی در هیتر نیروگاههای بخاری | 2002 | Dynamical Systems Analysis and Control |
| Ehsan Noohi | Sensorless Vector Control of PMS Motors | 2001 | Dynamical Systems Analysis and Control |
| Ramin Vali | Design and Implementation of an Embedded Microcontroller Based Card for Control of Nonlinear Systems Abstract In this thesis, design and implementation procedure of a microcontroller based card for implementing nonlinear control algorithms is reported. The board includes a 16-bit microcontroller from Intel MCS-96 family named 8xC196KC which features 8 channel 10-bit analogue to digital converter and 3 PWM output with 8-bit resolution. 8xC196KC computes 32-bit multiplies and divisions quickly however, it does not support floating-point operations which are very important in control law implementation therefore, a floating-point Library Function is used for 32-bit computations. The card has 2 expansion slots that improve the system capabilities; an example is a 4-channel analogue input and 2-channel analogue output with 12-bit resolution that is designed and tested to control the Ball and Beam system. A new version of hardware-software package named Grisly, which designs, simulates and implements state-feedback and output-feedback linear/nonlinear controllers, is developed to send control law parameters to the card under the Windows 98/2000 operating system. | 2001 | Dynamical Systems Analysis and Control |
| Hassan M. Abdar | The Modeling and Identification of an Inertial Measurement Unit (IMU) Abstract Inertial navigation systems (INS) is an important navigation method, due to their high degree of reliability and accuracy. These systems are categorized into stable platform and strapdown navigation systems. In strapdown inertial navigation systems, there exists an inertial measurement unit (IMU) in which suitable gyroscopes and accelerometer accompanied with their peripheral circuits are harnessed. The output signals of the gyroscopes and accelerometers are digitized and transferred through V/F. In this thesis, one particular IMU, which is widely used in industry, is analyzed in detail. In this IMU two dynamically tuned (DT) gyroscopes, and three closed-loop pendulum-type accelerometers are used, which has been first introduced in the thesis. Then, the models of these IMU components have been elaborated. Moreover, the experimental identification of the IMU has been reported. In which first the designed identification experiments are introduced, and then the resulting second order identified models are proposed. Finally, the performance of the identified models is verified through simulation. It is shown that, despite the simple form of the models, they can predict the dynamic behavior of the system with the desired accuracy. | 2001 | Dynamical Systems Analysis and Control |
| Iman Roshanfar | GPS & INS Simulation and GPS/INS Integration Abstract Navigation is the science of the determination of the position and velocity of a moving vehicle. There exist two navigation systems in industry, "positioning systems" and "dead-reckoning systems". In this thesis global positioning system (GPS) has been analyzed in detail, which is one of the most important positioning system used in industries. First the main feature of GPS such as system configuration, navigation equations and error dynamics have been elaborated. Then the simulation of the GPS has been developed in MATLAB environment assuming a C/A code receiver, in which, the SA effect was discussed. As one of the main technologies in dead-reckoning navigation systems, inertial navigation system (INS) has been also studied in this thesis. INS determines position and velocity, simply by integrating the measured accelerations. A strapdown INS has been simulated in the SIMULINK environment using the empirical error parameters. Due to the instability of the INS vertical channel, error values were grown unboundedly with time. Hence, integration of GPS and INS data has been proposed, and three main approaches to the integration of GPS and INS were surveyed. Then we have designed an extended Kalman filter (EKF) for the cascaded integration of a C/A code GPS and a strapdown INS. This filter provides the suboptimal solutions to minimize the variance of the error estimates of the INS using GPS and INS position data as measurements. The obtained results show a significant improvement of navigation data with the proposed algorithm. | 2001 | Dynamical Systems Analysis and Control |
| Mehdi Khalkhali | Impedance Control of Flight Simulator Yoke Abstract Flight simulators reduce the training costs of the pilots significantly, and therefore, is highly demanded in civil and military air forces. The flight simulator yoke simulates the dynamical behavior of a real airplane yoke. By a dynamical relation we mean a differential equation relating the torque applied by the pilot arm on the yoke and its resulting motion. Therefore, it is desired to obtain a desired dynamical relation between torque and motion by means of a controller. Using "Impedance Controller", a desired dynamical relation between force and motion can be obtained in applications where a system is interacting with a stiff environment. Hence, in this thesis the design of an impedance control for the flight simulator yoke is analyzed in detail. After introducing the mechanical hardware of the flight simulator yoke, a complete model of the system with reference to the impedance representation is developed. Then two classical impedance controller were designed and implemented on the system. By analysis the performance of the closed loop system, it is understood that using only one controller is not entirely successful to reduce the output oscillations caused by the pilot hand, and therefore, a 2DOF impedance control structure is proposed. It is shown that this structure is capable of not only generating the desired relation between the torque and motion of the yoke, but also reducing the output oscillation significantly. | 2000 | Flexible Robotics |
| Mohammad Azam Khosravi | Modeling and Robust Control of Flexible Joint Robots Abstract In this thesis, the robust control of flexible joint robots with the emphasis on the performance and control effort limitation is analyzed in detail. First, a special control algorithm, named composite PID, is elaborated, and the main drawback of it to provide solutions for limited control effort is described. In order to remedy this drawback, with a new approach to control synthesis, an H. framework is proposed. In this framework, linear identification techniques are used to represent the open-loop system nonlinear dynamics as a linear model with multiplicative uncertainty. Then, an controller is designed for the system with the emphasis on robust performance and especially limited control effort. By this means, relatively suitable tracking performance is obtained with much smaller control effort. These desirable performances cannot be obtained if in the uncertainty representation, sharp peaks were not neglected. Despite the practical importance of this method, above assumption causes robust stability of the closed-loop system cannot be claimed rigorously. In order to remedy this theoretical draw back and have the benefits of composite control in addition to controller, it is proposed to combine these methods, in which the PID controller of the composite control algorithm is replaced with an controller, designed for performance. It is observed that on the contrary to composite PID control, the composite control is robustly stable, despite control effort limitations. Moreover, the proposed composite control law can provide similar tracking performance to composite PID, with much smaller control effort. | 2000 | Parallel and Cable Robotics |
| Shaham Afshar | Identification and Position Control of a SCARA Robot Abstract Linear controller, especially PID controllers, are widely used in robotic applications for their simplicity and performance. In this research, a new and simple methodology to design PID controllers for a robot manipulator is proposed. Dynamic analysis of robot manipulators considering actuator dynamics reveals that the effect of nonlinear dynamics of the robot is highly attenuated because of the gear ratios. This fact rationalizes the use of linear controllers in robotic applications. On the other hand, a systematic way of designing a PID controller based on identification results are not well developed in the literatures. We propose identifying a linear model for the system by use of identification experiments, and illustrate a systematic way to design a PID controller based on frequency domain analysis for each joint. This method is implemented on a lab scale SCARA robot and the performance of the proposed controllers are examined through experiments. It is shown that the linear controller designed based on proposed method can effectively reduce the tracking error. despite a limited actuator effort. In order to compare the results to a nonlinear control strategy, sliding mode control is also implemented on the system. It is concluded that, despite the simplicity of the PID controller, better tracking performance is obtained with smoother control effort. Hence, proposed PID design methodology is recommended for industrial application | 2000 | Dynamical Systems Analysis and Control |
| Mahdi Tavakoli Afshari | Design, Identification and Control of the Rotational/Translational Actuator Abstract RTAC \ benchmark problem considers a nonlinear fourth-order dynamical system involving the nonlinear interaction of a translational oscillator and an eccentric rotational proof mass. This problem has been posed to investigate the utility of a rotational proof mass actuator for stabilizing translational motion. In the literature, a number of model-based stabilizing controllers have been proposed for the RTAC system. However, to implement such controllers, the values of model parameters are required which are generally difficult to determine rigorously. In this thesis, an approach to least-squares estimation of system parameters based on a set of identification tests is discussed and practically applied to the RTAC testbed. On the other hand, control objectives such as internal stability, fast settling, and good disturbance rejection in spite of limited control effort are well suited to robust control synthesis. Therefore, in order to design an controller, the nonlinear plant is viewed as a perturbed linear plant, i.e., a nominal linear plant in addition to uncertainty. Making most of the knowledge of system linearization around the equilibrium point, the task is accomplished via a practical idetification scheme. Experimental results verify that this approach can effectively condense the whole nonlinearities, uncertainties, unmodeled dynamics, and disturbances within the system into a favorable perturbation block. Next, an effective mixed-sensitivity problem is developed for the system to satisfy all performance requirements as well as robust stability despite actuator saturation. Simulation results exhibit the effectiveness of the resultant controller. In practice, motor deadzone due to stiction limits the degree of performance satisfaction. | 1999 | Dynamical Systems Analysis and Control |
| Reza Ghabcheloo | Design, Control and Implementation of ElectroMagnetic Suspension (EMS) System Abstract In this thesis, magnetic levitation techniques including electrodynamic suspension, and in particular, electromagnetic suspension are considered. In order to examine the behavior of such systems, a 1-DOF electromagnetic suspension testbed is designed and constructed. Specifically, governing equations as well as associated mechanical design are developed. Next, magnet design for a desired force-current-gap characteristic and design of a PWM drive for the magnet are accomplished. Two sensors are utilized to measure the system states: A resistor senses the magnet current whereas a capacitive sensor with the associated transducer serve to measure the air gap. The characteristics of the sensor are estimated through a point-to-point measurement scheme, followed by a least-squares estimation. The system is controlled by means of an IBM-133 computer. To read the sensor signals, and to implement the control law, a code is developed under Visual C ++. Next, the governing electromagnetic and mechanical equations as well as the state-space, linear and nonlinear equations corresponding to a third-order electromagnetic suspension system are presented. Three control methods are proposed for such a 1-DOF nonlinear, unstable system. Two nonlinear controllers are designed on the basis of the nonlinear model: Feedback linearization followed by state-feedback, and a combined PI/PID which makes use of a state transformation. Moreover, a linear PID is designed based on the linearized system. All of the above controllers are simulated and compared with each another. For the purpose of future research, the linear equations of a 3-DOF electromagnetic suspension system is developed and pitfalls of the system with more degrees of freedom are investigated. Notably, expandability to the 3-DOF case has been considered while designing the gap sensor and magnet which are supposedly the most important components in the electromagnetic suspension system. | 1999 | Dynamical Systems Analysis and Control |
| Hamed Damirchi | Multi-Level Data-Driven Sensor Modality Fusion implemented on the ARAS Cable Driven Robot End Effector Abstract When conceptualizing the algorithm running on an intelligent robot through the glasses of a reductionist, a subsystem responsible for getting a sense of the location of the agent shows to be among the intuitively deduced modules. Whether we view location as a parameter that defines our position with respect to a fixed origin, or we define it through a relative perspective, a robot needs to have a notion of its placement in the world to be able to make appropriate decisions and perform the necessary actions while reacting to the dynamic world around it. However, this dynamic nature of the world presents problems such as flawed describers and unreliable observations that make it challenging to use straightforward solutions to perform localization through low-level information gathered by the sensors mounted on the robot. Therefore, approaches are needed that are able to exploit the semantic information embedded in observed scenes and extract higher-level information about the world around them that are robust to such issues. Moreover, by leveraging multiple sensors, information from modalities where the source of data varies to a suitable extent inbetween the said modalities may be gathered and fused to form a joint high-level representation of the state of the robot, further adding to the reliability of the localization system. In this thesis, our goal is to design and experiment with neural network architectures and create learning paradigms that incentivize the extraction of robust features through a representation learning procedure where the inputs to the network are not preprocessed. We propose mechanisms and objectives that allow the network to disregard faulty input information while achieving interpretability that allows the system to communicate its uncertainty about the estimates based on the provided inputs. Moreover, we take a hybrid approach to global localization of the robot where physical and learning based models are combined to form a multilevel localization approach in order to increase the flexibility of the pipeline. We perform comprehensive experiments to show our motivation while comparing our approaches to the state-of-the-art methods quantitatively and qualitatively. We analyze the proposed approaches through custom designed interpretation methods to get in-depth intuition on how our algorithms add to the literature and improve upon the state-of-the-art algorithms. Thereafter, we provide an overview of the branches of our work that can be explored further while delineating the potential future of the field. | 2021 | Parallel and Cable Robotics |
Selected B.Sc. Project Reports
| Name | Title | Year | Research Group |
|---|---|---|---|
| Mohammad Mehdi Nazeri Ardakani | Victor's robotic arm simulation and torque control design and implementation on it Abstract Today robots have different applications, from industrial environments to urban traffic environments, natural environments, office buildings and residential and so on. precise control of motion of mobile robot arms is very important. mobile robot is the fourth generation of mobile robot robots which is designed and built in the KN2C laboratory of the Aras robotic group .In this thesis , torque control methods are implemented in order to accurately control the robot 's arm .Initially, the complete 3D model of the robot was prepared by linking the output of SolidWorks software to MATLAB software, and this model was used in a MATLAB simulation toolbox called Simscape.By adding torque sensors and actuators to this model, a suitable simulator of the real dynamic behavior of the robot arm has been prepared. Then, by performing identification experiments, a linearized model of the robot was obtained with compensation and without mechanical compensation of arm weight, and these models were used to design torque controllers. Quantitative evaluation of robot movement accuracy has been investigated and reported using this method in comparison with previous robot controllers. It has been observed that the use of torque control with the systematic method presented in this dissertation can be a good vehicle for implementing controllers designed on a real robot. | 2020 | KN2C |
| Behzad Mackizadeh | Integratation of SLAM with IMU Data and its Implementation on Victor Mobile Robot Abstract In general, robots can be classified into three categories: ground, areal and unverwate robotics. Since 2015, several prototypes of rescue robots are designed and implemented in KN2C Robotics Laboratory. Victor Robot is the fourth generation of UGV rescue robots that would participate in international robotics competitions. One of the most important challenges in the Rescue Robots League of those competition is simultaneous localization and mapping of the robot in uneven path and assigning the injured people on the prepared map. In this thesis, implementation of HectorSLAM as open source module is reported for localization and mapping with low processing cost and high update rate on Victor robot. Furthermore, by proper integration of the Hector SLAM algorithm with laser scanner and IMU sensor Odometry data, higher accuracy in the maps are obtained. By using this integration, the accuracy of simultaneous location and mapping in uneven locations is 35.65 cm over a distance of 30 meters, which is about eleven times more than that of the conventional methods. | 2020 | KN2C |
| Hossein Sheykhani Darani | Path planning design and implementation on a quadrotor in an uncertain environment Abstract هدف این پایان نامه ارائه روشی جهت برنامهریزی مسیر می باشد. اما وجود انواع نامعینی های موجود در واقعیت، این هدف را با چالش روبرو می کند. در این پایان نامه از بین این نامعینی ها، نامعینی در مدل حرکتی ربات به طور کامل مورد توجه قرار گرفته است. برای پاسخ به این چالش مسأله به زیر بخش های کوچکتری تقسیم شده است. به این صورت که ابتدا با استفاده از فیلتر کالمن توسعه یافته به مکانیابی ربات پرداخته شده است. سپس برنامهریزی مسیر با در نظر گرفتن نامعینی در مدل حرکتی ربات به صورت یک مسأله فرآیند تصمیم گیری مارکوف مدل شده و برای حل آن از یک الگوریتم مبتنی بر گراف استفاده شده است. همچنین برای پیمودن مسیر تولید شده توسط ربات، کنترلکنندههای کلیدزنی و خطیسازی پسخورد پویا به کار گرفته شده است. در انتها نیز تمام الگوریتمها در محیط شبیهسازی و واقعی بر روی یک ربات عمود پرواز چهار موتوره پیادهسازی شدهاند و نتایج آن ارائه شدهاند. همچنین به منظور بررسی تأثیر نامعینی در برنامهریزی مسیر، نتایج روش ارائه شده با حالتی که در آن مسیراز طریق الگوریتم A* و بدون در نظر گرفتن نامعینی به دست آمده، مقایسه شده است. | 2019 | Autonomous Robotics |
| Hamed Sadeghi | طراحي و پياده سازي سخت افزار كنترلي ربات راهبر در سامانه هپتيك آموزش جراحي Abstract در اين پروژه طراحي و پيادهسازي سختافزار مربوط به راهاندازي موتورهاي مورد استفاده در
| 2018 | Surgical Robotics |
| Hossein Sheikhi | Motion planning with constraint on motion model uncertainty for a quadrotor, its simulation and real implementation Abstract The motion planning goal is finding a sequence of robots' configuration in an obstacle-free space, which reaches the robot from an arbitrary configuration to a desired one. Motion planning it self sometimes is the goal and sometimes is a tool for another purpose. Robotics' uncertainties challenge the motion planning problem. In this thesis, the most important type of uncertainties which is uncertainty in robots' motion model is completely considered. To solve this challenge, the problem is divided into subchallenges. At first, the Extended Kalman Filter is used for robots' localization problem. Then, motion planning by considering motion model uncertainty is modeled as a Markov Decision Process, and for solving this part a graph-based algorithm is used. Finally, to traverse the paths between configurations a switching controller, and also a Dynamic Feedback Linearization controller is used. At the end, the results of all the simulation and real implementation are presented, furthermore to finds the importance of considering uncertainties, these algorithms are compared by an A* algorithms without considering uncertainties. | 2018 | Autonomous Robotics |
| Mohammad Amin Kashi | Design and Implementation of an LTR Controller and Proper Motion Planner in a Small Size Soccer Robot Abstract The Small Size Soccer League (SSL) is one of the World Cup robotics leagues. In this league, the quality of robot movement is very important. Therefore, in designing different parts of the robot, including hardware and software, factors that affect the quality of motion should be considered. In this report the design of a control system for the robot motion is elaborated. The motion control system includes a motion planner and a controller. The motion planner determines the safe route from origin to destination, and at each point the route determines the desired quality of movement. This includes the speed and acceleration of the robot. The controller also tries to move the robot according to the motion plan. In motion planning, we've used the A * search method in the visual graph for path mapping, and the trapezoidal method in velocity profile. We also used an LTR structure for the robot controller. In this structure an LQR controller is used in addition to an optimal Kalman filter, to reduce the noise of measurement in the presence of modeling uncertainties. The implementation result of such structure shows a promising performance for the closed loop robot motions. | 2017 | Autonomous Robotics |
| Mohammad Savadzadeh, Amirhossein Safari | Design and Implementation of ARAS 2RT Haptic Device Controller Hardware Abstract In this project, the design and implementation of the EPOS 2 Module 36/2 Starter Kit for controling the third axis of ARAS 2RT Haptic Device is reported. ARAS 2RT Haptic Device is used as a eye surgery training robot which has one transitional degree of freedom and two rotational degrees of freedom. The Starter Kit makes it possible to communicate with the driver card via USB and CAN interface, in order to control the third-axle motor. In order to communicate with the motors and to command them, software is developed under the C# programming language. Also, using the virtual wall test, the performance of this system has been evaluated in creating a stable wall with different sampling times and gains. The results of the practical tests have created the need for the use of this system. | 2017 | Surgical Robotics |
| Mina Mobahi, Sara Biglari | Design and Implementation of State Observerfor SSL Robot and Ball | 2015 | Autonomous Robotics |
| Fatemeh Akrami, Sara Adeli | ساخت سامانه متحرک لنزهای پروژکتور LED با استفاده از آلیاژ حافظهدار Abstract در این پایاننامه، طراحی و ساخت سامانه متحرک برای لنز پروژکتور LED با استفاده از آلیاژ حافظه دار مورد توجه قرار گرفته است. لامپ های LED در نسل جدید سیستم های نورپردازی به سبب فراهم کردن راندمان انرژی بسیار بالا، مورد توجه هستند. استفاده از تعداد زیادی LED در پروژکتورهای جدید باعث شده است تا بر خلاف سایر انواع پروژکتور، امکان استفاده از تک لنز بزرگ برای تمامی آنها مقدور نباشد. حتی در صورت استفاده از یک تک لنز لازم است که تمامی LED ها در یک صفحه کروی چیده شوند که این کار نیز با مشکلات ساخت برد و مشکلات ناشی از حرارت ایجاد شده آن مواجه است. گزینه دیگر که هم اکنون نیز در بعضی مصارف به کار می رود استفاده از تعداد زیادی لنز برای LED ها می باشد اما در این طرح ثابت بودن لنزها محدودیت اصلی آنها محسوب می شود. در این پروژه، استفاده از محرکهای ماهیچهگون، امکان فشردهسازی و بهرهمندی از پروژکتور LED را در کاربردهای فوق الذکر فراهم کرده است. سامانه ساخته شده ساختاری مشابه با ربات موازی استوارت دارد. ساختار موازی به کار رفته افزون بر فراهم کردن امکان سرعت عملکرد بالا، دو درجه آزادی برای پوشش زوایای مختلف و یک درجه آزادی برای تنظیم فراهم می نماید. با توجه به مدل غیرخطی و پسماند آلیاژ حافظه دار روش کنترلی VSC پیاده سازی شده است. نتیجه پیاده سازی های اولیه نشان می دهد استفاده از آلیاژ حافظه دار در این کاربرد مناسب بوده و با توسعه طرح پیشنهادی امکان تجاری سازی این محصول وجود دارد. | 2014 | --- |
| Pedram Agand, Ali Aalipour | Minimally Invasion Eye Surgery Paralogram Robot Designed for Vitrectomy Surgery Abstract Nowadays regarding to necessity of precision surgery in minimally invasive surgery (MIS), particularly eye surgery for intraocular operation such as vitrecotmy, widening demand for robotically assisted surgery has shade the world of industry. In MIS, the surgeon does not need to incise the skin totally to approach the organ; so the damages and complications after surgery are reduced grossly. One of new developing fields of robots in MIS is in ophthalmology i.e. vitrectomy. While performing vitreo-retinal surgery manually, the surgeon faces various challenges. Typically, delicate micrometer range thick tissue is operated, for which steady hand movements and high precision instrument manipulation (<10µm) are required. To achieve the minimum damage to the patient through vitroretinal surgery it is required that the incision point be fixed. In many other surgeries it is necessary to rotate tools about a fixed pivot point such as any kind of MIS surgeries. Therefore, remote center of motion (RCM) mechanism are recommended for most of medical robots. ARES is a spherical RCM mechanism with it’s unique parallel mechanism and three degrees of freedom (1 DOF for the needle). In spherical mechanisms each link may be considered as an arc of great circle on a sphere. All of the mechanism links are hinged together by revolute joints and the joints axis passes through the center of the sphere. Due to orientation of joints axis the mechanism has spherical workspace and all the links have pure rotational movement about the center that induces the RCM of the mechanism. In this robot we use two dynamixel MX64R motors for the parallel arms,and one DC motor for linear movment and design a board in order to communicate MX64R protocol (RS485) with matlab s-function in RTW mode and DC motor all in 1 msec. | 2014 | Surgical Robotics |
| Omid Esrafilian, Mohammad Farahi, Mohammad Amin Mahmoudzadeh | Design and implementation of Quadrotor and autonomous mobile target tracking based on image processing Abstract According to the increasing importance of UAVs in lots of industries, in this thesis we describe the design and implementation procedure of a Quadrotor as a sample of these UAVs that have the ability of flight and mobile targets autonomous tracking. This thesis is the result of two and a half year persistence of this team and although in a summery, the results of the experiments and experiences will be discussed. In this procedure the electronic hardware and software of robot will be studied at first and then robot control and measuring system will be presented and discussed, then we begin the main subject by studing the embedded systems, machine vision and image processing. In the final we pursue the tracking mobile targets by Quadrotor in details. | 2014 | Autonomous Robotics |
| Alireza Tajfar, Pouyan Eslami | Design and Fabrication of VTOL UAV (Quadrotor) | 2013 | Autonomous Robotics |
| Narges Hosseinzadeh | پیادهسازی روش تحلیلی-بازگشتی افزونگی بر روی ربات کابلی نصیر Abstract حل مسئلهی افزونگی در رباتهای کابلی، یکی از چالشهای موجود در حوزهی این رباتهاست. روشهای متفاوتی برای حل این مسئله وجود دارد که اکثرا مبتنی بر الگوریتمهای عددی میباشند. برای کنترل بههنگام ربات، نیاز است که زمان حل این مسئله، تا حد ممکن کم باشد که مشخصا این خواسته در روشهای مبتنی بر الگوریتمهای عددی، برآورده نمیشود. یکی از روشهای معرفی شده، برای حل مسئلهی افزونگی، روش تحلیلی-بازگشتی (AI)، است که به دلیل استفادهی آن از تحلیل در کنار روشهای بازگشتی، از سرعت خوبی برخوردار است. در این پایاننامه، پیادهسازی حل مسئلهی افزونگی ربات کابلی نصیر، با استفاده از روش AI انجام شده است. برای این کار، در ابتدا این روش در متلب شبیهسازی شد و سپس با استفاده از بلوک Embedded function بر روی RT-LAB پیادهسازی گردید و نتایج حاصله با نتایج پیادهسازی حل این مسئله به کمک الگوریتم بهینه سازی CFSQP، که پیشینهی ریاضی این روش بر اساس تلاش برای کاهش گرادیان متغیر میباشد، مقایسه و برتری زمانی روش AI نشان داده شد. در این پروژه، همچنین تحلیل سینماتیکی ربات کابلی نصیر از روش CFSQP در محیط C و در محیط سیمولینک (به صورت S-function) پیادهسازی شده است. | 2013 | Parallel and Cable Robotics |
| Zahra Marvi | ساخت سامانه متحرک لنزهای پروژکتور LED با استفاده از آلیاژ حافظهدار Abstract در این پایاننامه، طراحی و ساخت سامانه متحرک برای لنز پروژکتور LED با استفاده از آلیاژ حافظه دار مورد توجه قرار گرفته است. لامپ های LED در نسل جدید سیستم های نورپردازی به سبب فراهم کردن راندمان انرژی بسیار بالا، مورد توجه هستند. استفاده از تعداد زیادی LED در پروژکتورهای جدید باعث شده است تا بر خلاف سایر انواع پروژکتور، امکان استفاده از تک لنز بزرگ برای تمامی آنها مقدور نباشد. حتی در صورت استفاده از یک تک لنز لازم است که تمامی LED ها در یک صفحه کروی چیده شوند که این کار نیز با مشکلات ساخت برد و مشکلات ناشی از حرارت ایجاد شده آن مواجه است. گزینه دیگر که هم اکنون نیز در بعضی مصارف به کار می رود استفاده از تعداد زیادی لنز برای LED ها می باشد اما در این طرح ثابت بودن لنزها محدودیت اصلی آنها محسوب می شود. در این پروژه، استفاده از محرکهای ماهیچهگون، امکان فشردهسازی و بهرهمندی از پروژکتور LED را در کاربردهای فوق الذکر فراهم کرده است. سامانه ساخته شده ساختاری مشابه با ربات موازی استوارت دارد. ساختار موازی به کار رفته افزون بر فراهم کردن امکان سرعت عملکرد بالا، دو درجه آزادی برای پوشش زوایای مختلف و یک درجه آزادی برای تنظیم فراهم می نماید. با توجه به مدل غیرخطی و پسماند آلیاژ حافظه دار روش کنترلی VSC پیاده سازی شده است. نتیجه پیاده سازی های اولیه نشان می دهد استفاده از آلیاژ حافظه دار در این کاربرد مناسب بوده و با توسعه طرح پیشنهادی امکان تجاری سازی این محصول وجود دارد. | 2013 | Dynamical Systems Analysis and Control |
| Fereshteh Sabahi | Implementation of Analytic Iterative Redundancy Resolution Scheme in K. N. Toosi University of technology Cable Driven robot Manipulator | 2013 | Parallel and Cable Robotics |
| Hesam Shoori | Position and Force Control of Cable Driven Redundant Parallel Manipulator(KNTU CDRPM) Including Instrument Object Analysis | 2012 | Parallel and Cable Robotics |
| Samim Khosravi, Kamran Taran | پیادهسازی و کنترل از دور ربات واقعیت مجازی انعطاف پذیر Abstract یکی از اصلیترین کاربردهای سیستمهای تلهرباتیکی در جراحی از راه دور میباشد. در این کاربرد، برای کاهش جراحت هنگام جراحی و آسیبرسانی کمتر، انعطافپذیری ابزار بسیار مورد توجه میباشد. در این پروژه یک بازوی انعطاف پذیر به عنوان ربات رهرو به صورت واقعیت مجازی شبیهسازی شده است، بازوی مورد نظر در نرمافزار مایکروسافت رباتیک پیادهسازی شدهاست و یک کنترلکنندهی مستقل از مدل نیز برای کنترل موقعیت مجری نهایی آن استفاده شده است. شبکه اینترنت به دلیل نفوذ بالا و قیمت پایین بستر مخابراتی مناسبی برای کنترل از دور میباشد، لذا با استفاده از پروتکل TCP/IP بر روی شبکه LAN آزمایشگاه و با پیادهسازی تأخیر موجود در شبکه اینترنت به صورت مجازی بر روی آن، کانال ارتباطی لازم فراهم شده است. از یک دستگاه هپتیک Omni نیز هم به عنوان ربات راهبر استفاده شده است که توسط آن انتقال موقعیت و اعمال نیرو بر دست کاربر صورت میپذیرد. تاکنون راهکارهای متعددی برای مقابله با تأخیر ارائه شده است، از جملهی آنها متغیر موج میباشد، که ردیابی موقعیت در سمت ربات رهرو و نیرو در سمت راهبر برای محیطهای نرم با ضریب فنری و دمپری کم به کمک این ساختار به خوبی صورت میگیرد ولی برای راهبر محیطهای با صلبیت بالا این ردیابی با مشکل مواجه است. که این مورد در خصوص جراحی از دور موضوع چالشبرانگیزی است. | 2012 | --- |
| Keyvan Mohammadi, Milad Aal Kajbaf | شناسایی و کنترل محرک شیشه خودرو در کاربرد سابووفر Abstract با اتصال محرکهای پیزوالکتریک به شیشهی جلوی خودرو و ارتعاش آن، میتوان طیف فرکانس پایین سیگنالهای صوتی را پوشش داد که این سیستم میتواند جایگزین سابووفرهای حجیم، گران قیمت و پرمصرف فعلی باشد. این پایاننامه به طراحی کنترلکننده، در جهت بهبود کیفیت صدای سابووفر محرک شیشه میپردازد. از نقطه نظر فرکانسی، یک سابووفر ایدهآل، دارای منحنی اندازهی هموار و فاز خطی است. اما پاسخ فرکانسی سابووفر محرک شیشه دارای فرکانس رزونانس بوده و هموار نیست. در این پایاننامه، ابتدا به شناسایی سیستم پرداخته و با اجرای آزمایش در ناحیه کاری، پاسخ فرکانسی آن را بدست میآوریم. سپس تابع تبدیل مناسبی را برای آن برازش میکنیم. در راستای رسیدن به اهداف کنترلی طرح، ابتدا از کنترلکنندهی حلقه باز و سپس از شکلدهی تابع حساسیت برای طراحی کنترل خطی حلقه بسته استفاده شده است. به دلیل وجود نامعینیهای مدل، نیاز به کنترلکنندهای که عملکرد آن در حضور نامعینیها مقاوم باشد، وجود دارد. به همین دلیل برای این سیستم یک کنترلکننده مقاومH_∞ طراحی شده است. در پایان عملکرد سیستم حلقه بسته با کنترلکنندههای پیشنهادی در حوزهی فرکانس و زمان مورد بررسی و مقایسه قرار گرفته است. همچنین راهکارهای عملی پیاده-سازی واقعی این سیستم بر روی نمونهی آزمایشگاهی سابووفر ارائه شده است. | 2012 | Industrial Robotics |
| Afshin Dini, Mehdi Siavash | طراحی سختافزاری و تدوین نرمافزار سامانه BMS در یک بیمارستان نوعی Abstract امروزه با توجه به بالا بودن مصرف انرژی در ساختمانها و همچنین افزایش راحتی، آسایش، ایمنی و امنیت ساکنین، نیاز به یک تکنولوژی جدید در بخش ساختمان برای محقق ساختن خواستههای ساکنین است. این تکنولوژی تحت عنوان سامانهی مدیریت ساختمان (BMS) برای هوشمندسازی ساختمانها استفاده میشود. این سامانه در بخشهای مختلف یک ساختمان، راهکارهای متفاوتی را برای برآورده ساختن نیازهای ساکنین ارایه میکند که در این پروژه به بررسی راهکارهای مختلف و انواع تجهیزات و کنترلرهای ساخته شده توسط شرکت زیمنس در بخشهای سرمایشی، گرمایشی و تهویه مطبوع، امنیت و روشنایی پرداخته شده است. با توجه به ساختارهای موجود، این سه سیستم برای یک ساختمان نوعی طراحی و نقشههای مربوط به آن ارائه شده است. در پایان نیز نرمافزار HIT معرفی شده است که برای طراحی سیستمهای HVAC از آن استفاده شده است | 2012 | --- |
| Ali Amiri | طراحی و ساخت دستگاه تست همزمان مکانیکی و الکتریکی عایق های فشار قوی Abstract برای مقره های مختلف قبل از انجام هر نوع عملیات باید آزمون هایی انجام شود که یکی از آنها آزمون کشش همراه با ولتاژ می باشد. برای انجام این تست از دستگاه های کششی استفاده می شود که مکانیزم های مختلفی جهت اعمال نیرو در آنها استفاده شده است اما عمده ترین روش، استفاده از سیستم هیدرولیک بوده که خود دارای مزایا و معایبی می باشد. معایب موجود در روش هیدرولیک، استفاده کنندگان را به فکر به کار گیری روش های الکترونیکی در دستگاه کشش انداخته، تا هم دقت بالایی داشته و معایب سیستم قبل تا حدودی برطرف کرده باشد. در این پایان نامه گزارشی از انجام این جایگزینی ارائه خواهد شد. بدین منظور ابتدا به تعریف مقره و آزمون کشش می پردازیم و ضرورت تست همزمان مکانیکی و الکتریکی کشش را برای مقره ها شرح می دهیم. سپس مراحل آزمون استاندارد بر روی مقره ها بیان خواهد شد. در دو فصل بعدی نحوه اتصال نیرو سنج و سرو موتور به دستگاه بیان می شود و در انتها نحوه انجام تست بر روی دستگاه بیان خواهد شد. | 2012 | --- |
| Sahar Sedaghati, Homa Ammari | مقاوم سازی روش ردیابی ديداری مبتنی بر هسته تصویر Abstract در این پایاننامه مقاوم سازی ردیابی دیداری با استفاده از الگوریتم مبتنی بر هسته تصویر صورت گرفته است. در جهت برآورده شدن مقاوم سازی، بجای استفاده از تمامی اطلاعات تصویر که شامل نویز محیطی نیز میباشد، لازم است تا جسم مورد ردیابی با استفاده از ویژگیهای پردازش تصویر، در شرایط مختلف روشنایی و در حضور سایر اجسام موجود در پس زمینهی تصویر، شناسایی و استخراج شود. این مرحله نقش مهمی را در تعیین ورودی های کنترلیِ مورد نیاز جهت راندن ربات به نقطه هدف ایفا میکند زیرا فرمان حرکتیِ ربات بر اساس هسته تصویر پردازش شده شکل میگیرد. در این پروژه جهت مقاومسازی نسبت به نویز محیطی، به استخراج ویژگیهایی از تصویر جهت تعیین ورودی-های کنترلی پرداختهشده است. در این پایاننامه آزمایشات و پیاده سازی های عملی متعددی با توجه به شرایط مختلف محیطی صورت گرفته است که کیفیت این مقاوم سازی را تایید میکنند. | 2012 | Visual Robotics |
| Mahboubeh Malekdoost , Zeinab Khorasani | مدل سازی حرکت دینامیکی مار-ربات با الهام از حرکتهای طبیعی آن Abstract در این پروژه یک مار-ربات در دو نوع حرکت از انواع حرکتهای مار طبیعی، به نامهای سرپنتاین و کانسرتینا در فضای سیممکنیکس شبیهسازی شده است. در این شبیهسازی، از امکانات این فضا به عنوان جایگزین معادلات دینامیکی مار استفاده شده است. مار از دیدگاه سینماتیکی و دینامیکی مورد بررسی قرار گرفته است و اصطکاک مورد نیاز در هر دو نوع حرکت، بررسی و به مدل شبیهسازی شده-ی ربات اعمال شده است. مقدار انرژی مصرفی در هر دو نوع حرکت، از مجموع انرژیهای جنبشی و اصطکاک بدست آمده است. در نهایت، انرژی مصرفی ربات در حرکت مطابق سرپنتاین، به منظور دست یافتن به حرکت بهینه، با انرژی مصرفی ربات در حرکت به صورت کانسرتینا مقایسه شده است. | 2012 | Cybernetic Robotics |
| Bahareh Sabouri, Maryam Moafi | پیادهسازی ربات واقعیت مجازی و اعمال سیستم کنترل از دور توسط دستگاه هپتیک Abstract همگام با پیشرفت علم مهندسی و افزایش روزافزون خواست بشر برای شناخت و حضور ایمن در مکانهای ناشناخته و گاه خطرناک، شاخهای از علم رباتیک با نام کنترل از دور پا به عرصه نهاده است. ربات راه بر ، ربات رهرو و کانال ارتباط مخابراتی سه بخش اصلی کنترل از دور را تشکیل میدهند. ربات راه بر در حقیقت به جای محیطی که کاربر میخواهد بر روی آن تاثیر بگذارد عمل میکند و ربات رهرو هم مجری دستورات ربات راهبر در محیط مقصد است و وظیفهی کانال مخابراتی نیز ایجاد ارتباط بین این دو ربات است. در این پروژه هدف اصلی کنار هم قرار دادن این سه عضو، و ایجاد یک مجموعه کنترل از دور است. ربات راهبر یک دستگاه هپتیک میباشد و ربات رهرو نیز یک ربات شبیهسازی شدهی سه درجه آزادی است که در دو بخش گرافیکی و پیادهسازی مدل دینامیکی پیادهسازی شدهاست. شبکه اینترانت دانشگاه خواجهنصیرالدینطوسی نیز به عنوان کانال ارتباطی بین دو ربات انتخاب شده است. مهمترین بخش این پروژه شبیهسازی یک ربات سه درجه آزادی و کنترل از دور آن توسط دستگاه هپتیک است که در ادامه منجر به پیادهسازی یک سیستم کنترل از دور رباتیکی بر روی آن، و بررسی عملکرد آن میگردد. تمامی برنامههای این پروژه در محیط ++Visual C نوشته شده است و جهت ارتباط دو ربات از روش برنامهریزی سوکت استفاده شده است. همچنین بهمنظور بهبود عملکرد سیستم کنترل از دور رباتیک در حضور تاخیر شبکه مخابراتی، به بررسی متغیر موج و پیادهسازی آن پرداخته شده است. | 2011 | Surgical Robotics |
| Sheyda Eslami | شبیهسازی محیط ردیابی هدف یک ربات سیار با روش میدان پتانسیل Abstract رباتهاي سيار دستهاي از رباتها هستند که توانايي حرکت دارند و به جهت کاربردهاي فراواني که در صنايع مختلف دارند، توجه خاصي را به خود معطوف کردهاند. يکي از مهمترين مسائل در بحث جايگزين کردن ربات به جاي انسان، مسيريابي و هدايت ربات در محيط است. اين موضوع زماني اهميت مييابد که تصميمگيري در شرايط مختلف بر عهدهي ربات گذاشته شود. طراحي مسير ربات سيار به علت فضاي كاري بيشتر در مقايسه با بازوهاي مكانيكي همواره مورد توجه محققان بوده است. همچنين در محيطهاي صنعتي انواع موانع ثابت و متحرك در مسير ربات وجود داشته و لذا مسيريابي ربات ميبايست با در نظر گرفتن موانع و عدم برخورد ربات با آنها انجام شود. در اين پروژه مسئلهي هدايت يک ربات سيار در يک محيط با موانع ثابت و با استفاده از روش ميدان پتانسيل بررسي و پيادهسازي شده است. بدين منظور الگوريتمي ساده و کاربردي براي حل مسئلهي مسيريابي به روش ميدان پتانسيل معرفي شده و همچنين محيط گرافيکي براي ايجاد نقشهي محيط و شبيهسازي حرکت ربات در محيط طراحي و ساخته شده است. الگوريتم پيشنهادي در هر لحظه با توجه به اطلاعاتي که ربات از سنسور خود دريافت ميکند، پتانسيل نقاطه صفحه را حساب کرده و در هر مرحله ربات را به سمت نقطهاي که کمترين مقدار پتانسيل را دارد، هدايت ميکند. نتايج پيادهسازي اين الگوريتم براي چندين نقشهي مختلف که با توجه به محيطهاي واقعي طراحي شدهاند، بيانگر توانايي الگوريتم معرفي شده در حل مسئلهي مسيريابي به روش ميدان پتانسيل است. | 2011 | Autonomous Robotics |
| Soheil Kianzad | طراحي وساخت سيستم مايکرو محرک ديجيتال با استفاده از آلياژ حافظه دار Abstract در این پایان نامه طراحی و ساخت مایکرو محرک دیجیتال با بهره گیری از مواد هوشمند حافظه دار مورد بررسی قرار میگیرد. بدین منظور ابتدا ضرورت انجام این پروژه و نوآوریهای آن مورد مطالعه قرار گرفته و سپس با تعریف هدف انجام پروژه، مطالعات زیر بنایی، شامل مقایسه و تحلیل انواع تکنولوژیهای موجود صورت گرفته و همچنین لزوم استفاده از ساختارهای مختلف برای بهبود و عملیتر کردن این محرکها بیان میشود. در ادامه نحوه به کارگیری مزیتهای بیان شده از نظر نوع محرک و نوع ساختار برای پیاده سازی درمدل واقعی بیان گشته و قابلیتهای مدل طراحی شده و مدل ساخته شده ارزیابی میگردد. بررسی مدار مکانیکی و مشخصات فعال و غیر فعال و همچنین راندمان انرژی سیستم، بخش دیگری از این پروژه را به خود اختصاص میدهد. در نهایت با تحلیل یک کنترل کننده PID برای سیستم و مشکلات آن مدل جدیدی از کنترل کننده که با استفاده از ساختار ویژه این مایکرو محرک امکان پذیر شده اند، ارائه میگردد. | 2011 | --- |
| Kasra Khosoussi | توسعه وپياده سازی الگوريتم حل مسئله مکان يابی و توليد نقشه همزمان برای ربات های بسيار | 2011 | Autonomous Robotics |
| Amir Mobarhani | بررسی و پياده سازی روشی جهت هدايت ربات پايه متحرک خود مختار در محيط ساختار يافته و توليد نقشه محيط به طور همزمان | 2010 | Autonomous Robotics |
| Farzaneh sedaghat, Mehrnaz Salehian | طراحی و پياده سازی سيستم هدايت بصری بر روی يک ربات صنعتی برای اجسام بدون نشانه تصويری | 2010 | Visual Robotics |
| Mobin saeidi, Hirad Tehranchian | پیاده سازی سخت افزاری و نرم افزاری سیستم حلقه بسته نیرو – موقعیت ربات موازی کابلی Abstract امروزه رباتهای موازی در صنعت کاربرد فراوانی دارند و از میان آنها رباتهای کابلی به دلیل فضای کاری گسترده مورد توجه قرار گرفتهاند. یک نمونه ربات موازی کابلی با هشت محور حرکتی در گروه رباتیک ارس در حال ساخت میباشد که پروژه حاضر در راستای ایجاد امکان کنترل موقعیت و نیروی وارد بر مجری نهایی توسط دو عملگر از این ربات انجام گرفته است. عملگرها موتورهای AC (و درایور آن) میباشد که به منظور کنترل بههنگام آنها از نرمافزار RT-LAB استفاده میشود. برای تامین گشتاور مورد نیاز برای این ربات کابلی از جعبه دنده استفاده شده و در ادامه برای اتصال کابل به جعبه دنده و کنترل مجری نهایی از کابل جمعکن استفاده شده است. موتور و کابل جمعکن و جعبه دنده بر روی بدنه ربات که ساخته شده از پروفیل آلومینیوم میباشد، قرار میگیرند. برای اعمال فرمانهای کنترلی به موتورها و دریافت مقادیر اندازهگیری شده، از کارتهای ورودی و خروجی استفاده شده است. پس از ایجاد امکان اعمال فرمان به موتورها به طراحی حلقههای کنترل نیرو و موقعیت پرداخته شده که در این پایاننامه نحوه طراحی، به صورت کامل توضیح داده شده است. در حلقه کنترل نیرو از یک سنسور مقاومتی برای آگاهی از میزان نیروی وارده به کابل استفاده شده که برای استفاده از آن در حلقه کنترلی یک نگهدارنده سنسور طراحی و ساخته شده است. در ادامه منحنی الاستیکی کابل بدست آمد که استفاده از آن برای کنترل ربات لازم میباشد. با مشاهده منحنی بدست آمده از آزمایش کابل، دیده میشود که ناحیه مرده موجود در کابل جمعکن مانع از تغییر پیوسته منحنی میگردد. همچنین وجود قسمتهای غیرخطی از جمله ناحیه مرده و اشباع سبب ایجاد دشواریهایی در حلقه-های کنترلی میگردد. که در انتهای پایاننامه پیشنهادات مورد نظر، ذکر شده است. | 2009 | Parallel and Cable Robotics |
| Farbod Farshidian | طراحی و پیاده سازی سیستم کنترل از راه دور ربات دو درجه آزادی با بازوی کشسان Abstract امروزه با پیشرفت علوم مهندسی و تلاش بشر برای دستیابی به مکانهایی که حضور انسان در آنها مقدور نمی باشد و یا باعث صدمات به محیط اطراف میشود. شاخهای از علم رباتیک با نام کنترل از راه دور پا به عرصه نهاده است. در این ایدهی نوین، مهندسان قصد دارند تا بدون حضور فیزیکی انسان در محیطی دوردست او را قادر سازند که بر آن محیط با خواست و اراده خود تاثیر بگذارد. از جمله کاربردهای حال حاضر این شاخه میتوان به رباتهای فضایی و زیر دریایی که از راه دور کنترل میشوند اشاره کرد. در این میان مهندسان قصد دارند با استفاده از این تکنولوژی امکان جراحیهای از راه دور را فراهم کنند. در این جراحی بیمار و پزشک جراح در مکانهای متفاوتی هستند و از طریق رباتهای واسط با هم مرتبط میشوند. ربات راه بر ، ربات رهرو و کانال ارتباط مخابراتی در اصل سه بخش اصلی کنترل از راه دور را تشکیل میدهند. ربات راه بر در حقیقت به جای محیطی که کاربر میخواهد بر روی آن تاثیر بگذارد عمل میکند. و ربات رهرو هم جانشین انسان در محیط مقصد است. واضح است که کانال مخابراتی نیز وظیفه ایجاد ارتباط بین این دو ربات را بر عهده دارد.
| 2009 | Surgical Robotics |
| Mohammad Reza Sadeghi, Soheil Rayatdoost | مقاوم سازی روش ردیابی بصری و پیاده سازی آن بر روی ربات میتسوبیشی پنج محوره Abstract امروزه، با توجه به گسترش روز افزون علم رباتیک در صنعت، نیاز به داشتن رباتهایی که توانایی برقراری ارتباطی سادهتر و دقیقتر با محیط کاری خود داشته باشند امری ضروری مینماید. در این راستا ایجاد قابلیت بینایی برای رباتها، در کانون توجه اندیشمندان این علم قرار گرفته است. در گسترش این زمینه، حوزههای مختلفی همچون رباتیک ، پردازش تصویر و زیر شاخههای گستردهی علم کنترل با هم تلفیق شدهاند تا ارتقای روزافزون این زمینه را یاری نمایند. همانند دیگر بخشهای دنیای علم و دانش در این عرصه نیز رقابت همچنان باقی است و اندیشمندان این علم میکوشند تا روشی با کمترین هزینه و بیشترین دقت و حداکثرسرعت را ابداء و به صنعت ارائه دهند.
| 2009 | Visual Robotics |
| Ebrahim Amini, Yaser Mohseni | تحليل و طراحي دستگاه جمع آوري دادههاي ژئوفيزيكي Remote Acquisition Module Abstract شناسایی منابع نفت و گاز و تشخیص جایگاه، ابعاد، ساختار و حجم آنها در بهینه سازی حفاری و کنترل وضعیت این منابع دارای نقش تعیین کنندهای است. تجهیزات مربوط به شناسایی منابع بر مبنای تحلیل امواج لرزهای و سایزمیک عمل نموده و به آشکارسازی ساختار درونی زمین به همراه لایهها و حفرههای مختلف آن میپردازند. شناسایی ساختار درونی زمین توسط سیستم جمع آوری و تحلیل دادههای ژئوفیزیکی انجام ميشود که یکی از مهمترین بخشهای این سیستم، دستگاهRemote Acquisition Module (RAM) بوده و هدف پروژه بنا به درخواست شرکت ژئوفيزيك دانا تحلیل، طراحی و ساخت نمونهای مشابه از این دستگاه در داخل کشور با هزینهای کمتر از معادل خارجی آن است. | 2008 | Industrial Robotics |
| Mahya Shahbazi, Seyed Farrokh Atashzar | طراحی و پیاده سازی سیستم ردیاب بصری برروی یک ربات صنعتی میتسوبیشی Abstract امروزه، با توجه به گسترش روز افزون علم رباتیک در صنعت، نیاز به داشتن رباتهایی که توانایی برقراری ارتباطی سادهتر و دقیقتر با محیط کاری خود داشته باشند امری ضروری مینماید. در این راستا ایجاد قابلیت بینایی برای رباتها، در کانون توجه اندیشمندان این علم قرار گرفته است. در گسترش این زمینه، حوزههای مختلفی همچون رباتیک ، پردازش تصویر و زیر شاخههای گستردهی علم کنترل با هم تلفیق شدهاند تا ارتقای روزافزون این زمینه را یاری نمایند. همانند دیگر بخشهای دنیای علم و دانش در این عرصه نیز رقابت همچنان باقی است و اندیشمندان این علم میکوشند تا روشی با کمترین هزینه و بیشترین دقت و حداکثرسرعت را ابداء و به صنعت ارائه دهند.
| 2008 | Visual Robotics |
| Shayesteh kiaei, Shaghayegh Nazari | طراحي و ساخت ربات پایه متحرک Melon و پیاده سازی روش تعقیب مسیر بر روی آن Abstract ساخت یک ربات خود مختار متحرک کامل گامی اساسی در جهت تسهیل زندگی انسان و صرف انرژی و وقت کمتر برای انجام کارهای او می باشد. به همین جهت امروزه موضوع ربات خود مختار متحرک جایگاه ویژه ای در زمینه های تحقیقی مورد علاقه پژوهشگران دارد. می توان گفت مسأله مسیر یابی و دوری از موانع محوری ترین نقش را در توسعه یک ربات خود مختار متحرک ایفا میکند، چرا که لازمه تعریف هر عملکردی برای ربات خود مختار متحرک این است که ربات قادر به پیمودن مسیری منتهی به مقصد باشد. این اهمیت ویژه ما را بر آن داشت تا پژوهشی را در این زمینه آغاز کنیم که گزارش آن در قالب پایان نامه موجود تدوین گردیده است. هدف اصلی این پژوهش قادر ساختن ربات پایه متحرک Melon با بهره گیری از سنسورهای لازم برای تأمین اطلاعات مورد نیاز ربات به منظور ردیابی مسیز مناسب حرکت می باشد. ربات Melon اطلاعات مورد نیاز خود برای شناسایی محیط اطراف و موانع از یک دوربین و یک فاصله یاب لیزری دریافت می کند و با ترکیب اطلاعات بدست آمده از این دو سنسور شناخت لازم از محیط برای یافتن مسیر و رد موانع را کسب می کند. استفاده از هریک از سنسورها به تنهایی نقایصی دارد که با بهره گیری از سنسور دیگر جبران می شود. محوری ترین نقش دوربین و فاصله یاب به ترتیب فراهم ساختن درکی از رنگ محیط و اجزای آن و فاصله تا موانع می باشد.
| 2008 | Autonomous Robotics |
| Bita Fallahi, Nina Marhamati | کنترل موقعیت موتور AC توسط نرمافزار RT-LAB Abstract امروزه رباتهای موازی در صنعت کاربرد زیادی دارند، و از میان آنها رباتهای کابلی به دلیل فضای کاری گسترده مورد توجه قرار گرفتهاند. یک نمونه ربات موازی کابلی با هشت محور حرکتی در گروه رباتیک ارس در حال ساخت میباشد که پروژه حاضر در راستای ایجاد امکان کنترل بههنگام یکی از عملگرهای این ربات انجام گرفته است.
| 2007 | Parallel and Cable Robotics |
| Alaleh Vafaei, Masoomeh Azadegan | پيادهسازی روش تشخيص خطا بر روی سيستم آزمايشگاهی کنترل سطح | 2007 | Dynamical Systems Analysis and Control |
| Leila Hamidi | مطالعه و شبيه سازی تاثير صفر در سيستم های SISO خطی | 2007 | Dynamical Systems Analysis and Control |
| Sasan Barisi | مدل سازی، شبیه سازی و کنترل بازوهای مکانیکی در محیط گرافیکی Abstract در اين پژوهش مسأله مدل سازی، شبیه سازی و پیاده سازی کنترل کننده برای بازوهای روباتیکی در محیط نرم افزار Matlab و به کمک جعبه ابزار SimMechanics مورد بررسی قرار گرفته است. به دست آوردن و تحلیل معادلات دینامیکی سیستم های روباتیکی از دشواری های خاصی برخوردار است. بنابراین استفاده از نرمافزارهایی در تسریع به دست آوردن معادلات حاکم بر سیستم های روباتیکی، کاری اجتناب ناپذیر میباشد. شبیه سازی در محیط Matlab علاوه بر سرعت بخشیدن به محاسبات، امکان استفاده از جعبهابزارهای متنوع برای طراحی سیستم های کنترلی را فراهم می آورد. در ابتدا برای فهم پیچیدگیهای معادلات حاکم بر سیستم های روباتیکی، از ساختار آشنای بازوی ماهر با دو درجه آزادی استفاده شده است. پس از مقایسه حل تحلیلی با حل شبیه سازی شده، سایر قابلیت های جعبه ابزار SimMechanics مورد بررسی قرار گرفته است. این قابلیت ها شامل انواع تحلیل های مرسوم در آنالیز روبات می باشد. سپس ساختار به مراتب پیچیده تر شانه هیدرولیکی که از جمله ساختارهای موازی محسوب می گردد مورد مدل سازی و شبیه سازی قرار گرفته است. پس از ارزیابی صحت مدل، نحوهی پیاده سازی کنترل کننده خطی تشریح شده است. در نهایت نیز به کمک جعبه ابزار واقعیت مجازی محیط گرافیکی سهبعدی برای شبیه ساز ساخته شده است. معرفی جعبه ابزار SimMechanics به عنوان یکی از جدیدترین نرمافزارها برای مدل سازی سیستم های مکانیکی با روش های پیشرفته حل عددی، از اهداف این پژوهش بوده است. | 2006 | Parallel and Cable Robotics |
| Hoda Akbari, Golnoosh Hosseini | طراحی و ساخت کارت انتقال سيگنالهای الکترو مايو گرام به کامپيوتر و پردازش و دسته بندی آن توسط شبکه عصبی | 2006 | Cybernetic Robotics |
| Asghar Ataollahi, AliReza Moradian Lotfi | طراحی و پياده سازی يک بازوی روباتيک دو درجه آزادی با مفاصل انعطاف پذير Abstract پيش از انجام اين پروژه در آزمايشگاه کنترل صنعتي ( گروه روباتيک ارس ) يک بازوي روباتيک تک درجه آزادي با سيستم انتقال قدرتِ « هارمونيکدرايو » وجود داشت ، که در برخي پروژههاي مرتبط با مفاصل انعطافپذير همچون « کنترل امپدانس سکان شبيهساز پرواز »]1[ مورد استفاده قرار گرفته بود. اما با توجه به حجم پروژههاي تعريف شده در اين موضوع به ويژه براي دانشجويان کارشناسي ارشد و حتي دکترا در سالهاي اخير ، نياز به يک « روبات کشسان مفصل » با درجه آزادي بيشتر ( حداقل دو درجه ) ضرورت يافت تا امکان پيادهسازي نتايج پروژههاي مزبور فراهم گردد.
| 2005 | Flexible Robotics |
| Mohammad Hayati, Meysam Javaheripour | طراحی كارت واسط برای روبات شانه هيدروليكی Abstract پيشرفتهای چشمگير صنعتی امروز تا حدود زيادی مرهون ظهور روباتهاست . امروزه کمتر عرصهای از فناوری را می توان يافت که روباتيک در آن نقشی نداشته باشد. از صنايع بزرگ خودروسازی و هوانوردي تا پزشکی ، تحقيقات فضايی و نانو تكنولوژي ، روبات ها جای انسان را در انجام كارهاي سخت و پيچيده گرفته اند. در اين ميان رايانه ها به عنوان انعطاف پذيرترين ، سريعترين و دقيقترين ابزارهاي كنترل وظيفه هدايت روباتها را بر عهده دارند. ارتباط رايانه ها با دنياي خارج از طريق مدارات واسطي انجام ميشود كه هر روز به تنوع و قدرت آنها افزوده ميشود .موضوع اين پروژه نيز طراحي مجموعه مدارات واسطي است كه بين رايانه و يك روبات هيدروليكي ارتباط برقرار كند. اين روبات كه بر اساس ساختار شانه انسان طراحي و ساخته شده است، داراي سه درجه آزادي و چهار عملگر است. براي كنترل اين روبات بايد اين چهار عملگر به صورت موازي از طريق رايانه فرمان بگيرند. به اين منظور بايد اطلاعات نيرو و موقعيت هر عملگر به رايانه ارسال و فرمان مناسبي را كه رايانه محاسبه ميكند به عملگر ها ارسال شود. دريافت داده از روبات و تبديل فرمان رايانه به جريان لازم براي حركت عملگرها وظيفه مجموعه واسط ميباشد. در اين پروژه گذرگاه ISA به دليل سادگي و قابليت مناسب مبناي طراحي كارت واسط قرار گرفته است. | 2005 | Parallel and Cable Robotics |
| Ehsan Peymani | مدلسازی فيزيکی سيستم کنترل فشار و پيادهسازی کنترلکننده مود لغزشی Abstract پروژه حاضر بر دستگاه کنترل فشار، ساخت شرکت آلماني GUNT، که در آزمايشگاه کنترل فرآيندها قرار دارد تعريف شدهاست. بخش نخست اين پروژه، مدلسازي دستگاه کنترل فشار ميباشد. مدلسازي شامل مسيري است که از خروجي کنترلکننده يا فرمان دستي بصورت سيگنال جريان آغاز ميشود و پس از عبور از مبدل با اعمال فشار مناسب موقعيت شير ورودي توسط عملگر نيوماتيکي تنظيم ميشود. هوا پس از عبور از لولهها وارد يک مخزن شده و از يک شير خروجي که بطور دستي تنظيم ميشود خارج ميشود. مدلسازي ديناميکي سيستم برمبناي قوانين فيزيکي حاکم بر سيستم انجام شدهاست. سيستم داراي 2 ديناميک، موقعيت شير ورودي و فشار مخزن، ميباشد. برخي از پارامترهاي سيستم بوسيله اصول شناسايي سيستم به دست آمدهاند. در بخش نهايي هدف کنترل فرآيند فشار بر مبناي يک ساختار مقاوم است تا سيستم حلقه بسته نسبت به اغتشاشهاي مختلف و نامعيني مدلسازي مقاوم باشد. نامعينيهاي سيستم در مدلسازي بصورت نامعيني پارامتريک در مدلکردن سطح مقطع موثر شيرخروجي ديده شدهاست. از آنجايي که شير خروجي بوسيله کاربر تنظيم ميشود، حذف اثر اغتشاش حاصل از عدم دقت کاربر در تنظيم آن و نيز حذف اثر اغتشاشي تغييرات کمپرسور از اهداف اصلي سيستم حلقه بسته است. پيادهسازي کنترلکننده بصورت کامپيوتري انجام شدهاست. | 2005 | --- |
| Soodeh Behnam , peyman sheikholeslami | بررسی کارشناسانه سخت افزار و نرم افزار PLC هاي S7-300/900 زيمنس | 2003 | Industrial Robotics |
| Sara Khayamim, Sepideh Samavatian | بررسی روش های تشخيص خوردگی در خطوط لوله نفت و گاز توسط توپک هوشمند | 2003 | --- |
| Reyhaneh Razeghi, Mona Safdari | طراحی و پياده سازی نرم افزار مشابه ساز گرافيکی حرکت های ديناميکی روبات های صفحه ای | 2003 | --- |
| Mohammad Ali Ahmadi Pajooh, Masoud Sargazi | طراحی تطبيقی سخت افزار و نرم افزار کارت کنترل موقعيت / نيرو روبات شانه هيدرو ليکی | 2003 | Parallel and Cable Robotics |
| Sommaye Sanaei, Mehdi Khalaji, Mehdi yousefi | بررسی کارشناسی PLC زيمنس و نرم افزار Step 5 و آناليز دستگاه اتوماتيک ريخته گری D&A201 | 2002 | Industrial Robotics |
| Sadegh Mottaghian | تعيين موقعيت و نقشه دو بعدي محيط يک ربات متحرک با استفاده از اطلاعات سونار | 2002 | Industrial Robotics |
| Mojgan Hamidi, Sahar laghaei | شناسايی الکترونيکی و کنترلی شاخه رباتيک افزونه و راه اندازی و کنترل حلقه بسته آن | 2002 | Parallel and Cable Robotics |
| Javad Karami, Arash Roohi, | طراحی و ساخت اجزای الکترونيک و نرم افزار سيستم صنعتی | 2002 | Industrial Robotics |
| Hanieh Esmaeilloo | شناسایی و طراحی کنترل کننده برا ی ربات دو محوره | 2001 | Industrial Robotics |
| Mohammad Laali, Morteza Esmaeili | طراحی و پياده سازی نرم افزار کنترلی سيستم اتوماتيک تضمين کيفيت گژن پين | 2001 | Industrial Robotics |
| Abdolvahed Lalaei | طراحی و ساخت سيستم های حرکتی روبات ارس II با استفاده از موتورهاي بدون جاروبک DC | 2000 | --- |