Design and Implementation of a Robust Nonlinear Control Scheme in Teleoperation with Time Varying Delay in Eye Surgery Application
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.