Disturbance Observer Design for Robotic and Telerobotic Systems

Employing disturbance observers is an effective way of enhancing the stability and performance of the control systems subject to disturbances. Disturbance observers have been extensively used for control of mechatronic systems since their introduction in the 1980s. This thesis studies the design of nonlinear disturbance observers for robotic manipulators and their applications in the control of telerobotic systems. A novel framework is introduced, based on linear matrix inequalities, for the design of nonlinear disturbance observers for serial robotic manipulators. This design method removes the restrictions encountered in previous design methods. In spite of the many applications of the disturbance observers in mechatronic systems, there are few studies that address the design of such observers for telerobotic systems. Moreover, these studies cannot guarantee the stability of telerobotic systems with time delay. This thesis presents a rigorous theoretical basis for the disturbance observer based control of telerobotic systems with variable time delays.