Variable Structure and Ultimate Boundedness control and stabilization of flexible robotic systems

In this thesis we study the control of two link light weight elastic manipulator in the presence of uncertainty. The control of flexible robotic arm with uncertainty such as variable payload, joint angle frictional torque etc., is an interesting and important problem; Here we consider control of joint angles and stabilization of the flexible modes caused by the manuever of robotic arm by two methods. These are: (i) Variable Structure control and (ii) Nonlinear Ultimate Boundedness control. Nonlinear Ultimate Boundedness control is a continuous control wherein the joint angle tracking error is uniformly ultimately bounded in the closed-loop system; Analytical derivations of these two schemes are presented. A control logic is included which switches the stabilizer when the joint angle trajectory enters a specified neighborhood of the terminal state; Extensive simulations were carried out for several conditions of uncertainty and the results are presented. (Abstract shortened with permission of author.)