GLOBALLY STABLE ROBUST TRACKING OF NONLINEAR-SYSTEMS USING VARIABLE STRUCTURE CONTROL AND WITH AN APPLICATION TO A ROBOTIC MANIPULATOR

The globally stable robust output tracking for a class of nonlinear systems is considered. Based only on the knowledge of the bounds on the uncertainties, a variable structure control (VSC) law is developed under the structure matching assumption. It is shown that the outputs of the closed-loop system asymptotically track given output trajectories despite the uncertainties while maintaining the boundedness of all signals inside the loop. The scheme is then applied to the control of a two degree-of-freedom (DOF) robotic manipulator with variable payload. © 1990 IEEE