ADAPTIVE VARIABLE-STRUCTURE TRACKING CONTROL FOR CONSTRAINED ROBOTS

The problem of controller design for constrained robots with the consi deration of computational efficiency is addressed. An efficient adapti ve variable structure control algorithm, based on a reduced dynamics f ormulation, is presented for trajectory tracking of an end-effector on a constrained surface with specified constraint forces. It is shown t hat the objective can be achieved without exact knowledge of robot dyn amics and on-line calculation of nonlinear dynamic functions. The cont rol algorithm is constructed with at most three control parameters to be adjusted adaptively, and that number is determined independently of the number of degrees of freedom of the robotic manipulators. A numer ical example is presented to illustrate the developed method.