Robust adaptive sliding mode control of a redundant cable driven parallel robot

Abstract

In this paper we consider the application problem of a redundant cable-driven parallel robot, tracking a reference trajectory in presence of uncertainties and disturbances. A Super Twisting controller is implemented using a recently proposed gains adaptation law [1], thus not requiring the knowledge of the upper bound of the lumped uncertainties. The controller is extended by a feedforward dynamic inversion control that reduces the effort of the sliding mode controller. Compared to a recently developed Adaptive Terminal Sliding Mode Controller for cable-driven parallel robots [2], the proposed controller manages to achieve lower tracking errors and less chattering in the actuation forces even in presence of perturbations. The system is implemented and tested in simulation using a model of a large redundant cable-driven robot and assuming noisy measurements. Simulations show the effectiveness of the proposed method.