A novel adaptive terminal sliding mode control for parallel manipulators: Design and real-time experiments

This paper deals with the design of a new robust adaptive controller for parallel manipulators based on sliding mode and modelbased adaptive control. More precisely, the proposed controller relies on continuous finite-time terminal sliding mode (TSM) control and the linear-in-the-parameters property of the inverse dynamics of the manipulator. The main motivation behind the proposed scheme is to improve the tracking performance of fast and accurate parallel manipulators while guaranteeing the closed-loop system's robustness. Based on the linear-in-the-parameters property of the inverse dynamics of the manipulator, an adaptive law is proposed in order to estimate in real-time the dynamic parameters of the manipulator. The proposed controller has the advantage of relying on the desired reference trajectories instead of measured ones which can improve its robustness and efficiency. To demonstrate the effectiveness of the proposed controller, real-time experiments are conducted on a four-degree-of-freedom parallel manipulator called Veloce.