A Robust Adaptive Sliding-mode Controller with Bound Estimation for Permanent Magnet Spherical Actuator

This paper presents a novel tracking controller for a three degrees-of-freedom permanent magnet spherical actuator (PMSA). The controller is designed on the basis of the establishment of dynamics model under uncertainties. The major construction of the controller lies in the use of the matrix regressor to isolate unknown parameters from the PMSA. Moreover, sliding-mode control and robust control are adopted to make errors converge to zero and restrain and eliminate distributions and uncertain factors. The stability of the closed-loop system using designed controller is confirmed through Lyapunov theorem. Simulation results are provided to validate the effectiveness of the proposed controller.