Robust chatter-free continuous VSC for the speed control of electrical motor drives using adaptive feedback gain

This paper proposes a robust speed controller using a chatter-free continuous variable structure control (CVSC) with adaptive feedback gain. The switching surface of the proposed CVSC with an integral component is designed to guarantee the exponential stability and insensitivity to uncertainties and disturbances. The switching function of the discontinuous VSC (DVSC) is substituted by the continuous function to remove chattering. The feedback gain k is designed and tuned using the Lyapunov theory. It is adapted online relying on the speed error and the machine parameters to eliminate the problems of the conventional CVSC. A fair comparison between the proposed CVSC and classic control methods is presented. A hybrid stepper motor (HSM) drive is carried out in Matlab/Simulink, and experimentally using DSP-DS1102 to confirm the effectiveness of the proposed CVSC. The results prove that the adaptive CVSC is robust to uncertainties and disturbances compared to the DVSC and classic control methods.