Design and simulation of iterative sliding mode controller with differentiator for servo systems

A iterative sliding mode control based on a differentiator for the nonlinear servo system with periodic interference is presented. The iterative sliding mode controller is designed using the states which are estimated by a differentiator. The sliding mode control ensures the robustness of system. The iterative learning control is used to compensate for static error. The using of a differentiator saves hardware cost and avoids the noise amplification brought by conventional differential method. Finally, this method is applied to control of a flight simulator servo system. Simulation results show that the proposed method not only reduces chattering but also can obtain more robustness and better tracking performance.