Discrete-time second order sliding mode control for permanent ring torque motor

For the characteristics of direct drive permanent magnet ring torque motor servo system is influenced by parameter variation and load disturbance, a robust position controller is designed by discrete-time second order sliding mode algorithm in this paper. In order to guarantee position signal to track its reference signal strictly by employing prescribed convergence algorithm, the position sliding mode is selected properly. The discontinuous control effects on the higher differential, and eliminates the chattering phenomenon theoretically. The simulation results show that position controller designed provides the servo system with perfect tracking ability, strong robustness against parameters variation and load disturbance, and attenuates chattering effectively.