Global back—Stepping adaptive sliding mode control of naval gun servo system with backlash

Abstract

A compensation approach for global back-stepping adaptive sliding mode control to deal with the nonlinear backlash in naval gun servo systems has been proposed in this paper. First, by introducing an approximate dead-zone model into the double inertia system and considering the nonlinear disturbances during the firing at level 5 sea conditions, the state space model of the system is established, which is divided into three subsystems. Then, based on the back-stepping control theory, the Lyapunov function is constructed step-by-step using the recursive approach. By combining the sliding mode control in Step 3, the adaptive law of uncertain parameters is given, and the global back-stepping adaptive sliding mode controller is designed. In addition, the global stability of the closed-loop system is proved by Barbalat’s lemma. The simulation results show that, compared with proportional integral differential control, this approach can compensate the backlash more effectively, reduce the torsional oscillations in both the driving torque and load velocity, and ensure a higher position tracking accuracy and robustness of the system under the same operating conditions.