Research on backstepping control of stabilizing-tracking system for self-propelled anti-aircraft gun with backlash nonlinearity compensation

In view of the backlash nonlinearity in the stabilizing-tracking system for self-propelled anti-aircraft gun, a backstepping control design method based on full-order terminal sliding-mode is proposed by considering the structural characteristics of the system and the dynamic load disturbance caused by the motion. The position loop signal of the system is unified in the geodetic coordinate system, the position feedback is calculated by using the equivalent closed-loop method, and the state space model of the stable tracking system with backlash is constructed with the approximate dead time function of backlash nonlinearity. Aiming at the problem that it is difficult to observe the disturbance torque at the load side, a finite time disturbance observer is designed to estimate it quickly and accurately with load acceleration. Based on the backstepping control theory and the chattering free full-order terminal sliding-mode method, a global backstepping controller is designed to make the error converge to the field near zero in finite time, and the uniform ultimate boundedness of the system is proved by Lyapunov method. The simulation results show that compared with PID control, the proposed method can effectively compensate the backlash nonli-nearity, significantly weaken the chattering phenomenon, and has higher pointing accuracy in stabilizing conditions.