Backstepping Control of Attitude Adjustment Servo Platform Based on LS_SVM

To improve the performance of high-precision servo systems with compound disturbance problem, two least squares support vector machine (LS_SVM) systems were employed to approximate the compound disturbance of the high precision servo systems. The kernel functions and regularization parameters of LS_SVM were attained by particle swarm optimization (PSO) algorithm offline. An adaptive backstepping control system based on the LS_SVM method was designed by using the backstepping control theory and choosing Lyapunov function in turn. The stability of the developed system was proved through the stability of Lyapunov. Simulations show that the compound disturbance of the system could be effectively compensated by LS_SVM. Without considering the compound disturbance, the proposed controller could reduce its response time by 20% compared with the classic three-loop PID controller. However, when considering the compound disturbance, the proposed controller could reduce its response time by 25%, and increase its steady-state precision by 34.09%compared with the classic three-loop PID controller. At the same time, the proposed controller could effectively inhibit the influence on the system performance caused by the change of system parameters, so it has strong robustness.