An SMC-Based Accurate and Robust Load Speed Control Method for Elastic Servo System

In this article, a modified sliding mode speed controller is designed in order to improve the load speed control performance of an elastic motor drive system with internal and external disturbances. First, based on the load speed deviation and its first-order and second-order differentials, a two-dimensional sliding surface function is presented. The parameters of the sliding surface are determined by a novel particle swarm optimization method. The method has improved inertia weights and evaluation functions, which can improve the accuracy and efficiency of the parameter search and enhance the immunity and robustness of the system. Second, on the basis of the integral of time-weighted absolute error criterion, the parameters of the exponential approach law are determined, which improves the tracking accuracy. Finally, the designed sliding mode control with high tracking accuracy, fast dynamics, and strong robustness is verified by both simulations and experiments.