Wavelet Neural Network Control for Linear Ultrasonic Motor Drive

Abstract

A wavelet neural network (WNN) control system is proposed to control the moving table of a linear ultrasonic motor (LUSM) drive system to track periodic reference trajectories in this study. The design of the WNN control system is based on adaptive sliding-mode control technique. First, the structure and operating principle of the LUSM are introduced. Second, since the dynamic characteristics and motor parameters of the LUSM are nonlinear and time-varying, a WNN control system is designed based on adaptive sliding-mode control technique to achieve high-precision position control. In the WNN control system, a WNN is used to learn the ideal equivalent control law, and a robust controller is designed to meet the sliding condition on the sliding surface. The adaptive learning algorithms of the WNN and the bound estimation algorithm of the robust controller are derived from the sense of Lyapunov stability analysis. Finally, the effectiveness of the proposed WNN control system is verified by some experimental results in the presence of uncertainties.