Tracking Control of an Ultrasonic Linear Motor Actuated Stage Using a Sliding-mode Controller with Friction Compensation

Abstract

The purpose of this paper is to investigate the nonlinear friction and compensation for a piezoelectric ceramic ultrasonic motor (USM). Although the architecture of the USM is different from the general electric-mechanical motor, the mathematic model for the USM motor can use the same friction model to formulate the friction phenomenon. To establish the feedforward controller, the system identification for the USM is needed to study to design the model-based controller. To obtain the optimal system parameters of the USM, PSO and CSS algorithms are studied to identify the system parameters for the nonlinear friction model. For the controller design, a non-model based controller, using back-propagation neural network controller to perform tracking tasks, and the model-based controller, which consists of the feed-forward controller based on the system identification and the sliding-mode control, are discussed in this paper. Finally, the two real-time tracking tasks are used to validate the proposed method.