Adaptive Sliding Mode Robust Control for Virtual Compound-Axis Servo System

Abstract

A structure mode of virtual compound-axis servo system is proposed to improve the tracking accuracy of the ordinary optoelectric tracking platform. It is based on the structure and principles of compound-axis servo system. A hybrid position control scheme combining the PD controller and feed-forward controller is used in subsystem to track the tracking error of the main system. This paper analyzes the influences of the equivalent disturbance in main system and proposes an adaptive sliding mode robust control method based on the improved disturbance observer. The sliding mode technique helps this disturbance observer to deal with the uncompensated disturbance in high frequency by making use of the rapid switching control value, which is based on the subtle error of disturbance estimation. Besides, the high-frequency chattering is alleviated effectively in this proposal. The effectiveness of the proposal is confirmed by experiments on optoelectric tracking platform.

Robust Adaptive PID Controller for a Class of Uncertain Nonlinear Systems: An Application for Speed Tracking Control of an SI Engine

“…The sliding mode control (SMC) method is one of the control strategies to dominate the parametric uncertainties and external disturbances, while the control principle is without precise system model information [15][16][17][18]. Nevertheless, if the sliding mode exists, the chattering phenomenon is the main obstacle for SMC application [19][20][21]. In much research work, alleviations chattering phenomenon of the sliding mode incorporated with a low-pass filter has been studied [22][23][24][25][26] because it can make a compromise between the alleviation of the chattering and the control accuracy.…”