Observer-Based Adaptive Finite-Time Contact Force Tracking Control for Pneumatic Polishing System
Yan Shi, Zhiguo Yang, Yixuan Wang, Shaofeng Xu, Zhibo Sun, Jifan Wu, Changhui Wang
Abstract
Pneumatic drive has the advantage of flexible contact, widely used in large-diameter complex optical surface element processing device drive. Polishing is the core step in the machining process of large-diameter complex optical surface elements. The high-precision control of the contact force between the polishing device and the machining element directly affects the machining accuracy of the surface element. The current research on the polishing force control strategy does not fully consider the constraints of the pneumatic polishing system and the saturation of the cylinder as an actuating element, which cannot further improve the response speed of the control algorithm. In view of the above problems, this paper proposes an adaptive finite-time force tracking control strategy for pneumatic polishing system by fully considering the saturation characteristics of the actuator and the constraint conditions. The algorithm further simplifies the control parameters, improves the computational efficiency of the controller, and realizes accurate force tracking in finite time. The finite-time stability of the control strategy is verified by theoretical analysis. An experimental platform for pneumatic polishing force feedback control is built to verify the effectiveness of the control strategy and its adaptability to pneumatic polishing system.