PRECISION CONTOUR TRACKING USING FEEDBACK-FEEDFORWARD INTEGRATED CONTROL FOR A 2-DOF MANIPULATION SYSTEM

This paper presents a novel approach for precision contour tracking through combining feedback PID and feedforward position domain ILC (PDILC) control for a multi-axis manipulation system. Traditional control approaches in time domain suffer from poor synchronization of relevant motion axes and result in restriction for contour tracking tasks. In the proposed PID & PDILC design, a 2-DOF system is treated as a master-slave cooperative motion system. The position information of the master motion axis is integrated into the PDILC controller of the slave motion axes, which makes the PDILC learn from contour errors instead of individual axis errors. The selection and tuning of parameters for the PID and PDILC were conducted based on the computation in a lifted matrix format of the stability and convergence conditions. The performance of the PID & PDILC controller was evaluated by comparisons with PID and cross-coupled ILC controller through experiments on a multi-axis precise positioning stage. The proposed PID & PDILC design enhances the precision contour tracking of the testbed.