Disturbance Rejection and Robust Tracking Using a Compound Control Approach for RFC Linear Motor Motion Stage
摘要
In the era of the 4th industrial revolution, the demand for high-performance, high-efficiency, andultra-precision motion stages is increasing alongside the development of AI and high-density semiconductor circuits. The rapid acceleration of these motion stages generates substantial reaction forces, which in turn cause vibrations in the machine base, potentially shortening equipment lifespan and compromising product quality. Although reaction force compensation (RFC)linear motor stages address these forces by leveraging the inertia and vibration of a moving magnet track, residual vibrations after motion completion can compromise position tracking accuracy. Several control approaches such as disturbance observer (DOB) and sliding mode control (SMC)have been investigated to reduce settling time under these conditions. This study presents a compound control designed to enhance disturbance rejection and robust tracking in RFC linear motor motion stages. This approach combines a DOB and an improved super-twisting (IST) SMC with a proportional-integral-velocity (PIV) control. To assess the effectiveness of each control component, SMC, ISTSMC, and DOB were individually tested in conjunction with PIV control. The DOB effectively mitigated frictional disturbances, while the SMC or ISTSMC bolstered the system's robustness against parameter variations. The compound method significantly reduced friction induced errors, improved tracking performance, and ensured robustness against parameter variations.