In the 4^th Industrial Revolution, advancements in semiconductor technology demand high performance, efficiency, and precision, highlighting the importance of high-speed and ultra-precise motion stages. To improve positioning performance of a motion stage, robust torque generation by current controllers alongside position control is crucial. This paper explored a custom current control for linear motor motion stages. We built a linear motor motion stage with a 560 mm stroke, 5 m/s speed, and 280 N continuous thrust supported by air bearings and equipped with a passive reaction force compensation. Custom user code for position and current controls of PowerPMAC motion controller was developed for the motion stage. The position control code included frequency domain system identification, disturbance observer, and repetitive learning control while the current control code featured vector or d/q-axis current controllers and disturbance observer. We developed a current control tuning GUI to adjust the current control gain by injecting an excitation signal into the motion controller and measuring the frequency response of the open-loop transfer function. Experimental results confirmed the effectiveness of the custom current controller for evaluating static and dynamic performance.

The residual vibration during the high acceleration and deceleration of a motion stage degrades the manufacturingsystem productivity and lifespan. Although a passive RFC mechanism with a movable magnet track reduces the residual vibration of the system base, a magnet track resonance may occur according to the motion profile, and the mover inposition error increases due to the residual vibration of the magnet track. We investigated input-shaping methods for a linear motor motion stage with a passive RFC mechanism. An air-bearing linear motor motion stage with the passive RFC mechanism is built, and the dynamic characteristic of the passive RFC mechanism is identified using a freevibration test. Then, mover velocity profiles are generated using various input-shaping methods. Further, the effects of the input-shaping methods on the air-bearing linear motor motion stage are investigated by comparing the magnet track oscillation, settling time, and mover in-position error. Finally, several input-shaping methods are applied to reduce the mover rise-time delay for the proposed linear motor motion stage. A properly shaped input motion profile removes the residual vibration of the passive RFC mechanism without any additional devices, as well as reducing the transmitted reaction force and the in-position error.