Both energy and cost-effective semi-active RFC (reaction force compensation) method for linear motor motion stage

Residual vibration of the system base due to the rapid acceleration of a motion stage may significantly reduce life span and productivity of the manufacturing equipment. Although a passive reaction force compensation (RFC) mechanism was developed to reduce the residual vibration of a linear motor motion stage, the passive RFC cannot adjust its dynamic characteristic against the motion profile variation. An active RFC mechanism using an additional coil can tune spring and damping of the RFC system according to the motion profile of the mover, but both cost and energy consumption of the active RFC are very high and it is not suitable for green manufacturing. In this paper, we develop a semi-active RFC method by switching an extra coil for a linear motor motion stage to tune damping of the RFC system against the motion profile variations. First, we investigate the effect of switching the extra coil with free vibration test of the magnet track, which shows that the damping of the RFC can be adjusted by the open-close ratio of the extra coil. In addition, two kinds of motion profiles such as long and short stroke motions are used to confirm the semi-active RFC by switching the extra coil. The effectiveness of the semi-active RFC method was verified with simulations and experiments.