Improvement of settling performance by mode switching feedback compensation in fast and precise positioning

This paper presents a mode switching feedback (FB) compensation methodology based on rolling friction properties for the fast and precise positioning. Rolling friction in mechanism behaves as a nonlinear elastic component in the micro displacement region, and deteriorates the settling performance with slow responses. The authors have already proposed a rolling friction model-based friction compensation which could suppress the slow settling response. The conventional approach, however, could not effectively suppress vibratory settling responses due to unknown modeling errors and/or plant perturbations, resulting in the performance deterioration in positioning accuracy. In this study, therefore, a mode switching FB compensation considering the rolling friction properties is applied to provide the required settling performance with well-suppression of both the vibratory response and the slow response. The proposed approach has been verified by experiments using a prototype of industrial positioning devices.