Feedback controller design considering plant dynamics of table drive system in microscopic displacement region

This paper presents a feedback controller design approach of a ball screw-driven table system in the microscopic displacement region. Since friction behaves as a nonlinear spring in the microscopic displacement region, while it behaves as Coulomb and a viscous friction in the coarse displacement region, frequency characteristics of the system vary depending on the above regions. In this paper, the stability condition in the microscopic displacement region is clarified, and the appropriate parameters of the feedback controller are obtained. The effectiveness of the proposed control approach has been verified using a prototype of a ball screw-driven table system.