Disturbance compensation in inching motion of ball screw-driven table system

This paper presents a compensation approach for nonlinear friction in a ball screw-driven table positioning system. In the compensator design, effects of nonlinear friction on the positioning performance at the inching motion are especially paid attention, where a precise nonlinear friction characteristic with nonlinear spring behavior is mathematically modeled and considered. Based on the friction characteristics, a model-based feedfoward disturbance compensation (FDC) approach is applied to improve the disturbance suppression capability. The effectiveness of the proposed positioning control approach with the FDC has been verified by experiments using a table drive system on machine stand.