Sinc-Function-Based Friction Compensation for Ball-Screw-Driven Stage in Zero-Velocity Region including Non-Velocity-Reversal motion

Abstract This paper presents a heuristic friction compensation approach for handling the rolling friction behaviors of ball-screw-driven stages in the zero-velocity crossing regions including non-velocity-reversal motion. The rolling friction behaves in a nonlinear way, and would significantly deteriorate the control performance. Since the alteration of elastic energy in mechanical components of a stage system is different between the velocity-reversal motion and non-velocity-reversal motion, sophisticated compensation approaches become necessary to cope with the both cases. In this study, a velocity pattern recognition algorithm is proposed as the first step in the design process to classify the velocity patterns in zero-velocity crossing region. Then, sinc function is utilized to model the nonlinear rolling friction of the ball-screw-driven stage. Thanks to the few parameters of the sinc function, it is possible to approximately compute the released displacement in the non-velocity-reversal motion, and the friction compensation approach can therefore be applied in a feedforward manner. It is verified by experiments that the proposed approach can precisely compensate the nonlinear friction to improve the control performance.