Sensor-less estimation of positioning reversal value for ball screw feed drives

Motion accuracy of the feed drive systems deteriorate due to wear of the bearing and ball screw during the long term use. It is known that the wear makes larger positioning reversal value. In this study, a sensor-less estimation method for the positioning reversal value of ball screw driven feed drive systems based on the servo signals is proposed. The proposed method analyses the relationship between amplitude of feedback position and motor torque during swept sine wave motion. It is experimentally confirmed that the proposed method can estimate the positioning reversal values adequately.