Compensation of Axial Vibrations in Ball Screw Drives

This paper presents a precision control strategy for ball screw drives. Axial vibrations are modeled and actively compensated in the control law, which enables the realization of high positioning bandwidth. Lead errors, arising from imperfections of the screw, are modeled and removed from the loop by offsetting their effect from the command trajectory and position feedback signals. Effectiveness of the proposed strategy is demonstrated in high speed tracking experiments conducted on a ball screw drive, where a linear positioning accuracy of 2.6 um has been maintained while traversing the axis at 1000 mm/s feed with 0.5 g acceleration.