Accurate control of ball screw drives using pole-placement vibration damping and a novel trajectory prefilter

• Published in: Precision engineering Vol. 37; no. 2; pp. 308 - 322
• Main Authors: Gordon, Dan J., Erkorkmaz, Kaan
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-04-2013
• Subjects: Active control; Active damping; Ball screw drive; Ball screws; Control; Controllers; Feedforward; Filters; Pole-placement; Prefilters; Tracking; Trajectories; Vibration damping; Ball screw drive; Active damping; Pole-placement; Control; Feedforward
• ISSN: 0141-6359; 1873-2372
• DOI: 10.1016/j.precisioneng.2012.09.009

► We present a simple and effective controller that enhances the accuracy of ball screw drives by applying vibration damping. ► The base design uses pole-placement for damping out structural vibrations while imposing desired rigid body dynamics. ► A new prefilter is developed that removes quasi-static correlations of the commanded trajectory from the tracking error. ► The proposed design is compared to the mainstream P-PI position velocity cascade controller used in industry. ► The proposed design achieves better disturbance rejection, and 20–50% smaller dynamic positioning error.
This paper presents a pole-placement technique to achieve active vibration damping, as well as high bandwidth disturbance rejection and positioning, in ball screw drives. The pole-placement approach is simple and effective, with an intuitive physical interpretation, which makes the tuning process straightforward in comparison to existing controllers which actively compensate for structural vibrations. The tracking performance of the drive is improved through feedforward control using inverted plant dynamics and a novel trajectory prefilter. The prefilter is designed to remove tracking error artifacts correlated to the velocity, acceleration, jerk and snap (fourth derivative) of the commanded trajectory. By applying the least-squares method to the data from a single tracking experiment, the prefilter can be tuned quickly and reliably. The proposed controller has been compared to the P-PI position–velocity cascade controller commonly used in industry. The controller design, stability analysis and experimental results are discussed in the paper.