Control of a two-mass structure driven by a ball-screw stage

This paper investigates the control of a linear ball-screw stage driving a two-mass load. Due to the high speed-reduction ratio, the angular displacement of the driving motor is insensitive to the flexible oscillations. The bandwidth of the closed-loop system is thus constrained by the light damping of the flexible load. As a remedy, an accelerometer is installed on the flexible load. A lead compensator based on acceleration and angular displacement feedback is devised via root-locus analysis. Performance of the control system is illustrated with numerical simulations and confirmed by experimental results.