Inverse-feedforward and robust-feedback control for high-speed operation on piezo-stages

This article demonstrates an approach to compensate for tracking errors resulting from hysteresis and vibration when operating piezo-stages and to achieve precision motion control on them. In order to achieve this goal, inverse-feedforward control and H _∞-feedback control were utilised to augment each other. Experimental results showed that pure feedforward control would suffer from modelling uncertainty and pure feedback control would be limited on its bandwidth; therefore, both of these could compensate for partial tracking errors. In contrast, the proposed approach integrated the merits of feedforward and feedback controls to improve the tracking performance when operating piezo-stages in long-stroke and high-speed.