Controller design and verification for a rotational piezo-based actuator for accurate positioning applications in noisy environments

In this paper the controller design for a high precision rotational stage based on a piezoelectric actuator is presented. As for almost all the structures based on the smart materials, this task is complicated by the presence of hysteresis and mechanical resonances. Moreover, when the structure is meant to operate in noisy environments, also the external disturbance rejection becomes a priority. To accomplish the aim of having high resolution also in the presence of strong external disturbances, a control strategy to obtain a high external disturbance rejection is designed, exploiting the high gain of the system resonance itself. Closed loop experimental results are shown in order to verify the tracking and disturbance rejection capabilities of the proposed controller.