Step consistency active control method for inertial piezoelectric actuator using embedded strain gauges

Inertial piezoelectric actuators (IPAs) are widely used in micro-nano manipulation, biomedicine, and other fields as the simple structure and excitation signal. However, the step consistency is difficult to guarantee in a large stroke range due to the limited machining accuracy of the mover and inherent roll back, which limits the practical application in these precision fields. Therefore, a step consistency active control method for IPAs is proposed based on bending hybrid motions, which uses embedded strain gauges as the force sensors to acquire the pressure between the mover and the actuator. The IPA is driven by horizontal bending motion, and the pressure can be dynamically adjusted by vertical bending motion to ensure the constant pressure and achieve a constant step. Experiments results show that the maximum standard deviation of the step is 0.41 μm under the active control of 350 Vp-p and 1 Hz driving voltage within 2 mm stroke range in 500 driving cycles, and the maximum standard deviation of the step is 1.14 μm under the non-active control with the same conditions, which show that the proposed method evidently improves the step consistency of IPA in a large stroke range.