Design and Experiments of a Single-Foot Linear Piezoelectric Actuator Operated in a Stepping Mode
A single-foot linear piezoelectric actuator is proposed in this paper, and a new exciting method for the stepping motion is discussed. The proposed actuator works in the hybrid modes of the second horizontal bending vibration and the second vertical bending vibration. Two intermittent sinusoidal signals with a phase difference of 90° are applied on the horizontal and vertical PZT elements, respectively, to obtain a discontinuous elliptical motion at the driving foot, which can move the runner linearly step by step. The structure of a single-foot linear piezoelectric actuator is designed and the mechanism for the linear driving is clarified. Then, modal and transient analyses are carried out by using ANSYS software to get the resonance frequencies of the bending modes and the movement trajectory of the driving foot. Finally, a prototype of the piezoelectric actuator is fabricated, and experiments are carried out. The experiment results show that the displacement resolution, the maximum velocity, and the maximum thrust of the proposed piezoelectric actuator are about 0.21 μm, 827.5 mm/s, and 27 N, respectively.