An umbrella-shaped flexible mechanism piezoelectric actuator with driving foot trajectory control

Abstract

Traditional stick-slip piezoelectric actuators generally have problems such as large backward motion and small load capacity, which affect the driving effect. In this study, the effect of no backward motion and large load capacity is realized by controlling two sawtooth wave-driven piezoelectric stacks on the basis of umbrella-shaped flexible mechanism. The trajectory of the driving foot is simulated by transient simulation and verified by experiment. A prototype of actuator is made, and the effects of voltage, symmetry of sawtooth wave, and the phase difference of the two waves on the driving effect are investigated through experiments, and the optimal driving waveform is found. Experiments have shown that no displacement regression and stable driving is achieved when driving with two sets of sawtooth waves with 100 V, 100% symmetry and 20 V, 70% symmetry. With this drive waveform at 1 Hz, the maximum horizontal and vertical loads are 150 g and 1400 g, respectively. And the maximum driving speed is 13 935 μm s−1 when the driving frequency is 7000 Hz. Experimentally, it is proved that the actuator is able to realize smooth driving and large load capacity without backward motion, and has the same forward and reverse working performance, which has greater research value and market application scenarios.