Active suppression of the backward motion in a parasitic motion principle (PMP) piezoelectric actuator

Abstract In the piezoelectric driving field, backward motion commonly exists in output displacement curves of the actuators designed by various driving principles, which deteriorates the output performances and increases difficulty in subsequent control. To suppress the backward motion, a synergic motion principle (SMP) was proposed in this paper, which employed two piezoelectric stacks (PESs), one for driving and the other for lifting. By synergic driving of these two PESs, the contact force during the driving process could be effectively controlled and thus the backward motion could be actively suppressed. To verify the feasibility, an actuator prototype was designed and fabricated, and an experimental system was established to test its output performances. By theoretical analysis and experiments, the relationship of the driving voltages for these two PESs was determined. Under the optimized experimental conditions, it showed that the actuator could output stepping displacement without backward motion when working under the SMP. By comparing the results with those obtained when the actuator worked under the parasitic motion principle (PMP), the feasibility and validity of the proposed SMP for suppressing the backward motion were further confirmed.