Achieving Highly Smooth and Linear Displacement Output of Stick-Slip Piezoelectric Actuators by an Active–Passive Collaborative Driving Method

Nonlinear one-step displacement and nonsmooth interstep transitions are commonly observed in nonresonant stepping piezoelectric actuators, which deviate from the desired smooth and linear displacement output and pose challenges for subsequent control strategies. At present, the generation of highly smooth and linear displacement output remains arduous, especially under various horizontal loads and preload deformations. To solve this problem, a method of active–passive collaborative driving (APCD) was proposed. Based on this method, a stick-slip piezoelectric actuator was developed, and the corresponding dynamic model was established. Then, a series of experimental tests were performed. Results demonstrated the feasibility of the APCD method in achieving highly smooth and linear displacement output. Notably, the actuator employing the APCD method demonstrated smooth and linear motion across horizontal loads from 0 g to 30 g, preload deformations from 0 mm to 0.5 mm and phase differences from 140 to 200 degrees. Furthermore, the actuator showed superior motion characteristics including high smoothness, linearity, stability, and consistency under various vertical loads and preload deformations, as well as excellent performances in terms of smoothness, linearity, and stability across a range of voltages and frequencies.