A multiple feedback parameter contact force closed-loop control piezoelectric actuator with high working performance retention

At present, piezoelectric actuators still have problems such as poor working performance retention need to be solved. The working performance of stick–slip piezoelectric actuator is closely related to the contact force between the slider and the driving foot. However, there are few studies on the active control of contact force. To improve the working performance retention of the piezoelectric actuator, this study proposes a stick–slip piezoelectric actuator with multiple feedback parameter closed-loop control for the first time. The contact force is measured in real time by the pressure sensor, and the contact force is controlled by the synthesize waveform. The cRIO9035 controller with FPGA is used to achieve high-frequency acquisition, processing, and output of signals. The driving characteristic surface of stick–slip piezoelectric actuator is proposed for first time. The corresponding control methods are proposed for two different working conditions. The experimental results show that the contact force closed-loop control reduces the fluctuation range of the contact force from 2 N to 0.05 N which can solve the problem of working performance retention deterioration caused by the changes in contact force. The contact force – displacement multiple feedback parameter closed-loop control can solve the problem of working performance retention deterioration caused by sudden changes in paralleled load force. The proposed actuator with closed-loop control can achieve stable drive under two working conditions that ordinary actuators cannot work. This study has certain significance for improving the working performance retention of stick–slip piezoelectric actuators and promoting the application of piezoelectric actuators.