Design And Experimental Study Of Friction Asymmetric Piezoelectric Actuator

Piezoelectric actuators are widely used in Nano positioning systems because of their remarkable advantages such as fast response speed,high positioning resolution and freedom from electromagnetic interference.So far,piezoelectric actuators have been widely used in various research and industrial fields,such as aerospace,optical engineering,ultra-precision machining,and biomedicine.However,the piezoelectric driver always has a certain back-off phenomenon during the driving process,which greatly affects the driving effect of the piezoelectric driver and limits the further application of the piezoelectric driver.Therefore,for researchers in the field of piezoelectric actuators,how to suppress the back-off phenomenon of piezoelectric actuators has become one of the researches focuses.In this paper,based on the asymmetry of friction on the surface of wheat awns,a frictional asymmetric piezoelectric actuator is designed.Using the piezoelectric stack as the driving source,two sets of parallelogram flexure hinges with the same tilt direction are arranged inside the U-shaped plate.When the two sets of parallelogram flexure hinges move relative to the rotor,the shape of the two sets of parallelogram flexure hinges variables are different,resulting in different friction between the contact surfaces on both sides of the rotor which forming a torque to drive the rotor,finally only one piezoelectric stack is used to achieve alternate stepping.A frictional asymmetric piezoelectric drive rotation device was developed,and its overall structure was designed.Based on the finite element analysis method,the structure of the parallelogram flexure hinge is optimized,and the optimal parameter results are obtained.The dynamic model of frictional asymmetric piezoelectric actuator is constructed,MATLAB/SIMULINK software is used for simulation analysis.The simulation results verify the feasibility of the design.An experimental test system was built,and the piezoelectric actuator was tested and analyzed.The step displacement of the driver is stepped.When the input voltage is between 30V-100 V,the minimum step displacement of the driver is 1.763μm,the maximum output speed is 20.583mm/s,the output torque is 10-4Nm.The experimental results show that the designed piezoelectric actuator uses the frictional asymmetric principle to achieve alternate stepping and effectively suppresses the backlash,which not only ensures the driving efficiency but also effectively improves the driving speed.In this paper,the research on the frictional asymmetric piezoelectric actuator has made a certain contribution to the field of restraining backlash of the piezoelectric driving device,and has certain reference value in restraining backlash and improving the output speed.