| Precision drive and positioning is one of the key technologies in cell engineering,precision/ultra-precision machining,aerospace,microrobotics,optical engineering,precision instruments and other fields.Piezoelectric actuators have been widely concerned because of their high precision,small size,no electromagnetic interference,light weight and rapid response.In order to solve the problem that it is difficult to realize high-speed and high-resolution positioning in a single working mode of piezoelectric actuator,a multi-mode piezoelectric actuator is designed by combining the characteristics of resonant and non-resonant piezoelectric actuators,and its simulation analysis,output performance test and scratch application are carried out.The main research work is as follows:Based on the driving principle of resonant and non-resonant actuators,the structure design of multi-mode piezoelectric actuators is developed.By using finite element simulation,the influence of the structure size on the natural frequency of the stator is studied,and the main dimension parameters are determined.The modal analysis,harmonic response analysis,strain analysis and stress analysis of the stator are carried out,and the feasibility of multi-mode operation of the actuator is verified.Further,a prototype is developed,a test platform is built,and the output performance of the actuator is tested and analyzed.The speed-frequency characteristics,speed-voltage characteristics,speed-load characteristics,stepping output characteristics,resolution characteristics and speed-preload characteristics of the actuator in resonant and non-resonant modes are studied.The results show that the actuator can work normally in two modes,and the best working frequency of resonant mode is 21600 Hz,the maximum speed is 115mm/s,the resolution is 0.454μm,and the best working frequency range of non-resonant mode is 1-100 Hz.At 100 Hz,the forward and reverse velocities are 22.89μm/s and 21.27μm/s,respectively.The forward resolution is 72 nm and the reverse resolution is 30 nm.In addition,aiming at the step control of the actuator,by combining the characteristics of the multi-mode piezoelectric actuator,a resonance-non-resonant hybrid drive mode is proposed,that is,the resonance mode is started in the back section of the non-resonant mode.The effect of the amplitude of sinusoidal voltage on the single step displacement characteristics is studied under sawtooth voltage with different frequency and amplitude.The results show that by changing the amplitude of sinusoidal voltage,the active control of displacement curve can be realized at low speed.The motion process of this mode is illustrated by analyzing the single step displacement characteristics,and the best sinusoidal voltage amplitudes corresponding to different frequency and amplitude sawtooth voltages are obtained.Finally,the scratch test application of the actuator is carried out.For 1015 aluminum alloy material,the scratch test is carried out respectively in the non-resonant mode and the resonance-non-resonant hybrid drive mode.In the non-resonant mode,the influence of scratch load on the residual scratch morphology and other characteristics is studied.In the resonance-non-resonant hybrid drive mode,the influence of sinusoidal voltage and scratch load on the residual scratch morphology and other characteristics is studied,and the causes of the appearance and disappearance of material accumulation phenomenon are analyzed,and the method of eliminating material accumulation in the resonance-non-resonant hybrid drive mode is proposed.In conclusion,this paper combines the characteristics of resonant and nonresonant piezoelectric actuators,proposes a multi-mode piezoelectric actuator,carries out the actuator structure design,simulation analysis,output performance testing and scratch application,provides a certain reference for the design and application of multimode piezoelectric actuators. |
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