Research On Modeling Simulation And Energizing Circuit Of Piezoelectric Impact Motor

Piezoelectric impact motors(PIMs)use piezoelectric ceramics as driving elements,whose stators produce asymmetry periodic motions energized by saw-tooth signals.Utilizing inertia-friction effects,stick-slip motions are formed at the interfaces of stators and sliders,so that the sliders are pushed to realize single direction stepping movements.PIMs not only can be operated in the stepping driving mode with a sub-micron displacement resolution,but also can work in the smooth driving mode with a speed of several millimeters per second and scanning driving mode with a nanometer displacement resolution,which effectively relieves the contradiction between the large travel range and high precision and shows a good development prospect in the cross-scale miniature precision positioning and manipulation systems.However,the nonlinear factors of piezoelectric ceramic elements,including the hysteresis and creep with voltage energization,not only influence the positioning accuracy in the scanning driving mode,but also accumulate error of stepping motion in the stepping driving mode,which seriously affect the practical applications of PIMs.In this dissertation,through the studies of modeling simulation and energizing circuit of PIMs,methods are explored to improve the open-loop control accuracy of PIMs in the three driving modes.The main works includes:1.Dynamic theoretical model of PIMs are established,dynamic characteristics in the three driving modes are simulated,and the main factors influencing the positioning accuracy are analyzed.2.Typical energizing circuits for piezoelectric ceramics are analyzed,applicable charge energizing circuit for PIMs are designed,and influences of the main circuit parameters on the driving performances are analyzed.3.An experimental platform is established.The driving performance of a linear PIM N-422.50 are compared and analyzed with voltage and charge energizations.Experimental results show that charge energizing circuit can meet the requirements of the three driving modes of PIMs.It gets a good linearity among the frequency range from 0.5 Hz to 100 Hz in the scanning driving mode,and have a stable stepping displacement among the frequency range from 1 Hz to 100 Hz in the stepping driving mode.The studies in this dissertation show that the charge energization for piezoelectricimpact drive mechanisms has good research values and application prospects in cross-scale precision positioning fields.