Research of micro-positioning system based on piezoelectric actuator

In order to satisfy the request of machining accuracy and fast response of ultra-precision machining, a micro-positioning system based on piezoelectric actuator and flexure hinge structure is designed. The mechanical property of hinge structure is analyzed in theory and its inherent frequency is obtained by experiment. A controllable high voltage circuit is designed to actuate PZT, and its static and dynamic characteristics are analyzed by experiments of linearity test, sinusoidal and step response. Combined with the measurement system of a diffraction grating, hysteresis and frequency response characteristics of piezoelectric ceramic actuator, a micro-positioning control algorithm is proposed based on the maximum slope method. According to experiments of the computer sample control system which is built, the positioning travel range is 19 mum, the positioning accuracy is better than 0.1 mum, the positioning time is less than 0.2 s.