Research And Test On The Driving Force And Motion Parameters Of Piezoelectric Inertial Actuator

Piezoelectric inertial drive is a new device which uses the inertia force by piezoelectric element to drive and control. Driving force is the resource of the actuator, the quantitative analysis of it plays an important role of mechanism optimization. The motion parameters including displacement, velocity and accelerated speed is the important standard of output characteristics. In this paper the driving force is analyzed quantitatively, the detection experiment and verified experiment are designed. A self-detection circuit is designed based on direct piezoelectric effect. Artificial neural network is used to predict the motion parameters. The main content is as follow:Output characters and the equivalent circuit model of the bimorph are analyzed. The outputs of bimorph of direct/inverse piezoelectric effect are deduced. The influence on displacement and executive force of varying size of bimorph is analyzed by Matlab software. The relationship of output electric charge and displacement is deduced. The impedance of bimorph is analyzed and tested by universal meter and impedance analyzer.The displacement response, speed response and acceleration response of the piezoelectric vibrator in the sine, triangle and square wave are analyzed. The time and frequency characteristics of the inertia force for sine, triangle and square wave under the basic frequency are drawn. The dynamic character is simulated by Simulink module.The testing experiment and validation experiment are designed and preceded. Detection method is put forward in which a light piezoelectric accelerometer with wide frequency range is used. The driving force is obtained by test result from sensor multiplying weight of the mass block. The frequency response is obtained by FFT arithmetic. Based on the motion principle of the motor, verify experiment is designed and detection results are validated by the friction method.A new test method without sensor of driving force is proposed for piezoelectric inertial mechanism. One piece of crystal is used as sensor. The test circuit was designed to obtain the piezoelectric charge and convert into acceleration. The acceleration of the bimorph was tested and verified by independent acceleration sensor.The prediction of motion parameters by artificial neural network is put forward. The relationship of sensing signal, the output of the test circuit and the motion of the actuator is analyzed. The BP neural network model is built with the input parameter from the test circuit and the output parameter from step size of the actuator.