Study On Piezoelectric Motor Based On Synchronized Switching Control

Piezoelectric is a newly developed energy transducer which converts the electric energy into mechanical energy through the vibration of piezoceramics. It is widely used in aerospace, bio-medical and among others for that it has many advantages such as small size, large torque, compact structure, low-speed, free of electromagnetic interference, power-off self-lock and so on compared with the conventional motor. From the 1980 s when the Piezoelectric motor was birthed to now, varieties of piezoelectric motor prototypes with new principle and structure has been invented and it has become an emerging leading topic. But there are still much insufficient such as badly worn, inefficiency and so on. In order to solve the problem of service life of the sliding friction coupling transmission type piezoelectric motors and achieve a balanced performance in terms of high force, speed and efficiency. In this paper, based on the original driving theory and combined with experiments, a more optimal structure of the piezoelectric motor was designed.In this paper, the characteristics of piezoelectric ceramics were explained firstly. Then, after analyzing the mechanism of piezoelectric motor controlled by synchronized switch, combining with the experiment, the mechanical structure of the piezoelectric motor was designed. In addition, through accomplishing the dynamics model and simulation for the piezoelectric in Maplesim, a deeper understanding of the impact of the control parameters on the piezoelectric motor’s working process was obtained. At last, an experimental platform was set up to measure the characteristics of piezoelectric motor.Mechanical switch was driven by a square wave voltage with an amplitude of 2Kv and piezoelectric vibrator was driven by a sinusoidal voltage, the voltage amplitude is 80 v and the frequency is101 Hz.A series of displacement curve were gained while changing the phase of the driving voltage from 0° to 360°and two best were selected from those curves. It illustrated that the single step distance is 5um and the average speed is 0.8mm / s when the piezoelectric motor moves forward under the condition that the square signal is in advance of the sinusoidal signal130°. While the square signal is in advance of the sinusoidal signal 310°, the piezoelectric motor moves backwards and have the similar single step distance and average speed with the former after analyzing the two curves. The results of the experiment show that the piezoelectric motor possess a good stepping characteristics.