principle of piezoelectric sensor to measure movement

                       principle of piezoelectric sensor to measure movement

The stator is composed of two groups of piezo disc element sheets and toothed elastomers, and the rotor is in contact with the stator with a certain pressure. The two groups of piezoelectric sheets are excited and superimposed into a traveling wave in the middle of the elastic body. The surface of the stator elastic body make an elliptical motion. The rotor of piezo ceramic cylinder contacts the peak of the stator elastic body with a certain pressure and is driven by a friction force to make a rotary motion. The traveling wave type for ultrasonic motor realizes that the stator periodically pushes the rotor into multiple points continuously, which greatly reduces the friction and wears the contact surface.

Piezo ceramic sphere opens the way for the development of the ultrasonic motor and practical application of this type of motor. It was in 1987 that this was a sign of ultrasonic motors moving from the laboratory for commercial applications. it is developed the first ring-shaped ultrasonic motor for camera automatic zooming, and it was in the camera industry. In China, although some progress has been made in the development of ultrasonic motors, and some prototypes have been successfully tested, they are basically still in the laboratory stage. Workers in the electromechanical field need to work together to change this situation.

As the ultrasonic motor of piezoelectric plate sensor changing with temperature, it is power supply voltage, load torque, and static pressure between stator and rotor, the resonance frequency of the piezoelectric ceramic drifts; and the ultrasonic motor parameters change at every moment, the system presents a highly nonlinear; it is complex multi-variable, strongly coupled, and time-varying systems. The motor is a special two-phase structure. There is an piezoelectric plate vibration sensorbetween the electromechanical parameters and the electromechanical coupling Therefore, so far, there is no accurate mathematical model that can fully express the dynamic and steady-state characteristics of ultrasonic motors.

Theoretical studies have been conducted on the mathematical model of dynamic and steady-state characteristics of ultrasonic motors. Considering that the main working characteristic of the ultrasonic motor,which is to apply an alternating voltage with a certain angle of two phases to each other, the inverse piezoelectric effect of 4KHZ piezoelectric plate sensor causes the piezoelectric ceramic to resonate and drives the stator ring to vibrate, and then passes the setting, The friction between the rotors drives.