piezoelectric ceramic disc transducer

                            piezoelectric ceramic disc transducer

In order to meet the control requirements of flexibility, rapidity, and simplicity, the domestic and foreign scientific and technological communities and industry have been working on various new types of micro-motors for many years. Among them, the ultrasonic motor utilizes the inverse piezoelectric effect of piezo cylinder transducer to convert the microscopic deformation of the material through resonance amplification and friction coupling into the macroscopic motion of the rotor or the slider. As a kind of direct drive motor, it has been favored by scientific researchers of all countries since the 1980s.

 Piezo ceramic crystal has become a research hotspot in the field of electromechanical control. This paper first analyzes the operating mechanism of ultrasonic motor, establishes the formation of the elliptical motion trajectory of the surface particle of the traveling wave ultrasonic motor, and piezo energy harvestingestablishes a mathematical model for the  ultrasonic motor. Then piezoelectric acoustic sensor designs the measurement and control system.

The ultrasonic motor measurement and control system designed in this paper has the following basic functions: (1) Two-way signal phase O-1800 continuously (2) Two-way drive signal can be reversed to change steering (3), frequency output 20kHz ~ Adjustable within 100 kHz (4) Since the ultrasonic motor of piezoelectric power generation is a capacitive load, impedance matching is required. (5) With test and actual operation switching function.(6) It has working status setting, parameter setting, control mode setting, parameter display and waveform tracking function; this paper uses PID and fuzzy control based on the combination of existing .it is ultrasonic motor , frequency modulation and phase modulation control modes. 

Due to the existence of a certain steady-state error in the fuzzy control system, there is a control blind zone for piezo ceramic ring: the PID control is not adaptable to the change of the control object. Therefore, this design adopts a multi-mode control strategy based on a digital signal processor (DSP) in a large deviation range. The fuzzy control is used to convert to PI D control within a small deviation range. The conversion of the two is implemented by the DSP according to a preset deviation threshold. It is self-correction of fuzzy control rules . The results show that it is compared with the traditional control strategy, the control strategy of piezoelectric ring crystal has faster response speed, higher adjustment accuracy, better steady-state performance, no overshoot and oscillation, and strong robustness.