Study And Design Of The Control System Of Piezoelectric Ceramic

With the development of precision engineering and micro-nano technique, precision positioning technology is the basic key technique in domains of ultra-precision machining, optoelectronics, bio-engineering etc. PZT is widely used in precision positioning technology for its small size, great load capacity, high speed responsibility and other characteristics as an ideal micro-displacement actuator.PZT control system designed in this thesis is applied to drive PZT which used as piezoelectric micro-displacement actuator. The thesis first introduces the physical properties of PZT, drive methods of piezoelectric actuators. Drive methods is analyzed and compared with each other. The present situation of their study is also showed in the thesis. Acorrding to design requirement, the PZT Control consists of three parts: hardware circuit, firmware of MCU, PZT control software. The hardware circuit mainly consists of linear amplifier, USB interface, A/D converter, D/A converter, MCU, DC power etc. MCU outputs digital-signal, it is converted to0-5V analog-voltage. The analog voltage is amplified by linear amplifier to output voltage range of0-200V on PZT. MCU samples voltage on PZT with A/D converter. The digital-signal which is in proportion to the voltage on PZT is send to PC. MCU firmware, which is programmed with assembly language, receives, identifies and executes instructions from PC. With subroutine of digital-analog conversion, analog-digital conversion, periodic voltage calculation, timer interruption, MCU could finish different output functions of discrete signal, regular periodic signal, irregular periodic signal, and it also could sample the output voltage at intervals. PZT control software with friendly GUI is developed on studio of Visual C++. It has fuctions such as instruction control, serial communication, data access, voltage graphical display etc. The key words and the innovations are as follows:(1) Communication control protocol is designed to achieve communication between PC and MCU, and the computer software can control PZT.(2) PZT control system can read voltage datas from excel and output irregular periodic signal.(3) PZT control system can generate periodic signals, such as sine wave, square wave, triangle wave, and parameters of the signal can be adjusted.(4) PZT control system samples the output voltage while it drives PZT, and graphically display the voltage datas.The last tests show the control system easy to use and run stable. PZT control system achieves the aims of design.