Design On The PZT Micro-positioning System

With the continuous development of technology and continuing to explore the fieldof human research, Operation objects deep from the macro into the micro-depth field. Inthe precision operations processing such as ultra-precision machining and precisionmeasurement, need to achieve higher accuracy, and system’s dynamic performancerequirements are also increasing.Traditional micro-positioning mechanism has a greater inertia, slow response,complex structure, poor stability. Piezoelectric ceramic micro-positioner has small size,large output force, high resolution of displacement, high frequency response no noiseand no heat, etc; meanwhile, the flexible hinge structure has no mechanical friction, theinternal structure of compact, smooth movement, high sensitivity characteristics, somaking as a guide to flexible hinge mechanism, driven by a piezoelectric ceramicpositioning platform can be widely applied. However, the piezoelectric ceramics arecapacitive load and nonlinear by the hysteresis, creep characteristics caused. This makesdifficult to the practical application of piezoelectric ceramics.In response to these problems, the method of this paper combining theory withpractice, from the microscopic point of view, analysis of the mechanism of piezoelectricceramics, and study the characteristics of the piezoelectric ceramics. According to thesecharacteristics design the piezoelectric positioning platform. Because of piezoelectricceramic is capacitive load, So drive power chooses capacitive load drive power toachieve the design，consisting of high voltage regulator circuit, multi-stage amplifiercircuit and discharge circuit. Test the output voltage range of drive power, linearity ofthe output voltage and dynamic characteristics of the power supply. The results of testshow that the drive power have good driving performance. Using STM32F103controller chip as the lower computer to complete control the positioning platform, dataacquisition and communication with the PC. Finally, established the mathematicalmodel of the entire system, using LabVIEW preparation of PC control program, usingdigital PID control algorithm, By MATLAB simulation the controll system andexperimental analysis. The results prove that under the closed-loop PID control thenonlinear and dynamic properties of piezoelectric positioning platform has been greatlyimproved, improved the positioning accuracy of the entire platform.