Design Of Driving System For Piezoelectric Bidimensional Oscillating Mirror

In the device of combining light beam, each optical maser is equipped with piezoelectric bidimensional oscillating mirrors to compensate the light path excursion of the laser. In the project, the deflection angle of the oscillating mirrors in two directions must be less than ±1mrad and the whole travel positional accuracy must be within 20μrad. So Driving System of the bidimensional oscillating mirror should be designed to realize the requirement of high positional accuracy.General framework about the hardware of the piezoelectric bidimensional oscillating mirror’s driving system is built in this design. The principle of each module including control module、driving power module and detection circuit loop module is discussed. The choose and peripheral circuit design of DSP chip and FPGA chip、circuit design of DAC and ADC is discussed in the control module. Principle、requirement analysis、chip choosing and circuit design is included in the driving power module. The working principle of amplifying circuit and the circuit design is discussed in the detection circuit loop module. Performance of the hardware circuit is tested in the next step and experiment results show that each target of the hardware circuit can meet the requirements.Then the modified asymmetric PI hysteresis module is built based on the hysteresis of Piezoelectric. Problem about asymmetric hysteresis curve is solved and the fitting precision is improved. Based on the modified asymmetric PI hysteresis module, feedforward control arithmetic is designed with the method of bisection. The feedforward control arithmetic can compensate for the nonlinearity which is caused by the hysteresis of Piezoelectric. Then the PID feedback control arithmetic is designed. The feedforward control arithmetic is combined with the feedback control arithmetic and the compound control arithmetic can be created. The tracking accuracy can reach 16.2μrad.In this thesis, the drive mode is payed close attention to in the condition of deflexion with a small angle. Theoretical research and experiments show that the performance of the piezoelectric is improved in this research and this research has great theoretical significance and practical value in the use of the device of combining light beam with piezoelectric bidimensional oscillating mirrors.