Research On Piezoelectric Driven Fine Oscillating Mirror Control System

In order to achieve coaxial combining of multi-wave lasers, the deflection angleof the2D oscillating mirror is within1μ arc. The oscillating mirror system requiresvery high precision, which is influenced by the delay and slow-changingcharacteristics of piezoelectric. Therefore, this thesis has set up a mathematicalmodel of piezoelectric based on its delay and slow-changing characteristics. Afeed-forward PID control algorithm based on the inverse-delay model of the2Doscillating mirror is put forward so as to build a high-precision driving andcontrolling system of a2D oscillating mirror. The main contents of the thesis is asfollows.First, a controller and a driver of the2D oscillating mirror is designed. Thecontroller has TMS320F28335as its central processor and some peripheral circuits.The driver is designed using high-voltage power amplification to realize10-timesamplification.Second, a dynamic inverse-delay model is put forward and a feed-forward PIDcontrol algorithm is designed based on the delaying, slow-changing characteristics ofpiezoelectric and the dynamic characteristics of the2D oscillating mirror. The coreidea is to first design the feed-forward control circuit based on the dynamicinverse-delay model of the2D oscillating mirror, and then design the feedbackcontroller using PID control algorithm to realize closed-loop control of the2D oscillating mirror.Third, a set of performance testing experiments are implemented to study thecharacteristics of the2D oscillating mirror driving and controlling system. In theopen loop condition, linearity of the system, output stability and sinusoidal dynamicresponse are tested. In the closed loop condition, the output precision, repetitionprecision and dynamic inverse characteristics are tested. Results show that thispiezoelectric driven2D oscillating mirror control system has good static deflectingperformance and dynamic tracking performance.