摘要
分析了相位生成载波(PGC)调制解调法测量微小振动的基本原理,搭建了迈克耳孙型干涉测量系统,研究了声波频段信号微振动的测量。在此基础上分析了压电陶瓷(PZT)调制时振动频率随机波动以及相位不匹配对解调造成的影响。理论和实验表明PZT调制的稳定性对最后解调的波形有很大的影响,调制频率的稳定可以消除解调引入的信号失真,相位的匹配能使解调信号信噪比达到最大。为减小PZT的影响,对实验系统进行了改进。
The basic principle of measuring micro-vibration based on phase generated carrier （PGC） modulation- demodulation method is analyzed. A Michelson interferometer measurement system is set up and the micro-vibration measurement of acoustic frequency band signal is studied. Based on this, influences of random fluctuations of the vibration frequency and the phase mismatch in the modulation of the piezoelectric ceramic （PZT） on the demodulator are analyzed. Theoretical and experimental results show that the stability of the PZT modulation has a great impact on the final demodulated waveform. The stability of the modulation frequency can eliminate the signal distortion caused by demodulation, and phase matching makes the demodulated signal to noise ratio （SNR） maximum. In order to reduce the influence of PZT, the experimental system is improved.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2013年第2期209-214,共6页
Chinese Journal of Lasers
关键词
相干光学
振动测量
相位生成载波
频率波动
相位不匹配
锁相环
coherence opfics
vibration measurement
phase generated carrier
frequency fluctuation
mismatch of phase
phase-locked loop
