基于激光自混合干涉法的微振动测量  

Measurement of Micro-Vibration Based on Laser Self-Mixing Interference

作　　者：罗会甫[1] 王扬红 朱炜[2] 陈强华[1] 吴欢[1] 马斌武[2] 赵振峰[1] LUO Hui-fu WANG Yang-hong ZHU Wei CHEN Qiang-hua WU Huan MA Bin-wu ZHAO Zhen-feng(School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, China School of Electrical and Mechanical, Beijing Institute of Technology, Beijing 100081, China)

机构地区：[1]北京理工大学机械与车辆学院,北京100081 [2]北京理工大学机电学院,北京100081

出　　处：《北京理工大学学报》2017年第6期584-589,共6页Transactions of Beijing Institute of Technology

摘　　要：激光自混合干涉法由于其测量精度高、光路简单、准直性好等优点,十分适合于微小振动的测量.然而在测量微振动时,由于被测目标振幅微小且大多情况下其表面反射系数很低,造成测量信号的幅值较小以及光反馈导致的信号波形倾斜不明显,给测量信号解调带来了很大难度.在自混合干涉光路中添加一个预反馈镜,构成带预反馈的干涉光路系统,可将测量信号增强2~4倍.同时,推导"基频-极值点判定算法"的频率幅值解调公式,建立了模型算法,实现自混合干涉信号的解调.理论分析和实验表明,频率测量的误差小于2.5%,振幅测量的误差小于5%.Laser self-mixing method is very suitable for the measurement of small vibration because of its high precision, simple optical path and better collimation. However, in the measurement of micro-vibration, because of the small amplitude of the object, the low coefficient of the surface and the small amplitude of the measured signal, it caused a great difficulty for the demodulation of the signal with the unobvious inclination of the signal waveform due to the optical feedback. A pre-feedback mirror was added in the self-mixing interference light path to form a feedback optical path system, which could enhance the measurement signal to 2-4 times. At the same time, the frequency and amplitude demodulation algorithm named ＂fundamental formula-extreme point＂ was derived and a model was built to realize the demodulation of the signal. The theoretical analysis and experimental results show that the error of the frequency is less than 2.5%, and the error of the amplitude is less than 5%.

关 键 词：激光自混合干涉 预反馈 基频 极值点 

分 类 号：TH741[机械工程—光学工程]