激光自混合干涉测振仪的硬件系统设计

Hardware System of Semiconductor Laser Self-Mixing Interference Vibrometer

基于激光自混合干涉技术的特点,设计了一种新型半导体激光自混合干涉测振仪系统。系统将频率调制引入自混合干涉中,实现对振动物体的非接触式测量。介绍了激光自混合干涉测振仪的原理、仪器系统的光路系统设计、信号的调制模块设计、解调模块设计以及DSP系统的采集处理模块设计。该仪器体积小、成本低、易于准直、可以非接触式测量,能够测量振动频率在50 kHz内的物体,其中包括非周期性振动。可以测量出振动物体的振动频率、振幅以及还原振动波形,振动幅度测量精度可以达到0.325μm,频率精度为1 Hz。

A new type semiconductor laser self-mixing interference vibrometer system is presented. Frequency modulation system is introduced in the self-mixing interference to achieve the objects of the non-contact vibration measurement. The article mainly introduces the laser self-mixing interference vibrometor system in principle, the optical system design of the vibrometer system, signal modulation module design, demodulation module design and DSP gathering and processing module design. The vibrometer system is small in size, low in cost, easy to be collimated, and used to non-contact measurement. The system can measure the object whose vibration frequency is from 0 to 50 kHz, the vibration scope measuring accuracy a- chieves 0. 325 μm, the frequency precision is 1 Hz.