提出了一种基于激光多普勒法测量微小阻尼振动的方法。采用双光束干涉测量系统,得到激光干涉差拍信号。通过对实验的差拍信号进行频率分析,得到微小阻尼振动的频率;通过判断在差拍信号中的目标运动翻转点,得到振幅的大小;根据运动翻转点附近的微小位移与电压值的关系,利用阻尼振动的性质得到阻尼系数。通过仿真模拟和实验,证明基于激光多普勒法测量微小阻尼振动具有方法容易、信号质量好、精度和灵敏度高且误差小等优点。

A small damping vibration measuring method by Doppler effect is proposed. A twin-beam laser Doppler detection system for a small damping vibration measuring is presented,and the beat-wave signal is acquired successfully. By analyzing the frequency of the beat-wave,the frequency of object to be measured is obtained;its amplitude is evaluated and the turning point of the beat wave is found out;Using the relationship between the small displacement around the turning point and the amplitude and damping vibration property,the damping coefficient is obtained. By theoretical derivation simulating,and experimentation,small damping vibration measurement using laser Doppler effect was acquired. This method can promote the survey accuracy and reduce the relative error.