激光光栅多普勒效应微小振动测量  

Small Vibration Measurement Using Laser Grating Doppler Effect

作　　者：杜振辉[1] 李淑清[2] 蒋诚志[1] 陶知非[3] 高华[1] 谢艳[1] 

机构地区：[1]天津大学精密测试技术及仪器国家重点实验室,天津300072 [2]天津科技大学电子信息与自动化学院,天津300222 [3]石油地球物理勘探局,涿州072751

出　　处：《光学学报》2004年第6期834-837,共4页Acta Optica Sinica

基　　金：国家自然科学基金 (4 0 2 74 0 4 6 )资助课题

摘　　要：为了提高测量微小振动的精度和动态范围 ,提出一种基于激光光栅多普勒效应的微振动测量系统。通过对差拍信号的频率分析 ,以峰值频率比值的方法可以排除干扰获得被测振动频率 ,找到振动的翻转点并判断振幅的大小 ;推导了在翻转点附近的微小位移与电压值的关系 ,对于小于计数当量值的位移由测量电压得到 ,提高了微小振动位移的测量精度以及系统测量的最小分辨率、动态范围。实验系统的频率范围为 0 .5～ 5 0 0Hz,振幅为2 0～ 10mm ,相对误差小于 1% ,其动态范围大于 10 0dB。In order to increase the accuracy and dynamic range of measuring small vibration, a measuring system using grating Doppler effect is proposed. 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. The relationship between the small displacement around the turning point and the amplitude is deduced. Accordingly the displacement less than the equivalent value can be calculated by the amplitude ratio. This method can promote the survey accuracy, and dynamic range, and find out other vibration characteristics of the object to be measured with the simple instrument. When frequency range to measure vibration is in 0.5～ 500 Hz, and the amplitude is in 20 nm～10 mm, the experimental results show that the relative error is less than 1%, and the dynamic range is better than 100 dB.

关 键 词：光学测量 多普勒效应 激光光栅 振动测量 频率分析 最小分辨率 

分 类 号：TB92[一般工业技术—计量学]