摘要
为了得到远程物体的微米级振动的频率信息,采用基于散斑图像的远程振动频率提取方法,以波长为532nm连续激光器作为光源照射50m远处被测物体表面,通过高速摄像机记录物体表面反射空间内的散斑图样提取物体的微振动频率。采用激光散斑图像的数据处理方法,进行了研究分析和实验验证,利用长焦镜头对远程散斑图像进行适当散焦处理,然后提取视频散斑图像间互相关系数峰值点与原点之间的矢量大小来获取散斑的变化信息,同时对一定宽频率范围内的振动频率进行提取。结果表明,用该方法得到的激光散斑远程微振动频率的提取准确度达99.22%。该数据结果为激光散斑应用于远程频率振动检测提供了一定的论证依据。
In order to obtain the frequency information of remote object’ s micron vibration, the remote detection technique of micro vibration information bases on laser speckle interferometer was used. The CW laser of 532nm wavelength was used as light source to light the to-be-detected object surface 50m away. A high speed camera was used as speckle image acquisition system. At first, telephoto lens was used to do the appropriate defocus processing of remote speckle image. Then, the changing information of speckle was obtained from the vector size between the peak value of correlation and the origin point. At the same time, the vibration frequency information in a certain wide frequency range was extracted. The results show that, extraction accuracy of remote micro vibration frequency by laser speckle is up to 99. 22%. The study can provide some argumentation basis for acoustic vibration based on laser speckle.
出处
《激光技术》
CAS
CSCD
北大核心
2016年第6期801-805,共5页
Laser Technology
基金
公安部技术研究计划资助项目
关键词
激光光学
激光散斑
振动频率远程探测
散焦
互相关系数
laser optics
laser speckle
vibration frequency remote detection
defocus
correlation coefficient
