电子散斑归一化互相关法测位移

Electronic speckle pattern normalized cross-correlation method for displacement measurement

把粗糙物体表面受到相干光照明时产生的散斑场看作是一个稳态随机信号,在此基础上,本文提出了一种能做到大量程,高精度位移测量的新方法——电子散斑归一化互相关法测位移或称电子散斑照相法测位移.该法实质上是借助数字图像处理技术,通过物体位移前后二个散斑场之间的相关性来进行位移测量方法的发展.文中给出了理论分析和实验系统.实验结果表明,该法有诸如准实时,大量程(毫米级),高精度和线性可靠等优点.

Regarding the speckle pattern caused by a coherently illuminated optical rough surface in the recording plane as a stable random signal, we propose here a new approach——the Electronic Speckle Pattern Normalized Cross-correlation Method or called as Electronic Speckle Pattern Photography (ESPP)——for the displacement measurement. This method, based on the normalized cross-correlation function, is the modified Speckle Pattern Correlation method in the application of the digital image processing technique to the speckle pattern metrology. Our experimental results show that ESPP for the displacement measurement has the advantages of measuring large-range displacement in high accuracy without loss of insensitivity to the environment disturbance and the quasi-real time processing property respectively as that in the Speckle Photography and that in the Electronic Pattern Interferometry.