基于CCD激光衍射暗纹间距的精确测量算法研究

激光衍射测量技术对于测量微小尺寸的工件有很大优势,但是由于较高级次暗纹的光强较微弱,被中央明条纹光强所掩盖,以及散斑和CCD热噪声的影响,暗条纹中心距很难精确测量.将CCD视频信号先进行自适应滤波,消除噪声影响,再利用差分法和取平均值的方法找到暗点的粗略位置,进而用最小二乘法进行局部拟合,确定精确暗点位置.实验表明用改进方法处理暗条纹精度较高.

CCD - based Laser Diffraction on Dark - strips Distance Precision Measurement Algorithm

laser diffraction measurement technique for measuring small size is a great advantage,however,the higher the grade of dark stripe,the weaker the light intensity,and the central stripe of light intensity are overshadowed. Speckle and CCD thermal noise impact,dark stripes from the center is difficult to accurately measured. This paper presents CCD video signal conducts adaptive filter to remove noise impact,using differential and average method to find the rough location of dark spot, with the last partial least squares fitting method to find the precise location. Experiments show improved approach to higher precision dark stripes.