文章基于Beckmann散射模型，提出一种表面粗糙度的在线测量方法。以半导体激光器为光源构成远心光路，通过线阵CCD记录粗糙物体表面的散射光场。计算机分析处理得到表面粗糙度特征值Sn，在较大的范围内表面粗糙度Ra和Sn有很好的对应关系。该测量方法结构简单、精度高、速度快，可以对不同加工方法的工件表面粗糙度实现非接触实时检测，在工件的在线检测方面有很好的发展前景。

This paper present a kind of on-line measurement of the surface roughness based on Beckmann's theory about the scattering of light. We use a laser diode to form a telecentric beam path system, and record scattering light field of the rough surface by linear array CCD. We get optical scattering characteristic value Sn by computer analysis, and there is a better corresponding relationship between surface roughness Ra and Sn in a larger measming range. This measurement method of simple structure, high precision, fast speed, which can realize non-contact and on-line measurement to different processing methods, and has a good development prospect on line measurement of the workpiece.