提出了一种基于同轴光显微成像的加工表面双向反射分布函数(BRDF)测量方法,采用激光共聚焦显微镜获得了不同粗糙度样块表面的BRDF测量值。测量结果表明,样块表面BRDF会随着粗糙度及微观形貌变化,该测量方法能够获得不同微面元的BRDF测量值。建立了BRDF参数模型,采用遗传算法对测量数据进行处理,确定了最优模型参数。将模型计算结果与测量结果进行了误差分析,最大相对均方根误差为9.97%。结果表明,建立的BRDF模型具有可行性,能准确地描述加工表面反射信息。

A measurement method of bidirectional reflectance distribution function (BRDF) on the cutting surface is proposed based on the coaxial optical microscopic imaging. The BRDF measurement values on sample surfaces with different roughnesses are obtained by using the laser confocal microscopy. The measurement results show that, the BRDF on the sample surface varies with the roughness and the micro-topography, and this measurement method can obtain the BRDF measurement value on different microfacets. The BRDF parameter model is built and the optimal model parameters are obtained when the measurement data are processed by the genetic algorithm. The error analysis between the model calculation results and the measurement results is carried out and the maximum relative mean square root error is 9.97%. The results show that the established BRDF model is feasible and can accurately describe the reflection characteristics on the cutting surfaces.