基于梯形棱镜的激光三角法内孔测距传感器  

Inner Hole Range-Finding Sensor with Laser Triangulation Based on Trapezoid Prism

作　　者：熊志勇[1] 赵斌[1] 

机构地区：[1]华中科技大学机械科学与工程学院仪器科学与技术系,湖北武汉430074

出　　处：《光学学报》2011年第12期95-100,共6页Acta Optica Sinica

基　　金：国家973计划(2007CB714000)资助课题

摘　　要：为了实现对孔类零件特别是深孔零件的孔深测量及底面的表面形貌测量,设计了一种激光三角法内孔测距传感器。对该传感器所使用的机械光学设计、系统成像特性及基于Zemax的像差分析与评价等进行了研究。首先,利用聚焦透镜将激光器发出的光线聚焦到待测面上,使光斑足够小。接着,利用梯形棱镜的全反射特性将所需散射光线限制在一个狭小的范围内。最后,利用成像透镜将光线聚焦在CCD靶面上,根据CCD上光斑的位置和待测孔深的几何关系,求出内孔的深度和底面的表面形貌。实验结果表明,系统在0～1.6mm范围内测量精度为1μm,该设计可以很好的解决测量内孔时物理空间受限的问题,同时结合三角测量原理,使该系统能够满足工业生产线上的结构简单、稳定性好、调试和维护方便、精度高以及速度快等要求。In order to realize the inner-hole-depth measurement and the profile of the bottom surface measurement of parts with holes, especially deep-hole parts, an inner hole measuring sensor with laser triangulation was designed. The applied designs such as mechanical structure and optical designs, system imaging characteristics, and the analysis and evaluation of optical aberration based on the software Zemax were investigated. First of all, by using focusing lens, the laser light is focused to the surface to be measured, and flare is small enough. Then, put the required scattering light limit in a narrow range using the trapezoid prism total reflection characteristics. Finally, an imaging lens is used to make light foculize on CCD target surface. According to the geometric relation between the flare on CCD and hole depth, the depth of the hole and the profile of the bottom surface was calculated. Experimental results indicated that the measurement precision can reach 1 μm, and the design of using trapezoidal prism can well solve the problem of physical space limited as measuring inner hole. The combination with the principle of laser triangulation technique makes the system satisfy the requirements of simple structure, stabilization, higher precision and rapid speed.

关 键 词：测量 孔深测量 激光三角法 全反射 亚像素精度 

分 类 号：TH741[机械工程—光学工程]