球面惯性元件激光共焦曲率半径测量系统  

Laser confocal radius measurement system for spherical inertial elements

作　　者：邱丽荣[1] 王超峰 赵维谦[1] QIU Lirong;WANG Chaofeng;ZHAO Weiqian(School of Optics and photonics,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]北京理工大学光电学院

出　　处：《中国惯性技术学报》2019年第2期266-271,共6页Journal of Chinese Inertial Technology

基　　金：国家自然基金重点项目(61635003)

摘　　要：针对球面惯性元件散射特性导致其曲率半径测量难度大、精度低的问题,研制了一套球面惯性元件激光共焦曲率半径测量系统。系统通过针孔滤波降低探测器接收散射光的比例来抑制散射光的影响,利用共焦回馈技术提高返回光探测强度,以适应低反射率球面惯性元件的探测。采用共焦轴向光强响应曲线的峰值点精确对应物镜焦点的特性,对被测元件的猫眼和共焦位置进行精密定位,通过激光干涉仪获取两点间距离,继而实现曲率半径的高精度测量。以半球型动压气体轴承作为实验对象进行了实验。理论分析和实验结果表明,系统相对扩展不确定度优于20×10^-6,提出的测量系统为具有散射特性的球面惯性元件曲率半径的高精度测量提供了技术途径。In view of the difficulty and low accuracy in measuring the radius of curvature caused by the scattering characteristics of spherical inertial elements,a laser confocal radius measurement system for spherical inertial elements is developed.The system uses pinhole filter to reduce the proportion of the scattered light received by the detector to restrain the influence of scattered light.Confocal feedback technology is used to improve the detection intensity of returned light to adapt the detection of spherical inertial elements with low reflectivity.The peak point of the confocal axial response curve corresponds to the focus of objective lens.According to this characteristic,the cat’s eye position and the confocal position of the measured elements is precisely positioned,and the distance between the two points is obtained by a distance measurement interferometer,then the radius can be measured accurately.The experiment is conducted with hemispherical gas-dynamic bearing as the experimental object.The theoretical analysis and experimental results show that the relative expanded uncertainty of the system is better than 20×10^-6,and the proposed measurement system provides a technical approach for high-precision measurement of curvature radius of spherical inertial elements with scattering characteristics.

关 键 词：激光共焦 曲率半径测量 球面惯性元件 抗散射 

分 类 号：U666.1[交通运输工程—船舶及航道工程]