激光差动共焦反射式超大曲率半径测量系统研制

Development of laser reflection differential confocal ultra-large radius measurement system

针对球面超大曲率半径测量中存在的测量精度低、抗环境干扰能力差的难题,研制了一套激光差动共焦反射式超大曲率半径测量系统。该系统采用反射式测量光路,利用差动共焦响应曲线对被测件的猫眼和反射位置进行高精度定位,并用测长干涉仪记录位置信息,最后结合物镜顶焦距解算出超大曲率半径值。理论分析与实验表明,该系统定焦精度高,测量范围大,抗环境干扰能力强,相对测量误差优于2×10^-4,-15 m超大曲率半径测量结果的重复性可达1.2×10^-4,实现了超大曲率半径的高精度测量。

To solve the low measurement accuracy and poor resistance to environmental interference in the ultra-large radius measurement field,a laser reflection differential confocal ultra-large radius measurement system is developed.The system adopts reflective measuring optical path,and uses the curve of the differential confocal system to precisely locate the cat's-eye and reflection positions of the tested device.The displacement information of the tested device is recorded by interferometer,and then combined with the vertex focal length of the objective lens to calculate the ultra-large radius value.Theoretical analysis and experimental results show that the system has high focusing accuracy and large measurement range and high anti-environment interference ability,and its relative measurement error is less than 2×10^-4,and its measuring repeatability reaches at 1.2×10^-4 for-15 m ultra-large radius,and the system realizes the highprecision measurement of ultra-large curvature radius.