FAST反射面单元铝合金背架高精度拼装技术

High-precision assembling technique for aluminium alloy backing structure in FAST reflector units

国家天文台500m口径球面射电望远镜FAST主动反射面基准面是一个口径500m、半径300m的球面,由主体支承结构、促动器、反射面单元组成.本文从反射面单元工装定位、螺栓紧固控制、拼装精度控制、测量技术等重点着手,深入分析解决了铝合金背架拼装难点,总结研发了小拼单元面形数字化(智能化)摄影高精度拼装方法.本工程摄影测量自动化、智能化的高效应用成功解决了反射面单元高精度拼装快速测量的难题,确保了FAST项目能够顺利完成实施,也可为同类大型钢结构建筑的施工提供参考.

The active reflector datum of FAST（Five-hundred-meter Aperture Spherical Telescope）is a sphere with a diameter of 500 meters and a radius of 300 meters.It is composed of primary supporting structure,actuators and reflector units.Key points including tooling positioning of reflective surface,bolt fastening,assembling precision control and measurement technique are analyzed in this paper,so as to solve the difficulties in assembling the aluminium alloy backing structures.The assembling method which utilizes the digital intelligent photography to control the unit shape is investigated.This method is automatic,intelligent and efficient,so that rapid measurement with high precision for reflector units is successfully achieved.As a result,the aluminium alloy backing structure for the FAST project is constructed successfully.The method discussed in this paper also provides reference for similar large steel structures.