高分辨率视频摄远物镜光学系统设计及成像实验

Optical System Design of High Definition Video Telephoto Objective and Its Imaging Experiment

为了满足斜拉桥拉索表面缺陷的远程检测要求,基于摄远型物镜结构原理设计加工了高分辨率视频摄远物镜光学及机械系统。根据物方300 m外分辨4 mm线宽的分辨率要求,按照焦距f′=320 mm计算,确定摄远物镜像方分辨率为234 cycle/mm。选择适当初始结构,用光学设计软件OSLO进行焦距缩放、替换玻璃、减少镜片等多步骤优化,最后得到相对孔径为1/5.7、视场角为2ω=1.379°、分辨率达到250 cycle/mm的摄远物镜光学结构。合理设计光机结构,加工装调实验样机。分辨率测试实验证明其实际物方分辨率可以达到300 m远分辨4 mm线宽。在斜拉桥工程现场成像实验表明该系统符合实际工程结构表面缺陷远程检测的要求。

In order to satisfy the remote detection requirements for the surface defects on the cables of cable stayed bridges, an opto-mechanical system of a high definition video telephoto objective is designed and manufactured. According to the objective definition requirement of 4 mm at the distance of 300 m, the imaging definition of 234 cycle/mm with a focal length of 320 mm is determined. A proper initial configuration is chosen, and then some optimization procedures are carried out with the optics design program OSLO, including the focus zooming, glass exchanging, lens reduction, etc. Finally an optical configuration of the telephoto objective is obtained with the relative aperture of 1/5.7, the field angle of 2 ω =1.379°, and the definition of 250 cycle/mm. The opto-mechanical structures are designed rationally and the experimental objective is manufactured. The definition testifies that its actual objective definition reaches 4 mm at the distance of 300 m. The site imaging experiment results at the location of a cable stayed bridge show that this system satisfies the remote detection requirements for the surface defects on the real engineering structures.