一种大视场高分辨率的复眼光学系统设计

Design of large field of view and high-resolution compound eye optical system

针对传统无人机载成像系统无法实现大视场与高分辨率共存的问题,设计了一款大视场高分辨率无人机载复眼相机系统,该相机由曲面子眼阵列、光学中继系统和图像探测器三部分组成。中继系统使用了非球面设计,减小了系统体积。单个子眼焦距为20 mm,视场角为10°,中继系统为一鱼眼透镜,焦距为7 mm,可将子眼阵列所成焦曲面像转为平面像。总系统视场达到122°×106°,F数为3,焦距为3 mm,在飞行高度1 000 m时对地分辨率为0.8 m。仿真结果显示,各个光学子通道调制传递函数(modulation transfer function, MTF)在208 lp/mm处均大于0.3,系统在给定的公差范围内像质能够满足要求。与现有无人机载复眼系统相比,该文设计的系统视场更大,分辨率更高,且体积更小。

To address the problem of traditional unmanned aerial vehicle(UAV)imaging systems being unable to achieve the coexistence of large field of view and high resolution,a large field of view and high-resolution UAV-borne compound eye camera system composed of a curved sub-eye array,an optical relay system and an image detector was designed.The non-spherical design was used for the relay system to reduce the system volume.Each sub-eye had a focal length of 20 mm and a field of view of 10°.The relay system used a fisheye lens with a focal length of 7 mm to convert the curved focal surface formed by the sub-eye array into a planar image.The overall system had a field of view of 122°×106°,an F-number of 3,and a focal length of 3 mm,achieving a ground resolution of 0.8 m at a flying height of 1000 m.The simulation results show that the modulation transfer function(MTF)of each optical sub-channel is greater than 0.3 at 208 lp/mm,and the image quality of the system meets the requirements within the given tolerance range.Compared to existing UAV-borne compound eye systems,the proposed system offers a larger field of view,higher resolution and smaller size.