UAV-Mounted Small, Large-Field, High-Resolution Curved Compound Lens Design

文章设计了一款适用于无人机载高性能成像的曲面复眼相机系统，兼具大视场、高分辨率和小型化特点。系统由曲面子眼阵列、中继转像系统和平面接收器组成，子眼焦距为12 mm，半视场角为6˚，中继转像系统焦距为8 mm，搭载像元尺寸为3.75 μm的传感器。中继转像系统的引入使得各子眼参数完全一致，并将曲面子眼阵列的曲面像转化为便于平面接收器接收的平面像。系统总视场达到112˚，体积仅为60 mm × 60 mm × 72 mm，F数为3.5，焦距为3.75 mm。在对地距离500 m的高空拍摄时，地面分辨率达到0.5 m。仿真结果表明，系统各视场子眼在奈奎斯特截止频率处的MTF值均大于0.3，并满足光学成像系统公差表“Q5”等级要求。最后经过仿真分析验证，系统在−20℃至50℃温度区间内可以正常工作。与现有无人机载相机系统相比，该设计在实现更大视场和更高地面分辨率的同时大幅减小了系统体积，为无人机载相机的高性能成像提供了创新解决方案。In this paper, a curved compound eye camera system suitable for UAV-borne high-performance imaging is designed, and it has the characteristics of a large field of view, high resolution, and miniaturization. The system consists of a curved sub-eye array, a relay image system, and a planar receiver, with a sub-eye focal length of 12 mm and a field of view of 6 degrees, and a relay image rotation system with a focal length of 8 mm, and a sensor with a pixel size of 3.75 μm. The introduction of the relay image rotation system makes the parameters of each sub-eye completely consistent and transforms the surface image of the curved sub-eye array into a planar image that is convenient for the plane receiver to receive. The total field of view of the system reaches 112˚, the volume is only 60mm × 60 mm × 72 mm, the F-number is 3.5, and the focal length is 3.75 mm. In aerial shooting at a distance of 500 meters, the ground resolution reaches 0.5 meters. The simulation results show that the MTF values of each field of view eye of the system at the Nyquist cut-off frequency are all greater than 0.3 and meet the requirements of the “Q5” level of the tolerance table of the optical imaging system. Finally, the simulation analysis verified that the system can work normally in the temperature range of −20˚C to 50˚C. Compared with the existing UAV-borne camera system, this design achieves a larger field of view and higher ground resolution while significantly reducing the system size, providing an innovative solution for high-performance imaging of UAV-borne cameras.