本文以空间超大幅宽低畸变红外变焦扫描成像系统为研究对象, 分析给出地面畸变与成像系统瞬时视场角的关系, 提出变速扫描成像并推导了扫描角速度公式。为解决匀速360°旋转扫描效率低和双向摆动扫描成像需安装扫描线矫正器所导致的系统复杂性高、可靠性低的缺点, 设计了一种正弦加速度快速回扫的方法。对变速扫描以及正弦加速度快速回扫方法进行了仿真及实验, 结果表明扫描控制系统慢速扫描与快速回扫之间状态切换稳定, 扫描起止角度误差仅为1.44角秒, 扫描速度稳定度为±0.5%, 扫描成像过程时间误差为83 μs, 回扫时间误差为250 μs, 整个扫描周期时间偏差小于1倍像元积分时间(355 μs), 扫描效率达86%, 在提高了扫描效率的同时减小对扫描机构的冲击与振动, 满足成像要求。正弦加速度快速回扫方法对机载红外扫描成像系统快速回扫运动设计也具有一定指导意义。

The relation between ground distortion and instantaneous field of view of the imaging system was analyzed; variable-speed scanning imaging was proposed and angular scanning speed formula was derived with infrared zoom scanning imaging system of super-swath low distortion in space as research object in this paper. Meanwhile, a kind of rapid fly-back method of sine acceleration was designed to solve the shortcomings such as low scanning efficiency of uniform 360° rotation, scanning line appliance needed to be installed for two-way swing scanning imaging and high complexity and low reliability of the system. Simulation and experiments were conducted on variable-speed scanning and rapid fly-back method of sine acceleration in this paper and the result indicates that the state shift between slow scanning and rapid fly-back of scanning control system is stable and the start and stop angle error of scanning is just 1.44 arc-second; scanning speed stability is ±0.5%; time error in scanning imaging process is 83 μs and fly-back time error is 250 μs; time deviation of the whole scanning period is less than pixel integral time (355 μs) and scanning efficiency reaches 86%, thus scanning efficiency is improved and impact and vibration of scanning mechanism are reduced meanwhile to satisfy imaging requirements. Rapid fly-back method of sine acceleration will provide a reference for rapid fly-back motion design of airborne infrared scanning imaging system.