高精度亚像素显示技术动态天体模拟器

摘要

为了解决常规姿态敏感器非在轨标定设备实测结果与设计精度存在偏差、且缺乏模拟目标天体特征功能的实际问题,本文提出一种利用多棱镜结合的LCOS光学拼接方式与亚像素显示技术相结合的高精度动态天体模拟器设计方法,实现对星点位置以及目标天体特征的精确模拟.详细论述了传统LCOS拼接形式两片光阀对比度低的原因,提出了基于两片PBS和两片半反半透镜的拼接架构改进方案;设计了小畸变、复消色差的高成像质量准直光学系统.重点阐述了亚像素显示技术的思想及方法,利用亚像素技术分别对动态星图和目标天体进行仿真并进行了实验测试.结果表明:模拟器的两片LCOS显示对比度相同,动态星图的星间角距误差小于±6″、星等模拟范围达到连续8个等级、星等模拟精度优于±0.3mV;可以提供目标天体特征模拟图片.高精度亚像素显示技术动态天体模拟器消除了LCOS显示对比度差异,达到了姿态敏感器识别特征点的准确性要求,基本可以满足敏感器非在轨精度标定与功能测试的要求.%For general attitude sensors ,there is a deviation between the actual measurement results and design precision of non-on-orbit calibration equipment .In addition,they lack the simulation function for the target celestial body''s characteristics .In this work ,we combined a polarization splitting prism and semi-reversing semi-transparent prism to complete liquid crystal on silicon (LCOS optical splicing manner.With sub-pixel display technology,in which many pixels were used to express one feature point,a high-precision dynamic celestial simulator was designed for solving the problems mentioned above.First,the reasons for the low contrast ratio of two light valves in the traditional LCOS splicing manner were described in detail .Then,the improvement plan for the splicing structure was put forward .Subsequently,an apochromatic collimation optical system with small distortion and high imaging quality was designed.Furthermore,ideas and methods of sub-pixel display technology were investigated Finally,sub-pixel technology to conduct simulate a dynamic star map and target celestial body was employed .The results show that the contrast ratio of the LCOS splicing screen of a dynamic celestial body simulator,w hich can simulate a target celestial body,is high .Moreover ,the angular travel error between two stars in the dynamic star map is less than ± 6".In addition,the stellar magnitude simulation context reaches eight continuous grades.The stellar magnitude simulation precision is better than ± 0.3 mV.The results meet the precision requirements for feature point recognition of an attitude sensor .The high-precision dynamic celestial simulator may meet the basic requirements for ground precision calibration and functional testing of a sensor.