复杂光照环境下空间目标相对位姿测量方法研究

Research on relative pose measurement method of space target in complex light environment

为解决空间复杂光照环境下可见光相机获取的图像照度不一、信息失真、特征不完整导致的目标航天器相对位姿求解困难的问题,提出了一种基于图像增强和弧段特征的双目视觉相对位姿测量方法。首先通过基于带色彩保留的多尺度Retinex(Multi-scale Retinex with Chromaticity Preservation,MSRCP)自适应图像预处理方法提升空间暗弱光、局部强曝光环境下的图像质量;然后利用基于边缘弧支撑线段的椭圆检测算法提取目标航天器表面星箭对接环的弧段特征,并拟合得到椭圆轮廓;最后利用双目相机搭建了空间相对位姿测量物理仿真实验平台,建立双目空间椭圆锥测量模型解算目标的六自由度相对位姿,实现了近距离正常光照和暗弱光照场景下目标航天器相对位姿求解。实验结果显示:在正常光照场景下,相对位置平均误差不超过±20 mm,相对姿态平均误差不超过±0.3°;在暗弱光照场景下,相对位置平均误差不超过±30 mm,相对姿态平均误差不超过±1°。研究成果为近距离空间交会对接等在轨服务任务中的目标识别与测量提供了参考,具有技术借鉴价值。

To solve the problems of difficulty in measuring the relative pose of the target spacecraft caused by differ⁃ent illumination,information distortion and incomplete feature of the image obtained by the visible light camera under complex lighting conditions in space,a binocular vision relative pose measurement method based on image enhancement and arc feature was proposed.An adaptive image preprocessing algorithm based on multi⁃scale Retinex with chromaticity preservation(MSRCP)was applied firstly to improve the image quality in the environment of spatial dim light and local strong exposure.Secondly,an ellipse detection algorithm based on the edge arc support line segment was applied to ex⁃tract the arc segment features of the docking ring on the surface of the target spacecraft and fit them into an elliptical con⁃tour.Finally,a binocular vision camera was used to build a physical simulation platform for relative pose measurement,and a binocular space elliptical conic measurement model was established to calculate the six degrees of freedom relative pose.The relative pose of target spacecraft was achieved in normal and dim light scenes at close range.The experimental results showed that the average error of relative position is less than±20 mm and the average error of relative attitude is less than±0.3°under normal lighting condition,and the average errors of relative position and pose are less than±30 mm and±1°,respectively,under dim lighting condition.The research results provide a reference for the identification and measurement of targets in on⁃orbit service missions such as close⁃range space rendezvous and docking,and have techni⁃cal reference value.