【作者】 陈伟；

【导师】 王惠南；

【作者基本信息】 南京航空航天大学 ， 导航、制导与控制， 2016， 硕士

【摘要】 随着航天科技的高速发展,目标航天器相对位姿测量技术在交会对接、在轨维护、空间捕获等各类航天任务中占据着越来越重要的地位。其中基于视觉的位姿测量方法具有体积小、质量轻、成本低、功耗低以及稳定性好等优点,在航天器近距离逼近阶段中得到了广泛的应用。本文对基于单目以及双目视觉的目标航天器相对位姿测量技术进行研究,旨在找到更为实用、简洁度高、实时性好、可靠性强的位姿解算算法。首先,对旋转和位移矩阵、欧拉角、四元数等传统的刚体位姿变换描述工具进行说明,然后重点介绍了马达代数这一可以统一描述位置和姿态的新型数学工具,并推导了马达代数框架下点和直线的运动模型。另外对单目以及双目视觉的测量原理进行了研究,建立了相机成像模型以及畸变矫正模型。其次,针对合作以及非合作目标航天器,分别设计了不同的位姿视觉测量方案。其中合作目标上设置有尺寸、空间位置已知的特征光点,测量时通过双目视觉对其进行识别,然后解算出位姿值;对于非合作目标航天器则提出了一种单目视觉和激光测距相结合的位姿测量方案,通过单目相机识别目标上的矩形面从而计算出其姿态值,然后通过激光测距仪获取其相对位置信息。在此基础上,本文还重点推导了马达代数框架下的合作以及非合作目标位姿解算算法,算法所需计算参数较少,简洁度高,实时性好,数值仿真实验显示其精度能满足实际测量要求,且受噪声影响较小。最后,搭建了一种基于微软体感设备Kinect的位姿测量地面演示验证平台,对所提出的非合作目标航天器位姿解算算法进行了充分的验证。更多还原

【Abstract】 With the rapid development of aerospace science and technology, relative position and attitude determination of target spacecrafts occupies a more and more important position in many kinds of space missions, such as rendezvous and docking(RVD), on-orbit maintenance and so on. Visual measurement methods are widely used in the close approximation stage of two spacecrafts, which have the advantages of small volume, low cost, low power consumption. In this paper, visual measurement technology of position and attitude determination is researched in order to find some more practical algorithms with higher concise degree, better real-time performance and higher reliability.Firstly, traditional description tools for rigid body position and attitude are introduced, including rotation and displacement matrix, Euler angles and quaternions. Then a new mathematical tool known as motor algebra is presented, which can uniformly describe the relative position and attitude of rigid body. Then motion models of points and lines descripted by motor algebra are deduced. The original three-dimensional nonlinear spiral motions of rigid body now can be expressed as a more compact linear form. Besides, principles of monocular and binocular visual measurements are studied, on the basis of which camera imaging model and distortion correction model are established.Since cooperative and non-cooperative target spacecrafts have different characteristics, this paper accordingly design different visual measurement methods for their position and attitude determination. Usually there are several pre-set light points on cooperative spacecrafts with known size and location. We use binocular vision to recognize these points and then calculate position and attitude through their pixel coordinates. As for non-cooperative target spacecraft, a new measurement scheme based on multi-sensor is proposed, using monocular camera to identify one rectangular plane on spacecraft and calculate its attitude, and using laser rangefinder to obtain its relative position. This paper also deduces two new position and attitude calculating algorithms using motor algebra, which require less calculating parameters and possesses high concise degree and better real-timing. Simulation results show that their precision can satisfy the measurement requirements.At last, this paper builds a ground platform using Microsoft Kinect for position and attitude determination demonstration, and the algorithms proposed before are adequately validated.更多还原