基于PSD和光源调制的合作目标位姿探测方法

PSD and light source modulation based cooperative target pose detection method

摘要:

空间目标的相对位置与姿态探测是航天器对接领域的研究重点，探测方法主要分为遥测法和光学测量法两大类.其中，后者依靠其速度快、稳定性高、信息量大等优势，成为了近距离位姿探测的主要方法.我们通过双目视觉模型可计算出空间合作目标上特征光点深度信息，再根据特征光点间已知的结构、尺寸等约束信息，实现对目标姿态的解算.本文依据PSD相较于CCD和CMOS传感器，有无需图像特征提取过程、响应速度快、位置分辨率高等优势，且双目立体视觉系统的仿生学结构可直接获取到探测目标的深度信息，提出了采用双PSD视觉模型，并配合特征光点的亮度与顺序联合调制实现对空间合作目标的位姿探测方法.实验结果表明，当光标靶姿态调整±30°时，系统的平均测量误差为2.541°，当姿态角小于15°时，俯仰角和偏航角的平均偏差分别为0.923°和0.563°；大于15°时，受限于光源发散角度的影响，俯仰角和偏航角平均偏差分别增加至4.566°和4.106°，系统能够快速、稳定解算光标靶的空间位姿.

Abstract:

The relative position and attitude detection of space targets is the focus of research in the field of spacecraft docking, and the detection methods are mainly divided into two categories: telemetry and optical measurement methods. Among them, the latter has become the main method for close-range position and attitude detection relying on its advantages of high speed, high stability and large amount of information. The depth information of the characteristic light points on the spatially cooperative target can be calculated using the binocular vision model, and the target attitude can be obtained based on the known structure, size and other constraint information among the characteristic light points. The PSD has the advantages of having no image feature extraction process, responding fast and having high resolution for positions, compared with CCD and CMOS sensors, and the bionic structure of binocular stereo vision system can help directly obtain the depth information of the detection target. Therefore, this paper proposes a dual PSD vision model with joint modulation of luminance and order of feature light points to achieve the positional detection method of spatial cooperative targets. The experimental results show that the average measurement error of the system is 2.541° when the attitude of the cursor target is adjusted ±30°. The average deviation of the pitch angle and yaw angle are 0.923° and 0.563° when the attitude angle is less than 15°. The average deviation of the pitch angle and yaw angle increase to 4.566° and 4.106° when the attitude angle is larger than 15°, restricted by the divergent angle of the light source; the system can quickly and stably solve the spatial attitude of the cursor target.