航天器自主交会对接的高精度目标定位方法

A High Accuracy Target Positioning Method for Autonomous Rendezvous and Docking Between Spacecrafts

根据航天器自主式交会对接的实际应用背景和技术需求,针对交会对接过程中所要求的高精度、实时性和强抗扰的技术指标,在合作目标特性分析的基础上,将高斯曲面拟合与双线性插值相结合,提出了一种高精度的合作目标定位方法。首先根据目标图像的灰度分布进行双线性插值和高斯曲面拟合,在此过程中可同时利用目标原有像素和插值点的亚像素信息,使拟合曲面各幅值点的坐标精度达到亚像素级,以确定目标的中心位置。仿真图像和实拍图像的试验结果表明,此定位方法具有亚像素级的定位精度,其总体定位误差可达到1/20个像素左右,并能满足实时性要求,可以在航天器交会对接与空间遥操作等方面的应用中发挥重要作用。

According to the practical background and technical requirements for autonomous rendezvous and docking （ARVD）, a high accuracy target positioning method is proposed by combining Gaussian surface fitting with bilinear interpolation in view of the performance indices such as real-time and high accuracy as well as strong anti-disturbance in the process of ARVD. The analysis of target gray-level distribution is employed to carry out the bilinear interpolation and the Gaussian surface fitting in which both real target pixels and interpolated sub-pixel points can be used so that the positioning accuracy can achieve sub-pixel level for the estimation of target center position. A series of experimental results with both simulation images and real images demonstrate that the proposed method has advantages of both excellent positioning accuracy and real-time performance in that the overall positioning error can reach approximately 1/20 pixels. Therefore, the proposed method may be applied in the ARVD, space teleoperation and other relative motion fields to play a important role in engineering practices.