基于星体边缘和轨道投影的光学自主导航算法

Optical Autonomous Navigation Algorithm Based on Astral Edge and Orbit Projection

针对光学导航中存在的通过星体(球体)图像部分边缘点拟合椭圆参数计算轨道参数产生中间误差的问题,提出利用边缘点映射轨道参数的直接投影模型,避免拟合椭圆参数的方法。在小孔成像模型基础上,建立了边缘点与轨道参数的直接投影数学模型,对其映射过程进行了理论推导,利用列文伯格-马夸尔特迭代算法进行求解轨道参数。用实际探测器以及镜头参数进行数值仿真验证,结果表明:该方法在相同边缘点的条件下,轨道精度可以达到5‰。与传统方法相比,这种方法避免了椭圆的拟合过程,减少了引入中间误差过程。

In order to solve the problem of calculating the orbit parameters with elliptic parameters fitted by partial edge point in the target image in optical navigation(sphere),a direct projection model of orbit parameters mapped by edge points is proposed to avoid the fitting of parameters.Based on the pinhole imaging model,the direct projection mathematical model of the edge points and the orbit parameters is established.The orbit direct projection model is theoretically deduced.And the Levenberg-Marquard algorithm is used to obtain the orbit parameters.The simulation results show that the orbit accuracy can reach 5‰ under the same edge points.Compared with the traditional method,this method avoids the ellipse fitting process and reduces the intermediate error process.