Ultra Short Range Approaching Navigation Algorithm For Space Non-cooperative Targets

Space non-cooperation target refers to the orbit and the state of unknown spacecraft and other space objects,its research can be applied to the reuse of abandoned spacecraft,space trash cleaning,the capture satellite and so on,in order to achieve ultra short range approaching navigation for space non-cooperative targets.In this paper,we choose the three-dimensional reconstruction around the target in the ultra-short distance segment,and carry out the relative attitude calculation process according to the picture taken around the fly.In the process of approaching the target,we use the laser scanning to obtain its point cloud data,by the registration with the 3D reconstruction result to obtain the navigation data,and then uses the extended Kalman filter to complete the process of approaching the target.In this paper,we use the three-dimensional reconstruction technique to reconstruct the three-dimensional point cloud coordinates of the target by using the RANSAC(Random Sample Consensus)algorithm and the beam method to adjust the three-dimensional weight of the target.By the use from the POSIT(Pose from Orthography and Scaling with Iterations)algorithm,the actual depth information of the target is obtained,and the relative pose information of the target and its size information are determined.Provide available data for subsequent arrests process.After obtaining the target point cloud,this paper uses the traditional ICP(Iterative Closest Point)algorithm to proceed with the geometric principle of the normal vector difference of the surface part,preprocess the point cloud with the normal vector,Vector angle relationship between the point cloud to simplify the processing,remove the redundant point,thereby improving the registration calculation speed and accuracy.And then the rough registration of the point cloud is the global registration process,which effectively adjusts the initial position of the point cloud target.The final improvement process adopts the nearest neighbor search algorithm based on k-D tree(k-Dimensional Tree)The three important properties of the k-D tree are optimized by the iterative optimization,so that the relative distance of the two points is the smallest,and the accuracy of the ICP algorithm is improved to obtain more accurate point cloud registration As a result,for the subsequent navigation process to provide more accurate data and more reliable results.Finally,in order to improve the navigation accuracy of the ultra short range task,the inertial and rotational angular velocities are obtained for the non-cooperative target of the spin-stable space.The information is obtained by thelaser scanner in the approximation process.The extended Kalman filter is used to Approximation of the navigation algorithm to simulate the filtering process.