Visual Autonomous Relative Navigation Algorithm Based-on Motor Algebra for Spacecrafts
Along with the development of space science and technology, it is not a heart-stirring thing to launch a satellite successfully any more. But we pay greatly attention to space autonomous rendezvous and docking(AR&D)in space operations, such as maintaining, assembling, attacking etc. And that autonomous relative navigation is one of key technologies of these space actions. Currently, celestial Navigation System (CNS), Inertial Navigation System (INS), Global Navigation Satellite System (GNSS), such as GPS, GLONASS, GALILEO and Compass etc, and the integrations of them are some methods of autonomous navigation for space. But these methods must be depended on the high speed links of the communications network. Moreover,the precision of CNS is always worse,and can not meet the rigorous requirement of the space activities. INS can not be used for long-term space navigation applications for its errors being accumulated. High accuracy can be met by Carrier Differential Global Positioning System(CDGPS) ,but it is difficult to calculate the ambiguities of CDGPS.Fortunately, autonomous relative navigation based on machine vision is a direction all over the world currently, and is very suitable for autonomous spacecraft navigation because it has some advantages, such as low-cost,high precision,autonomous ability,easy practicality etc. However,there are some disadvantages of some relative navigation algorithms based-on machine vision, such as complicated description, huge calculation burden,and lack of real-time ability etc. Whereas,motor algebra can represent the rigid motion of 3D objects, and can calculate the rotation and translation transformations simultaneously. So it is more effective for dealing with relative navigation of spacecrafts. In this paper,on the basis of the attitude dynamics of spacecrafts and the theory of machine vision, an autonomous relative navigation algorithm for spacecrafts based on motor algebra and EKF (Extended Kalman Filtering) is proposed. Firstly, how to represent a line transform unit using motor algebra is introduced. Then, the feature line point of the line transform unit is defined. And then, on the basis of the attitude dynamics of spacecrafts and the theory of EKF, we build the state and observation equations. Finally, the simulations show that this algorithm is an accurate valid method in relative navigation of spacecrafts.
Motor Algebra Visual Autonomous Navigation Spacecrafts
Li Kezhao Yuan Jianping Yue Xiaokui
College of Astronautics,Northwestern Polytechnical University,Xian 710072
国际会议
The 11th International Space Conference of Pacific-basin Societies(第11届环太平洋国际航天会议)
北京
英文
223-230
2007-05-16（万方平台首次上网日期，不代表论文的发表时间）