Research On Autonomous Rendezvous And Docking Technologies For Micro-Satellites Space Station

Autonomous Rendezvous and Docking (ARD) for spacecrafts is achieved by autonomous navigation, guidance and control methods. Profiting from the development of ARD technologies, On-orbit service has come out as a new research area recently. A new type of distributed satellite system named as Micro-Satellites Space Station (MSSS) is proposed based on such background. With respect to the requirement of docking, storage and separating for daughter-satellites, a novel ARD system for MSSS is presented, analyzed and validated in this paper. The research includes the contents as follows:In general, the key modules of ARD technologies for MSSS are mentioned and the programming scheme for developing procedure is also given.Deriving from the traditional“probe-cone”structure, a“serial-perch”docking mechanism is developed to carry out loading, storing and undocking functions. A parameterized virtual prototype is numerically simulated for demonstrations of mechanism performance focusing on error tolerance. By analysis of simulation results, a conclusion about the trade-off between docking period and impact energy when selecting the approach velocity is obtained, together with the primary factor leading to invalidation and the optimization strategy accordingly.The dynamic control problem during the final approach period is researched by LOS visual navigation system and orbit-attitude associated control method. Due to the wide tolerance of docking mechanism, a loosened control precision results with a simple and practicable control law based on Lyapunov stabilization theory. The coupling effects of orbit and attitude control output are also considered.Numerical simulations for relative orbit control during the final approach period are accomplished by Matlab and STK. The results show that V-Bar and R-Bar approach methods both satisfy the tolerance requirement of“serial-perch”docking mechanism. Comparisons of the two methods are also mentioned. The simulations for relative attitude control provide a validation for precision demands of orbit control and docking mechanism. Otherwise, feedback parameters can be optimized to result in a lower consumed energy. In addition, adequate precision margins have been added for both position and attitude, ensuring the reliability of whole system.This paper constitutes one of the important technologies for Micro-Satellites Space Station. It could also be used as reference for research of on-orbit services and distributed space tasks.