The Robust Adaptive Control Method Of Spacecraft's Rendezvous Within A Short Distance

The spacecraft rendezvous and docking technology is one kind of technologies that tracing the spacecrafts and the aircraft location in track at the same time, in order to make them operate at the same speed and then connect physically. The tech is very important in many situations, for example,in rescuing the broken satellites, travelling goods for international space-station and preparing for space war in the future. Therefore, spacecraft rendezvous and docking technology should be paid much attention. In this context, this paper focuses on the dynamic model of spacecraft rendezvous and docking technology and the control algorithms for close autonomous rendezvous.Therefore, based on our self-intersection of the different characteristics of close phase is divided into relatively close to the stage and the final approach phase,in close to the stage, based on analyzing the dynamic model of spacecraft rendezvous and docking in inertial coordinate system, and according to the characteristics of orbit control in this problem, the 3-2coordinate rotation transformation is presented, and the three-dimensional dynamic model of the relative motion between two spacecrafts in sight coordinate system is established, using vector analysis method as tool. Compared with the dynamic model in inertial coordinates system, the dynamic model in sight coordinate system has no limit on the eccentricity of the orbit of target spacecraft, that is to say, it applies to any form of target spacecraft reference trajectory, this model has general applicability.In the final approach phase, taking into account the distance between the two spacecraft close, you can ignore the impact of Earth's gravity, cylindrical coordinate system was established based on the dynamic model.This study makes a comparison of three classic spacecraft rendezvous and docking technologies for close rendezvous. Although all three methods can get the controlling aim, each has its disadvantages. The parallel- rendezvous is one kinematics method, which doesn't fully utilized the dynamics model, so the performance can't be optimal; although the corridor-rendezvous can be approximately optimal, it operates at the scheduled window and within the corridor, so it is not suitable for tracing non-cooperative target spacecraft; C-W rendezvous is an open loop control method, its capability in conquering distuebances is weak.In this research we focus on analyzing the characteristics of close spacecraft rendezvous and docking, simplifying the three-dimensional model that is presented. Considering the inevitable interferences, measurement errors and uncertainties of dynamics in flight,we present a robust adaptive control strategy for close spacecraft rendezvous and docking.The method can overcome the impacts of many interferences in spacecraft rendezvous and docking, such as non-spherical perturbations of the Earth, the third body gravitational perturbations, and solar radiation pressure perturbation.It can make the system run asymptotically stable. This strategy is simple and effective, and it can meet the accuracy requirements for close spacecraft rendezvous and docking...