Research on the strategy method for the final translation phase of space autonomous rendezvous

In this paper, a Multi-mode switching guidance control strategy is proposed for the final translation phase space autonomous rendezvous and docking precision-guided control problem. Firstly, dynamic model for spacecraft rendezvous is established and analyzed under the target coordinates. Secondly, the final translation phase is divided into two parts, constant speed translation phase and inconstant speed translation phase. In the constant speed phase, PID controller is used for ensuring control precision. Considering the uncertainty and nonlinear characteristics of the system, a fuzzy controller is designed to realize the precise guidance for inconstant speed translation phase. The whole control process is based on the error threshold control method to reduce fuel consumption. The simulation results demonstrate the effectiveness of the proposed guidance control strategy. Finally, the method of converting the continuous control law into the relay-type control law is discussed. The relay-type control law is easier to realize in engineering application.