Research On Attitude Control Method Of Relative Motion In Space Rendezvous And Docking

With the deepening of research on space rendezvous and docking technology,the study of high-precision,high-stability spacecraft relative motion attitude control methods plays a crucial role in completing the spatial rendezvous and docking task.This paper takes the spacecraft rendezvous and docking as the subject background,conducts research on the field of relative motion control of the rendezvous and rendezvous,and proposes three control methods that can stabilize the relative attitude of the spacecraft.Firstly,the relative motion attitude control model for the spacecraft’s rendezvous and docking relative motion is established.The fundamental theories of stability,the precise robust differential theory,the particle swarm optimization algorithm,and the basic design ideas of sliding mode control are introduced.Then,based on the non-singular fast terminal surface(NFTSM),three controller design schemes are proposed.The dynamic sliding mode controller combines the linear sliding mode with the non-singular fast terminal sliding mode and eliminates chattering by integrating the symbol function.Simulation shows that this method can achieve relative attitude control stability,but there is still a certain degree of buffeting.And the design process shows that the method has some limitations.On this basis,a new non-singular fast terminal sliding mode surface is proposed and a corresponding controller is designed.The simulation results show that the controller can achieve better control effect than the dynamic sliding mode controller.Considering that the spacecraft relative attitude control system is a hierarchical system,combining with the characteristics of non-singular fast terminal sliding surface,the third controller is designed by using Backstepping method to design a simple controller.Simulation experiments prove the correctness and superiority of the controller.Finally,a comprehensive comparative analysis of the three controllers presented in this paper is made.Using the reference evaluation index as a standard,a comparative analysis of convergence speed,error accuracy,and anti-jamming capability of the three controllers is performed.The results show that the controller combined with Backstepping and non-singular fast terminal sliding mode has the best performance.At the same time,it is pointed out that excessively pursuing the optimal reference evaluation index will lead to a slower system convergence rate,and an appropriate increase in this index will result in a better control effect.