Attitude-Orbit Coupling Dynamics And Adaptive Control Of Spacecraft Based On Dual Quaternion

With the continuous development of aerospace technology and the increasing complexity of space missions,higher requirements are placed on the dynamic modeling and precise control of spacecraft.The traditional spacecraft attitude and orbit control is to model the spacecraft attitude motion and orbit motion separately,and then design the corresponding control method according to the different space tasks performed by the spacecraft.Although this modeling and control method meets some space missions with low accuracy requirements,it cannot meet its accuracy requirements when performing tasks such as rendezvous and docking,space formation branches,and satellite on-orbit services.Aiming at this problem,this paper establishes a spacecraft attitude-orbit coupling dynamics model based on the dual quaternion method,and studies the spacecraft adaptive control method based on this model.The main research contents are as follows :(1)Firstly,the characteristics and methods of describing the spatial motion of rigid body by dual quaternion are studied,and its general dynamic equation is derived by dual quaternion.On this basis,taking the space approaching motion of two spacecrafts as the background,the dynamic model of spacecraft attitude-orbit integration is established based on dual quaternion.Aiming at the problem of attitude-orbit coupling in the model,the attitude-orbit coupling characteristics are analyzed.(2)Based on the spacecraft attitude-orbit coupling dynamic model,a PD-like controller is designed.The asymptotic stability of the control law is proved by Lyapunov theory.The controller is simulated in the background of spacecraft rendezvous and docking.In order to further improve the robustness and control effect of PD control,fuzzy control is used to further optimize the fixed parameters of PD controller,and fuzzy rules are designed according to the actual control requirements.Finally,the control time and robustness of the two control methods are compared by simulation.(3)Two adaptive tracking controllers are designed for the uncertainty of parameters such as mass and inertia of spacecraft in space rendezvous and docking tasks.Firstly,considering the constant disturbances such as gravity and gravity gradient torque and unknown external disturbances,an adaptive control law considering external disturbances is designed,and the stability of the closed-loop system is verified based on Lyapunov method and Barbalat theory.Considering that the above adaptive control law formula is more complex and the calculation is cumbersome,an adaptive control law based on parameter adaptive identification is designed.Finally,two adaptive controllers are simulated to verify the robustness of the designed controller.