Dynamics Modeling And Control Of Integrated Spacecraft Attitude And Orbit Based On Lie Group SE(3)

The dynamics modeling and control methods of spacecraft attitude and orbit motion determine the success or failure of space missions.Attitude and orbit control play important roles in space missions such as space rendezvous and docking,target monitoring,and on-orbit service.The traditional separated modeling of attitude and orbit motion and independent control mode cannot fully consider the coupling effect of rotational and translational motion,and cannot meet the requirements of some missions for the high efficiency and high precision.As a result,the integrated modeling and control of spacecraft attitude and orbit with high efficiency and high precision are of important theoretical significance and engineering application value for spacecraft close operation mission.The modeling method and the control algorithm for the integrated relative motion of spacecraft attitude and orbit are studied in this dissertation.The main contents are as follows.(1)Considering spacecraft attitude and orbit integrated dynamics modeling and control problems,the spacecraft non-centroid dynamics of relative motion is constructed within the framework of Lie group SE(3)based on the centroid relative motion dynamics model.The configuration error of relative pose is designed based on Morse-Lyaponov function on SE(3).In addition,the rationality of this description is proved.Compared with the dual quaternion,matrix in SE(3)used to describe the pose is unique,which can avoid the unwinding phenomenon in attitude control.(2)The adaptive finite time control algorithms for the spacecraft relative pose tracking task in close range are studied.The parametric uncertainties of spacecraft and external disturbances are considered.Based on the terminal sliding mode and reaching law methods,the fast power finite-time,double power fixed-time and modified double power fixed-time control algorithms are proposed for the tracking system,in which the last one is based on a novel switched double power reaching law proposed in this dissertation.Meanwhile,the spacecraft inertia parameters and external disturbance are estimated by the adaption laws.The stabilities of the closed-loop system driven by the control laws are proved by quadratic Lyapunov function method.The effectiveness of the control schemes is verified and compared by numerical simulations.(3)For spacecraft relative pose tracking task in close range,the adaptive high order sliding mode technology applied for spacecraft control system is studied.First of all,based on the equivalent control,an improved fixed-time generalized super-twisting algorithm is proposed,and also a novel dual-layer adaption law for gain parameter.Lyapunov function method and homogeneity method are used to prove that the fixed-time convergence of the generalized super-twisting algorithm.In addition,the boundedness of the variable gain driven by the adaption law is proved.Next,the adaptive generalized super-twisting algorithm is applied to estimate the disturbance of a first-order system.The effectiveness and superiority of the proposed algorithm is demonstrated by comparing with similar methods.Then,the generalized super-twisting algorithm with variable gain is applied for the spacecraft pose tracking control system,and two control schemes are designed.One is the adaptive disturbance observer based fixed-time control scheme,and another is an adaptive fixed-time second-order sliding mode control scheme.Active disturbance rejection control(ADRC)scheme can accurately estimate the lumped disturbance and compensate effectively.The adaptive second-order sliding mode control scheme can effectively suppress the influence of various uncertainties and reduce the magnitude of control input,and thus,reducing the energy consumption.Finally,the effectiveness of the two control schemes is verified by numerical simulations.(4)For the non-centroid docking mission of two spacecrafts,the feedback control problem without velocity measurement is studied.Based on the homogeneity method,two finite-time output feedback control schemes are designed.In the first scheme,a thirdorder extended state observer based on high-order sliding mode is proposed to estimate the velocity and lumped disturbance,which is proved to possess better performances than the existing similar ESOs in theory.Then,in the framework of homogeneity theory,a second-order sliding mode active disturbance rejection output feedback controller is designed based on a nonsingular terminal sliding mode surface.In the second scheme,an adaptive velocity observer is designed based on the variable gain super-twisting algorithm.Then,a terminal sliding mode controller is designed by using the former sliding mode surface in the framework of homogeneity theory.Numerical simulations are performed to demonstrate the observation accuracy and rapidity of the two kinds of observers and their influences on the spacecraft pose closed-loop control system.(5)For the spacecraft pose tracking control task considering actuator characteristics,the optimal control problem of spacecraft relative motion is studied.First of all,according to the inverse optimal form of Sontag,a inverse optimal feedback control law with linear form is designed.Considering that the accuracy of the general inverse optimal control is not high.The terminal sliding mode is introduced to design an inverse optimal feedback control law,which will lead to a higher accuracy than the general one in theory.In addition,a disturbance observer is designed to estimate the lumped disturbance of the system and compensate in the feedback law,so as to improve the robustness of the control law.Finally,the effectiveness of the two inverse optimal control algorithms and anti-disturbance inverse optimal control algorithms are demonstrated by numerical simulations.