Integrated Attitude And Orbit Dynamics Modeling And Coordinated Control For Spacecraft

With the maturity and development of aerospace technology, the new space missions tend to be more complex, the requirement for spacecraft dynamics and control is getting stricter. Moreover, the coupling between attitude and orbit, the existence of external disturbance and model uncertainties make it more complicated for integrated dynamics and control of spacecraft. To solve these problems, this dissertation focuses on integrated attitude and orbit dynamics modelling and integrated control. The main researches are listed as follows.Due to the advantages of dual quaternion in describing attitude motion and orbit motion with a unified mathematical framework, the integrated dynamics modeling of spacecraft attitude and orbit motion based on dual quaternion was studied. Firstly general space movement of spacecraft is described in an integrated manner utilizing dual quaternion.Integrated attitude and orbit kinematics and dynamics of single spacecraft is established. On this basis, dynamics and kinematics modelling of relative integrated orbit and attitude are deduced. The coupling effect of attitude and orbit is analyzed in the modelling. For the situations of mas and inertia uncertainties, the disturbance caused by model uncertainties in dynamics modeling is analyzed. For the tracking control problem of spacecraft integrated attitude and orbit, a PD controller is designed, and it is proved by a rigorous theoretical analysis of the Lyapunov method that the whole resulting closed-loop system is globally and symptotically stable. Finally, simulations are performed to demonstrate the validity and effectiveness of the dynamics.For the integrated control problem of spacecraft relative attitude and orbit, based on the research of integrated attitude and orbit dynamics of rigid spacecraft, a sliding mode controller (SMC) controller is designed in the presence of model uncertainties and external disturbances. then the globally asymptotic stability was analyzed by Lyapunov method. A fast terminal sliding mode controller (FTSM) is presented to achieve the integrated attitude and orbit finite-time control of rigid spacecraft. Considering the singular problems of the controllers, nonsingular terminal sliding mode controller is designed. Moreover, it is proved by a rigorous theoretical analysis of the Lyapunov method that the coupled attitude and orbit controller can ensure finite-time convergence in the presence of model uncertainties and external disturbances. Finally, numerical simulations are performed to demonstrate the validity and effectiveness of the presented approach.If the external disturbances and model uncertainties cannot be obtained due to the complicated space environment, two adaptive control algorithms are presented to achieve integrated attitude and orbit tracking. The first control algorithm adaptive sliding mode control which does adaptive identification to the perturbation, and the second control algorithm is robust adaptive control which is independent of model parameters. The two control strategies ensure that the closed-system is global asymptotic stable and the error dual quaternion and angular velocity motor error converge to the zero equilibrium point asymptotically, and implement identification of inertia matrix. They are robust to external disturbances and model uncertainties.