Relative Attitude Dynamics And Control In Satellite Formation Flying

This thesis mainly studies on the dynamics and control issues of relative attitude in formation flying, aiming to provide some useful theoretical reference for the practical applications of satellite formation flying.This thesis firstly presents some orbit design reference criteria for the accompanying satellite in formation flying, which is based on the research of formation relative configuration. These guidelines are only applied to the ideal formation, in witch the satellites's orbits are near circular and perturbation effects are not considered. The eccentric elliptical orbits and non-ideal situation is not involved.For the situation that accompanying satellite tracks and observers target satellite, the desired attitude of the accompanying satellite is uncertain, if there are no other tasks restrictive conditions. Therefore, more restrictive conditions are needed to plan and design desired attitude. The thesis determines the desired attitude by two ways. One is based on orbit informations and the other is based on relative orbit information. In these processes the constraint of angular velocity and the constraint of quaternion are added respectively. Forthermore, the thesis researches the attitude dynamics and control when the task requires that the solar panel face to the sun as much as possible. Similar research methods can be used in the formation application, which requires a satellite comunicate two satellite at the same time. Cotrol law based on quaternion is adopted to achieve long duration, large angle attitude tracking maneuver. Lyapunov stability theory was used to prove the asymptotic stability of the closed-loop control system.For the situation of relative attitude maintaining consistency in formation flying, the quaternion feedback control law is still available. If the differences of attitude angle and the angular velocity between the chase satellite and the target satellite are small enough, it can be thought approximately that the relative attitude kinematic equations are decoupling. The control law can be designed under the premise mentioned above, such as the use of linear-quadratic design method.To observe a specific surface of the target satellite, the chaser satellite must perform the attitude and orbit tracking control at the same time. The thesis developed relative orbit and relative attitude dynamics equations, and an effective control law. Further, considering the uncertainty of inertia, an adaptive control method is developed to obtain the correct inertial ratio.The thesis presents a strategy for triangular formation configuration. Relative orbit and attitude joint control ensures that the distance between the satellites would remain unchanged. Because of the characteristic of triangular structure, a triangular formation configuration is maintained. But this approach does not guarantee that the formation does not change the overall direction.Finally, the thesis holds a preliminary discussion on attitude passive stability of the solar sail spacecraft in the plane situation. The asymmetric structure of the solar sail is designed. Simulation proves that the structure can make the solar sail attitude to be passive stable on the spiral trajectories.