Research On Attitude Determination And Control For On-orbit Servicing Integrated Platform And Design For Relative Measure System On Ground Experiment

For the designs of guidance, navigation and control system for on-orbit servicing, key techniques of optimal attitude evaluation, steady attitude control and relative measure in the final access phase are studied. The main achievements obtained in this dissertation are as follows:The modeling of attitude dynamics for the on-orbit servicing integrated platform is researched by using quasi-coordinate Lagrange method. A six degree-of-freedom mathematical model of the spacecraft with a center rigid body and solar paddles is built. A rigid/flexible coupled and pure rigid dynamics models are built according to conditions of different hypothesizes. The specific applications are analyzed and the calculation model of space disturbance torques is introduced.The problem of optimal attitude evaluation for on-orbit servicing integrated platform is researched. The essential of attitude determination problem for on-orbit servicing integrated platform is analyzed and the simplified attitude determination model is obtained. The sensor scheme with gyro and star-sensor is designed. The optimal attitude evaluation technology for the integrated platform is researched by extended Kalman filter. The error modeling of the gyro drift is introduced and the state equations of error evaluation are improved. Finally, the simulation results verifies the feasibility.A new attitude control conception named"decentralized cooperative control"for the on-orbit servicing integrated platform is proposed. The attitude dynamic model for the integrated platform is built. The basic concept of"decentralized cooperative control"is proposed, the command allocation bases and rules of cooperative control for integrated rigid platform are studied. The flywheel control laws and magnetic unload control laws of attitude control system are improved. The problem of eliminating precession and nutation for attitude control system is solved. Simulations analyses of attitude control law, convergence control scheme and cooperative control scheme for integrated platform shows the proposed scheme is reasonable and feasible.For the final access phase of on-orbit servicing integrated platform, a relative integrated navigation system fusing a MEMS-based Inertial Measurement Unit and a Vision Sensor System is designed. The basic component and the main theory of MIMU/Vision integrated navigation system are described. The 3-DoF relative navigation model of MIMU/Vision integrated navigation system is derived, in which the error modeling of the gyro drift is improved according the experimental analytical results. Considering vision sensor time delay, a new data synchronization method is proposed. A new laboratory test-bed for the ground experiments of on-orbit servicing is introduced, on which the integrated navigation algorithm is demonstrated. Finally, the numerical simulation and experiment results verifies the availability and feasibility of the MIMU/Vision integrated navigation system.