The Recursive Method Of Satellite Attitude Dynamics And Kinematics Without Metrical Information

The thesis is based on the background of the attitude-determining task of some long-life satellite, and a short-term attitude recursion algorithm with high precision for satellites without any measuring information was studied. For long-life satellites, it cannot guarantee that the gyros can be continuously used for a long time, and the probable way is that they are used as cold standby. Therefore the short-term autonomous attitude recursion algorithm for satellites without attitude sensor and gyro measurement information was studied, thus it may decrease the dependence of the system on gyros under certain conditions(mainly for short-term invalidation of star sensor data), and it can provide attitude reference for the controller. This algorithm can also guarantee the basic target pointing for the satellite body, avoid the attitude divergence, and provide enough time for the state recovery of measuring system. Through analysis of satellite dynamics and kinematics, it can be seen that the recursion precision of attitude and angular velocity without any measuring information, is related to the precision of the satellite moment of inertia and external disturbance torque. Therefore, firstly in this thesis we derive the satellite attitude dynamics and kinematics model, and present the theoretical evidence for the attitude recursion without sensors. Secondly, we design an estimation algorithm of satellite disturbance torque based on second-order Kalman filtering algorithm, and the simulation results show that the algorithm precision is pretty good. Subsequently, the satellite angular velocity and attitude recursion algorithm without measurement information is designed according to the simplified dynamics/kinematics equations, and in the algorithm the disturbance torque is forward fed. On the basis of this algorithm, the error model and error formulae are deduced, and the influence of each error source on the precision of recursion algorithm is analyzed theoretically. At last, the mathematical simulation is conducted on the attitude recursion control algorithm for satellites without.measuring information. The simulation results demonstrate the influence of initial attitude and angular velocity error, disturbance torque, and moment of inertia error etc. on the recursion algorithm precision. It lays a good basis for the engineering application of the algorithm.