Robust Control Research On Attitude System Of A Three-Axis Angular Momentum Wheel Satellite

This thesis describes the attitude control system for the three-axis zero momentum stabilization satellite with flexible solar panel. Thus, with the purpose of improving the control system performance and technology, robust control theory has been applied to obtain some new methodologies for attitude control design. The main research in the thesis is as following:Firstly, the model of the attitude control system is obtained. The attitude kinematics model of the satellite is developed employing Euler-angler representations and coordinate transformation. According to the law of angular momentum, the attitude dynamics model of rigid satellite is obtained. Based on the result of finite elements analysis, the attitude dynamics model of the flexible satellite is obtained. Transform functions of both the constraint and non-constraint model with collocated sensors and actuators are derived.Secondly, the controller is design by robust control theory. The attitude dynamics model of the satellite with flywheel is derived. Based on the reasonable assumption, the simplified model for the pitch loop is given. By H∞control theory, both the robust stability and the disturbance rejection performance are considered in the standard H∞control problem. The synthesis of a suitable H∞controller, using a composite weighting function is described.Finally, satellite control system, which is studied by simulation eventually, is analyzed for further research. Based on the method of singular value decomposition, the robust stability and the disturbance rejection performance of the attitude control system have been analyzed. The pole-zero cancellations in the controller design is discussed. Classical PID controller for the pitch loop is designed. The attitude control system with the H∞controller or PID controller is studied by simulation in the case of a variety of parameter perturbations. Based on the simulation results, comparison and analysis has been made between H∞controller and PID controller from the perspective of qualitative and quantitative.