Study On Feed-forward + H_∞ Loop Shaping Compound Control Of An Early-warning Satellite

The object of this dissertation is Early-warning satellite in the Space Based Infrared System.A feed-forward +H∞loop shaping compound control scheme is designed to realize a quick and highly accurate automatic tracking and pointing control of the staring camera of ballistic missiles, meanwhile in order to compensate the disturbing torques generated by the scanning camera.A dynamics model is established by employing the Lagrange method. Aiming to tackle the problem of modeling uncertainty and disturbance uncertainty with the early warning satellite system, the theory of H∞loop shaping is employed to design a satellite attitude controller, the robust stability of which is meanwhile analyzed with the method ofμanalysis. Mathematical simulation demonstrates that the H∞loop shaping controller designed is not only of robust stability but of high control accuracy and efficiency.The staring camera operating modes were analyzed, based on the research of the rule the staring camera follows when tracking the ballistic missiles. A pointing control scheme of the camera is designed. A H∞loop shaping feedback controller is designed based on the dynamics model which is established by DQ transformation, the robust stability of which is meanwhile analyzed. Verify the camera tracking and pointing system can track the ballistic missile quickly and accurately.Aiming to tackle the problem of the scanning movement of the scanning camera on the early-warning satellite will have periodic disturbance on the system, a feed-forward controller that can compensate the disturbing torques generated by the scanning camera is devised according to the law of conservation of momentum. A feed-forward +H∞loop shaping compound control scheme is designed. As proved by mathematical stimulation, this feed-forward +H∞loop shaping compound control scheme not only possesses robust stability, but also can effectively compensate the disturbance generated by the scanning camera. The compound control scheme realize a quick and highly accurate automatic tracking and pointing.