Attitude Control For Satellite With Flexible Appendages

Since the satellite was designed with compact structure and simple configuration at early stage, satisfied attitude control accuracy can be achieved while considering the satellite as the rigid body during the design of attitude control system. However, the satellite structure is becoming more complicated and the appendage is becoming bigger in size and more in quantity in order to satisfy the modern space missions. These flexible appendages are apt to vibrate due to the attitude maneuver of satellite or external disturbance. When the low order vibration frequency of flexible appendages is approximating the band width of attitude control system, the vibration signal will enter the control system through measurement device to bring impact on the accuracy or even the stability.In this paper we study the satellite with flexible appendages first, based on satellite channel pitch control system design as an example. In order to realize the high accuracy attitude control of satellite with flexible appendages, attitude control system consisting the controller and structural filter was designed. First of all, we analysis and model the rigid body dynamics model of the satellite and the satellite with flexible attachment for detail; secondly, we design PD controller and traditional filter for pitch channel of satellite attitude control; Again, we study the uncertainty of the satellite with flexible appendages on orbit, simulated the system with frequency change. Finally, on the basis of existing theoretical work and simulation results, based on recursive least squares method, designed the adaptve filter controller. We establish a control system for satellite flexible appendages and meet mission requirements. The design of the attitude control system, even when the flexible appendage vibration frequency changed conditions, also can maintain a higher precision attitude control.