一种重力梯度小卫星实时姿态控制方法研究

重力梯度卫星是一种利用重力梯度力矩来实现对地定向的卫星.它在达到重力梯度稳定之前还需要消旋、重力梯度捕获等过程,需要一定的主动控制.本文针对重力梯度小卫星的动力学特性,在卫星本体坐标系下建立了数学模型.考虑到小卫星的质量和功耗限制,选取了功耗、质量较小的磁力矩器作为控制手段.依据当地的地磁场强度调整磁力矩器磁矩大小,从而产生相应的磁力矩对卫星进行主动控制.依此方法,在Matlab/Simulink中建立模型进行仿真运算.在对仿真结果进行分析的基础上加入星载计算机实物进行半物理实时仿真.仿真结果表明,这种控制方法可以满足重力梯度小卫星所需要的主动控制要求.

Real-time Attitude Control for Gravity Gradient Micro-satellite

Gravity gradient micro-satellite is a kind of satellite that orientates itself with respect to the earth using gravity gradient moment.Before reaching the state of the stability of gravity gradient, active control is required for the micro-satellite to complete gravity gradient capturing and dumping of the angular velocity.In view of the dynamics of the gravity gradient micro-satellite, a mathematical model of the micro-satellite in a body fixed frame is proposed.The magnetic torque is chosen as the executor which has a small mass and needs a low power.The magnetic torque is adjusted with the local geomagnetic intensity and the micro-satellite will obtain the active control torque.According to the result of mathematical simulation, the real-time on-board computer is used in the hardware-in-loop simulation.The result of semi-physical simulation shows that the method can be used for the gravity gradient micro-satellite.