含热诱发扰动的挠性卫星L_1自适应控制

L_1 Adaptive Control of Flexible Satellite with Thermally Induced Disturbance

为了揭示挠性帆板的热诱发运动机理及其对卫星本体姿态机动的影响,采用拉格朗日能量法建立了主刚体带挠性梁模型受到突加热流时系统的动力学模型,分析了帆板热诱发运动的特性。假设系统的模型参数未知,设计了L1自适应控制器,仅卫星的姿态角和姿态角速度作为反馈量,将帆板热致振动和变形作为未建模动力学特性,实现卫星考虑帆板热扰动力矩的快速姿态机动控制。数值仿真结果表明,环境温度突然变化引起的帆板运动包括准静态变形和振动两部分,同时引起的姿态误差也包括常值偏差和姿态振动,所设计的控制器在系统考虑热引起的扰动时仍可以有效地实现卫星的快速姿态机动,且系统各阶挠性模态稳定,参数估计收敛。

To find out the principle of thermally induced motion of solar panel and its effect on satellite attitude maneuver,the dynamics model of the rigid body with a flexible beam suffered to sudden heat flux is established by using Lagrange method and the thermally induced motion of the panel is also analyzed. Given that system parameters are not known,L1 adaptive controller is designed by using only attitude angle and attitude rate as the feedback signals and the thermally induced distortion and vibration as the unmodeled dynamics. The satellite attitude angle maneuver under the thermally induced disturbance can be performed. Numerical simulation results show that solar panel’s motion contains quasi-static distortion and vibration and the attitude error including constant steady state error and attitude vibration,under the condition of sudden surrounding temperature change. The attitude maneuver can be accomplished rapidly by using the designed L1 adaptive controller in the presence of thermally induced disturbance. And flexible modes of the panel are stable and system parameters converge to a stable state.