柔性航天器单轴姿态机动的鲁棒稳定性分析

Robust stability of flexible spacecraft during attitude maneuver

为了研究带有两帆板柔性航天器滚转姿态机动的稳定性问题,建立了该飞行器滚转运动的姿态动力学模型,并在建模时考虑了帆板的弯曲振动.利用基于二次型性能指标的最优控制理论,采用状态反馈的方法,设计了一种LQ控制律.采用灵敏度方法给出了系统的鲁棒界,即系统的确保幅值裕量和确保相位裕量.基于灵敏度方法对系统鲁棒性的分析结果和实际闭环系统的仿真结果分别验证了设计的控制律不仅可以使柔性航天器完成大角度的滚转姿态机动,而且能在相当大的参数摄动下保持系统的鲁棒稳定性.

To investigate the stability concerning reorientation of flexible spacecraft with two panels, a one-axis attitude dynamical model with consideration of bending deformations of flexible appendages was established. Based on the states feedback method and the LQ optimal control theory, a control law with flexible parameters in the control gains is presented. Analysis with the sensibility method not only indicates that the control law is able to stabilize the attitude of the spacecraft, but also manifests that the control law has the capability of keep- ing the robust stability of the spacecraft, even under the parameter perturbed with a quite large scale. Further- more, simulation results illustrate that the control law provides a satisfying robust stability for the spacecraft.