柔性航天器IPACS建模与动力学分析

利用拟坐标下的拉格朗日方程和动量矩定理,建立了带变速控制力矩陀螺群(VSCMGs,Variable Speed Control Moment Gyroscopes)的柔性航天器的能量/姿态一体化控制系统(IPACS, Integrated Power/Attitude Control System)的动力学模型,该模型适合于姿态控制律设计及VSCMGs操纵律设计.采用动量管理和VSCMGs构型选取相结合的方法,有效地避免了VSCMGs设计时可能出现的奇异问题.分析了采用VSCMGs的柔性航天器IPACS中的动力学耦合问题,并以某大型航天器为例进行了数值仿真.分析和仿真结果显示出,当VSCMGs的力矩轴接近(或陷入)奇异或进行储/放能切换时,VSCMGs都会对柔性附件造成显著影响.

IPACS modeling and dynamical analysis of a flexible spacecraft

The dynamical equations of a flexible spacecraft with VSCMGs(variable speed control moment gyroscopes) are established via the Lagrange equations in terms of quasi-coordinates and the momentum theorem.The equations are suitable for both attitude control law design and VSCMGs steering law design.Singularity may occur when VSCMGs are used for attitude control and energy storage,which is avoided effectively via momentum management and configuration design of VSCMGs.The dynamical coupling between the IPACS(integrated power/attitude control system) and vibration of flexible spacecraft with VSCMGs is analyzed.The numerical simulation for a large-scale flexible spacecraft with IPACS is carried out.The simulating results show,when either the torque axes of VSCMGs are near singularity(or enter singularity) or the power is conversed,that the motion of VSCMGs markedly influences flexible appendages.