带弹性附件的航天器的动力学与变结构控制

为了研究一类挠性航天器的动力学特性、姿态的稳定控制以及弹性附件振动的有效抑制问题，首先用拟坐标下的拉格朗日方法建立了中心刚体上铰接有给定数目弹性附件的航天器的准确动力学方程，然后在基于非线性和低阶模态的动力学模型基础上用变结构控制方法设计了系统的反馈控制律，使星体姿态和弹性附件的振动同时得到了有效控制。研究结果表明，这样一类系统的动力学方程为系数时变的非线性微分方程，弹性附件的低阶模态对主体的姿态运动起主要影响作用。基于非线性和低阶模态模型基础上的变结构控制律对这样一类系统具有良好的性能。

Dynamics and variable structure control of a spacecraft with elastic appendages

In order to study the dynamics, attitude stabilization control and the suppression of appendage vibration for a kind of elastic spacecraft, accurate dynamical equations were established by the Lagrangian approach using quasi coordinates for a spacecraft which contains a rigid platform and a given number of elastic appendages, and a feedback control law was then designed using variable structure control method based on nonlinear and low mode dynamical models. The numerical simulation results showed that the attitude of the spacecraft and the vibration of the appendage were both under effective control by the control law; the dynamical equations of such a system are nonlinear differential equations with time-varying coefficients, and the low mode vibration of the appendages has a significant effect on the attitude motion of the platform. The variable structure controller based on a nonlinear and low mode model performs well for such a system.