摘要
针对集群航天器电磁编队系统强非线性的动力学特性,提出了一种基于非奇异终端滑模的有限时间控制方法。首先,建立了电磁力模型,分析了远场偶极子模型的适用范围;其次,建立了电磁编队动力学方程;接着,针对非线性动力学方程,设计了有限时间收敛的非奇异终端滑模面和控制律,使控制方法对电磁力模型不确定性具有鲁棒性,同时证明了系统状态可在有限时间内到达滑模面,而且也可在有限时间内收敛到零;最后,针对本文提出的方法进行了数值仿真。结果表明:当星间距离大于线圈半径的6.76倍时,远场偶极子模型的估计误差小于10%。基于终端滑模的有限时间控制方法相比线性二次型最优控制具有更快的收敛性能。
The finite-time control method based on non-singular terminal sliding mode is proposed in this paper for the electromagnetic formations of fractionated spacecraft on the ground test bed, which has high nonlinear characteristics. Firstly, the electromagnetic force model is established, and the scope of application of the far-field magnetic dipole is analyzed. Secondly, the nonlinear dynamics equations are derived. Then, the finite-time stable nonsingular terminal sliding mode manifold and control law are proposed, which have robustness to modeling errors. The system states can not only be controlled to the sliding mode manifold infinite-time, but also can converge to zero along the sliding mode manifold infinite-time. Finally, the numerical simulation is implemented to validate the presented control law. The results show that the far-field approximation model errors are less than 10% when the separation distance is larger than 6.76 times of the coil radius. Furthermore, the finite-time control method based on terminal sliding mode has better convergence performance than linear quadratic regulator （LQR）.
出处
《航天控制》
CSCD
北大核心
2011年第6期22-27,33,共7页
Aerospace Control
关键词
集群航天器
电磁编队
磁偶极子
远场模型
终端滑模
有限时间收敛
Fractionated spacecraft
Electromagnetic formations
Magnetic dipole
Far-field model
Ter-minal sliding mode
Finite-time convergence
