双电磁航天器编队构型保持自适应控制

电磁航天器编队飞行是指利用若干个航天器之间的电磁力进行相对运动控制的新型编队飞行.分析了两颗电磁航天器编队飞行的相对运动的基本原理,基于能量消耗均衡性的考虑,给出了根据控制力求解其控制磁矩的解析解.基于极坐标建立了电磁航天器非线性相对运动动力学模型,从外界不确定干扰力和电磁计算模型的远场近似两个角度,分析了该动力学模型的参数不确定性.针对编队构型保持问题以及参数不确定性,设计了近地圆轨道上两颗电磁航天器编队构型保持的自适应控制律并进行了数值仿真分析.仿真结果表明:相对运动模型和自适应控制律是有效的,编队构型能够收敛到期望值,同时对不确定参数进行了准确的估计,说明利用星间电磁作用进行航天器编队构型保持是可行的.

Adaptive control for two-spacecraft electromagnetic formation keeping

Electromagnetic spacecraft formation flying is a new type of spacecraft formation using electromagnetic forces between spacecraft to control relative motion. Primary principles of the relative motion of a two-craft electromagnetic formation were discussed. Analytical solutions of control magnetic moments according to commanded control forces for the case of two-spacecraft electromagnetic formation were developed considering the energy consumption equilibrium. Nonlinear relative motion dynamic models for a two-spacecraft electromagnetic formation were derived based on polar coordinates. Parameter uncertainties of the equations because of the approximation of the electromagnetic model and unknown disturbed forces were analyzed. Nonlinear adaptive feedback control laws for formation keeping were then designed, and the closed-loop dynamic procedure of a two-spacecraft electromagnetic formation in a low earth circular orbit was simulated. Results indicate that the relative motion equations and the adaptive control laws are valid. The formation can effectively converge to desired states and the unknown parameters are estimated accurately. The simulations demonstrate that electromagnetic forces between spacecraft can be used to realize spacecraft formation keeping and the electromagnetic formation flying is feasible.