无阻力双星串行编队相对位置有限时间控制

研究无阻力卫星构成的双星串行编队相对位置的有限时间控制问题。首先，选取两颗卫星位置连线中点为参考坐标系原点，考虑J2摄动项，建立了双星相对位置的动力学模型。与传统的主从式卫星编队模型中假设主星为理想运动不同，本文的建模方法同时考虑了两颗卫星受到扰动的情况。而后，为使无阻力卫星编队相对位置快速达到期望状态，采用自适应参数更新律和加幂积分技术设计控制律，实现了闭环系统的实际有限时间稳定。最后，通过数值仿真校验了本文控制器的有效性和鲁棒性。

Finite Time Relative Position Control for Drag Free Dual Satellite Serial Formation

Relative position control for a serial-formation formed by two drag-free satellites is investigated in this paper. Firstly, a relative motion model is derived based on a novel coordination whose origin is set on the middle point of the two satellites′ position, taking J2 perturbation into consideration. Different from the traditional leader-follower model, in which the orbit dynamics of the leader is established under ideal conditions, disturbances acting on both satellites are taken into account in the new relative motion model. A control algorithm is developed based on adaptive parameter updating plus power integrator technique, thus guaranteeing practical finite-time stability of the closed-loop system. And then, relative position error between the two satellites can be steered to the desired value at fast convergence rate. Finally, numerical simulation is carried out to show both effectiveness and robustness of the proposed algorithm.