航天器终端接近的有限时间输入饱和避碰控制

针对航天器终端接近问题,解决了追踪航天器在跟踪到达期望目标点的过程中不与目标航天器发生碰撞的难题。首先,在目标航天器轨道系下建立了航天器的相对运动和避碰模型。其次,考虑外界扰动上界已知和未知两种情形,均给出了有限时间避碰控制器,且所设计的控制器都具有输入饱和特性。最后,应用Lyapunov稳定性理论证明了在所提出的控制器作用下系统是有限时间收敛的,并且,利用避碰势函数证明了所设计的控制器能够实现避碰。仿真结果表明,所提出的控制器是有效的。

Finite-time and collision avoidance control for spacecraft terminal approach with input saturation

This paper solves the avoid collision problem of spacecraft terminal approach to realize that a chaser spacecraft does not collide with the target spacecraft when reaching to the expected target point. The spacecraft relative motion and the collision avoidance model are established under the orbital coordinate system of target spacecraft. Two finite-time collision avoidance controllers are presented respectively in cases with/without knowing the upper bound of external disturbances, and the designed controllers have input saturation characteristics. Finally, Lyapunov stability theory is applied to prove the finite-time convergence of the designed controllers, and the collision avoidance potential function is used to prove that the controllers can realize the collision avoidance. Simulations demonstrate the effectiveness of the proposed controllers.