航天器避障交会有限时间滑模控制

针对航天器安全交会过程中的避障问题，提出一种基于有限时间滑模变结构控制与人工势函数相结合的控制方法。首先，对斥力势进行修正使得势函数在期望状态的值为零。其次，基于速度偏差和引力梯度设计滑模面，并考虑障碍物的速度设计控制律。利用Lyapunov稳定性定理分析证明在存在外部干扰情况下，系统能够在有限时间内收敛到期望状态并保持渐近稳定。最后，利用数值仿真来验证所设计的控制律的正确性和有效性。仿真结果表明，该方法能够有效实现规避动态障碍物，满足安全交会的要求。

Finite Time Sliding Mode Control for Spacecraft Rendezvous with Collision Avoidance

To deal with the problem of obstacle avoidance during the process of spacecraft safe rendezvous, a control methodology based on finite-time sliding mode control and artificial potential function is presented. Firstly, a correction for repulsive potential function is conducted so that the value of the potential function is zero at the desired state. Then, combining velocity error and gravity gradient to design a sliding surface. In order to design the control law, the velocity of the obstacles is taken into consideration. Using the Lyapunov stability theory to analyze and prove that the system can converge to the desired state in finite time and keep asymptotic stability in the presence of disturbances. Finally, numerical simulation is used to verify the validity and effectiveness of the proposed control law. According to the numerical results, this method can guarantee avoiding dynamical obstacles whilst satisfying the requirements of the safe rendezvous.