多航天器系统分布式固定时间输出反馈姿态协同跟踪控制

Distributed fixed-time output feedback attitude coordination tracking control for multiple rigid spacecraft

针对角速度信息不可测条件下的多航天器系统姿态协同跟踪控制问题,提出一种基于积分滑模的分布式固定时间姿态协同跟踪控制方法.基于bi-limit齐次性理论设计一种新型的固定时间收敛的积分滑模面.为估计出不可测的航天器信息,提出一种固定时间观测器,同时为减少航天器间的通信信息流,引入滑模估计器估计领航者的姿态信息.结合固定时间观测器、滑模估计器和积分滑模方法设计分布式固定时间输出反馈姿态协同跟踪控制器,保证各跟随航天器在固定时间内实现对领航者姿态的协同跟踪.通过代数图论和Lyapunov理论证明闭环系统的固定时间稳定性.通过对比仿真结果验证所提出的控制方法的有效性和优越性.

A distributed fixed-time attitude coordination tracking control scheme is proposed based on integral sliding mode for multiple rigid spacecraft on condition of that the angular velocities of members are not available. A novel integral sliding mode is designed based on the bi-limit homogeneous technique, which achieves fixed-time convergence.A fixed-time observer is proposed to obtain an estimation of unmeasurable spacecraft information and a sliding-mode estimator is introduced to estimate the leader’s attitude, which reduces the communication flow between spacecraft.By combining the fixed-time observer, the sliding mode estimator and the integral sliding mode method, a distributed fixed-time output feedback attitude coordination tracking controller is designed to guarantee that follower spacecraft simultaneously track the leader’s attitude in fixed time. The fixed-time stability of the closed-loop system is ensured by employing the algebraic graph theory and Lyapunov techniques. Simulation comparison results show the effectiveness and superiority of the proposed control scheme.