Abstract: Aiming at the challenges of multiple nodes, complex topology and large amount of calculation in the spacecraft formation flight system, the traditional centralized state estimation is difficult to apply due to the high pressure of communication and calculation and low fault tolerance. An interval state estimation scheme is proposed based on distributed observer network. Each local observer only uses part of the output information, interacts with the neighbor observer with a given communication topology, and completes the joint estimation of the global state through a cooperative mechanism. The theoretical criterion for ensuring that the true state of the system is always included in the estimation interval is established based on the positive system theory. Furthermore, by combining Lyapunov stability theory, Riccati equation and regional synchronization theory, the sufficient conditions for ensuring the uniform bounded stability of the observation error dynamic system are given.Numerical simulations verify the effectiveness and feasibility of the proposed distributed interval estimation strategy. This method can significantly reduce the system overhead while ensuring that the theory is rigorous and easy to implement : compared with similar distributed methods, the communication traffic is reduced by more than 70%; compared with the centralized method, the computational complexity can be reduced by more than 90% with the increase of scale, which greatly improves the scalability, robustness and practical application potential of the system.

Key words: spacecraft formation flight system, distributed observer, interval estimation, Lyapunov stability theory, Riccati equation