Quality evaluation-based resilient distributed state estimation over time-varying networks via multi-hop communication

Abstract

This paper studies the problem of resilient distributed state estimation for a linear system using a set of agents connected through time-varying networks containing some Byzantine agents, where the Byzantine agents can arbitrarily manipulate the messages that they send or relay to other agents. First, an evaluation mechanism is introduced to assess the quality of the estimate generated by each agent at each step. Based on the quality evaluation and the multi-hop communication, a novel resilient distributed state estimation scheme is proposed, which enables each regular agent to evaluate the messages received from its time-varying multi-hop neighbors and discard the suspicious ones in real time. Then, to facilitate the stability analysis, the relationship between the estimates and the corresponding quality evaluations is established and the upper bound of the quality evaluations is derived. Specifically, the graph conditions under which all regular agents can estimate the state of the system exponentially fast at any given rate and even in finite time despite the existence of Byzantine agents are established. Different from the existing results requiring the time-varying networks to contain a sufficient amount of redundancy within bounded adjacent intervals, the proposed scheme can reduce the network redundancy requirement and allow the intervals over which such redundancy is preserved to grow over time. Finally, an example is simulated to validate the effectiveness of the proposed scheme.