Distributed fixed-time observers for linear time-invariant systems
A class of distributed fixed-time convergent observers is designed based on the bi-limit weighted homogeneous approximation theory and observability decomposition for the distributed state estimation of linear time-invariant systems.Firstly,for a single-input-single-output integrating chain system,a centralized fixed-time observer is designed for the system using bi-limit weighted homogeneous estimation.Then,the linear time-invariant system is decomposed into observable and unobservable subsystems based on the observability decomposition.Each agent in the sensor network reconstructs local observable sub-states in a fixed time based on the centralized observer by using only the system output measurements,and then state information between the agents is used to construct a consistent algorithm to estimate the local unobservable sub-states in a fixed time,thus realizing state omniscience in a fixed time.Unlike previous works,this paper does not need to construct a specific Lyapunov function to give an expression for the convergence time.Finally,the effectiveness of the designed observer is verified by simulations.