On the Effects of Modeling Errors on Distributed Continuous-time Filtering
Xiaoxu Lyu, Shilei Li, Dawei Shi, Ling Shi
TL;DR
This work analyzes distributed continuous-time filtering under modeling errors by introducing a nominal performance index $\Sigma_u(t)$ and the estimation error covariance $\Sigma_e(t)$. It derives a nominal distributed Kalman filter using parameters $A_u$, $C_{i,u}$, $Q_u$, and $R_{i,u}$, and obtains coupled Lyapunov-type equations governing the evolution of $\Sigma_u(t)$ and $\Sigma_e(t)$. Key results include bounds on $\Sigma_e(t)$ in terms of $\Sigma_u(t)$ and Frobenius-norm deviations, a divergence condition when the process-noise covariance is incorrect, and a relation framework between the two indices that depends on the consensus gain $\gamma_u$. Numerical simulations on vehicle tracking validate the theoretical bounds and illustrate the potential for divergence under modeling errors, offering guidance for robust nominal-design in sensor networks.
Abstract
This paper offers a comprehensive performance analysis of the distributed continuous-time filtering in the presence of modeling errors. First, we introduce two performance indices, namely the nominal performance index and the estimation error covariance. By leveraging the nominal performance index and the Frobenius norm of the modeling deviations, we derive the bounds of the estimation error covariance and the lower bound of the nominal performance index. Specifically, we reveal the effect of the consensus parameter on both bounds. We demonstrate that, under specific conditions, an incorrect process noise covariance can lead to the divergence of the estimation error covariance. Moreover, we investigate the properties of the eigenvalues of the error dynamical matrix. Furthermore, we explore the magnitude relations between the nominal performance index and the estimation error covariance. Finally, we present some numerical simulations to validate the effectiveness of the theoretical results.
