Outlier-Resistant Distributed Filtering for Multi-Rate Nonlinear Systems Under Amplify-and-Forward Relays

In this paper, the outlier-resistant distributed filtering problem based on amplify-and-forward relays is studied for discrete time-varying nonlinear multi-rate systems with multiple measurement delays over sensor networks, where the augmenting method is utilized to transform the multi-rate system into a single rate system. An amplify-and-forward (AF) relay is set between the sensor and the filter to extend the transmission distance of the signal and ensure the communication transmission quality. The outlier-resistant distributed filter is constructed by introducing a saturation function to limit the innovations, then the upper bound on the filtering error covariance is obtained and the filter gain is designed to minimize such obtained upper bound. Finally, a numerical example is used to show the effectiveness of the outlier-resistant distributed filtering algorithm based on AF relays.