Distributed fault-tolerant detection via sensor fault detection in sensor networks

This work addresses the design of a distributed fault-tolerant decision fusion in the presence of sensor faults when the local sensors sequentially send their decisions to a fusion center. A collaborative sensor fault detection (CSFD) scheme is proposed here to eliminate unreliable local decisions when performing distributed decision fusion. Based on the pre-designed fusion rule, assuming identical local decision rules and fault-free environments, an upper bound is established on the fusion error probability. According to this error bound, a criterion is proposed to search the faulty nodes. Once the fusion center identifies the faulty nodes, all corresponding local decisions are removed from the computation of the likelihood ratios that are adopted to make the final decision. Performance evaluation results indicate a significant improvement in fault-tolerance capability from the proposed approach over the conventional decision fusion without utilizing CSFD.