Distributed Reference-Free Fault Detection Method for Autonomous Wireless Sensor Networks

Compact and low-cost sensors used in wireless sensor networks are vulnerable to deterioration and failure. As the number and scale of sensor deployments grow, the failure of sensors becomes an increasingly paramount issue. This paper presents a distributed, reference-free fault detection algorithm that is based on local pair-wise verification between sensors monitoring the same physical system. Specifically, a linear relationship is shown to exist between the outputs of a pair of sensors measuring the same system. Using this relationship, faulty sensors may be detected within subsystems of the global system. Moreover, faulty sensors suffering from sparse spikes in their measurements can be identified with spike magnitudes and times accurately estimated. An appealing feature of the proposed method is that the need for reference sensors and complete knowledge of the system input are not required. Due to the pair-wise nature of the proposed algorithm, it can also be performed in a completely decentralized fashion. This ensures the method can be scaled to large sensor networks and lead to significant energy savings derived from reduced wireless communication compared to centralized approaches.