Fault Location for the Intermittent Connection Problems on CAN Networks

Fieldbus technology plays an important role in manufacturing systems. Hence, the reliability of the network is critical to the performance and the safety of the system. Among various factors that affect the reliability of the network, the intermittent connection (IC) of the network cable is a common but challenging troubleshooting problem since its location is difficult to identify. IC problems may result in degraded network performance or system level failures in severe cases. In this paper, a novel model-based fault location method is developed for IC problems on controller area networks. By passively capturing IC-induced network errors, two sets of error events are defined for each node, based on which generalized zero inflated Poisson models are used to describe the patterns of the error events. A two-step IC fault location procedure is proposed by examining the statistical significance of the corresponding error events using the fitted models. Case studies are conducted to demonstrate the proposed method on different IC location scenarios. Experiment results show that the locations of the IC problems identified by the proposed method agree well with the experiment setup conditions.