Improvement of a fault diagnosis algorithm using a signed digraph with considering stuck faults in sensors

A diagnosis system to search multiple origins of failures using a signed digraph has been developed. Under the situation in which measured values of sensors are stuck normal values, the system cannot find multiple origins of failures properly and often makes erroneous or impossible diagnosis. In order to overcome this problem, an improved algorithm which can search the candidates of multiple origins and also the sensors with stuck faults is proposed. The usefulness of this proposed algorithm is demonstrated by its application to tank-pipeline systems.