Abstract
In this paper, the dynamic model of ’credibility’, which is used as main parameter of judgment in immunity-based system diagnosis, is extended so that diagnosis system can quickly judge fault if a specific fault mode occurs in a sensor. The amount of change of credibility changes according to size of similarity between actual output of a sensor and estimated output of it. The estimated output is calculated by using relationship among outputs of other sensors if a specific fault mode occurs in the sensor. The effectiveness of the proposed method is evaluated by experiments.