An approach of fault diagnosis for electronic system of aircraft based on trapezoid fuzzy fault tree

Due to the lack of failure recording data events, it´s very difficult to evaluate the fault probabilities of aircraft electronic system from the past occurrences, especially in the civil aviation. Using the conventional fault-tree analysis is not expected to obtain the exact value the of bottom events. Aiming at shortcoming of the current fault diagnosis, we propose a new approach combining the traditional fault tree with trapezoid fuzzy number, and establish fuzzy fault tree to solve this problem. In this paper, taking the cabin pressure regulating system as example, we evaluate the probability of top event and the importance degree of each bottom event.