The Cbr-based Aircraft, Airborne Equipment Failure Diagnosis System

With the development of the aviation technique, the scale of the modern civilian plane and the on-board equipments are more and more complex. So it promotes a challenge that how to carry out the fault diagnosis and maintenance for the plane on the base of assuring the safety, low costs and usability. At present, the domain experts raise a concept about healthy monitoring, forecasting and management. Meanwhile, the work of real-time fault diagnose has been researching in the field of civilian plane.According to the trend of the airplane fault diagnosis, the diagnostic technique and diagnostic method about fault diagnosis based on CBR are studied. The BIT messages are considered as a kernelled factor, in the base of which the case express, case retrieve, and the right of fault symptom are worked over. And then a fault diagnose expert system is established.Firstly, according to the characteristic of the fault diagnosis on the on-board equipments, a method that accomplishing fault diagnosis about a plane adopting CBR strategy based on BIT message, flight parameter, FDE and other fault symptoms is brought forward. Secondly, the frame method is applied to represent the history fault cases, which can represent the knowledge exactly. The Rough Sets theory is used to process the fault symptoms to reduce the number and dimension of the symptoms and to calculate the weightiness of every symptom. The weightiness is utilized to decide the sequence of symptom retrieved, and the bigger one is matched first. The times of history matched successfully is used to decide the sequence of history cases retrieved. In the matching process, the reciprocal of symptom weightiness is set as a local restrict condition, and Nearest Neighbor method is set as a whole matching strategy, which can achieve the most referenced results veraciously. Finally, a fault diagnosis expert system based on CBR method is designed and realized. The system is tally with the CBR flow and can realize the requirement of the fault diagnosis and meet the designing target.