Study On Spacecraft Fault Diagnosis Expert System Based On Fault Tree

With scientific and technological development, the design of a spacecraft must have the fault detection and diagnosis capability, which is a critical issue that the design of a spacecraft can not be neglected. The functions of a spacecraft include three main aspects, such as task management, health management and operation of payload. Among which fault diagnosis is one of the important function.Firstly, this paper introduces the basic principle of fault tree, and then emphatically introduces fault tree analysis. The establishment of the FT, fault tree pretreatment and fault tree of the quantitative and qualitative analysis are studied in detail.Secondly, the paper introduces in detail the basic theory of rule-based expert system and the various parts of composition and functions of expert system integration advantages. We propose a new idea which combines fault tree analysis with rule–based expert system. By connecting fault tree to diagnosis knowledge base, we can express knowledge totally, systematically, and logically when building fault tree. It realizes knowledge acquisition when the fault tree is used to obtain diagnosis rule base.Thirdly, reasoning mechanism is a hot focus of expert system. If we do not have a good inference rules, we have to search all events one by one, which will spend greater consumption but have low efficiency. This paper uses ITEM software to analyze fault tree, then uses the fault tree theory which based on minimal cut sets to the expert system inference mechanism. This can greatly increase the probability of a hit, reducing the number of blind tests.Finally, by using program language VC++ and SQL2000 under Windows XP, and applying the diagnostic method of artificial intelligence and the object-oriented programming design technology, we try to develop the fault diagnosis expert system of spacecraft, which verified has better application prospect.