航天器热故障诊断专家系统推理机的设计

航天器在飞行过程中,经常发生各种故障,因此需要充分进行地面模拟试验.在航天器地面热试验的故障分析过程中,除了形成了可供故障诊断用的规则以外,还得到了许多具体的事例.后者很难用规则来准确地描述,但却是人类专家最珍贵的经验,必须加以利用.据此提出了基于事例推理和基于规则推理的混合推理机制,给出了具体的流程图,并就两种推理给出了相应的冲突消解策略.

Design on inference engine of the spacecraft thermal fault diagnosis expert system

When a spacecraft is on mission, various unpredictable faults often occur. It is very important that spacecrafts should be capable of diagnosing thermal faults automatically because most of them are difficult to be repaired on orbit, which requires a credible inference engine. And many rules and cases for fault diagnosis can be obtained after the spacecraft thermal test fault analysis. Those cases are difficult to describe in exact rules, but they are the most important experience in the spacecraft test. Combined with the rule-based reasoning and the case-based reasoning, the hybrid inference engine was produced, and the corresponding conflict resolutions were given. In rule-based reasoning, similarity judgement is used to resolve the conflict, and the numerical method differs from the non- numerical one. In case-based reasoning, the method of priority, ranking and credibility can be used; and the method of ranking is preferred to resolve the conflict if the number of all the cases is little.