基于分布式专家系统的运载火箭故障诊断技术

Fault diagnosis technology of launch vehicle based on distributed expert system

针对运载火箭结构庞大,各分系统纵横交错、相互耦合的特点,基于分布式专家系统思想,提出了一种分布式运载火箭故障诊断技术方案.该方案采用产生式知识表达技术,将专家知识通过由测点表、征兆表、规则表和结论表组成的4表结构来表示,具有表述清晰、易于扩展和移植的特点.推理机制采用分布式推理和分级推理相结合的方式.分布式推理将运载火箭的系统级故障与各分系统级故障分别同时进行诊断,可有效提高诊断速度.分级推理将危害级别高的故障优先进行诊断,因此运载火箭一旦有危害程度大的故障发生时,可以及时发现、及时处置,从而使故障对系统的影响降至最低.

A distributed fault diagnosis system scheme for launch vehicle was presented based on distributed expert system because of the characteristic of the launch vehicle including many subsystems which coupled with each other. In knowledge acquisition, the scheme used the production rule representation and described the experts＇ knowledge by the four-table structure composed by measure point table, symptom table, rule table and result table, which has the excellent versatility and transportability. Furthermore, the scheme combined the distributed inference and multi-level inference as the inference strategy. Because the distributed inference analyzes the system faults and each subsystem faults respectively at the same time, it can improve the diagnosis speed effectively. In addition, the multi-level inference can diagnose the faults with the high hazard rating preferentially. Therefore, once the highly hazardous faults of the launch vehicle happen, the fault diagnosis system can find them in time and give the maintenance measure to reduce their harm to the lowest level.