基于定性约束的故障诊断设计

Fault diagnosis design based on qualitative constraint

在B.J.Kuipers的QSIM算法基础上,提出了比较约束概念用于消减推理空间。给出了各定性约束的传递规则,用于对系统的推理仿真。以系统故障的观测结果为初始状态,依据约束流的传播,诊断变量异变的位置和原因,并把诊断结果进行正向推理,消除部分冗余。在压缩制冷系统实例中,根据制冷系统的定性微分方程建立约束关系。针对制冷效果不佳的症状,仿真诊断出故障源为系统中有空气或氟利昂充液量过大的故障,与实际系统相一致。

Based on the QSIM algorithm of B. J. Kuipers, comparative constraint was presented to reduce the diagnosis space. The transfer regulation of qualitative constrain was used in the simulation and reasoning of system diagnosis. This algorithm took observed faulty state as the beginning, to diagnosis the location and cause of variable discrepancy according to the transfer regulation of qualitative constraint, reasoned from diagnosed faulty to examine the result and deleted the redundancy of diagnosis result. In the example of condensation refrigeration system, the constraint relation was built according to qualitative difference equation. Aim at the bad efficiency of refrigeration, the mixture of air or Freon superfluously was diagnosed as the result faulty source, consistent with the factual system.