基于组合逻辑的故障诊断方法

Fault Diagnosis Method Based on Combinatorial Logic

针对复杂系统故障传播和故障分析的模糊性和不确定性,首先,在逻辑Petri网和模糊Petri网的理论基础上,根据逻辑Petri网的传值不确定性以及模糊Petri网对模糊信息的表示和推理能力的特点,提出模糊逻辑Petri网的概念及推理规则,考虑不同故障源对故障的影响程度,将概率信息引入模糊逻辑Petri网,对故障源赋予置信度,使故障诊断过程更符合实际。其次,利用模糊逻辑Petri网对故障诊断系统进行建模,用模糊逻辑Petri网描述了系统故障状态组合的逻辑关系,并进一步简化了系统模型的表达形式,具有良好的封装性、重构性和可维护性,在一定程度上缓解了状态组合空间爆炸问题。针对故障的传播性,采用可达性分析方法对故障信息的传播路径进行模拟论证,提高了故障诊断效率。最后,通过离心式压缩机故障诊断过程实例分析,验证了该方法的有效性和可行性,提高了故障诊断过程的准确性和高效性。

Aiming at the ambiguity and uncertainty of the fault causes in the fault diagnosis of complex systems,firstly based on the value-added uncertainty of logical Petri nets and the fuzzy information representation and reasoning ability of fuzzy Petri nets,the concept and inference rules of fuzzy logic Petri nets are proposed.Consider the extent to which different sources of failure affect the fault.The probability information is introduced into the fuzzy logic Petri net,and the confidence level is given to the fault source,which makes the fault diagnosis process more realistic.Secondly,the fuzzy logic Petri net is used to model the fault diagnosis system.The fuzzy logic Petri net is used to describe the logical relationship of the system fault state combination,and the expression of the system model is further simplified.It has good encapsulation,reconstruction and Maintainability,to some extent,alleviated the problem of state combination space explosion.According to the propagation of faults,the reachability analysis method is used to simulate and propagate the fault information propagation path,which improves the fault diagnosis efficiency.Finally,through the example analysis of the centrifugal compressor fault diagnosis process,the effectiveness and feasibility of the method are verified,and the accuracy and efficiency of the fault diagnosis process are improved.