故障响应指导下基于测试集的故障诊断方法

Fault diagnosis method based on test set under fault response guidance

通过对电路中故障输出特征进行研究,结合增强故障诊断(ADD)测试候选诊断求解方法,提出了故障响应指导下的候选诊断求解方法ALFDD。依据当前测试激励下实际输出响应与预期输出响应不相同的单故障更可能是故障诊断解的原理,提出了候选单故障集合的概念。针对ADD方法中需对电路的所有单故障求解F_(same)的问题,给出仅对候选单故障集合求解F_(same)的方法。该方法一方面避免了对所有单故障都进行对比并求解F_(same)的问题,提高了诊断求解效率;另一方面有效删除了F_(same)中包含的冗余候选诊断解,提高了候选诊断解的分辨率;此外,还增加了候选故障集中所包含的真实诊断解的数量,提高了候选诊断解的准确率。实验结果表明,与ADD方法相比,ALFDD方法候选诊断分辨率和准确率明显提高,求解效率也有较大提高。

In this paper,having deeply studied the fault output characteristics in circuits and the ADD candidate diagnosis solution method,we propose a candidate diagnosis solution method under the guidance of fault response,ALFDD,namely.We also put forward the concept of candidate single fault set,which is based on the principle that a single fault with different actual output response and expected output response under current test excitations is more likely to be a fault diagnosis solution.To overcome the problem that in ADD method to obtain Fsame all single faults of circuit should be compared,we give the method which only considers the faults of the candidate single fault set to obtain Fsame.This method has three merits.Firstly,it does not need to compare all single faults and improves the efficiency of solving problems.Secondly,it eliminates the reluctant candidate solutions concluded in Fsame effectively,so it improves the resolution of candidate diagnostic solutions.In addition,this method improves the accuracy of candidate diagnostic solutions,namely,increasing the number of real diagnostic solutions in the candidate fault sets.The test results show that,,compared with ADD,the proposed ALFDD method increases the resolution,accuracy and solution efficiency for selecting candidate diagnoses.