基于正态商分布的模拟故障容差处理新方法  

Research on tolerance processing method for analog circuit soft-fault diagnosis based on normal quotient distribution

作　　者：敖永才[1] 师奕兵[1] 张伟[1] 李西峰[1] 

机构地区：[1]电子科技大学自动化工程学院,成都611731

出　　处：《仪器仪表学报》2013年第3期698-706,共9页Chinese Journal of Scientific Instrument

基　　金：国家自然基金(61201131)资助项目

摘　　要：斜率故障模型较好地解决了线性模拟电路的软故障诊断问题,但软故障诊断过程中的容差影响问题仍然是一个富有挑战性的难题。提出了一种结合了斜率故障模型和正态商分布的模拟电路软故障诊断的容差处理新方法。对比分析了几种典型的基于斜率故障模型的容差处理方法,推导了容差影响下斜率故障特征的近似概率分布函数,给出了提高近似精度的基本条件。证明了正态商分布与标准正态分布在一定范围内的单调连续映射关系,并由此推导出容差影响下斜率故障特征变化范围的估计公式。设计了一种新的测点选择算法,大大减小了最优测点选择的计算量。实验证明,提出的故障诊断方法对容差影响下的软故障具有良好的定位精度。While the slope fault model method can solve the soft-fault diagnosis problem in linear analog circuit effectively, the challenging problem about tolerance is still unsolved. In this paper, a proposed normal quotient distribution method was combined with slope fault model to process the tolerance problem in soft-fault diagnosis for analog circuit. Firstly, several typical tolerance processing methods on the ground of the slope fault model were compared. Then, the approximating distribution function of the slope fault characteristic was deduced, and the basic condition was given to improve the approximation accuracy. The monotonous and continuous mapping between normal quotient distribution and standard normal distribution was proved. Thus the estimation formulas about the range of the slope fault characteristic were deduced. After that, a new test-nodes selection algorithm based on the approximating condition was designed, which can reduce the computation greatly. Finally, the experiments were done to illustrate the proposed method and demonstrate its effectiveness.

关 键 词：软故障诊断 模拟电路 正态商分布 容差 斜率故障模型 

分 类 号：TN710[电子电信—电路与系统]