基于EMD和SPS的容差模拟电路故障诊断

针对具有容差的模拟电路故障诊断难题,提出了结合经验模态分解(EMD)和子带多态谱(SPS)的提取模拟电路故障特征新方法。首先计算出待测试电路的二阶Volterra核序列,然后用EMD对Volterra序列进行分解,获得本征模态函数(IMFs),最后通过计算IMFs的倒谱(CS)和Hiltert谱(HS),对时频域的多态数字故障特征进行提取,从而将容差模拟电路中的软故障和非线性故障进行分离,完成模拟电路故障诊断。实验结果表明,该方法能够有效地解决故障混叠难题,提升故障元件定位和分离的能力。

Fault diagnosis of tolerance analog circuit based on EMD and SPS method

Aiming at the problem of fault diagnosis of analog circuits with tolerance, a subband polymorphic spectra (SPS) approach of fault feature extraction is proposed in this paper, which is based on empirical mode decomposition (EMD). Firstly, the second order Volterra kernel sequences of the circuit under test are calculated. Then the Volterra sequences are decomposed based on EMD and the intrinsic mode functions (IMFs) are obtained. By calculating cepstrum (CS) and Hiltert spectrum (HS) from IMFs, the polymorphic digital fault features in time frequency domain are extracted, the soft and nonlinear faults in analog circuits with tolerance are isolated and the fault diagnosis of analog circuit is achieved. The experiments results show that the proposed method in the paper can solve the fault aliasing problem effectively and improve the capability to locate and isolate fault components.