Study on the fault detection of railway signaling cable based on wavelet and virtual instrument

As the laying of railway signaling cable is always concealed with complicated running environment, the fault diagnosis of railway signaling cable has much considerable difficulties as a rule. In order to realize the automatic fault location and automatic judgment of the fault characteristics for railway signaling cable, a method of automatic fault location is introduced in the paper. Based on the traditional testing methods with low voltage pulse reflectometry, the peripheral circuits have been designed by MCU and CPLD which are the key units. The multi-resolution analysis and modulus maxima theory of wavelet have been applied to the automatic fault position of railway signaling cable with the programming language LabVIEW to achieve the intelligent fault detection of railway signaling cable completely. Meanwhile, the results of field testing have shown the system meets the requirements and the methods are correct and effective.