Fault Diagnosis for Compensating Capacitors of Jointless Track Circuit Based on Dynamic Time Warping

Wei Dong

doi:10.1155/2014/324743

Abstract

Aiming at the problem of online fault diagnosis for compensating capacitors of jointless track circuit, a dynamic time warping (DTW) based diagnosis method is proposed in this paper. Different from the existing related works, this method only uses the ground indoor monitoring signals of track circuit to locate the faulty compensating capacitor, not depending on the shunt current of inspection train, which is an indispensable condition for existing methods. So, it can be used for online diagnosis of compensating capacitor, which has not yet been realized by existing methods. To overcome the key problem that track circuit cannot obtain the precise position of the train, the DTW method is used for the first time in this situation to recover the function relationship between receiver’s peak voltage and shunt position. The necessity, thinking, and procedure of the method are described in detail. Besides the classical DTW based method, two improved methods for improving classification quality and reducing computation complexity are proposed. Finally, the diagnosis experiments based on the simulation model of track circuit show the effectiveness of the proposed methods.

Highlights

Track circuit is one of the most important basic equipment in train control system
Aiming at the problem of online fault diagnosis for compensating capacitors of jointless track circuit, a dynamic time warping (DTW) based diagnosis method is proposed in this paper
Different from the existing related works, this method only uses the ground indoor monitoring signals of track circuit to locate the faulty compensating capacitor, not depending on the shunt current of inspection train, which is an indispensable condition for existing methods

Summary

Introduction

Track circuit is one of the most important basic equipment in train control system. A remarkable drop in the receiver’s voltage will indicate a train’s occupancy In this way, the train control system can obtain the information which block sections are occupied and which block sections are empty. If the track circuits have some faults, the most serious consequence is to cause collisions of trains, resulting in catastrophes. The timely fault diagnosis for track circuit is significant to both safety and efficiency of the railway transportation system. Dynamic time warping (DTW) is a well-known dynamic-programming-based method to find an optimal alignment between two given sequences under certain constraints. Among main DTW methods, the classical DTW [22] aims at computing the DTW distance and optimal warping path using the dynamic programming method, which can be realized by calculating cost matrix and accumulated cost matrix. The approximate DTW and multiscale DTW [26, 27] were proposed to speed up DTW computations based on the idea to perform the alignment on coarsened versions of the sequences X and Y

Methods

Results

Conclusion