Abstract: To detect the exact fracture point of railway, a model of short-current amplitude envelope of cab is constructed based on transmission line theory when rail line occurres fracture, and the influence of fracture on short-current amplitude envelope is analyzed in this paper. Then the exact fracture point is detected by using characteristics of Multi-Resolution Singular Value Decomposition（MRSVD） detail signal of short-current amplitude envelope. Experiment results show that the proposed method can accurately detect the location of fracture point under different fracture equivalent impedances, and make up the shortage of current methods. Because of the analysis data are directly from the cab signal recorder and additional devices is not needed, the proposed method remedies the defects of existing detecting methods in respect of detecting costs and timeliness.

Key words: shunt-circuit currents amplitude envelope, Multi-Resolution Singular Value Decomposition（MRSVD）, fracture point

摘要： 为了检测出钢轨断裂点的准确位置，首先基于传输线理论建立钢轨断裂时的机车分路电流幅值包络仿真模型，分析了钢轨断裂对分路电流幅值包络的影响，然后利用对分路电流幅值包络进行多分辨奇异值分解后细节信号的奇异性特征检测钢轨断裂点的准确位置。实验结果表明，该方法可以有效检测出不同断裂点等效阻抗值下钢轨断裂点的准确位置，从而弥补了目前监测方法的不足。并且该方法的数据可以由机车自身的记录器提供，不需要增加其他检测设备，因此能够在降低检测成本的同时能满足检测及时性方面的要求。

关键词: 分路电流幅值包络, 多分辨奇异值分解, 断裂点