Application of VMD Algorithm in UGW-based Rail Breakage Detection System

As a solid medium of sound propagation, rails provide perfect acoustic features. In this way, rail breakage detection systems based on ultrasonic guided waves (UGW) have been recently developed. In outdoor applications of these systems, different types of interference are usually added to the received signal, which makes UGW signals difficult to distinguish and analyze, even leading to false alarms and affecting the system efficiency. In order to recover UGW signals in these systems, the application of a variational mode decomposition (VMD) algorithm to denoise and reconstruct UGW signals is proposed in this work. This algorithm can decompose the received signal into different intrinsic mode functions (IMF), which some are useful signals and the others are interference. Removing the interference part and the UGW signals can be reconstructed. By comparing the amplitude of reconstructed UGW signal with a predefined threshold, the rail status can be determined easier than before. Furthermore, by calculating the deviation between the reconstructed signal after the VMD algorithm and the original one, the effectiveness and suitability of the proposal is verified through some simulation results.