Railway track inspection based on the vibration response to a scheduled train and the Hilbert-Huang transform

With the development of high-density intercity railway networks, substantial investments are now required, in terms of labor and machinery, in order to be able to conduct safety inspections. This results in high operational costs. High-capacity and high-speed operations have resulted in levels of damage and deterioration of railway system components that have surpassed all expected values. Thus, traditional methods of periodic inspection, though still necessary, are no longer sufficient to detect the rapid development of defects on railway systems. Therefore, the direct use of operational trains as inspection vehicles to detect defects in real-time has become a current trend in the development of inspection techniques. This study applies an inspection technique previously reported in the literature to on-site testing of track. The response to vibrations on railway bridges, track system components and track irregularities are also studied. The effects are analyzed using the Hilbert-Huang transform approach. It is shown that the proposed data analysis method can be used in conjunction with the routine operation of trains to create a method for the monitoring of track defects.