An Automated System for Position Monitoring and Correction of Chord-Based Rail Corrugation Measuring Points

Rail corrugation impacts the riding quality and safety of railway systems. The chord-based method is one of the common methods for rail corrugation dynamic measurement. However, during the process of continuous operation, it is hard to ensure that the measuring points on the rail surface can trace the railhead centerline well the whole time. This introduces the position deviations to the system, and leads to the measurement results not reflecting the true rail irregularity state. To solve the problem, an automated system for position monitoring and correction of chord-based measuring points is constructed in this paper. The proposed system comprises the position monitoring subsystem (PMS) and the position correction subsystem (PCS). The PMS monitors the positions of measuring points with given sampling interval, and calculates the position deviations with respect to the railhead centerline. Once the deviation exceeds the preset range, the PCS makes corresponding operations to pull the measuring points back to the effective range. Extensive experiments show that the error of PMS is limited within 0.6 mm, and the PCS can correct the position deviations in a timely manner according to the correction criteria. Furthermore, with 20-cm image sampling interval, our system can run at 6 km/h under our experimental setup, which is higher than that of rail maintenance trains (up to 5 km/h).