Railway Track Irregularity Measuring by GNSS/INS Integration

Railway track irregularity measuring is a task of fundamental importance to guarantee operating safety and arrange proper maintenance, particularly for the high-speed lines. Conventional measuring methods cannot satisfy the requirements of accuracy and time-efficiency simultaneously. A GNSS/INS integrated technique is proposed based on the fact that railway track irregularity detection is essentially an issue of relative surveying. Key technologies of the integration algorithm aiming at track irregularity measuring are proposed to improve the performance of the GNSS/INS system. Results show that the proposed method can fulfill 1 mm relative accuracy in identifying track irregularities in the kinematic surveying mode, which means this method can satisfy the accuracy requirement for a high-speed line and is ten times faster than the conventional method based on total station.