RAIL CORRUGATION MEASUREMENT BASED ON DFB FIBER LASER SENSORS ON HEAVY HAUL RAILWAY

To meet the needs of rail corrugation measurement, this paper presents a rail corrugation measurement system based on distrubuted feedback (DFB) fiber laser sensors (FLs) which are highly sensitive, immune to electro-magnetic noise and installed on the bogie of the train. When the train passes the corrugated rail, the corrugation induced acceleration of the bogie will be detected by the FLs. An digital inertial algorithm based on digital filtering technique is proposed to accurately estimate the rail corrugation and wavelet analysis method is used to eliminate trend term in bogie acceleration signal. Field test is carried out on the Datong-Qinhuangdao Railway in north China. The test results of acceleration and rail corrugation recorded by FLs are in good agreement to those of rail inspection car, which shows that it's a practical method to use fiber laser sensors as corrugation detectors.