High-Performance FOG IMU and Algorithm for Railway Dynamic Inspection

Cross level, longitudinal level and track alignment are three prominent parameters in track inspection, especially under harsh conditions. Inertial measurement method is introduced in track geometry inspection called track surveying system. In this study, a high performance Fiber Optical Gyroscope (FOG) based IMU is used to measure these parameters. System structure, detection and filtering algorithm are demonstrated. The key point is that gyroscope with angular rate as output give the posture in 3D through integration. However, long time integration inlet drift of the angle calculation based on gyroscope. The algorithm in this paper presents the stability for the dynamic inspection. Meanwhile, with the help of error correcting and compensating methods, satisfactory results are achieved, comparing with the traditional non inertial method.