On-board Dynamic Measuring of Long-wave Track Irregularity based on Visual Inertial Fusion

Abstract This paper studies an inspection method to measure the long-wave track irregularities using signals of IMU (Inertial Measurement Unit) and Laser & Camera installed on a bogie, which is implemented in comprehensive trains. To reduce influence random noise vehicle vibration, mechanical structure optimized; spatial-dependent change "two-point chord" observed by high-precision FOC (Fiber Optic Gyroscope) laser camera components; angular velocity measurement deduced. eliminate high-frequency attenuation signal, sensor fusion algorithm based concept complementary filters presented. The velocity-based also used low spatial frequencies, while acceleration-based high frequencies. accuracy system evaluated from two aspects: internal external coincidence accuracy. test shows that repeatability alignment profile wavelength 200 m 0.5 mm 0.8 mm, respectively, trend item line design value maintain good consistency.