Dynamic Measurement Method of Track Irregularity Based on Complementary Filter

Abstract

The existing dynamic inspection of high-speed railway track mainly uses Inertial Reference Method (IRM) based on accelerometer and ranging sensor data. The accelerometer has the characteristics of low signal-to-noise ratio and large integral drift, which limits its measurement accuracy under long-wave track irregularity and low speed. Therefore, a dynamic measurement method of track irregularity based on complementary filter is proposed. Firstly, the hardware structure of the system is optimized and ranging sensors are installed on the front and rear of the bogie. Secondly, the "two-point-chord" measurement model on the rail surface is used to derive the angular velocity measurement method (AVMM) based on the fiber optic gyroscope data. By analyzing the amplitude-frequency characteristics of the transfer function of the measurement system, it is found that AVMM has attenuation when measuring the short-wave irregularity within 30 m. Therefore, the complementary filter method is proposed, that is, the acceleration measurement method and AVMM are fused and calculated. Finally, the accuracy of the three methods is analyzed by using the track-vehicle dynamics simulation. The results show that compared with AVMM, the complementary filter measurement method can effectively compensate for the deficiency of high-frequency attenuation when measuring the short-wave irregularity within 30 m. Compared with the acceleration measurement method, the measurement accuracy can be improved by 24% to 80%, thus it has the advantages of low noise sensitivity and little impact by detection speed.