Research On Vehicle Track Coupling Modeling And Track Irregularity Online Inertia Monitoring

Track irregularities are important excitation source of causing vehicle-track vibration, which also have significant randomness. Real-time monitoring of track irregularities has great significance for the safety of railway operation. On the basis of absorbing and summarizing predecessors’ research results, this paper proposed an on-line monitoring technique which sampling the vehicles operating inertia response to detect tack irregularities.Firstly, the classification of track irregularities according to the space direction and wavelength are introduced, as well as the management of irregularities in power spectrum. The transfer characterization from axle-box vertical acceleration, bogie pitch rate and bogie vertical acceleration, to track irregularities are analyzed, respectively.Secondly, a coupling dynamics model of vertical vehicle-track interactions is developed. The model consists of vehicle subsystem, track subsystem and wheel-rail coupling submodel. Based on MATLAB-GUI environment, dynamics simulation-based software system is designed and implemented. With wheel flat as model excitation, wheel and bogie vibration response are obtained. Comparing with the actual measured signal, the rationality and accuracy of the model are validated.Thirdly, an online monitoring method based on integration filter and adaptive algorithm is proposed. This method collects axle-box vertical acceleration, bogie pitch rate and train speed, processes the signal in the processing of integration filter, baseline correction, bandpass filter and adaptive compensation filter processing and then assesses the vertical track irregularities. Using less sensor provides a large amount of advantages such as low cost and good engineering applicability. Experiment result based on a segment of actual measured track irregularities shown the proposed method is capable of monitoring the long wavelength track irregularities accurately and effectively.Finally, this paper focuses on the track irregularities estimation method based on Extended Kalman Filter (EKF). Different from sampling only a single sensor, this method collect more inertia response from the bogie and car body. Combining with the observation equation and state-space equation of vehicle-track coupling, the track irregularities are estimated with EKF. Experiment results shown that the proposed method is capable of assessing track irregularities in each wave band accurately.