Shanghai-Nantong Yangtze River Bridge Track Detection And Smoothness Analysis Method

Track irregularity is one of the sources of disturbance in the vehicle-track system.Track irregularity will enhance the interaction force between the wheel and rail,which in turn will aggravate the track irregularity.In order to grasp the smoothness of the track alignment of the Shanghai-Nantong Yangtze River Bridge in time,relevant departments have conducted static and dynamic inspections of the track according to a certain inspection frequency,and have accumulated multiple phases of track inspection data.Reasonable processing of these track detection data and scientific evaluation of track geometry is the key to guiding the maintenance of the track alignment of the ShanghaiNantong Yangtze River Bridge and ensuring the safe and stable operation of the train.In response to these issues,this thesis studies the following contents:1.The track detection data of the Shanghai-Nantong Yangtze River Bridge can be regarded as a non-stationary and nonlinear signal sequence,which can be adaptively decomposed using the Variational Mode Decomposition(VMD)method,and then the hidden signal can be mined in the frequency domain.Information such as the characteristic wavelength contained in it.However,when VMD processes the actual orbit detection data,due to the lack of prior information,the optimal number of decomposition layers K and the penalty factor α cannot be determined,so the Particle Swarm Optimization(PSO)algorithm is introduced to optimize the parameters.In the optimization process,the average value of the correlation coefficient of the adjacent Intrinsic Mode Function(IMF)and the average bandwidth of the IMF component are calculated.and α are the optimal parameter combinations.2.Preprocess the track dynamic detection data of the Shanghai-Nantong Yangtze River Bridge,including removing abnormal data,band-pass filtering,and extending the signal length to improve end-point effects.The preprocessed orbit dynamic detection data is decomposed by PSO-VMD adaptively,and the average wavelength of each IMF component is calculated.Combined with the variance contribution rate analysis,the single wavelength range of orbit irregularity is extracted.3.Hilbert transform is performed on the IMF components obtained by decomposing the dynamic inspection data,and the Hilbert energy density distribution of the track irregularity is calculated and obtained.By comparing the energy fluctuations of different mileage sections,the section with relatively weak geometric state of the bridge track can be determined.4.Process and analyze the track static inspection data of the Shanghai-Nantong Yangtze River Bridge,and draw on the idea of the dynamic inspection inertial reference method to process the track inspection data,and use the horizontal and vertical deviation filtering method to process the static inspection data,which improves the measurement of the string measurement method.The problem that the reference line fluctuates with the fluctuation of the track wavelength can make the processed static inspection data more truly reflect the track irregularity.