Research On Online Safety Monitoring Of Key Components Of Urban Rail Vehicle Bogie

As the key component of urban rail vehicle, performances of bogie will directly affect the vehicle’s safe operation. With the speed increasing of urban rail transit, the structures of bogie become more and more complex, and the operating conditions of bogie are more severe. Besides the traditional periodical maintenance policy has a lag, it’s unable to discover and remove the faults in time, all which bring safety concerns to the bogie, so realizing the online safety monitoring of urban rail vehicle bogie is being concerned by more and more people.In the face of the complexities and diversities of bogie’s fault type, and according to actual needs, this paper selects the axle box bearings and gear boxes, which have high fault rate and serious harmfulness, as the research objects, and related theory and technology of safety monitoring method online are being studied, the main work is:(1) The analysis of key components of urban rail vehicle bogie fault and vibration mechanism has been finished. Through the analysis of common bogie fault types and reasons, with probability and degree of damage occurred under the actual situation, the axle box bearing and gearbox are chosen as the research object. Through the vibration mechanism research, it provides the theoretical basis for the safety monitoring methods of the urban rail vehicle bogie.(2) The urban rail vehicle bogie online safety monitoring hardware platform has been established. Based on the established urban rail vehicle safety monitoring system, the vibration characteristics of bogie in normal and fault conditions are simulated through Multi-body dynamics software, according the simulation conclusion, the selection and installation of sensors are completed, and ultimately the bogie of urban rail vehicle safety monitoring hardware platform has been build up, besides the common methods of data preprocessing of hardware acquisition system is analyzed. All these provide technical support for the studying of bogie online safety monitoring methods.(3) Studying and establishing the axle box bearing fault detection method based on improved wavelet transform and Hilbert envelope demodulation. Through the study of the existing bearing detection methods, the advantages and disadvantages of these methods are analyzed, and the wavelet transform and improved Hilbert envelope demodulation are adopted. Based on the traditional envelope demodulation method, then the wavelet transform is introduced, moreover the refinement and correction of the spectrum are combined, finally fault resolution is greatly improved. Through the test bench of the bearing fault data, the optimal selection of wavelet basis and the signal layers of reconstruction are completed, and ultimately the accuracy of the method is verified.(4) The gearbox of k proximity abnormal detection method is set up. According to the gearbox vibration characteristics in actual condition and the demand of online monitoring, a new method based on non-dimension parameters online safety monitoring of gearbox is adopted, after the wavelet decomposition of signal denoising, the sensitivity test of the non-dimension parameters is accomplished, combined with the k proximity algorithm, and finally the gearbox of k proximity abnormal detection method is established, laid the theoretical basis for the online safety monitoring of gearbox.(5) The urban rail vehicle bogie of safety monitoring key software modules are developed. Based on safety monitoring methods of axle box bearing and gearbox, with full use of high efficiency operation and friendly interface of C# and strong data calculation ability of MATLAB, the key software modules, the axle box bearing and gearbox, of urban rail vehicle bogie safety monitoring is completed by the method of combined programming. Through real-time measured data obtained from online safety monitoring hardware platform, then feature information is extracted, so as to realize the bogie online safety monitoring function of key components, and promote the engineering application of safety monitoring methods of urban rail vehicle bogie.