| Rail transportation mainly includes two parts: passenger loading and cargo loading, it has the characteristics of large capacity, high speed and economy etc., its security has been people’s attention. Wheel is an important part of the train, the stability of the walking route is the necessary condition to ensure the safe operation of the train. Due to the operation condition of wheel is extremely bad and the driver operation is not standard, and so on reasons, they are bound to cause wheel flats. Wheel flats are major hidden danger affecting the operation of trains but often overlooked by the workers, and the traditional test methods are of too much trouble. Therefore, developing a wheel flat of on-line test method is particularly important.This article tests the wheel flats based on vibration method, detection system is divided into signal collection part and signal analysis part. Germany Schenker VS080 vibration sensor signal acquisition part is adopted as a data acquisition device, VC6000 signal conditioners is adopted to regulate wheel flats signal, OPC protocol is adopted to implement the combination of the hardware and software, completing the acquisition, display and storage of wheel fault signal. Signal analysis part firstly models the wheel fault signal through MATLAB, then analyzes the wheel flats data, finding that the gaussian model is not suitable for non-stationary fault signal of pulse characteristic. Alpha stable distribution can be used to simulate the signal with obvious pulse. Secondly this thesis will combine the wheel flats signal and alpha stable, estimates the characteristic index and the dispersion coefficient,uses KLD method to classify the fault signal. Finally, the alpha stable distribution and Morlet wavelet has been combined to implement the fault signal test which is early in annihilation of the signal.The vibration wheel flats acquisition system has simple operation, realizes the online detection, has high degree of automation, has accurate test results. |
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