Research On Extraction Method Of Rail Corrugation Based On Flexible Virtual Ruler

For a long time,Chinese economy has been in a state of rapid growth,as one of the main modes of transportation for the public,the main artery of the national economy,the important national infrastructure and livelihood projects have played a very important role in economic development.With the continuous increase of railway mileage,the improvement of the train speed and the increase of train flow,the rapid development of high-speed train technology,the requirements of train on the smoothness of the rail surface are also increasing.The uneven corrugation of the rail surface(referred to as corrugation)will not only bring n oise to the train operation and affect the ride comfort of the train,but also increase the wheel/rail impact and shorten the service life of wheel/rail,and even endanger the traffic safety.Therefore,the rail corrugation is certainly regarded as one of the most important index for departments of rail maintenance to periodically measure and monitor.However,there is not a general mathematical model for the extraction of rail corrugation.The calculation of rail corrugation is still an incomplete problem in engineering,Therefore,the purpose of this paper is to design a general and standardized extraction model of rail corrugation,which can greatly supplement the definition and extraction method of rail corrugation.In this paper,the method of rail irregularity extraction is introduced from three aspects: rail smoothness signal acquisition,data preprocessing and rail corrugation extraction.In the aspect of rail smoothness sign acquisition,a hand push type rail corrugation is built to measure the geometric characteristics of the rail surface.In the aspect of rail smoothness preprocessing,the Empirical Mode Decomposition(EMD)is selected to extract the trend of the rail according to the non-linear and non-stationary characteristics of rail smoothness data,and a slope position matching algorithm is proposed to extend the original signal to sol ve the endpoint effect in EMD and optimize the trend extraction results.In the aspect of rail corrugation extraction,in view of the the imperfection of rail corrugation description and the blank of digital rail corrugation extraction,the fleible virtual ruler model is proposed,which makes the extraction of rail corrugation become a visible digital calculation process,and improves the rail corrugation extraction that cannot be processed before.The model can not only simulate the traditional way of extracting the rail corrugation,and slide the virtual ruler on the whole rail to obtain the corrugation value of the rail.Moreover,it can adaptively extend the length of the virtual ruler according to the measurement purpose and band demand,and flexibly give the value of the rail corrugation that meets the user’s goal.In addition,the standard definition of rail corrugation is improved,which provides a new idea and method for the measurement and evaluation of rail corrugation.Finally,a large number of simulation experiments and real data analysis show that using EMD method can extract trend items effectively.The practicability,accuracy and reliability of the elastic virtual string model are verified.