| Since the sixth major speed increase,the construction of high-speed railways has been fully developed,and the turnout structure has changed from the ordinary single-turn turnout to the current movable core rail turnout.The harmful space is eliminated,and the stability and safety of the high-speed train passing through the turnout are guaranteed.However,high-speed turnouts,as the most important part of high-speed railway lines,require regular maintenance.At present,domestic rail inspection trolleys only inspect basic rails.Although there are trolleys inspecting high-speed turnouts abroad,they are not popular due to high costs.In response to this situation,this article introduces machine vision detection technology on the basis of the traditional rail inspection trolley to achieve the detection of the position of the sharp rail relative to the basic rail and the position of the core rail relative to the wing rail.The main work is as follows:(1)Image acquisition and processing technology is the basis of machine vision detection technology.The detector uses the image acquisition system to upload the collected images,but due to the influence of factors such as the external environment,lighting and vehicle body vibration,the collected images will appear distorted.Therefore,before extracting the center line of the light bar from the collected image,a series of preprocessing operations are performed.In this article,a fusion algorithm based on Zhang-Suen and gray center of gravity method is used.Experiments show that the thinning effect of this algorithm is better than the traditional 11 thinning algorithms,and the center line of the extracted light bar reaches sub-pixel accuracy.(2)Established a mathematical model for high-speed turnout detection,using various sensors to measure parameters such as gauge,over-height and mileage.At the same time,the principle of line structured light assisted machine vision measurement is used to detect the value of the surface difference,gap and rail head width of the sharp rail and the core rail.(3)A high-speed turnout core rail detector is designed on the basis of the traditional rail inspection trolley.Unlike the T-shaped rail inspection trolley,the structure of the detector is Y-shaped,which is convenient for installing an image acquisition system.At the same time,the mechanical structure of each part of the detector is designed,and the detection equipment required by the detector is selected.In order to verify the detection accuracy of the high-speed turnout core rail detector designed in this article,the measurement experiment is carried out on the straight sharp rail of the 18 th turnout with a speed of 250 km / h.First,the manual measurement method is used,that is,using the surface difference ruler to measure the surface difference,the feeler gauge to measure the gap,and the steel ruler to measure the width of the rail head.Then,thehigh-speed turnout core rail detector is used for detection,and the results of the two tests are compared and analyzed.The results show that the detection accuracy of the detector meets the detection requirements. |
