Researches On The Online Detection Of Wheel Set Wear Parameters Based On Photoelectric Image

With the development of rail transportation,especially in the last few years,the speed of the vehicle has been greatly accelerated,and the whole railway transportation industry has got a rapid development.However,the higher speed also increases the safety hazard in the process of vehicle operation.wheel set is one of the most important running parts of the railway vehicle,which is closely related to the operation safety of the vehicle.Runing for a long time will aggravate wheel wear,therefore,it is of great practical significance to detect the shape parameter of wheel set.In the wheel set detecting method based on machine vision,image acquisition camera is very important to the imaging position of wheel set,and the position of the camera in the space is seriously affected the calculation precision of the the wheel set parameters in the later.Due to the impact of rails and sleepers,the camera can only be installed in special position which below the horizontal plane,and the narrow space has brought a lot of trouble to the manual adjustment of the camera.In order to decrease the installation position of the image acquisition equipment and reduce the difficulty of manual adjustment,the paper according to the requirements of the wheel set parameters detection index issued by the railway departments designed an on-line detection method wheel set wear parameters based on photoelectric image.By analyzing and calculating the imaging characteristics in the inclined field of view,this method can realize the detection of wheel wear parameters.The main research contents in this paper are as follows:1.According to the principle of optical imaging,the paper designed the on-line detection model of wheel set parameters.By analyzing the complex situation of the vehicle and the characteristics of the wheel set,a method for calculating the parameters of the wheel set is designed based on the images acquired from the tilt angle of view.2.Described the key parameters calculation algorithm of the wheel set algorithm in the detection method in detail.Put forward a calculation method based on geometrical optics imaging according to the characteristics of the camera mounting position on the imaging of the wheel set,and establish the key points relationship between the image and the space of wheel set parameters.Finally completed the transformation from the image to the space coordinates,and calculated wheel parameters.3.Designed the method to realize the parameters detection,which mainly include camera calibration,image acquisition,image processing and parameter extraction,etc,and gave a detailed description and formula derivation about the specific design and hardware selection for each part.4.Experiments are performed to testify the accuracy of parameter calculation method in the design,including camera calibration experiment and parameter calculation experiment.The camera calibration experiment is carried out to verify the accuracy of the camera space installation angle through the calibration board,and parameter calculation experiment test by calculate the distance between certain points on the calibration to simulate verifying the accuracy of wheel set parameter calculation.