Research Of Measurement Technology For Wheel-set Size Of Rail Vehicle On Couple 2D Line Laser Displacement Sensors

With the increasing of the speed of our country,the safety of the train is becoming more and more important.As an important part of the rail transit,the wheelset is subjected to more complicated loads and shocks,the high-speed operation of the train requires that the parameters of the wheelset meet the technical requirements of the high-speed operation of the train,Detection of the key size is of great significance to the safety of train operation.This paper combining with actual requirements of the project development plan of science and technology of Jilin province and a train manufacturing company,according to the principle of binocular structured light detection,the binocular line structure was studied on the detection technology of light.The main research contents and results are as follows:(1)In order to get a more complete data of wheel tread profile,a new method of binocular line wheel alignment is proposed,which is made up of two structured light.A method of registration in the frequency domain for the point cloud is proposed,the same feature of point cloud reduction to digital matrix,then polar coordinates transformation of the matrix,calculate the Fourier inverse transfer of the cross power spectrum,calculate the peak position of assault function,in order to get the relative rotation angle of two cloud.Similarly,we can get the translation vector of two point cloud matrix.(2)The accuracy of the point cloud registration method is verified.The following conclusions can be drawn from point cloud translation verification: There is no linear or nonlinear error in the translation registration,at the same time,the influence of the magnification factor on the detection accuracy is determined.The following conclusions can be drawn from point cloud rotation verification: The registration error is an odd function with periodic change,the paper puts forward that the registration error of rotation can be segmented and fitted,and then the optimal value is obtained by the iterative fitting of the straight line and the initial value obtained by piecewise fitting.(3)The noise of sensor itself are analyzed,tested again registration parameters after the same point cloud add noise,it can be concluded that the noise of sensor itself has no influence on the registration method.(4)Aiming at the problem of the global tilt of point cloud,principal component analysis to fit the datum plane with the wheel side data after the registration of point cloud,according to the plane parameters,the point cloud is rotated integrally,the rotating point cloud is calibrated in diameter direction,and the diameter calibration coefficient is determined.Finally,the three dimensional reconstruction model of wheel is given.(5)In this paper,an experimental platform for measuring wheelset with binocular structured light is established,a standard wheel and other wheelset is conducted several measurement experiment.Experiments show that the repeated measurement accuracy of wheel diameter is less than or equal to 0.07 mm for the measurement system,the repeated measurement precision of the end face runout and the radial runout is less than 0.04 mm,the measurement error of diameter is less than 0.05 mm,the measurement error of the end face runout less than 0.06 mm,the measurement error of radial runout less than 0.04 mm.Meet the requirements of wheelset measurement accuracy...