Research On Shape Errors Detection And Evaluation Method Of Electric Multiple Units Axle Based On Light Curtain

Since the beginning of the 21 st century,my country’s rail transportation industry has developed at an alarming rate.The people’s economic conditions and living standards have also been greatly improved with a series of policies since the reform and opening up.At the same time,people’s travel and Great changes have taken place in the transportation of goods.The application of EMU(electric multiple units)in transportation has become more and more extensive,and the utilization rate has increased significantly.Therefore,the requirements for the use performance and safety performance of the EMU are also increasing.Among them,the EMU axle that connects the wheels is an important component that transmits power to the wheels during the operation of the EMU,which has an important impact on the operation performance,safety performance and service life of the EMU,and the shape errors of the axle plays a key role in the evaluation of the axle quality.Therefore,the research on the detection and evaluation method of the shape errors of the EMU axle has important practical significance and application value.At present,although many enterprises and research institutions have reached the production standard in the detection of the shape error of the EMU axle,there are still many areas to be improved.For example,due to cumbersome measurement methods,it is impossible to realize online real-time detection of the shape error of the motor car axle,and the used shape error evaluation method is complicated,and the calculation time is long,which makes it impossible to be mastered by the workshop workers and the detection speed is slow.In response to these problems,this paper adopts a light curtain sensor-based measurement system for the surface data of the EMU axle,combined with a simple,feasible and high-precision form error evaluation method.Under the premise of ensuring the detection accuracy,the roundness error and cylindrical shape of the EMU axle are realized.Online detection of degree error and spatial straightness error.First of all,in this article’s EMU shape errors detection scheme,a set of EMU axle measurement system is built based on light curtain sensors.By controlling the various relative motions of the axles and sensors,the axle surface data required for the evaluation of the shape error is realized.Collection.Then,in terms of roundness error evaluation,the Hough transform technology applied in the field of digital image processing for graphic detection is introduced into the circle fitting,and based on Bayesian linear regression,the final circle fitting is realized,and the smallest inclusive area is applied.Method to achieve the final assessment of the roundness error.In the evaluation of cylindricity error,based on the circle fitting part in the evaluation of roundness error,the starting and ending sections are used to construct grid points respectively,and the grid search algorithm is used to realize the evaluation of cylindricity error.In terms of spatial straightness evaluation,the measurement points are transformed into the same coordinate plane through the projection and coordinate transformation of the measuring points,and the rotation approximation method is applied to realize the evaluation of the spatial straightness.Finally,in the course of the experiment,the evaluation results of roundness error,cylindricity error and spatial straightness error are compared with the results of other shape error evaluation methods to verify the correctness and stability of the evaluation method proposed in this paper.In addition,the measurement results in this article have higher accuracy,which shows that the axle parameter measurement and shape errors evaluation methods in this article are effective and feasible,and can meet the requirements of testing standards.