On-line Dynamic Detection Technology Of Wheelset Size And Research On Wheel-making Decision

Wheels are constant wear and tear when the train is running on the rail,so wheel profiles change.It is necessary to check the profile of train wheels precisely and timely in order to prevent train derailment.In addition,it is significant to study on wheel re-profiling technology to optimize the cost of maintaining wheel-sets.It can prolong expected life of wheels by making proper maintenance strategy to maintain wheels at minimum cost.Based on the work of domestic and oversea scholars,the online wheel profile and diameter measuring system and wheel re-profiling technology have been studied in the paper.Firstly,the overall structure of wheel profile and diameter measuring system is studied.And working principles of each module in the system are introduced.Then,the installation parameters of each laser sensor are designed based on working principles.Secondly,key algorithms of the measuring system have been studied and designed in the paper.And SolidWorks and AutoCAD are used to simulate the sensor output data.Algorithms,including coordinate transformation,data fusion,curve fitting and circle reconstruction are designed based on the simulation results.A wheel profile fitting method based on automatic extraction of segmentation points is proposed to get precise wheel prolife.Thirdly,the wheel profile and diameter measuring system is installed in the train depot.Then,a single train repeatedly passes through the detection area to acquire data.The experiment result shows that the measuring results has high accuracy and consistency.And results can meet requirements of on-site inspection.Lastly,the wheel re-profile technology is studied.The SPSS is used to analyze the interdependency between wheel diameter wear and wheel flange width.Flange width wear model based on state transition and wheel diameter wear model based on mathematical statistics are built separately.And single-stage and multi-stage planned turns strategies of an individual wheel have been built on the two models.Monte Carlo simulation is used to compare two strategies,and the result shows that multi-stage planned turns strategies of an individual wheel is better than single-stage strategies.The planed turns strategy model of the whole train wheels is further built based on diameter difference.Compare an actual wheel re-profile policy with the policy of model,the result shows that the wheel re-profile policy made by model can save 3mm of the wheel diameter,which means the model is practical.