Hardware And Software Design Of Wheel Profile Measurement System Based On Laser Scanning

With the unceasing speedup of the train in China,traffic safety has been closely related to people's livelihood.As elements that determine the reliability and safety in railway traffic,wheel-set must be detected with high-precision.The measurement methods of wheel tread profile at home and abroad can be divided into dynamic on-line measurement and static measurement.Online dynamic measurement cost is high;the traditional static measurement,using fourth checker,has a low efficiency.With the rapid development of the field of electronic equipment and sensors from twenty-first Century,measuring instruments for measuring wheel profile have been developed in order to improve the work efficiency.Taking the economic cost into account,combined with the development of domestic and foreign measuring instrument the design of wheel profile measuring instrument,a portable measuring system for measuring profile of train wheels is presented in this paper.Based on scanning method,a portable measuring system for measuring profile of train wheels is presented in this paper.Scanning part,which is pulled manually,consists of an 1-D laser sensor,whose accuracy reaches 0.05mm,and a magnetic grid sensor.Every 0.05mm of magnetic head movement will make the 1-D laser sensor send its current data to the tablets to get the wheel profile.The geometrical parameters,including flange thickness,flange height,rim width and QR(which is representative of vertical wear)can be calculated once the scanning is done.The systematic errors and the random errors have been analyzed in this paper.After the error compensation,the repeatability error is below 0.05mm,and the measurement accuracy of each parameter is below 0.1mm.The basic contents of this paper are as follows:1.Introduced the measurement system and the measuring principle2.Explained the current locomotive wheel tread standards,and calculated the equation of standard LM tread in rectangular coordinates.3.Programmed the software in Android system for measuring instrument.4.Analyzed the systematic error,caused by glass refraction,and the random error.Both the theoretical analysis and experiment have been done in this paper.