For the purpose of detecting the rail profile quickly and accurately

a rail profile measuring system based on high-precision laser profiler is proposed.Establishing a world coordinate system according to the rails and a rail profile measurement model is constructed.Four sets of high-precision 3 D laser profilers are used to scan the rail body to obtain four contour lines of the rail

and convert the coordinate system and matching to get the real contour of the rail

and complete the measurement and calculation of the profile size and characteristic parameters.Compared with manual measurement

the repeating errors of the rail height

rail head width and rail bottom width are between 0.015～0.027 mm

0.023～0.076 mm and 0.036～0.071 mm

respectively

and the absolute errors are between 0.012～0.032 mm

0.02～0.07 mm and 0.01～0.12 mm

respectively

by field test.It proves that the system can complete the inspection of the rail profile size efficiently and stably

and improve the measurement speed and precision.