Abstract: How to automatically measure geometric parameters of train wheels is a key problem, and it has not solved probably up to now. A novel and simple method for measuring geometric parameters of wheels is put forward. Most key geometric parameters, such as diameters at any given point of the tread, flange thickness, flange height, rim thickness, rim width, wheel flats etc., can be easily gotten by installing parallelogram mechanisms together with laser transducers. Wheels are dragged simply by a chain to pass through the measurement system when the measurement results are done, which has totally changed the situation that a measurement platform is required to support the wheel and makes it rotate in order to take measurements. Methods to calibrate the measurement errors of the system are also discussed, and some in-situ measurement results are given.

Key words: Geometric parameters, Laser transducers, Measurement, Parallelogram mechanisms, Train wheels, Chips, cutting force, GH706, PCBN tool, tool wear