Vision measurement technique of axle based on double beam

In order to improve the measurement efficiency and accuracy of axle diameter, this paper presents a new method for automatic measurement of axle. According to the data obtained from the scanned contour fitting and calculating the axle diameter. The system adopts the principle of double beam projection measurement. The precise measurement of large scale axis is accomplished by collimating beam and beam reflection. The system consists of two parts: the supporting device and the measuring sensor unit. Based on the scanning data acquisition, interpolation, fitting a straight, line fitting the entire axle contour, calculate the length and diameter of numerical train axle. Through the analysis of the experimental data, it can be seen that the double beam projection measurement sensor has the advantages of high measurement accuracy, large diameter measurement, good stability and so on. The repeatability error reaches 0.007 mm, and the measurement accuracy reaches 0.02 mm.The experimental results show that this method is feasible and it can solve the technical requirements for accurate inspection of axle size parameters in the process of production and processing of high-speed EMU.