On-line measurement of the straightness of seamless steel pipes using machine vision technique

In this paper, on-line and real-time laser visual alignment measurement tec hnique is studied to measure the spatial straightness of large objects. The basic principle of the visual alignment measurement is detailed. The mathe matics models of visual sensor, measurement system and their calibrations a re presented. Based on the technique, an experiment system is developed and the straightness of a 1500 mm long seamless steel pipe is inspected. The e xperiment results show that the measurement technique can achieve total on- line measurement and it offers high precision and stability, which is of pr actical importance for the application. (C) 2001 Elsevier Science B.V. All rights reserved.