Characterisation of a structured light probe system designed for internal pipework inspection
W Jackson1, G Dobie1, C MacLeod1, F Caldwell1 and C Forester2
1University of Strathclyde, UK
2Inspection Hire, UK
The integrity of industrial pipework is ensured through routine inspection. Interior visual inspection plays a key role in maintaining and characterising the deterioration of infrastructure over time. A remote visual inspection system consisting of a laser profiler and omnidirectional camera has been developed to inspect 3-6 inch-diameter pipes. The laser profiler provides geometric information of the interior surface, allowing quantitative analysis of corrosion/pitting, erosion and cracking. The dimensional accuracy of this analysis depends upon the systematic and sampling errors of the laser profiler. An error model detailing these errors is introduced, as well as a calibration framework to correct and account for them. The calibration method proposed allows for both manual correction of the optical elements as well as a software-based calibration approach. The calibration technique reduced peak sizing errors from 2.7 mm to 0.14 mm within 120 mm-diameter pipes. This provides a complete remote visual inspection system capable of producing 3D models of pipework with a known tolerance that is suitable for deployment within industrial environments.
