| 摘要 |
<p>A method of measuring a hollow object such as a pipe 20 comprises temporarily attaching to the pipe a reference target support 10, 12, 14, 16 such as a stencil that supports a plurality of scannable reference targets 22. When scanning the pipe with a movable scanner 28, most conveniently a hand-held scanner, the reference targets provide a positional reference for the scanner. A reference target support that is attachable to or movable along the pipe has a display face presenting and supporting a plurality of scannable reference targets 22. The display face can stand up (supports 10,12) from a surface of the object or may lie against (14, 16) a surface of the object. During a scanning operation the scanning device 28 feeds a scanning signal to a processing system 30 which applies triangulation and other processing techniques to the signal to determine the position and orientation of the scanning device 28 with respect to the pipe section 18. The scan output is a 3D model of the pipe end geometry. The model is post-processed to determine the cross-sectional geometry of the pipe end including internal and external diameter, wall thickness and out-of-roundness. The reference target support and the scanner may be movable together along a pipe as an internal inspection pig.</p> |
