基于NURBS曲面的管道三维成像技术研究

Three-Dimensional Imaging Technology of Pipelines Based on NURBS Surface

管道的三维成像是处理变形检测数据最直观但也是最复杂的方式,而曲面的三维重建算法是实现管道三维成像的关键。为此,基于非均匀有理B样条(NURBS)曲面的三维成像技术,通过管道检测数据反求双三次NURBS曲面的节点矢量与控制点,并对管道机器人在检测过程中可能发生的周向转动进行优化处理,使用C++编程语言与OpenGL生成管道的三维模型,并对比了相同变形管道中,是否考虑检测机器人的周向转动对于成像效果产生的影响。研究结果表明:基于NURBS曲面的三维重建算法对于管道局部变形(凹陷变形、挤压变形)的表面重构精度较高,其成像效果清晰、逼真,且考虑检测机器人的周向转动时,所生成的三维模型表面过渡更加圆滑。研究结果可为油气输送管道三维成像技术的进一步研究提供参考。

Three-dimensional imaging of pipeline is the most intuitive but also the most complicated way to process deformation detection data,and the three-dimensional reconstruction algorithm of surfaces is the key to achieving three-dimensional imaging of pipeline. In view of this,based on the 3D imaging technology of NURBS( non-uniform rational B-spline) surface,the node vectors and control points of the bicubic NURBS surface are reversely calculated through the pipeline detection data. The possible circumferential rotation of the pipeline robot during the detection process is optimized. The three-dimensional model of the pipeline is generated using the C++ programming language and OpenGL. The influence of the detection robot’s circumferential rotation on the imaging effect in the same deformed pipeline is compared. The research results show that the 3D reconstruction algorithm based on the NURBS surface has high accuracy for the surface reconstruction of the local deformation of the pipe( depression deformation,extrusion deformation),presenting a clear and realistic imaging effect. The surface transition of the 3D model is smoother with detection robot’s circumferential rotation. The study results can provide references for the further researches on the three-dimensional imaging technology of oil and gas pipelines.