  This paper is focused on delivering a solution that can scan and reconstruct
the 3D profile of a pipeline in real-time using a crawler robot. A structured
infrared (IR) laser ring projector and a stereo camera system are used to
generate the 3D profile of the pipe as the robot moves inside the pipe. The
proposed stereo system does not require field calibrations and it is not
affected by the lateral movement of the robot, hence capable of producing an
accurate 3D map. The wavelength of the IR light source is chosen to be non
overlapping with the visible spectrum of the color camera. Hence RGB color
values of the depth can be obtained by projecting the 3D map into the color
image frame. The proposed system is implemented in Robotic Operating System
(ROS) producing real-time RGB-D maps with defects. The defect map exploit
differences in ovality enabling real-time identification of structural defects
such as surface corrosion in pipe infrastructure. The lab experiments showed
the proposed laser profiling system can detect ovality changes of the pipe with
millimeter level of accuracy and resolution.
