A 3-D Tube Scanning Technique Based on Axis and Center Alignment of Multi-laser Triangulation

This paper presents a novel 3D tube scanning technique based on a multi-laser triangulation. A multi-laser and camera module, which will be mounted in front of a mobile robot, captures a sequence of 360 degree shapes of the inner surface of a cylindrical tube. In each scan of the sequence, a circular shape, which is composed of four partial ellipses, is reconstructed from a multi-laser triangulation technique. To reconstruct a complete shape of the tube, the center and axis of the circular shape in each scan are aligned to a common tube model. To overcome inherent alignment noises due to off-axis robot motion, sensor vibration, and etc., we derive and apply a 3D Euclidean transformation matrix in each scan. In experimental results, we show that the proposed technique reconstructs very accurate 3D shapes of a tube even though there is motion vibration.