A novel laser vision sensor for weld line detection on wall-climbing robot

●We design a cross structured light sensor to detect and measure the weld lines.●We model and calibrate the cross structured light sensor.●A new approach is presented to extract the laser stripe.●The sensor system is applied on a wall climbing robot platform.

In this paper, we present a cross-structure light (CSL) sensor, that consists a structured light projector and a camera, for weld line detection. The structured light projector projects cross laser beams on the weldment to form cross stripes, which are captured in images by a CCD camera for measurement. We use feature points, a planar target and a homograph matrix to calibrate the sensor. We also propose an effective approach to extract laser stripes in images for weld line detection. Experiments show that the CSL sensor can capture 3D information of the weldment with very low measurement error, and the weld line detection approach is effective in wall-climbing robotic platform navigation.