A simple technique for structured light calibration in welding robots

Abstract

Structured light calibration is one of the most crucial parts in a visual sensing system of welding robots. And the main aspect of the structured light calibration is the accuracy. Besides, a practical and simplistic calibration approach is preferable. In this paper, we propose a simple technique for structured light calibration. The vertical and horizontal lines are added to the planar object to facilitate points detection. The information from the camera calibration is fully used to detect the points on the light stripe. Then parameters of the structured light plane are estimated based on three non-collinear points definition. It could be said that the computation in this study is straight forward. Furthermore, it does not require any additional equipment. Thus, it is a truly simple and practical calibration method. According to the experimental results, the calibration errors are less than 0.2 mm. It shows that our proposed method is acceptable to measurement system of welding robots.