Features extraction of butt joint for tailored blank laser welding based on three-line stripe laser vision sensor

In this paper, a measurement method for features extraction of butt joint for tailored blank laser welding based on three-line stripe laser vision sensor is proposed. The measurement system is composed of a laser stripe vision sensor and a control module. A three-line stripe laser, a CMOS camera and a LED lighting unit are used to constitute the laser stripe vision sensor. Laser lines and narrow weld joint are both recorded in the image by vision sensor. And then the image is sent to the control module for evaluating in order to obtain high quality raw images. Additionally, the image processing algorithms for extracting the features of weld joint are discussed depending on the characteristics of laser beam welding of tailored blanks and the algorithm is as follows: firstly, the original image is filtered by Laws texture energy filter; secondly, the edge of joint is extracted by Canny operator; thirdly, the laser stripe is segmented by threshold; lastly, textural feature and laser stripe information are fused for extracting feature points of butt joint. Experiments are well conducted to verify the effectiveness of the proposed method.