Fig. 1. Structure diagram of laser vision system

Fig. 2. Image preprocessing procedure

Fig. 3. Image preprocessing effect. (a) Original image of weld laser detection; (b) median filtering results; (c) threshold segmentation results with Otsu method

Fig. 4. Extraction and filling of connected domain. (a) Extraction result; (b) filling result

Fig. 5. Extraction and filling of connected domain in complex noise environments. (a) Original image; (b) connected domain filling result

Fig. 6. Scanning line position determination diagrams. (a) α∈[0°,90°); (b) α=90°; (c) α∈(90°,180°)

Fig. 7. Flow chart of laser stripe skeleton extraction based on genetic algorithm

Fig. 8. Center points scanning of laser stripe

Fig. 9. Schematic of line fitting and error points elimination

Fig. 10. Feature point extraction of the weld seam

Fig. 11. Field working diagram of laser vision system. (a) To be welded; (b) welding

Fig. 12. Representative images collected during the test. (a) Proposed method; (b) Hough method

Fig. 13. Statistical graph of weld feature points extraction deviation. (a) Proposed method; (b) Hough method