A leading error compensation method for weld seam tracking based on dual-sensing and dual-wavelength

Purpose Leading error in line laser weld seam tracking significantly affects tracking accuracy. This paper aims to propose an accurate and reliable compensation method without increasing system complexity for weld seam tracking to improve tracking precision. Design/methodology/approach Based on the line laser seam tracking method, the seam image is simultaneously captured to obtain the angle offset of the seam relative to the sensor direction, which is then combined with the leading distance to calculate the leading error. The two sensing methods use different wavelengths and are captured simultaneously by a color industrial camera. The images of the two different wavelengths can be separated by extracting the RGB components, and the compensated tracking results are obtained after image processing. Findings The results of static positioning experiment indicate that the average absolute error in weld seam positioning is reduced to 0.099 mm after compensation. The real-time tracking experiments demonstrate that the proposed method preserves tracking accuracy even with changes in the sensor’s angle of deviation during welding, with the average absolute error being 0.248 mm. This method effectively enhances the precision of line laser weld seam tracking when the sensor exhibits a deviation relative to the welding direction. Originality/value By using the dual-sensing and dual-wavelength method for leading error compensation, the method effectively addresses the leading error issue while maintaining the advantages of the line laser seam tracking method.