The invention belongs to the technical field of
welding quality detection, and particularly relates to a visual image-based
welding seam defect detection method, which comprises the steps of
image acquisition, image preprocessing,
data analysis, data output, defect classification and
decision making,
system closed-
loop optimization and the like. According to the method, by synchronously collecting two-dimensional images, three-dimensional shapes and
heat distribution data of
metal welding seams and adopting a polarization filter and annular LED
light source combination scheme, multi-dimensional
conjoint analysis of physical defects and thermodynamic characteristics is achieved, basic characteristic data are extracted through primary
processing, quantifiable defect coefficient indexes are generated through secondary
processing, and the detection accuracy is improved. And finally, generating a comprehensive defect index through a multi-
modal fusion
algorithm, constructing a well-arranged intelligent analysis decision chain, and establishing a self-evolution mechanism of
data acquisition-analysis decision-model iteration through real-time interaction of a detection result and an
algorithm model. The
system can continuously optimize the
detection threshold value and the characteristic weight parameter according to the actual working condition of the
production line, and the continuous improvement of the detection sensitivity is kept.