Dimensional measurement method for hot forgings by combining a dimension correction model and green laser subpixel centerline extraction

To achieve accurate dimensional measurement of large forgings during the forging process, a method is proposed that combines a dimension correction model and green laser subpixel centerline extraction. Based on the green laser measurement, a dimensional correction measurement model is constructed by referring to the dual-position image data to compensate for the positional deviation of the forging. Then, to accurately extract the subpixel centerline of the green laser stripe, an anisotropic Gaussian kernel on the Riemannian manifold is constructed to address image deformation induced by refractive index changes around hot forgings. Finally, length measurement experiments were carried out in the laboratory. The experimental results show that the measurement error is controlled within 2 mm, and the accuracy meets the production requirements of large hot forgings.