Melt Pool Width Extraction Method in Laser Directed Energy Deposition Based on Variable Step Size Erosion Model

To solve the problem of insufficient melt pool width feature extraction accuracy caused by splash, arc light, and other interferences in the metal deposition process, a melt pool width extraction method based on the variable step size erosion model is proposed according to the characteristics of the spatial distribution of the melt pool size features. To achieve accurate measurement of the melt pool width, the melt pool image is first denoised using mathematical morphology and then segmented roughly using manual thresholding. Subsequently, the melt pool contour is iterated using an erosion model to obtain precise point localization information after fine segmentation, followed by the calculation of the melt pool width. Comparison experiments demonstrate that the method exhibits excellent accuracy and robustness in extracting melt pool width, while also showcasing high efficiency in fulfilling the requirements for closed-loop control. These findings lay the groundwork for the closed-loop control of the melt pool size.