Mechanical System and Template-Matching-Based Position-Measuring Method for Automatic Spool Positioning and Loading in Welding Wire Winding

Welding wire is a major type of welding consumable, which needs to be winded onto spools for sale. Currently, the winding process is accomplished manually due to obstacles such as automatic spool loading and clamping. When loading the spool, the angular position of the spool is a prerequisite for matching the drive rod on the spindle and drive bore on the spool. Therefore, this paper proposes a template-matching method combined with area-based matching and feature-point detection to measure the angular position of the spool, and presents a mechanical system that can rotate the spool to match the drive rod and push the spool onto the spindle. A novel feature-point distribution density (FPDD) method was developed to accelerate the matching process and improve matching reliability by pre-locating the searching area. The robustness and accuracy of the template-matching-based measuring method were validated using a built prototype of the mechanical system. The comparison result shows that the proposed method was superior in robustness, accuracy, and speed, and it was efficient for automatic spool loading in the welding wire winding process.