Measurement of ring spinning spun yarn spindle position based on binocular vision

Aiming at the problem of insufficient positioning accuracy of the ring spinning spun yarn automatic jointing machine using an automated guided vehicle platform after spun yarn breakage, a three-dimensional coordinate detection method of the ring spinning spun yarn spindle position based on binocular vision is proposed. The bottom column of the spindle was selected as the detection target, the contrast of the background of the bottom column of the spindle was physically enhanced, the picture of the bottom of the spindle was collected with a calibrated binocular camera, the two-dimensional coordinates of the midpoint of the bottom edge of the spindle bottom profile were obtained by the processing of the local picture, and the three-dimensional world coordinates of the midpoint of the bottom edge of the spindle bottom profile were calculated based on the method of single-pair feature-point matching. Comparing this paper’s single-pair feature-point matching method with the traditional multi-pair feature-point matching detection method (semi-global block matching), the experimental results showed that: the detection errors of both the single-pair feature-point matching method and the traditional semi-global block matching detection method were less than 2 mm; both methods satisfied the requirements of the positional detection accuracy of the spindle joints. The position detection method based on single-pair feature-point matching saved 80% of the program time compared with the traditional semi-global block matching method.