Aiming at the problem of approximate symmetry of the feature points in the pin matching process of the electrical connector and the large-angle rotation transformation between different images, it proposes a feature point matching algorithm based on the invariant of the six-point characteristic number. In this paper, the feature points were divided into two parts of convex hull and interior point. Then the invariance of the order of the points on the convex hull in the projective transformation was used to achieve the convex hull matching, and the similarity of interior point feature vectors based on convex hull feature points was used to achieve the interior point matching. The experimental results prove that the proposed algorithm can achieve the matching of the pin feature points well with certain robustness.
