A method for extracting the center of butt ring based on short-range short-arc segment images

Abstract

The invention relates to a docking ring circle center extraction method based on a close-range short-arc image. The docking ring circle center extraction method comprises the following steps: carrying out epipolar rectification on a binocular image containing a short-arc docking ring, dividing a threshold by using a standard deviation method, extracting a ring surface by means of regional attributes, and then extracting inner and outer edges; carrying out dense reconstruction on the extracted ring surface region by using a semi-global matching method to obtain three-dimensional point cloud in a camera coordinate system; calculating a ring surface normal vector of the point cloud, and projecting a coordinate in a plane vertical to the normal vector; distinguishing the inner and outer edges in a new plane, and respectively carrying out perfect circle fitting on the inner and outer edges; and finally, obtaining an accurate circle center coordinate of the docking ring by use of concentric ring constraint according to obtained centers and radiuses of the inner and outer edges. According to the docking ring circle center extraction method provided by the invention, from the characteristics of the docking ring, three-dimensional point cloud data are directly projected into a normal incidence spatial plan, ellipse fitting is simplified to circle fitting, and meanwhile, error points are eliminated by constraint conditions of inner and outer rings, and the docking ring circle center extraction method has the advantages of accurate result and small calculated amount.

Description

technical field

[0001] The invention relates to a method for extracting and estimating the center of the torus, in particular to a method for extracting the center of a docked ring based on short-distance short-arc images. Background technique

[0002] In the field of aerospace, the docking ring is a common target in space vehicles. Only by accurately estimating the pose of the docking ring target can accurate docking be carried out, so as to carry out space tasks such as material transportation and aircraft repair. Among them, the detection of the torus and the estimation of the center of the torus are the key steps in pose estimation. For decades, the pose estimation of docking rings has always been a hot issue, and scholars have proposed many pose estimation methods.

[0003] At present, the pose estimation of the spacecraft is mainly carried out for the cooperative target, that is, the marker points can be marked on the cooperative target, and the pose estimation can be...

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