A High-Accuracy Algorithm Combing Shape Prior with Algebraic detected elliptical arc distance for Circle Pose Measurement

Existing the detected ellipse coefficients-driven circle-pose measurement algorithms suffer from low measurement accuracy as well as measurement failure in the presence of partial occlusions. This paper proposes a high-accuracy circle pose measurement algorithm that combing the shape prior constraint with the detected elliptical arc data and accurately obtain the image contour of the spatial circle to measure circle pose. This algorithm selects the spatial circle projection contour as the shape prior item; the algebraic detected elliptical arc distance is defined as the sum of points-to-contour distance between detected elliptical arc points and the spatial circle projection contour, which is elliptical arc data item. It defines the likelihood function based on these items so that the circle pose parameters can be obtained by minimizing the algebraic detected elliptical arc distance. The proposed algorithm avoids performing ellipse fitting; it utilizes the shape prior constraint of the spatial circle and the algebraic point-to-contour distance to effectively reduce the impacts of partial occlusions on the pose measurement results. Experiment results demonstrate that the algorithm can reliably and accurately measure the circle pose in presence of occlusions.