Rotation axis calibration of a turntable using constrained global optimization

For determining the rotation axis as the baseline to transform between camera and turntable coordinate frames, rotation axis calibration of a turntable using constrained global optimization is proposed. At the beginning, camera parameters are calibrated using multiple views of only one pattern positioned differently and 3D corner points are retrieved with the pattern placed onto the rotation turntable in a 360° view. Then the rotation axis direction vector is decided under the constraint of the distance between each closed circle trajectory plane and each circle with its center is determined by fitting the circle with global least squares method, respectively. Experimental results demonstrate that the proposed method is effective for estimating the parameters of rotation axis.