AbstractIn this paper, an accurate 3D model analysis of a circular feature is built with error compensation for robot vision. We propose an efficient method of fitting ellipses to data points by minimizing the algebraic distance subject to the constraint that a conic should be an ellipse and solving the ellipse parameters through a direct ellipse fitting method by analysing the 3D geometrical representation in a perspective projection scheme, the 3D position of a circular feature with known radius can be obtained. A set of identical circles, machined on a calibration board whose centres were known, was calibrated with a camera and did the model analysis that our method developed. Experimental results show that our method is more accurate than other methods.
A typical slope has been comparatively analyzed with 2D and 3D FEM, it is showed that the length of surface load at top surface of slope shorted, the stability factor of slope of 3D model increased, which is far more than that of 2D model. In a certain degree, the safety factor got by 3D model is bigger than that of 2D model, so the safety factor of slope is underestimated by 2D model analysis sometimes.
A 3D Model Analysis of Knee Prosthetic Motion (1st Report, A 3D Mathematical Model of Knee Joint after Total Knee Arthroplasty)