An Interpolator for NURBS Curve Machining with High-Speed and High Accuracy

NURBS has been widely used in CAD／CAM for modeling complex parts．To improve the capability of CNC machines in machining complex parts，modern interpolators capable of generating NURBS curves are required．In this paper a real-time interpolator for NURBS curves based on parameter prediction and correction is presented．The proposed approach provides good performance in two respects to meet the requirements of high-speed and high accuracy machining．First，the calculation time is significantly reduced by applying preprocessing，avoiding to compute the derivative and radius of curvature of curves．Second，feed-rate can adapt to the curve’s curvature to limit the contour error and feed-acceleration within the allowable range．