NURBS曲线高速高精度加工的插补控制
An Interpolator for NURBS Curve Machining with High-Speed and High Accuracy
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摘要: 针对复杂零件高速精密加工的需求,提出了一种NURBS曲线的实时插补算法.它基于NURBS曲线的矩阵表示,通过适当的插补预处理、运用参数预估计与校正的插补策略以及合理的近似计算方法,简化了插补的实时计算,保证了算法的实时性.特别是引入了插补误差和进给加速度的实时监控,使进给速度能随曲线曲率自适应调整,实现了NURBS曲线高速高精度加工的插补控制.Abstract: 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.
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