NURBS曲线插补算法及加减速控制研究

针对复杂零件高速高精密加工的需求,提出了一种基于阿当姆斯微分方程的NURBS曲线实时插补算法。通过对算法的合理简化与近似,保证了算法的实时性。此算法基于轮廓误差和法向进给加速度控制,使进给速度能随曲线曲率自适应调整。与之相适应,配合此插补算法,利用NURBS曲线的对称性预测减速点,提出了一种新的插补前抛物线-直线-抛物线S形加减速控制方法。该方法具有位置精度高、速度无突变、过渡平滑、计算简便等优点。通过采用MATLAB对插补轨迹仿真和实例分析,证明了插补算法和加减速控制方法的正确、合理、有效性。

A Study of NURBS Interpolation Algorithm and ACC-DEC Control

To improve the capability of CNC machines in complex parts maching,modern interpolators capable of generating NURBS curves are required.In this paper,a new NURBS interpolation algorithm is developed.It effectively predigests calculation of interpolation process and ensures the real-time characteristics of the interpolation algorithm by adopting the rational predigestion and approximate calculation.Through this algorithm the feed speed can be self-adapted based on chord error contrlling and feed acceleration controlling.A new ahead parabola-line-parabola S shape Acceleration-Deceleration controlling method is suggested which predicts deceleration-point in the real-time interpolation using the symmetry characteristic of NURBS curve.The algorithm has merits such as higher positon accuracy,no impact and simple calculation and so on.Through path emulation and instance analyses with MATLAB,the interpolation Algorithm and ACC-DEC Control is proved to be correct,rational and effective.