NURBS曲线实时插补进给速度控制的研究

摘要

Numerical control technology marks the core of modem manufacturing, in which CNC in-terpolation module is one of the most important modules of numerical control technology.NUKBS curve is one type of free curves, which can be applied to numerical control field due to its lots of advantages ;While the interpolation of NURBS curve as well as accuracy and speed of acceleration/deceleration control are the key index of CNC system.Through analyzing the principle of NURBS curve path interpolation,approximate NURBS spline parameters are proposed based on Taylor expansion formula.Considering the relationships between curvature and velocity fluctuating as well as the relationship between chord error and interpolation period, feedrate fluctuation could be adjusted and controlled to idea level through adjusting feeding speed according to chord error.%数控技术标志着现代制造业的核心,数控插补模块是数控技术中最为重要的模块之一.NURBS曲线是自由曲线的一种,由于其NURBS曲线的诸多优越性,使其能够很好的应用到数控领域中.NURBS曲线插补及加减速控制的精度和速度是CNC系统的重要指标.通过分析NURBS曲线的插补原理,提出了基于Taylor展开公式逼近NURBS样条参数.同时考虑速度波动于曲率的关系,弦误差与插补周期的关系,根据弓高误差调节进给速度,能够将进给速度波动控制在理想水平.