摘要
由于NURBS曲线的弧长是曲线参数的非解析积分形式,因而曲线弧长的准确参数化是插补计算的关键。通常,基于泰勒展开或曲线弧长多项式拟合的近似求值方法被用于插补计算;然而,截断误差的引入最终会导致速度指令波动,影响数控加工精度。针对具有最小速度指令波动的NURBS曲线插补算法研究,首先提出了曲线参数-弧长的三阶拟合多项式方法;然后以该方法计算结果为初值,并提出了求取精确曲线参数的弦截速度校正方法;最后进行了仿真验证。仿真结果表明,所提出的方法计算量小,提高了曲线参数的计算精度,相比于现有的方法,速度指令波动有很大减小。
In regard to NURBS curves,because its arc length of the curve is the integral form of non-analytical parameters,so the accurate parameterization of the arc length of curves is the key to interpolation calculation.However,the introduction of the truncation error will lead to feedrate fluctuations and affect the accuracy of CNC machining.In regard to the study of the interpolation algorithm for NURBS curves with minimal feed fluctuation,this paper gives curve parameters-arc three order polynomials fitting method.Then we give the secant feedrate correction method to get exact value after getting initial value with polynomials fitting method.At last we take a simulation test.The simulation results show that the proposed method has small amount of computation,improves the accuracy of the curve parameters,and decreases feed fluctuation significantly compared to the current methods.
出处
《机电一体化》
2014年第5期26-30,共5页
Mechatronics
关键词
插值算法
多项式拟合
速度指令波动
interpolation algorithm
polynomial fitting
feed fluctuation
