高速数控机床平滑路径规划分析

Smooth Path Planning for High Speed CNC Machines

高速数控机床切削速度大于60 m/min,加速度大于2g,对于小曲率及不连续切线加工,易导致冲击尖峰,产生机械振动,降低切削质量,缩短设备寿命。目前,通过路径平滑技术可消除刀具路径的不连续性,但该技术仅限于线性刀具路径。提出基于双回旋曲线倒角的路径平滑方法,该方法可将任意直线、弧组成路径转换为曲率连续路径,通过路径的弧长参数化,简化插值。通过数控激光切削机床测试可知,平滑圆角可在圆弧与圆弧之间或圆弧与直线之间拟合。与贝塞尔曲线圆角比较分析可知,该方法提高了进给速度,缩短了循环时间,且所得曲率轮廓更平滑。

The cutting speed of high-speed CNC machine tool is more than 60 m/min and the acceleration is more than 2g.For small cur-vature and discontinuous tangent machining,it is easy to cause bump peaks,produce mechanical vibration,reduce cutting quality and shorten the life of equipment.At present,the discontinuity of tool path can be eliminated by path smoothing technology,but this technol-ogy is limited to linear tool path.A new path smoothing method based on chamfer of double gyration curve was proposed.By this method,any straight line and arc path could be converted into curvature continuous path,and interpolation was simplified by parameterizing the arc length of the path.According to the test of NC laser cutting machine tool,smooth corner can be fitted between arc and arc or between arc and straight line.Comparing with Bessel curve roundness,this method improves feed speed,shortens cycle time and smoothes curva-ture profile.