数控加工运动的平滑处理

为了满足高速加工的要求,提出假设圆弧过渡法来处理两相邻运动矢量拐角处的速度,过渡小圆弧的半径能随加工精度的变化而自动地调整,通过限制加工小圆弧的最大速度来限制拐角处的速度,利用超前分析的方法,根据减速所需的最大距离提出了一种多程序段运动平滑算法,实现进给速度提前减速,从而防止刀具在拐角处发生过载,并有效地减少了工件形状在拐角处,或小半径圆弧的加工误差;用等效的梯形加减速方法实现了S型曲线加减速的分析,导出了S型曲线加减速实时精确的插补算法,从而克服了用查表法来近似计算速度的缺点。这些算法简单、有效,已在最新开发的高速铣床上得到应用。在高速加工时获得了高的加工精度。

Adaptive Algorithm for Feedrate Smoothing of High Speed Machining

To satisfy the need of high speed machining,assumptive arc is used to contour two adjoining moves together on the corner to make smooth paths,the radius of small transit arc can be adjusted with contour accuracy, and the federate on the corner can be limited through limiting the maximum speed of small arc.A look-ahead algorithm of series of moves is proposed for the process of speed adjustment in advance,which avoids the occurrence of overload of cutter tool on the corner and reduce the servo track error of part on the corner or of small arc move.Equivalent trapezoidal velocity profile is used to analyze the speed of S-curve velocity profile and work out the accurate interpolation method of S-curve velocity profile which overcomes the disadvantage of looking up table to calculate federate speed approximately,thus high resolution and fine surface quality can be obtained while machining speed is high.The algorithm is effective and has been adopted by CNC system of newly developed high-speed milling machine.