A:  F=FPO (endfeed, quadf, cubf)

endfeed = 程序段末尾的速度

quadf = 二次方多项式

cubf = 三次方多项式

常规的多项式定义：

F(x) = a0 + a1*x + a2*x2 + a3*x3

a0 = 起始值，上段程序段进给速度。starting value, feed of the previous block

a1 = 直线多项式系数linear polynomial coefficient

a2 = 二次多项式系数quadratic (square law) polynomial coefficient "quadf"

a3 = 三次多项式系数cubic polynomial coefficient "cubf"

计算直线多项式系数：

a1 = endfeed - a0 - a2 - a3

例：(from DOCONCD)

N1 F1000 FNORM G1 X8 G91 G64; constant feed profile, incremental dimension data

N2 F2000 X7; setpoint velocity change as a step function (sudden change)

N3 F=FPO(4000, 6000, -4000) ; feed profile via the polynomial with feed 4000 at the

end of the block - this acts on the next motion

N4 X6...

N4程序段的起始进给速度2000mm/min，而到达程序末尾为4000mm/min。根据多项式定义实现插补。公式中X范围从N4程序段起始位置0到终止位置1。

a1 = 4000 - 2000 - 6000 - (-4000) = 0 进给速度：

At the start of the distance to be moved through (x=0) : F = 2000 + 0*0 + 6000*0 +

(-4000)*0 = 2000 mm/min

At the center of the distance being moved through (x=0,5): F = 2000 + 0*0,5 +

6000*0,5 + (-4000)*0,5 = 3000 mm/min

At the end of the distance moved (x=1) : F = 2000 + 0*1 + 6000*1 + (-4000)* 1

= 4000 mm/min