
PROGRAMMING22. RISC PROCESSOR
B–63534EN/02
638
: Cutting surface of block N3
V
: Cutting point compensation between
blocks N2 and N3
C1
: Cutting surface of blocks N1 and N2
C2
C1
C2
V
C1
N1
N2
N3
L1
S2
S1
R
Z–axis
Y–axis
Tool center path
Programmed path
C–axis on the
cylindrical surface
Fig. 22.2 (g) When the Diameter of an Arc Is Less Than the Parameter
Value
(1) The tool moves at a specified feedrate while cutting point
compensation is being applied between blocks.
(2) The actual speed indication and feedrate during circular interpolation
are as described below.
Actual speed indication
The speed component of each axis after cutting point compensation
at a point in time during circular interpolation is as follows:
Fz’=Fz – – – Speed component of linear axis
Fc’=Fc+(Vce–Vcs) – – – Speed component of rotation axis
Fy’=–(Vce–Vcs)
180
rp
– – – Speed component of offset axis
Fz : Speed component of a cylindrical interpolation linear axis
before cutting point compensation
Fc : Speed component of cylindrical interpolation rotation axis
before cutting point compensation
Vcs: Rotation axis component of a tool contact point vector (Vs
in the figure) at the start point at a point in time
Vce: Rotation axis component of tool contact point vector (Ve in
the figure) at the end point at a point in time
r : Radius of the cylinder of a rotation axis
Accordingly, the actual speed indication during circular
interpolation is greater than the specified value when |Fc’| >
|Fc|(inner offset of the arc). Conversely, the actual speed
indication during circular interpolation is less than the
specified value when |Fc’| < |Fc|(outer offset of the arc).
D Feedrate during cutting
point compensation