
4.INTERPOLATION FUNCTIONS PROGRAMMING B-63944EN/02
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- Cutting point compensation
(1) Cutting point compensation between blocks
As shown in Fig. 4.10(b), cutting point compensation is achieved
by moving between blocks N1 and N2.
(a) Let C1 and C2 be the heads of the vectors normal to N1 and
N2 from S1, which is the intersection of the tool center
paths of blocks N1 and N2
(b) After the tool moves to S1 according to the command of N1,
the tool moves through V on the C-axis as a result of
cutting point compensation, then through
rV ××−
180
π
along the Y-axis.
Z-axis
C-axis on the
cylindrical surface
Y-axis
S1
C1
C2
N1
N2
V
Cutting surface of block N2
Programmed path
V : C-axis component of C1 - C2
C1 : Cutting surface of block N1
C2 : Cutting surface of block N2
Fig.4.10 (b) Cutting point compensation between blocks
(2) Cutting point compensation in a circular command block
As shown in Fig. 4.10(c), the movement required for cutting
point compensation is made simultaneously with circular
interpolation in block N1.
(a) Let C0 be the head of the vector normal to N1 from S0,
which is the tool center position at the start point of circular
block N1. Let C1 be the head of the similar vector at the end
point.
(b) As the tool moves from S0 to S1, a superimposed
movement is made by the C-axis component of (C1 - C2)
(V in the figure) on the C-axis, and a superimposed
movement is made by
rV ××−
180
π
along the Y-axis.
along the Y-axis.
That is, the following expressions are valid. As movement
is made through L as shown in Fig. 4.10(c), the
superimposed movements are made on the C-axis and
Y-axis as follows:
VC
rVY )(
180
∆−=∆