
B-63784EN/01 PROGRAMMING 14.COMPENSATION FUNCTION
- 539 -
- Block immediately before the offset cancel command (G40)
In the block immediately before the compensation cancel command
(G40), a compensation vector is created from the movement vector of
that block and the tool vector at the end point of the block as shown
below :
Tool center path (after compensation)
Programmed path
V
M1
V
M2
V
T1
V
C1
V
C2
V
T2
G40
Fig.14.14.2 (f) Block Immediately before G40
The compensation vector (V
C2
) of block 2 is created so that it is
perpendicular to V
T2
and lies in the plane formed by the tool vector
(V
T2
) at the end point of block 2 and the movement vector (V
M2
) of
block 2.
- Method of compensation vector calculation
In leading edge compensation, the compensation vector is calculated as
follows :
(1) Tool vector(V
T
)
(2) Movement vector
The movement vector (V
Mn+1
) of block n+1 is obtained from the
following expression :
ú
ú
ú
û
ù
ê
ê
ê
ë
é
−
+
−
+
−
+
=
+
n
Z
n
Z
n
Y
n
Y
n
X
n
X
n
M
V
1
1
1
1
(3) Compensation vector
The direction of the compensation vector (V
Cn
) of block n is
defined as follows :
(1) (V
Mn+1,
V
Tn
) > 0 (0deg < θ < 90deg.)
V
Cn
V
Tn
V
Mn+1
V
Cn
θ
θ
V
Tn
V
Mn+1
Direction of V
Cn
(V
Mn+1
× V
Tn
) × V
Tn
θ represents the included angle
between V
Mn+1
and V
Tn
.
(0° ≤ θ ≤ 180°)
Fig.14.14.2 (g) Direction of the compensation vector (1)
n
: Absolute coordinate value of X axis
at end point of block n
Y
n
: Absolute coordinate value of Y axis
at end point of block n
Z
n
: Absolute coordinate value of Z axis
at end
oint of block n