
The following two pairs of "computed basic angles" exist that direct the tool axis
toward the + X axis direction.
(B 90 degrees; C 180 degrees)
(B 270 degrees; C 0 degree)
<1> When the current rotation axis angles are (B -70 degrees; C 30 degrees)
The "output angles" are (B -90 degrees; C 0 degree).
: 0 degree is adopted because it is nearer to the current position (30
degrees) of the C-axis that is the master axis. For the B-axis, 270
degrees is adopted which is the same pair. However, this is changed to
-90 degrees (270 degrees - 360 degrees) which is the nearest to the
current position of the B-axis (-70 degrees).
<2> When the current rotation axis angles are (B 80 degrees; C 500 degrees)
The "output angles" are (B 90 degrees; C 540 degrees).
: 540 degrees (180 degrees + 360 degrees) is adopted because it is nearer
to the current position (500 degrees) of the C-axis that is the master axis.
For the B-axis, 90 degrees is adopted which is the same pair.
<3> When the current rotation axis angles are (B 60 degrees; C 90 degrees)
The "output angles" are (B 90 degrees; C 180 degrees).
: Since the two candidates are equally near to the current position
(90 degrees) of the C-axis that is the master axis, a judgment is made
based on the current position of the B-axis. 90 degrees is adopted
because it is nearer to the current position (60 degrees) of the B-axis that is
the slave axis. For the C-axis, 180 degrees is adopted which is the same
pair.
<4> When the current rotation axis angles are (B 180 degrees; C 90 degrees)
The "output angles" are (B 270 degrees; C 0 degree).
: Since the two candidates are equally near to the current position
(90 degrees) of the C-axis that is the master axis, a judgment is made
based on the current position of the B-axis. In this case, however, the two
candidates are also equally near to the current position of the B-axis
(180 degrees). Therefore, the candidate is adopted in which the C-axis
(master axis) is nearer to 0 degree.
That is, the pair is adopted whose C axis angle is 0 degree and whose B
axis angle is 270 degrees.
When the slave axis angle is 0 degree, the direction of the tool axis becomes fixed
regardless of the master axis angle.
In that case, the master axis does not move from the current angle.
An explanation is shown below using a machine having a "BC type and tool axis Z" as
an example.
B-63534EN/02-05
Edit
Apprv. Desig.
Sheet
Title
Draw
No.
Date
Design
Description
Date
FANUC Series 16i/160i/160is-MB,18i/180i/180is-MB5,
18i/180i/180is-MB OPERATOR’S MANUAL
Concerning the addition of TOOL CENTER POINT
CONTROL FOR 5-AXIS MACHINING
Oct.27.2003
T. Horie
35/35