
A-79348E
Title
Draw
No.
31/88
page
FANUC Series 30i-MODEL A
Tool center point control
for 5-axis machining
Ed. Date Design Description
Date Jan.16.’04 Design. Apprv.
The "output angle" is explained below using a tool rotation type machine as
an example.
This example illustrates a machine having a "BC type tool axis Z."
X
Y
Z
C-axis: 1st rotation axis (master)
B-axis: 2nd rotation axis
Fig. 1.1 (h) BC type tool axis Z
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 rotary 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 group. 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 rotary 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 group.
<3> When the current rotary 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 group.