
A-78640E
Sheet
Title
Draw
No.
04 Feb.08.’03 Part of (4) is added or modified. Addition of 2.16.5
03 Jul.02.’02 A. Fukumoto Part of (3) is added or modified. T.Endo
02 May.13.’02 A. Fukumoto Addition of Tool Radius control for 5-axis machining etc T.Endo
Ed. Date Design Description
Date Jan.25.’02 Desig. A.Fukumoto Apprv. T.Endo
FANUC Series 16i /18i -TB
Specifications of AI High-Precision Contour Control /
I Nano High-Precision Contour control
85/190
2.19.3 Description
• Spiral interpolation functions
Spiral interpolation in the XY plane is defined as follows.
(X-X
0
)
2
+(Y-Y
0
)
2
=(R+Q')
2
X
0
: X coordinate of the center
Y
0
: Y coordinate of the center
R : Initial radius in spiral interpolation
Q' : Radius increment or decrement
The above equation can be rearranged using the following.
X
S
: X coordinate of the start point
Y
S
: Y coordinate of the start point
I : Vector from the start point to the center (X coordinate)
J : Vector from the start point to the center (Y coordinate)
R : Initial radius in spiral interpolation
Q : Radius increment or decrement per circle of the helix
L' : Current number of circles minus 1
θ : Angular displacement between the start point and the current
position(degree.)
The equation is transformed as follows.
(X-X
S
-I)
2
+(Y-Y
S
-J)
2
= (( R + (L’ +
360
θ
)Q)
2
• Controlled axis
For the conical interpolation function, a total of four axes, two axes in the same
plane and two other axes, can be commanded. The axis not on the plane can be a
rotation axis.
• Difference of end point
If the difference between the position of specified and calculated end points of a
helix along an axis in the specified plane exceeds the value set in parameter,
alarm is issued. If the difference of in height between the position of specified
and calculated end points of a helix exceeds the value set in parameter, alarm is
issued. Please refer to following figure for detail.