# Fanuc Series 15i/150i-MA (Programming) Operators Manual

4.INTERPOLATION FUNCTIONS PROGRAMMING B-63324EN/03
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3) Three-dimensional tool compensation vector at the last point
Position :The vector is on the plane containing the point,
previous point, and next point. It is perpendicular to
the straight line connecting the previous and next
points.
Direction :The direction of the vector is close to that of the
three-dimensional tool compensation vector at the
previous point. (When the direction of three-
dimensional tool compensation vector V at the point
is close to that of three-dimensional tool
compensation vector V0 at the previous point, the
angle θ between V0 and V satisfies the following
condition : |θ| < 90° )
Magnitude :The magnitude of the vector is the offset
corresponding to the offset number specified by G41.
After the system exits from the spline interpolation mode, the
three-dimensional tool compensation vector produced at the last
point is used.
4) Other specification
- If a point after the first point and the previous and next points
are on a straight line, the vector plane cannot be determined
for the three-dimensional tool compensation vector at the
second or subsequent point. If this happens, the vector plane
is determined by the straight line and the three-dimensional
tool compensation vector at the previous point.
Fig.4.14 (b) Vector 1
- If the points before and after a point other than the first point are
identical, the three-dimensional tool compensation vector at the
second or later point is produced in the direction of the straight
line connecting the point and the previous (or next) point.
Fig.4.14 (c) Vector 2
- If a point after the first point and the previous and next points are
all identical, the three-dimensional tool compensation vector at
the previous point is used as that at the point.
- Specify three points subjected to spline interpolation for which
the three-dimensional tool compensation vectors are produced in
such a manner that they make an obtuse angle. If they make an
P
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P
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P
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V
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V
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P
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P
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P
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V
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