
B--63003EN--1/02
7. FEEDRATE CONTROL/ACCELERATION
AND DECELERATION CONTROL
592
When a block specifies circular feed per minute and bit 3 (CIR) of
parameter No. 8475 is set to 1, the feedrate of the tool is automatically
determined so that the acceleration along each axis does not exceed an
allowable acceleration.
The allowable acceleration is determined from the maximum cutting
feedrate (set in parameter No. 1432, No. 1430, or No. 1422) and the time
needed to reach the maximum cutting feedrate (set in parameter No.
8470).
During circular interpolation, the tool is controlled so that it always
moves along the path at the specified feedrate. At this time, the total
acceleration of the tool, consisting of the acceleration along each axis, is
calculated as follows:
F
2
R
Acceleration=
F: Feedrate
R: Arc radius
A feedrate is calculated, as shown below, so that the total acceleration
does not exceed the smaller of the allowable accelerations along the two
axes of circular interpolation. If a specified feedrate is greater than the
calculated feedrate, the tool is decelerated to the calculated feedrate.
Rmin(∼
x
, ∼
y
)
F=
= min(∼
x
, ∼
y
)
F
2
R
∼
x
, ∼
y
: Allowable accelerations
along X--axis and
Y--axis
Feedrate determination
based on an allo wable
acceleration du ring
circular interpolation