CT70104B_e.doc / Nov-15
Page 6 / 29
1
2
3
r
o
r
i
Zone c
r
o
r
i
1
2
3
Zone c
V
Line
V
Line
V
Line
V
Line
V
circ
V
cir
c
V
=
circ
V
Line
cos
ß
ß
Also it is required to have a smooth profile with no angles and edges, where all values of
acceleration and deceleration are reduced to the possible physical minimum.
As a result of these requirements we find a speed profile as follows:
Line speed
V
L
Speed profile
-1/2 L
0
+1/2 L
(a)
(a)
(b)
(b)
(c)
Typical profile of the rotational speed with a cutting cycle at cutting length "L"
Zone (a) results from the ratio between the cutting length and the active rotating circumference
of the tool.
Length > circumference reduces the speed of this zone (with respect to line speed) and may
include temporary standstill.
Length < circumference however increases the speed of this zone. Zone (b) is an over swing
zone, necessary to allow an edge-free transition from zone (a) to zone (c).
Zone (c) is the penetration zone of the tool, and the shape of the profile is ruled by the
geometry of the machine, requiring a reciprocal cosine curve in this situation.
The CT701 firmware continuously calculates an optimized speed profile from the
geometric properties of the machine with consideration of actual cutting length
and momentary line speed.
Very short control loop cycles combined with the smart algorithms of profile
calculation provide excellent accuracy, efficiency and performance.
