Documentation HG G-73650ZD | English, Revision 05 | Date: 09.03.2017 | www.goetting-agv.com
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Chapter 5: Commissioning
5.8.4 Optimising the speed ramps
A number of ramps are active in the speed control. The ramp of the navigation controller
can be adjusted with the parameter
Speed Ramp
on the Configuration –> Speed Controller
page (see section 5.4.7 on page 92).
This ramp refers to a time: If the parameter is set to 0.5, the vehicle reaches 0.5 m/s after
one second and 1 m/s after two seconds.
It is important here that the vehicle must be
technically capable of building up these accelerations.
What makes this even more
difficult is that the speed profile that arises on creating the segments with CAD6 contains
fixed-location speeds. This means that the acceleration resulting from the speed profile in
the segment file is higher at high speeds than at speeds.
Example:
Support point clearance = 0.5 m
In the case of a speed change from 1.1 m/s to 0.9 m/s, the vehicle travels an average
of approx. (1.1 m/s + 0.9 m/s) / 2 = 1 m/s. From the first to the second support point,
it requires approx. 0.5 m / 1 m/s = 0.5 s. This results in a necessary acceleration of
approx. 0.2 m/s / 0.5 s =
0.4
m/ss
.
In the case of a speed change from 0.3 m/s to 0.1 m/s, the vehicle travels an average
of approx. (0.3 m/s + 0.1 m/s) / 2 = 0.2 m/s. From the first to the second support
point, it requires approx. 0.5 m / 0.2 m/s = 2.5 s. This results in a necessary accelera-
tion of approx. 0.2 m/s / 2.5 s =
0.08 m/ss
.
ATTENTION!
If the vehicle is unable to follow the speed required by the segments, there is a danger that
at the end of the segment it brakes beyond the end of the segment.
