Operating Manual HG G-98830YA | English, Revision 02 | Date: 21.06.2021
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Chapter 5 – Operating Principle
The distances between the transponders can therefore be at most so large that it is
ensured that the vehicle with the odometry does not deviate so far from the track
that the transponder antenna no longer hits the next transponder. The closer togeth
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er the transponders are, the higher the accuracy of the tracking. However, for com
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plex driving maneuvers many transponders are needed in some sections. On the
other hand, it must be ensured that the transponder antenna never receives more
than one transponder signal at a time.
When two transponder antennas are used on a vehicle, omnidirectional vehicles in
particular can localize themselves and also clearly determine their orientation.
5.3 Position Detection with a Navigation Controller
A downstream navigation system such as the Götting navigation controller calcu
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lates the position of the vehicle within the facility from the following data:
the known position of the antenna on the vehicle (usually with offset to the nav
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igation point),
the measured relative position of the transponder under the antenna,
the known position of the transponder in the local coordinate system (defined
by the transponder list).
Once several transponders have been read in succession, the controller can also de
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termine the orientation of the vehicle.
Figure 8
Sketch: Track guidance / free navigation with transponders
For path planning, a driving course consisting of segments is stored in the navigation
controller. This course is subdivided into virtual support points, which form the virtu
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al track. The navigation controller can thus calculate a sequence of segments for
each destination that the vehicle must travel. It then guides the vehicle from support
point to support point. To do this, it interpolates the route over several support points,
specifies the driving speed and calculates the required steering angles in curves.
Whenever it can determine the deviation between the odometrically estimated and
the actual position via the localization of a transponder, it also calculates the correc
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tion path that brings the navigation point back onto the virtual track.
Götting has developed the navigation controller HG G-73650, which can process the
data of certain common incremental encoder types. It is also able to use different
Götting positioning systems to adjust the actual position.
The navigation controller HG G-73650 can use, for example, the transponder anten
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na described here, the laser scanner, guide wire sensors, magnetic sensors and also
GPS signals for position detection. It also manages courses and converts the posi
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tions of the sensors mounted on the vehicle into the coordinate system of the facility.
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Transponder antenna
Transponder
Navigation point
Virtual track
Calculation of the track
Support points set virtually on the driving course for path planning
Vehicle
Direction of travel (X direction)
with junction
to the support point
