Documentation HG G-73650ZD | English, Revision 05 | Date: 09.03.2017 | www.goetting-agv.com
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Chapter 4: Software
3.
Unit: Unit of the value
The following values can be changed:
–
Min. Dist. Reading: Minimum distance that must be travelled before a transponder is
accepted again. It should be
at least half an antenna width
to prevent repeated
activation of the transponder calculation in the event of problems in the border area
of the antenna (see documentation of transponder antenna).
–
Delta Angle Max: Maximum angle difference between the angle changes calculated
by the gyroscope and those calculated by the wheels in 10 ms. If the difference
exceeds the threshold set here, the accuracy of the position deteriorates artificially
and an emergency stop is triggered.
–
Single Antenna calculation: Enables the calculation with only one antenna. On some
vehicles with two or more antennas, a calculation with only one antenna leads to a
deterioration in the accuracy. In such cases, the calculation with only one antenna
can be avoided.
–
Gyro: Enables the position calculations with one gyroscope. If the gyroscope is
enabled, it also must be present, as otherwise an error occurs. With the gyroscope,
the accuracy of the odometry can be improved in most cases. The advantage of the
gyroscope is that is less dependent on load with regard to payload, air pressure and
slip. The disadvantage of the gyroscope is the drift and the resulting necessity for
drift compensation.
This averaging of the drift rate should be carried out at
intervals of a maximum of approx. 15 minutes with the vehicle at a stand-
still (4.3.10 on page 73).
–
Cycles Correction: Specifies the number of calculation cycles in which a position cal-
culated via the transponders is included in the position of the vehicle. If the value is
10, the calculated position is adopted in 10 steps into the position of the vehicle. As
the navigation controller carries out 100 calculations per second, the correction of a
value of 10 takes 0.1 seconds.
–
Load Position at Startup: Enables saving the current position at a standstill. This posi-
tion is then reloaded when the navigation controller is switched on. However, this is
not recommended for vehicle that can be carried or moved without the navigation
controller. During commissioning, loading the position when switching on is not rec-
ommended either, as it is best to start a number of measurements with the zero posi-
tion.
–
Tolerance Trans. Distance Abs: Tolerance of the transponder distances. A position cal-
culation with transponders is only carried out if the distance between the transpon-
ders measured by the odometry matches the distance from the transponder table.
This parameter specifies the tolerance in metres by which the distance measured by
the odometry may deviate. A common value is 0.1 metres.
–
Tolerance Trans. Distance Rel.: Same as 'Tolerance Trans. Distance Abs', only that the
tolerance is specified relatively here. 1 means that at two metres between the tran-
sponders a maximum of 0.02 metres error is permitted.
4.3.9 Configuration –> Sensor Fusion GPS
In the case of sensor fusion with GPS, the position determined by the GPS is not adopted
directly into the vehicle position. Instead, an odometry is corrected with the help of the GPS
positions. The correction takes place by means of controllers that minimise the error be-
