Introduction
English, Revision 07, Date: 07.03.2018
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Some steering servos and motor controller can be directly controlled by the steering
controller so that a vehicle control unit is not required in every application. Related to
monitoring, redundancy and customized modifications to the vehicle, a
vehicle
control unit
(e.g. PLC) is recommended for large vehicles.
If emergency stop devices are to be used, a vehicle control unit must be used in com-
bination with the track guidance controller to ensure maximal safety.
1.3.3
Sensor Fusion
The steering controller receives information from the sensor fusion about the position.
The sensor fusion can be connected internally (preferably when navigating with tran-
sponders or Sky Trax Tags) or externally (e.g. in the case of a laser scanner). The sen-
sor fusion provides the steering controller the following data (called
pose
):
-
position on X coordinate
-
position on Y coordinate
-
velocity
-
angle
The sensor fusion establishes these values based on the data of the connected sen-
sors (e.g. transponder antennas, laser scanners, GPS system). If required, systems
with physical guidance tracks can be integrated (e.g. inductive guide wire, optical
guidance).
There is a selection of different odometric sensors available, such as incremental / ro-
tary encoders. Optionally the accuracy and load-dependence of the odometry can be
enhanced by using the Götting Gyro HG 84300. It is also possible to calculate the
odometry from two sources and compare their results. This way, the sensor failures
can be identified.
1.3.4
Track Controller
The task of the track guidance controller is to move the vehicle from the current posi-
tion (given by the sensor fusion) to the next support point. The controller also calcu-
lates the rest of the track along several support points (it forms what are known as
regressions) and delivers the virtual track that the vehicle can drive on.
The tracks between the support points are reconstructed with smooth functions (re-
gressions over several support points) so that a continuously controlled movement of
the vehicle is possible. The values of position, accuracy, 16 free and 16 defined bits
are stored at each support point.
