formation driving. In these scenarios, control algo-
rithms can be tested and evaluated under the influence
of real communication link behavior (limitations in
medium access etc.) and also different communica-
tion protocols can be tested easily. Of course, also
some limitations exist. As the hardware nodes are lo-
cated quite close to each other, long distance com-
munications and the consequential channel behavior
cannot be simulated. Nevertheless, for detailed sim-
ulations of the interaction of communication proto-
cols, control engineering and the underlying system
in multi-robot teams and formation scenarios, the pre-
sented architecture is suites very well and allows an
easy and fast setup of significant simulations.
5 CONCLUSIONS
In order to simulate the behavior of networked multi-
robot systems in general a model for the communica-
tion channel has to be to implemented and verified.
In most cases this is only possible with simplifica-
tions and limitations and the simulated channel is not
representing a real communication channel anymore.
Therefore, the conclusions drawn from the simulation
of the tested algorithm might not be as meaningful as
desired.
The presented approach offers a possibility to re-
alize easily a meaningful simulation with real com-
munication hardware for network robotic scenarios.
It provides the exact behavior of the complete, com-
plex communication stack without any approximation
or simplifications. Thus, the behavior of multi-robot
algorithms can be directly investigated with all the
changes in the communication and data flow between
the robots. In the combination with a simulator like
USARSim is is possible to simulate network robotic
systems with basic physics and real communication.
The setup of a hardware communication in the
loop simulation is much easier than the setup of a
meaningful communication channel simulation com-
bined with a multi-robot simulation. There are even
less uncertainties in the behavior of the system when
you later go to real hardware.
Therefore, it is very easy to test the behavior of
algorithms for typical applications of network control
systems like teleoperation of robots or robot forma-
tion driving with a real communication channel be-
fore going to the real hardware. Due to the standard-
ized interfaces which are used, such kind of setups
also allow for an easy evaluation of different type of
wireless communication systems like e.g. WLAN,
UMTS, HSDPA/HSUPA, Bluetooth, WiMax. Espe-
cially testing of swarm behavior is very meaningful,
because like in the real system naturally the nodes in
the communication hardware in the loop simulation
are very close to each other.
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