Military Communications and Information Technology: A Trusted ...

Chapter 3: Information Technology for Interoperability and Decision...
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B. UGV RTS-HANNA
Our multi-robot system consisted of a ground vehicle and two UAVs. This
section provides information about the ground vehicle. The following section will
cover the UAVs.
The unmanned ground vehicle is called RTS-HANNA (see Fig. 2). It is based
on an off-the-shelf Kawasaki Mule 3010 Diesel chassis which has been retrofitted
with a drive-by-wire interface (by PARAVAN GmbH). That interface enables
manual as well as full computer control of the vehicle. Due to the manual control,
HANNA is fully street-licensed. Its maximum velocity is 40 km/h, and its maximum
payload is 600 kg.
HANNA can be equipped with a multitude of sensors. For environmental
perception, two continuously rotating 3D laser rangefinders RTS-ScanDriveDuo
with an update rate of 0.8 Hz each for close range, one Velodyne HDL-64E with
an update rate of 15 Hz for long range, one Ibeo Lux for fast obstacle detection
within the main driving direction, and a Microsoft Kinect are mounted. For
the navigation, odometry, a gyroscope, and two GPS receivers are available. HANNA
communicates either by WiFi, or a serial link in the unlicensed industrial, scientific
and medical (ISM) radio band, or by GSM/UMTS.
HANNA has five embedded PCs at her disposal, used for processing the sensor
data, for navigation and to control her, in our case by BML orders, cf. [15] for more
details. Software for those PCs is developed using the robotic framework RACK
(Robotics Application Construction Kit). To make the PCs capable for executing
ROS components, we, in general, cross-compiled ROS and made the ROS libraries
and API available to our middleware RACK. In particular, a kind of gateway
module has been implemented. That module is part of the RACK communication
system, but is also able to publish and subscribe to ROS topics. It receives the BML
tasks and organizes their execution by publishing corresponding tasks for the UAVs
as ROS topics. It also publishes sensor data for the BML-GUI. In short, HANNA
is running the ROSCore and the BMLConnector in the ROS context, the gateway
module to connect both worlds, and the rest of the software components in RACK.
HANNA navigates on a known road network available in OpenStreetMap
(OSM) format. To navigate to a certain point of destination, a simple A* search
for a shortest path in the OSM geodata is initiated, cf. [16] for details. To follow
the planned path, a hybrid feedback controller, introduced in [17], is applied. This
service uses reactive obstacle avoidance and local path re-planning.