3. DESIGN AND AUTOMATION OF THE RESCUE
VESSEL
Design and automation of the unmanned and autonomous
rescue vessel is a central element of the defined Searchand-Rescue-Operation.
The rescue vessel was designed
as a catamaran vessel (twin hull). It is equipped with
1 Safety related broadcast message
two electrical podded drives. This concept offers a better
agility and the possibility to save the person with a basket
between the hulls. The salvage of the POB takes place via
a hydraulically operated net basket, which is fixed at its
rear edge, see Clauss et al. (2010) for further information
about the design of the rescue vessel.
The central computer unit of the automation structure is
the navigation computer built as standard Industrial-PC
(PC/104) extended by additional interface cards to link
the sensors and the further devices of the control hierarchy.
The integrated navigation system consists of a fluxgate
compass, a Multi-(D)GNSS 2
receiver and a speed log to
obtain speed, heading, and position data of the rescue
vessel. Furthermore, the rescue vessel is equipped with a
remote-controllable infrared and a daylight camera for the
final salvage of the POB within the last ten meters.
The podded drives, the step motors, and the hydraulic
net basket are controlled with an auxiliary programmable
controller (SPS) on the field level. Therefore, different field
bus systems are integrated in the vehicle. Additionally, an
Ethernet network was established to connect the various
controllers and computers within the control hierarchy.
The developed control systems for motion control of the
vehicle are running as software routines on the navigation
computer. Therefore, the real time operating system
MATLAB/xPC-Target is used.
During the rescue process, numerous data are transmitted
by the established radio interfaces. The data include video
and audio streams as well as control and sensor data. The
required quality and stability will be reached by using
different redundant radio systems with various frequencies
and bandwidths to exchange the data. For instance, the
control and actuator data are transferred redundantly with
three different radio modems 3
to increase the reliability.
Thus, the delays can be reduced substantially during the
transmission.
Fig. 3 shows the complex automation structure, the used
devices, and their arrangement on board the rescue vehicle.
The yellow parts represent the communication and video
processing devices including the two camera systems. The
red devices belong to the control system and the sensors
are marked by green.