In urban search and rescue (USAR) operations, there is a considerable amount
of danger faced by rescuers. The use of mobile robots can alleviate this issue.
Coordinating the search effort is made more difficult by the communication issues typically faced in these environments, such that communication is often
restricted. With small numbers of robots, it is necessary to break communication links in order to explore the entire environment. The robots can be
viewed as a broken ad hoc network, relying on opportunistic contact in order
to share data. In order to minimise overheads when exchanging data, a novel
algorithm for data exchange has been created which maintains the propagation
flooding while reducing overheads. Since the rescue workers outside
of the structure need to know the location of any victims, the task of finding
their locations is two parted: 1) to locate the victims (Search Time), and 2)
to get this data outside the structure (Delay Time). Communication with the
outside is assumed to be performed by a static robot designated as the Command Station. Since it is unlikely that there will be sufficient robots to provide
full communications coverage of the area, robots that discover victims are faced
with the difficult decision of whether they should continue searching or return
with the victim data. We investigate a variety of search techniques and see how
the application of biological foraging models can help to streamline the search
process, while we have also implemented an opportunistic network to ensure
that data are shared whenever robots come within line of sight of each other or
the Command Station. We examine this trade-off between performing a search
and communicating the results.
A Doctoral Thesis. Submitted in partial fulfillment of the requirements for the award of Doctor of Philosophy of Loughborough University.