ANNUAL REPORT 2012

Ph D Graduation
Situation-Aware Vehicles
Supporting the Next Generation of Cooperative Traffic Systems
KRISTOFFER LIDSTRÖM
PhD thesis, Örebro University
Main supervisor: Tony Larsson (Halmstad University)
Co-supervisors Mathias Broxvall Örebro Universitet
Opponent: Dr. Steven Shladover, University of California at Berkeley, Berkeley, USA
Grading Committee: Professor Claes Beckman, Center for Wireless Systems, Royal Institute
of Technology KTH, Kista, Stockholm, Professor Simin Nadjm-Tehrani, Real-Time Systems
lab, Department of Computer and Information Science, Linköping University
Docent Paolo Falcone, Signals and Systems, Chalmers Institute of Technology, Göteborg
Wireless communication between road vehicles enables a range
of cooperative traffic applications including safety, efficiency
and comfort functions. A common characteristic of the envisioned
applications is that they act on environmental information
to intepret traffic situations in order to provide the driver
with warnings or recommendations. In this thesis we explore
both the detection of hazardous traffic situations in order to
provide driver warnings but also the detection of situations in
which the cooperative system itself may fail.
The first theme of this thesis investigates how traffic
safety functions that incorporate cooperatively exchanged
information can be constructed so that they become resilient
to failures in wireless communication. Inspired by how human
drivers coordinate with limited information exchange,
the use of pre-defined models of normative driver behavior is
investigated by successfully predicting driver turning intent at
an intersection using mobility traces extracted from video recordings.
Furthermore a hazardous driving warning criterion
based on model switching behavior is proposed and evaluated
through test drives. Maneuvers classified as hazardous in the
tests, such as swerving between lanes and not braking for traffic
lights, are shown to be correctly detected using the criterion.
Whereas robust coordination mechanisms may mask communication
faults to some degree, severe degradations in communication
are still expected to occur in non-line-of-sight conditions
when using wireless communication at 5.9 GHz.
The second theme of the thesis explores how communication
performance can be efficiently logged, gathered
and aggregated into maps of communication quality. Both innetwork
aggregation as well as centralized aggregation is investigated
using vehicles in the network as measurement probes
and the feasibility of the approach in terms of bandwidth and
storage requirements is shown analytically. In conjunction with
a proposed communication quality requirements format, tailored
specifically for vehicle-to-vehicle applications, such maps
can be used to enable application-level adaptation in response
to situations where quality requirements likely cannot be met.
Dr. Kristoffer Lidström
CERES Annual Report 2012
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