french institute of science and technology for transport ... - Ifsttar

Research orientation 2_Transport system quality, safety and optimization
Communication in
a mobile environment
Progress towards interoperability
Enormous implications of road safety.
The ANR PLATA project (Programmable Telematics
On-board Multistandard Radio Platform) sets out to implement
a new multistandard radio telematics platform for the
automobile sector based on emerging software radio technologies.
The flexibility of this technology makes it possible to use
different communications standards for vehicle/vehicle and
vehicle/infrastructure communications. The ultimate goal is
to provide Europe-wide interoperability between communication
systems.
In 2011, a PLATA project demonstrator was developed. At the
same time, a large number of simulations were performed,
making it possible to evaluate the scaling-up process and the
behaviour of the system with an increase in the number of
equipped vehicles. The framework that has been put in place
allows us to carry out realistic simulations of vehicle movement.
For this purpose; a simulator - SUMO (Simulation of Urban
Mobility) - was interconnected with the trajectory management
functionalities in the OPNET network simulator. The result was
that the trajectory and behaviour of each individual vehicle
could be identified. The next stage will be to simulate communications
with the OPNET software program. During trials
we have simulated the movement of several hundred vehicles
with the communications between them.
@ CONTACT
christophe.gransart@ifsttar.fr
55
Simulations on the Satory test track and on the
edge of the campus of Lille 1 University.
Energy and planning railway timetables
A new timetabling criterion
The ESTAS research unit is specialized in rail-related
themes and its expertise is widely recognized among its
partners (SNCF, RFF) as a result of several projects (the
national CIGIFRET project and the European ON-TIME
project). In 2009, it began to take energy into account
in its work on traffic management.
with a set of distinct possible solutions and can then construct
timetables that simultaneously meet passenger demand and
take account of energy consumption.
@ CONTACT
remy.chevrier@ifsttar.fr
The research into optimizing timetable planning which
has got under way since this decision therefore now includes
energy as a criterion. Planning of this type depends, in particular,
on train movement times allowing for disruptions and
drifting, i.e. when the train moves under its own inertia with its
motor turned off which leads to substantial savings. In 2011,
ESTAS proposed a method that generated a variety of driving
strategies using a number of speed profiles based on a trade-off
between journey times and energy consumption.
The method involves the multi-goal optimization of train movement
and is based on evolutionary algorithms for the competitive
optimization of energy consumption and journey times.
For a given optimization task the decision-maker is presented
Speed (m/s)
90
80
70
60
50
40
30
20
10
0
0
20 000
40 000
Benchmark
Alternative solution
60 000
Position (m)
80 000
100 000
120 000
140 000
Example of TGV speed profiles for a 135 km journey: the red plot shows
the minimized journey time and the green plot shows an alternative strategy
which saves energy while slightly increasing the journey time.
ANNUAL REPORT 2011 ifsttar.fr