AIB 2015-07: Experimental Validation and Mathematical Analysis of Cooperative Vehicles in a Platoon

[Thomas Ströder]

The following technical report is available from
http://aib.informatik.rwth-aachen.de:

Experimental Validation and Mathematical Analysis of Cooperative
Vehicles in a Platoon
Hilal Diab
AIB 2015-07

The infrastructure of roads in many countries is congested because of
the rapid increase of the amount of traffic flow in the past few years.
A significant part of this is due to the increase of freight transport,
which is continuing to grow. Nowadays, safety on the roads and saving
fuel should also be taken into consideration while finding the solutions
to road congestion. One suggested solution to the problem is to increase
the capacity of the highways.

This can be realized by forming platoons of vehicles and automatically
controlling the vehicles in order to maintain short, but at the same
time, safe distances between the different vehicles within the platoon.
The development of intelligent sensors and electronic control systems
within vehicles make autonomous driving in platoons possible. Enabling
vehicular wireless communication between the items of the platoon
improves the performance of the controlled platoon significantly.
Furthermore, enabling the platoon to communicate with other traffic
members, such as other vehicles, intelligent traffic lights and
infrastructure road units, allows the platoon to perform more complex
driving scenarios for autonomous vehicles, such as crossing intersections.

The first part of this thesis investigates the behavior of the platoon
when only communication between its items is possible. The safety of the
vehicles within the platoon is investigated, taking the effects of the
communication faults on the behavior into account. This analysis could
be helpful in the process of controller design, where the developed
controller should ensure stability despite network failures and should
achieve an optimal performance in every situation. Therefore, the
verification of the controller behavior was investigated by formal
verification methods: a reachability analysis of a dynamic and hybrid
system. The safety of practical relevant scenarios was checked.

In addition, a hardware platform was set up to test the platoon's
behavior under the influence of hardware shortage, such as noises and
time delays caused by hardware components. A 1:14 scaled platoon of four
trucks equipped with sensors and WiFi modules was designed. This
platform was used for testing different cooperative vehicle platoon
controllers by examining their performance and influence on the safety
in case of communication problems within the platoon.

The second part of this thesis studies the behavior of the platoon when
communication between the platoon and the intersection road unit is
enabled. The following scenario has been considered: When a platoon of
autonomous vehicles following a leader approaches an intersection, the
platoon should change its highway mode to other modes in order to cross
the intersection safely and efficiently. To realize that, information
about the actual position of the platoon together with information of
other vehicles in the intersection area are needed. Based on this
information the platoon has to decide which mode should be performed.
Therefore, we extended our platform with an indoor positioning system
which is able to provide the position to the objects in a test
environment independently. An intersection management system was
implemented in order to test different scenarios related to different
crossing modes of the platoon. Results showed that platoons can be
controlled efficiently and safely while crossing the intersection.