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.