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This thesis addresses the problem of road intersection safety with regard to a mixed population of automated vehicles and non-automated road users. The work derives and evaluates safety-critical scenarios at road junctions, which can pose a particular safety problem involving automated cars. A simulation and evaluation framework for car-to-car accidents is presented and demonstrated, which allows examining the safety performance of automated driving systems within those scenarios. Given the recent advancements in automated driving functions, one of the main challenges is safe and efficient operation in complex traffic situations such as road junctions. There is a need for comprehensive testing, either in virtual testing environments or on real-world test tracks. Since it is unrealistic to cover all possible combinations of traffic situations and environment conditions, the challenge is to find the key driving situations to be evaluated at junctions. Against this background, a novel method to derive critical pre-crash scenarios from historical car accident data is presented. It employs k-medoids to cluster historical junction crash data into distinct partitions and then applies the association rules algorithm to each cluster to specify the driving scenarios in more detail. The dataset used consists of 1,056 junction crashes in the UK, which were exported from the in-depth On-the-Spot database. The study resulted in thirteen crash clusters for T-junctions, and six crash clusters for crossroads. Association rules revealed common crash characteristics, which were the basis for the scenario descriptions. As a follow-up to the scenario generation, the thesis further presents a novel, modular framework to transfer the derived collision scenarios to a sub-microscopic traffic simulation environment. The software CarMaker is used with MATLAB/Simulink to simulate realistic models of vehicles, sensors and road environments and is combined with an advanced Monte Carlo method to obtain a representative set of parameter combinations. The analysis of different safety performance indicators computed from the simulation outputs reveals collision and near-miss probabilities for selected scenarios. The usefulness and applicability of the simulation and evaluation framework is demonstrated for a selected junction scenario, where the safety performance of different in-vehicle collision avoidance systems is studied. The results show that the number of collisions and conflicts were reduced to a tenth when adding a crossing and turning assistant to a basic forward collision avoidance system. Due to its modular architecture, the presented framework can be adapted to the individual needs of future users and may be enhanced with customised simulation models. Ultimately, the thesis leads to more efficient workflows when virtually testing automated driving at intersections, as a complement to field operational tests on public roads.

A travers des systèmes d’assistance à la conduite, l’automatisation de la conduite est introduite graduellement, avec le but de créer un transport plus sûr, confortable et moins polluant. Cette thèse discute le développement d’un système d’assistance à la conduite qui permet une conduite automatisée sur autoroute. La thèse présente le concept « Legal Safety », qui base le développement d’un système d’assistance à la conduite sur le code de la route international. Ceci permet de partager la route avec des conducteurs humains, sans nécessairement changer l’équipement sur l’infrastructure ou sur les autres véhicules. Le « Legal Safety » permet aussi un partage intuitif avec le conducteur du véhicule égo. Chapitre 1 situe le concept « Legal Safety » dans les concepts des systèmes d’assistance à la conduite existants, et discute la méthodologie de recherche de la thèse. Chapitre 2 présente les spécifications sur les composants de perception, contrôle et IHM et compare ces spécifications avec l’état de l’art de ces composants. Chapitre 3 propose le développement d’un composant de calculation de trajectories pour une conduite sur autoroute et discute la contribution de la thèse par rapport l’état de l’art. Chapitre 4 présente le développement du système sur les véhicules et simulateurs du laboratoire LIVIC et des projets HAVEit et ABV. Les différentes implémentations sur PC et sur ECU sont discutées. Chapitre 5 discute les contributions de la thèse. Ce chapitre conclue que le « Legal Safety » pour les composants décision, contrôle et IHM serait possible avec la technologie état de l’art. Une perception selon le « Legal Safety » pourrait être développée en moyen terme. / Vehicle automation is proposed as one of the solutions to make transport safer, more comfortable and more environmentally friendly. It is gradually being introduced through Advanced Driver Assistance Systems (ADAS). This work aims to contribute to this evolution, by discussing how driving systems can share the road with human drivers. It presents the legal safety concept for the design of a highly automated driving system for highways. The legal safety concept proposes to base driving system design on traffic rules. This allows fully automated driving in traffic with human drivers, without necessarily changing equipment on other vehicles or infrastructure. The driving system can interact with the human driver, via human rules. If needed, the driving system takes over control in order to avoid accidents. With the third set of rules of the legal safety concept, system rules, system components respect the limitations of other system components. The requirements on PERCEPTION, control and Human-Machine Interface (HMI) components of the legal safety system are discussed. The decision component, which is the central component of the legal safety system, is completely worked out from requirements to design. The legal safety system has been implemented on PC and automotive Electronic Control Units (ECUs). The integration and validation of legal safety components on LIVIC, HAVEit and ABV demonstrators are presented. The work concludes that, for highway environments, legal safety decision, control and HMI can be achieved with state-of-the-art technology, and legal safety perception could be available in medium term.

This thesis presents the very practical and novel approach of using the Graphical User Interface (GUI) to compute the entire set of Proportional Integral Derivative (PID) controllers given the transfer function or the frequency response of the system under consideration. Though there is a wide spread usage of PID controllers in the industry, until recently no formal algorithm existed on determining a set of PID values that will stabilize the given system. The industry still relies on algorithms like the Ziegler- Nicholas or ad-hoc approaches in determining the value of PID controllers. Also when it comes to model free approaches, the use of Fuzzy logic and Neural network do not guarantee stability of the system. For a continuous Linear Time Invariant system Bhattacharyya and others have developed an algorithm that determines the entire set of PID controllers given the transfer function or just the frequency response of the system. The GUI has been developed based on this theory. The GUI also evaluates the user input performance specifications and generates a subset of stable controllers given the performance criteria for the system. This thesis presents an approach of automating the computation of entire set of stabilizing Proportional Integral Derivative (PID) controllers given the system transfer function or the frequency response data of the system. The Graphical User Interface (GUI) developed bridges the gap between the developed theory and the industry.