This diploma thesis focuses on effects of active vehicle safety on the prevention of traffic accidents. In the introductory section, the term of active safety is defined and divided into four categories. In next four chapters, the particular elements of active safety are described in more detail and some selected elements are described in depth. Chapter seven includes a questionnaire; it enquires opinions of people about some of the elements of active safety. Practical road tests were conducted as part of this work. Theirs description and evaluation are in the last chapters.

This thesis work aims at performing a survey of those technologies generally called DriverAssistance Systems (DAS). This thesis work focuses on gathering information in terms ofaccident statistics, sensors and functions and analyzing this information and shall thruaccessible information match functions with accidents, functions with sensors etc.This analysis, based on accidents in United States and Sweden during the period 1998 – 2002and two truck accident studies, shows that of all accidents with fatalities or sever injuriesinvolving a heavy truck almost half are the result of a frontal impact. About one fourth of theaccidents are caused by side impact, whereas single vehicle and rear impact collisions causesaround 14 % each. Of these, about one fourth is collision with unprotected (motorcycles,mopeds, bicycles, and pedestrians) whereas around 60 % are collision with other vehicles.More than 90 % of all accidents are partly the result of driver error and about 75 % aredirectly the result of driver error. Hence there exist a great opportunity to reduce the numberof accidents by introducing DAS.In this work, an analysis of DAS shows that six of the systems discussed today have thepotential to prevent 40 – 50 % of these accidents, whereas 20 – 40 % are estimated to actuallyhaving the chance to be prevented.One of these DAS, automatic emergency brake (AEB), has been analyzed in more detail.Decision models for an emergency brake capable to mitigate rear-end accidents has beendesigned and evaluated. The results show that this model has high capabilities to mitigatecollisions.

When developing new active safety systems or improving existing systems, conducting performance evaluations is necessary. By performing these evaluations during early development stages, potential problems can be identified and mitigated before the system moves into the production phase. Testing active safety systems can be difficult since the characteristic scenarios may have complex interactions. Using real vehicles for performing these types of scenarios is difficult, expensive, and potentially dangerous. Alternative methods, such as using inflatable targets, scale models, computer simulations or driving simulators, also suffer from drawbacks. Consequently, using virtual reality as an alternative to the traditional methods has been proposed. In this case, a real vehicle is driven while wearing a head-mounted display that presents the scenario to the driver. This research aims to investigate the potential of such technology. Specifically, this work investigates how the chosen technology affects the driver. This investigation has been conducted through a literature review. A test platform was constructed, and two user studies using normal drivers were performed. The first study focused on the effects of visual time delays on driver behavior. This study revealed that lateral behavior changes with added time delays, whereas longitudinal behavior appears unaffected. The second study investigated how driver behavior is affected by different modes of virtuality. This study demonstrated that drivers perceived mixed reality as more difficult than virtual reality. The main contribution of this work is the detailed understanding of how time delays and different modes of virtuality affect drivers. This is important knowledge for selecting which scenarios are suitable for evaluation using virtual reality. / <p>The series name <em>Linköping Studies in Science and Technology Licentiate Thesis</em> is incorrect. The correct series name is <em>Linköping Studies in Science and Technology Thesis</em>.</p>

Indiana University-Purdue University Indianapolis (IUPUI) / Automotive technology has grown from strength to strength in the recent years. The main focus of research in the near past and the immediate future are autonomous vehicles. Autonomous vehicles range from level 1 to level 5, depending on the percentage of machine intervention while driving. To make a smooth transition from human driving and machine intervention, the prediction of human driving behavior is critical. This thesis is a subset of driving behavior prediction. The objective of this thesis is to predict the possibility of crash and implement an appropriate active safety system to prevent the same. The prediction of crash requires data of transition between lanes, and speed ranges. This is achieved through a variation of hidden Markov model. With the crash prediction and analysis of the Markov models, the required ADAS system is activated. The above concept is divided into sections and an algorithm was developed. The algorithm is then scripted into MATLAB for simulation. The results of the simulation is recorded and analyzed to prove the idea.

Active safety systems that warn automobile drivers of various types of impending collisions have been developed. How these systems alert drivers when integrated, however, is a crucial component to their effectiveness that hinges on the consideration of human factors. Drivers' ability to comprehend multiple alerts presented through a haptic driver seat was investigated in this dissertation. Twenty-four participants, balanced for age and gender, drove an instrumented vehicle on a test-track while haptic alerts (vibrations in the driver seat) were generated. Drivers' ability to transmit the information conveyed by the alerts was investigated through two experiments. The first experiment investigated the effects of increasing the number of potential alerts on drivers' response performance. The second experiment investigated whether presenting haptic alerts through unique versus common locations in the driver seat affects drivers' response performance. Younger drivers (between the ages of 18 and 25 years old) were found to efficiently process the increased information contained in the alerts, while older drivers were not as efficient. However, it is foreseeable that older driver performance decrements may be assuaged when a crash context is provided. A third experiment evaluated the haptic driver seat's ability to alert distracted drivers to an actual crash threat. Drivers that received a haptic seat alert returned their gaze to the forward roadway sooner, removed their foot from the throttle sooner, pressed the brake pedal sooner, and stopped farther away from an inflatable barricade than drivers that did not receive a haptic seat alert. No age or gender effects were found in this experiment. Furthermore, half of the drivers that received the haptic seat alert lifted up on the throttle before returning their eyes to the forward roadway. This suggests these drivers developed an automatic response to the haptic seat alerts through their experience with the previous two experiments. A three-alert haptic seat approach, the intermediate alternative tested, is recommended providing specific design requirements are met. / Ph. D.

Um die Fahrzeugsicherheit auch weiterhin zu verbessern, können Systeme der Aktiven Sicherheit ihren Beitrag leisten. Zu diesem Zweck werden u. a. Unfalldatenbanken mit precrash relevanten Parametern herangezogen, mit welchen der Systemnutzen frühzeitig auf das Unfallgeschehen analysiert wird. Aufgrund von Informationsdefiziten in der bisherigen Unfallrekonstruktion stellt das Treffen von fundierten Aussagen zur precrash Phase eine Schwierigkeit dar, wie z. B. die genaue Ausgangsgeschwindigkeit. Deshalb sind zum Teil ungesicherte Annahmen notwendig, um eine precrash Phase rekonstruieren zu können. Bisher ist in Unfalldatenbanken zu jeweils einem analysierten Unfall eine einzelne mögliche precrash Phase dokumentiert, so wie der Unfall möglicherweise ablief. Weitere mögliche Varianten der precrash Phasen, die ebenso zu selben Unfall geführt hätten bleiben unberücksichtigt. Um detaillierte Aussagen zum tatsächlichen Nutzungsgrad eines Systems in einem realen Unfall abzuleiten, wird ein automatisiertes Simulationstool vorgestellt, welches mit Hilfe stochastischer Methoden auf mögliche Varianten an precrash Phasen schließt, die zum selben realen Unfall führen. Für das Tool dienen als Eingangsgröße rekonstruierte Unfälle, die in den precrash Phasen zum Teil Informationsdefizite aufweisen. Hierbei variiert die Monte Carlo Methode, ein Zufallszahlengenerator, die unterschiedlichen Ausprägungen von ausgewählten Einflussparametern entsprechend deren Häufigkeit. Dieses Tool kompensiert somit die Informationsdefizite in precrash Phasen und baut zugleich eine synthetische Unfalldatenbank mit Varianten an precrash Phasen auf, mit dem Ziel, die Vorunfallphase statistisch repräsentativ und unabhängig von einer konkreten Rekonstruktionsvariante abzubilden. In anschließenden Simulationen jeweils mit den soeben variierten precrash Phasen werden die unterschiedlichen Auswirkungen eines vorausschauenden Systems ermittelt. Die verschiedenen Einflüsse eines Systems werden auch hier mit der Monte Carlo Methode berücksichtigt, wie z. B. die Reaktionszeit des Fahrers auf eine Warnung. Im Falle eines Systemeingriffes ist eine mögliche Veränderung der Unfallschwere bzw. wahrscheinlichen Verletzungsschwere zu betrachten. Mit dieser vorgestellten Methodik ist der tatsächliche Nutzen eines vorausschauenden Systems für die Unfallbeteiligten noch genauer feststellbar, da das Simulationstool ein breites mögliches Spektrum an precrash Phasen und Systemauswirkungen betrachtet.

The main objective of the present thesis focuses on the integration of the in-wheel electric motors into the conception and control of road vehicles. The present thesis is the subject of the grant 186-654 (2010-2013) between the Laboratory of Signals and Systems (L2S-CNRS) and the French Institute of Petrol and New Energies (IFPEN). The thesis work has originally started from a vehicular electrification project, equipped with in-wheel electric motors at the rear axle, to obtain a full electric urban use and a standard extra-urban use with energy recovery at the rear axle in braking phases. The standard internal combustion engines have the disadvantage that complex estimation techniques are necessary to compute the instantaneous engine torque. At the same time, the actuators that control the braking system have some delays due to the hydraulic and mechanical circuits. These aspects represent the primary motivation for the introduction and study of the integration of the electric motor as unique propelling source for the vehicle. The advantages brought by the use of the electric motor are revealed and new techniques of control are set up to maximize its novelty. Control laws are constructed starting from the key feature of the electric motor, which is the fact that the torque transmitted at the wheel can be measured, depending on the current that passes through the motor. Another important feature of the electric motor is its response time, the independent control, as well as the fact that it can produce negative torques, in generator mode, to help decelerate the vehicle and store energy at the same time. Therefore, the novelty of the present work is that the in-wheel electric motor is considered to be the only control actuator signal in acceleration and deceleration phases, simplifying the architecture of the design of the vehicle and of the control laws. The control laws are focused on simplicity and rapidity in order to generate the torques which are transmitted at the wheels. To compute the adequate torques, estimation strategies are set up to produce reliable maximum friction estimation. Function of this maximum adherence available at the contact between the road and the tires, an adequate torque will be computed in order to achieve a stable wheel behavior in acceleration as well as in deceleration phases. The critical issue that was studied in this work was the non-linearity of the tire-road interaction characteristics and its complexity to estimate when it varies. The estimation strategy will have to detect all changes in the road-surface adherence and the computed control law should maintain the stability of the wheel even when the maximum friction changes. Perturbations and noise are also treated in order to test the robustness of the proposed estimation and control approaches.

Indiana University-Purdue University Indianapolis (IUPUI) / Pedestrian Automatic Emergency Braking (PAEB) system for avoiding/mitigating pedestrian crashes have been equipped on some passenger vehicles. At present, there are many e orts for the development of common standard for the performance evaluation of PAEB. The Transportation Active Safety Institute (TASI) at Indiana University-Purdue University-Indianapolis has been studying the problems and ad- dressing the concerns related to the establishment of such a standard with support from Toyota Collaborative Safety Research Center (CSRC). One of the important components in the PAEB evaluation is the development of standard testing facili- ties at night, in which 70% pedestrian crash social costs occurs [1]. The test facility should include representative low-illuminance environment to enable the examination of sensing and control functions of di erent PAEB systems. This thesis work focuses on modeling low-illuminance driving environment and describes an approach to recon- struct the lighting conditions. The goal of this research is to characterize and model light sources at a potential collision case at low-illuminance environment and deter- mine possible recreation of such environment for PAEB evaluation. This research is conducted in ve steps. The rst step is to identify lighting components that ap- pear frequently on a low-illuminance environment that a ect the performance of the PAEB. The identi ed lighting components include ambient light, same side/opposite side light poles, opposite side car headlight. Next step is to collect all potential pedes- trian collision cases at night with GPS coordinate information from TASI 110 CAR naturalistic driving study video database. Thirdly, since ambient lighting is relatively random and lack of a certain pattern, ambient light intensity for each potential col- lision case is de ned and processed as the average value of a region of interest on all video frames in this case. Fourth step is to classify interested light sources from the selected videos. The temporal pro le method, which compressing region of interest in video data (x,y,t) to image data (x,y), is introduced to scan certain prede ned region on the video. Due to the fact that light sources (except ambient light) impose distinct light patterns on the road, image patterns corresponding to speci c light sources can be recognized and classi ed. All light sources obtained are stamped with GPS coordinates and time information which are provided in corresponding data les along with the video. Lastly, by grouping all light source information of each repre- sentative street category, representative light description of each street category can be generated. Such light description can be used for lighting construction of PAEB test facility.

Durch das I-FAS der TU Chemnitz wurde im Rahmen des AKTIV-Projektes eine Probandenstudie zur Akzeptanz von Systemausprägungen einer Aktiven Gefahrenbremsung (AGB) bei PKW durchgeführt. Unter Verwendung eines stehenden Hindernisses wurden sechs Systemausprägungen verglichen, die von den AGB-Partnern in zwei Versuchsträger implementiert wurden. Die sechs Systemausprägungen werden nahezu identisch bewertet, solange Probanden keine Vergleichsmöglichkeit zu anderen Systemausprägungen haben. Wenn es zu einem Fahrereingriff kommt, ist der Eingriffszeitpunkt des Fahrers unabhängig von der gefahrenen Systemausprägung.

L'objectif principal de cette thèse est l'étude de l'exploitation de systèmes moteurs-roues (machines électriques intégrées à la roue) pour le contrôle de la dynamique véhicule. Cette thèse est issue d'un co-financement (numéro 186-654, 2010-2013) entre le Laboratoire des Signaux et Systèmes (CNRS) et l'Institut Français du Pétrole et Énergies Nouvelles (IFPEN). Les avantages apportés par l'utilisation du moteur électrique sont avérés et de nouvelles techniques de contrôle sont développées pour optimiser son utilisation. Les lois de contrôle basent généralement sur la grandeur principale du moteur électrique: le couple transmis, qui peut être mesuré via le courant consommé. Une autre caractéristique importante du moteur électrique est son temps de réponse, avec le fait qu'il peut produire des couples négatifs, pour ralentir le véhicule, tout en stockant l'énergie. La nouveauté du présent travail est de considérer le moteur-roue électrique comme seul signal de contrôle dans des phases d'accélération et des phases de ralentissement, simplifiant l'architecture de la conception du véhicule et des lois de contrôle. Pour répondre à la demande conducteur tout en préservant un comportement sain du véhicule, des stratégies d'estimation de la limite d'adhérence seront présentées. En fonction de cette adhérence maximale disponible entre la route et les pneus, un couple adéquat sera calculé pour assurer un comportement stable dans des phases d'accélération aussi bien que de freinage. L'aspect critique étudié dans ce travail est la non-linéarité des caractéristiques d'interaction entre la route et le pneu et la complexité de son estimation dans des conditions variables. La stratégie d'estimation devra détecter tous les changements d'adhérence de route et la loi de contrôle calculée devra maintenir la stabilité véhicule même lorsque la friction maximale change. Certaines formes de perturbation et de bruit seront également prises en compte afin de tester la robustesse des approches d'estimation et de contrôle proposés. Parmi les systèmes de sécurité active les plus importants en phase d'accélération, le système de contrôle de traction (TCS) rétablit la traction si les roues commencent à patiner et le programme de stabilité électronique (ESP) intervient pour prévenir une perte menaçante du contrôle latéral du véhicule. Dans le cas du freinage, le système décisif est le système d'antiblocage (ou ABS), qui empêche le blocage des roues. On peut trouver d'autres systèmes embarqués, comme le système de distribution de force de freinage électronique (EBD), qui assure une distribution optimale de la force de freinage transmise aux roues, pour éviter de déraper et assure un ralentissement stable du véhicule. Les systèmes embarqués qui fournissent les estimations doivent être robustes aux bruits de mesure et aux perturbations. A fortiori, ces calculs doivent être faits en temps réel, donc une complexité réduite et une réponse rapide de la loi de contrôle sont nécessaires. Enfin, l'environnement dans lequel le véhicule fonctionne est dynamique, les caractéristiques d'adhérence peuvent varier en fonction de l'état de la route et de la météo. Ainsi, on ne peut prévoir les réactions du conducteur pouvant influencer la réponse globale du véhicule dans des situations d'urgence. Le contrôleur devrait prendre en compte tous ces aspects pour préserver un comportement stable du véhicule. Bien que le contrôle latéral du véhicule présente une importance majeure dans la stabilité globale du véhicule, le présent travail est concentré sur le contrôle longitudinal du véhicule, puisqu'il représente le point de départ de la dynamique véhicule. / The main objective of the present thesis focuses on the integration of the in-wheel electric motors into the conception and control of road vehicles. The present thesis is the subject of the grant 186-654 (2010-2013) between the Laboratory of Signals and Systems (L2S-CNRS) and the French Institute of Petrol and New Energies (IFPEN). The thesis work has originally started from a vehicular electrification project, equipped with in-wheel electric motors at the rear axle, to obtain a full electric urban use and a standard extra-urban use with energy recovery at the rear axle in braking phases. The standard internal combustion engines have the disadvantage that complex estimation techniques are necessary to compute the instantaneous engine torque. At the same time, the actuators that control the braking system have some delays due to the hydraulic and mechanical circuits. These aspects represent the primary motivation for the introduction and study of the integration of the electric motor as unique propelling source for the vehicle. The advantages brought by the use of the electric motor are revealed and new techniques of control are set up to maximize its novelty. Control laws are constructed starting from the key feature of the electric motor, which is the fact that the torque transmitted at the wheel can be measured, depending on the current that passes through the motor. Another important feature of the electric motor is its response time, the independent control, as well as the fact that it can produce negative torques, in generator mode, to help decelerate the vehicle and store energy at the same time. Therefore, the novelty of the present work is that the in-wheel electric motor is considered to be the only control actuator signal in acceleration and deceleration phases, simplifying the architecture of the design of the vehicle and of the control laws. The control laws are focused on simplicity and rapidity in order to generate the torques which are transmitted at the wheels. To compute the adequate torques, estimation strategies are set up to produce reliable maximum friction estimation. Function of this maximum adherence available at the contact between the road and the tires, an adequate torque will be computed in order to achieve a stable wheel behavior in acceleration as well as in deceleration phases. The critical issue that was studied in this work was the non-linearity of the tire-road interaction characteristics and its complexity to estimate when it varies. The estimation strategy will have to detect all changes in the road-surface adherence and the computed control law should maintain the stability of the wheel even when the maximum friction changes. Perturbations and noise are also treated in order to test the robustness of the proposed estimation and control approaches.