Autonomous vehicles is going to be a part of future transport of goods and people, but to make them usable in unpredictable situations presented in real traffic, there is need for backup systems for manual vehicle control. Teleoperation, where a driver controls the vehicle remotely, has been proposed as a backup system for this purpose. This technique is highly dependent on stable and large wireless network bandwidth to transmit high resolution video from the vehicle to the driver station. Reduction in network bandwidth, resulting in a reduced level of detail in the video stream, could lead to a higher risk of driver error. This thesis is a two part investigation. One part looking into whether lower resolution and increased lossy compression of video at the operator station affects driver performance and safety of operation during teleoperation. The second part covers implementation of two vision-based driver assistance systems, one which detects and highlights vehicles and pedestrians in front of the vehicle, and one which detects and highlights lane markings. A driving test was performed at an asphalt track with white markings for track boundaries, with different levels of video quality presented to the driver. Reducing video quality did have a negative effect on lap time and increased the number of times the track boundary was crossed. The test was performed with a small group of drivers, so the results can only be interpreted as an indication toward that video quality can negatively affect driver performance. The vision-based driver assistance systems for detection and marking of pedestrians was tested by showing a test group pre-recorded video shot in traffic, and them reacting when they saw a pedestrian about to cross the road. The results of a one-way analysis of variance, shows that video quality significantly affect reaction times, with p = 0.02181 at significance level α = 0.05. A two-way analysis of variance was also conducted, accounting for video quality, the use of a driver assistance system marking pedestrians, and the interaction between these two. The results point to that marking pedestrians in very low quality video does help reduce reaction times, but the results are not significant at significance level α = 0.05.

Intersection crashes are among the most frequent and lethal crash modes in the United States. Intersection Advanced Driver Assistance Systems (I-ADAS) are an emerging active safety technology which aims to help drivers safely navigate through intersections. One primary function of I-ADAS is to detect oncoming vehicles and in the event of an imminent collision can (a) alert the driver and/or (b) autonomously evade the crash. Another function of I-ADAS may be to detect and prevent imminent traffic signal violations (i.e. running a red light or stop sign) earlier in the intersection approach, while the driver still has time to yield for the traffic control device. This dissertation evaluated the capacity of I-ADAS to prevent U.S. intersection crashes and mitigate associated injuries. I-ADAS was estimated to have the potential to prevent up to 64% of crashes and 79% of vehicles with a seriously injured driver. However, I-ADAS effectiveness was found to be highly dependent on driver behavior, system design, and intersection/roadway characteristics. To generate this result, several studies were performed. First, driver behavior at intersections was examined, including typical, non-crash intersection approach and traversal patterns, the acceleration patterns of drivers prior to real-world crashes, and the frequency, timing, and magnitude of any crash avoidance actions. Second, two large simulation case sets of intersection crashes were generated from U.S. national crash databases. Third, the developed simulation case sets were used to examine I-ADAS performance in real-world crash scenarios. This included examining the capacity of a stop sign violation detection algorithm, investigating the sensor detection needs of I-ADAS technology, and quantifying the proportion of crashes and seriously injuries that are potentially preventable by this crash avoidance technology. / Ph. D.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18689号 / 工博第3967号 / 新制||工||1611(附属図書館) / 31622 / 京都大学大学院工学研究科機械理工学専攻 / (主査)教授 椹木 哲夫, 教授 西脇 眞二, 教授 松原 厚 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Over the last years, bicycles have been addressed in newly developed driver assistance systems for passenger cars on a voluntary basis, and beginning with the blind spot assist systems, this tendency has been picked up by vehicle regulations and systems are made mandatory. This paper intends to give a detailed summary of which vehicle regulations are currently addressing bicycles, when they come into force and if they will be mandatory in the EU. Also, the performance of already available active safety systems for bicycles (not covered by regulatory requirements) and their technological potential will be included.

Advanced Driver Assistance Systems (ADAS) and Autonomous Ground Vehicles (AGV) have the potential to increase road transportation safety, environmental gains, and passenger comfort. The advent of Electric Vehicles has also facilitated greater flexibility in powertrain architectures and control capabilities. Path Tracking controllers that provide steering input are used to execute lateral maneuvers or model the response of a vehicle during cornering. Direct Yaw Control using Torque Vectoring has the potential to improve vehicle's transient cornering stability and modify its steady state handling characteristics during lateral maneuvers. In the first part of this thesis, the transient dynamics of an existing baseline Path Tracking controller is improved using a transient Torque Vectoring algorithm. The existing baseline Path Tracking controller is evaluated, using a linearized system, for a range of vehicle and controller parameters. The effect of implementing transient Torque Vectoring along with the baseline Path Tracking controller is then studied for the same parameter range. The linear analysis shows, in both time and frequency domain, that the transient Torque Vectoring improves vehicle response and stability during cornering. A Torque Vectoring controller is developed in Linear Adaptive Model Predictive Control framework and it's performance is verified in simulation using Simulink and CarSim. The second part of the thesis analyzes the tradeoff enabled by steady state Torque Vectoring between improved limit handling capability through optimal tire force allocation and drivability demonstrated by understeer gradient. Optimal tire force allocation prescribes equal usage in all four tires during maneuvers. This is enabled using steering and Torque Vectoring. An analytical proof is presented which demonstrates that implementation of this optimal tire force allocation results in neutralsteering handling characteristics for the vehicle. The optimal tire force allocation strategy is formulated as a minimax optimization problem. A two-track vehicle model is simulated for this strategy, and it verified the analytical proof by displaying neutralsteering behavior. / Master of Science / Advanced Driver Assistance Systems (ADAS) and Autonomous Ground Vehicles (AGVs) have the potential to increase road transportation safety, environmental gains, passenger comfort and passenger productivity. The advent of Electric Vehicles (EVs) has also facilitated greater flexibility in powertrain configurations and capabilities that facilitate the implementation of Torque Vectoring (TV), which is a method of applying differential torques to laterally opposite wheels to enhance the cornering performance of ground vehicles. Path Tracking (PT) controllers that provide steering input to the vehicles are traditionally used for lateral control in AGVs and ADAS features. The goal of this thesis is to develop Torque Vectoring algorithms to improve a vehicle's stability and shape its steady state behaviour through a corner during low lateral acceleration maneuvers. An existing baseline Path Tracking controller is selected and evaluated. The effect of implementing Torque Vectoring along with this Path Tracking controller is studied and it is found to improve the stability of the vehicle during cornering. This is verified in simulation by designing and implementing the Torque Vectoring algorithm. Finally, a Torque Vectoring strategy is proposed to manage the handling of the vehicle during low acceleration cornering.

The increase in the number of deaths due to ground traffic accidents is a global problem. In such context, the development of new vehicular technologies is considered an alternative to improve road safety. Within the field of new vehicle technologies, it is possible to find driver assistance systems. These systems interact in an active or passive way with the driver, reducing their workload by presenting information about their surroundings, which may imply the safer direction of a land vehicle. Taking into account that one of the main reasons for road traffic fatalities in the world is the lane change in a road, hereby we created a cooperative driver assistance system for the lane change, arising from the combination of a kinematic model and a probabilistic graphical one. By combining these two models, we try to improve the response in the assistance of the system, given the direct dependence of the system with a human. Due to the latter, the response of such systems cannot be deterministic in nature. One of the motivations to use probabilistic graphical models is the flexibility of this machines learning technique in modeling the problem addressed in this thesis. In addition to this contribution of applying a specific probabilistic graphical model in our assistance system, other contributions can be found in this thesis, including the development of a Driving simulation platform with a reconfigurable structure. The ability to reconfigure the structure of the driving simulator platform was of great importance for the development and evaluation of the assistance system hereby proposed in each of its stages. In addition, the decision to model a cooperative approach in our assistance system is due to the great potential of the vehicular communications with respect to improving transport safety and efficiency. The moderate cost that is being projected in vehicular communications is another relevant fact. Finally, the description and application of our assistance system model can be considered as a possibility in the area for the development of an application that needs a close response to the reality, based on the uncertainties present in the problem under consideration. / O aumento no número de mortes por causa de acidentes de tráfego terrestre é um problema global. No âmbito dessa problemática, o desenvolvimento de novas tecnologias veiculares é considerado uma alternativa para melhorar a segurança viária. Dentro do domínio das novas tecnologias veiculares, é possível encontrar sistemas de assistência ao motorista. Esses sistemas interagem de maneira ativa ou passiva com o motorista, conseguindo reduzir sua carga de trabalho, apresentando informações de seu entorno, o que pode implicar uma direção mais segura de um veículo terrestre. Levando em consideração que um dos principais motivos de mortes por acidentes de tráfego terrestre no mundo é a mudança de faixa em uma pista, neste trabalho, realizamos a tarefa de criar um sistema cooperativo de assistência ao motorista para a mudança de faixa, a partir da combinação de um modelo cinemático e de um modelo gráfico probabilístico. Mediante a combinação destes dois modelos, procuramos melhorar a resposta na assistência por parte do sistema, dada a dependência direta que o sistema tem dos humanos. Por essa última razão, a resposta deste tipo de sistemas não pode ser determinística por natureza. Uma das motivações para utilizar os modelos gráficos probabilísticos é a flexibilidade da técnica de machine learning em modelar o problema abordado nesta tese. Além dessa contribuição de aplicar um modelo gráfico probabilístico específico em nosso sistema de assistência, outras contribuições podem ser encontradas nesta tese, incluindo o desenvolvimento de uma plataforma de simulação para a condução, com uma estrutura reconfigurável. A capacidade de poder reconfigurar a estrutura da plataforma de simulação foi de grande importância para o desenvolvimento e avaliação do sistema de assistência proposto nesta tese, em cada uma de suas etapas. Além disso, a decisão de modelar um enfoque cooperativo, em nosso sistema de assistência, se deve ao grande potencial que tem as comunicações veiculares com respeito à melhora da segurança e da eficiência do transporte. O custo moderado que está sendo projetado nas comunicações veiculares é outro fato relevante. A descrição e aplicação de nosso modelo final podem ser considerados mais uma possibilidade na área para o desenvolvimento de uma aplicação, que precise de uma resposta próxima da realidade, a partir das incertezas presentes no problema considerado.

The increase in the number of deaths due to ground traffic accidents is a global problem. In such context, the development of new vehicular technologies is considered an alternative to improve road safety. Within the field of new vehicle technologies, it is possible to find driver assistance systems. These systems interact in an active or passive way with the driver, reducing their workload by presenting information about their surroundings, which may imply the safer direction of a land vehicle. Taking into account that one of the main reasons for road traffic fatalities in the world is the lane change in a road, hereby we created a cooperative driver assistance system for the lane change, arising from the combination of a kinematic model and a probabilistic graphical one. By combining these two models, we try to improve the response in the assistance of the system, given the direct dependence of the system with a human. Due to the latter, the response of such systems cannot be deterministic in nature. One of the motivations to use probabilistic graphical models is the flexibility of this machines learning technique in modeling the problem addressed in this thesis. In addition to this contribution of applying a specific probabilistic graphical model in our assistance system, other contributions can be found in this thesis, including the development of a Driving simulation platform with a reconfigurable structure. The ability to reconfigure the structure of the driving simulator platform was of great importance for the development and evaluation of the assistance system hereby proposed in each of its stages. In addition, the decision to model a cooperative approach in our assistance system is due to the great potential of the vehicular communications with respect to improving transport safety and efficiency. The moderate cost that is being projected in vehicular communications is another relevant fact. Finally, the description and application of our assistance system model can be considered as a possibility in the area for the development of an application that needs a close response to the reality, based on the uncertainties present in the problem under consideration. / O aumento no número de mortes por causa de acidentes de tráfego terrestre é um problema global. No âmbito dessa problemática, o desenvolvimento de novas tecnologias veiculares é considerado uma alternativa para melhorar a segurança viária. Dentro do domínio das novas tecnologias veiculares, é possível encontrar sistemas de assistência ao motorista. Esses sistemas interagem de maneira ativa ou passiva com o motorista, conseguindo reduzir sua carga de trabalho, apresentando informações de seu entorno, o que pode implicar uma direção mais segura de um veículo terrestre. Levando em consideração que um dos principais motivos de mortes por acidentes de tráfego terrestre no mundo é a mudança de faixa em uma pista, neste trabalho, realizamos a tarefa de criar um sistema cooperativo de assistência ao motorista para a mudança de faixa, a partir da combinação de um modelo cinemático e de um modelo gráfico probabilístico. Mediante a combinação destes dois modelos, procuramos melhorar a resposta na assistência por parte do sistema, dada a dependência direta que o sistema tem dos humanos. Por essa última razão, a resposta deste tipo de sistemas não pode ser determinística por natureza. Uma das motivações para utilizar os modelos gráficos probabilísticos é a flexibilidade da técnica de machine learning em modelar o problema abordado nesta tese. Além dessa contribuição de aplicar um modelo gráfico probabilístico específico em nosso sistema de assistência, outras contribuições podem ser encontradas nesta tese, incluindo o desenvolvimento de uma plataforma de simulação para a condução, com uma estrutura reconfigurável. A capacidade de poder reconfigurar a estrutura da plataforma de simulação foi de grande importância para o desenvolvimento e avaliação do sistema de assistência proposto nesta tese, em cada uma de suas etapas. Além disso, a decisão de modelar um enfoque cooperativo, em nosso sistema de assistência, se deve ao grande potencial que tem as comunicações veiculares com respeito à melhora da segurança e da eficiência do transporte. O custo moderado que está sendo projetado nas comunicações veiculares é outro fato relevante. A descrição e aplicação de nosso modelo final podem ser considerados mais uma possibilidade na área para o desenvolvimento de uma aplicação, que precise de uma resposta próxima da realidade, a partir das incertezas presentes no problema considerado.

<div>Due to recent advances in sensor technology and the exponential increase in computation power of electronic control units (ECUs) along with their increasing affordability, active safety and vehicle automation have become major trends in the commercial vehicle industry. New regulations for increased safety are also a major driver behind the industry's increased interest in that topic. As a result, being a crucial part of vehicle automation, steering systems had to be adapted to enable Active Steering. Consequently, commercial vehicle steering designers introduced the concept of torque and angle overlay using an electric motor in series with the conventional hydraulic steering system. However, despite the fact that these systems are becoming more prevalent in the market, they still suffer from inefficiencies intrinsic to the conventional hydraulic steering system still being used. These inefficiencies are a result of</div><div>flow metering losses due to the use of control valves to regulate the pump flow output, as well as inside the steering gear with the use control valves to build assistance pressure.</div><div><br></div><div><div>In this research project, we investigate the potential use of the proven pump Displacement Control (DC) technology in steering on-highway commercial vehicles. DC pumps have been shown to signicantly improve system efficiency as they allow the removal of control valves typically used to regulate </div><div>ow [1]. Instead, the displacement of the pump can be directly controlled to vary the pump's flow rate and direction,</div><div>and thus eliminating throttling losses. The DC technology has been successfully used in a steer-by-wire conguration for an articulated frame steering vehicle and has been shown to signicantly improve efficiency and productivity, as well as result in a reduction in fuel consumption [2].</div></div><div><br></div><div><div>In this work, we propose a steer-by-wire system, using DC pump technology, for on-highway commercial vehicles, and present the dierent possible congurations in which it can be implemented. Moreover, the benets and drawbacks of the steer-by-wire system are researched and identied. Subsequently, the system is designed and validated in simulation, on laboratory test setup, as well as on a test vehicle to prove its feasibility.</div></div><div><br></div><div><div>Chief among the drawbacks of the steer-by-wire system is potential failures that can lead to the complete loss of the steering function of the vehicle. As a result, different possible fail-safe mechanisms are researched from which the most suitable ones are proposed to allow the steer-by-wire system to fail safely. Moreover, two of the proposed fail-safe mechanism are implemented onto the test vehicle to prove and validate their feasibility.</div></div><div><br></div><div><div>Furthermore, an alternative way of using displacement controlled pumps for active steering is be proposed. For this concept, we investigate the possibility of actively controlling the driver's steering effort by varying the pump displacement while maintaining the mechanical link between the steering wheel and the road wheels. If successful, this method will allow for a more efficient way of providing steering assistance as it does away with the conventional control valves used to build pressure and regulate pump flow, and thus eliminating throttling losses. This method has also the advantage of having an intrinsic fail-safe mechanism with manual steering being always possible should the hydraulic or electric systems fail.</div></div>

Durch die Entwicklung und Einführung moderner Fahrerassistenzsysteme soll der Komfort und die Sicherheit des Autofahrens erhöht werden. Das Fahrerassistenzsystem Speed Control verbindet die Ergebnisse der Forschungsarbeiten der letzten Jahre aus dem Bereich des Straßenentwurfs und der Fahrzeugtechnik. Dieses System warnt den Kraftfahrer vor sicherheitskritischen Stellen in der Linienführung von Außerortsstraßen. Es empfiehlt dem Fahrer eine sicher und komfortabel fahrbare Geschwindigkeit für den vorausliegenden Streckenabschnitt. Dafür wurden in Abhängigkeit des Fahrertyps Modelle zur Prognose und Beschreibung des Geschwindigkeits- und Beschleunigungsverhaltens entwickelt. Die Umgebungsbedingungen (Tag, nass) werden dabei mit beachtet. / By developing and implementing modern driver assistance systems the comfort and safety of driving shall be improved. The driver assistance system Speed Control combines the last year’s research work results in the fields of road design and automotive engineering. This system alerts the driver to safety critic spots in the alignment of roads. It recommends a safe and comfortable driving speed for the road segment ahead. Therefore driver type depending models to predict and describe the speed and acceleration behaviour were developed. Withal environmental conditions (day, wet) are regarded.

Originally presented as the author's Thesis--Technische Hochschule Aachen, 2008. / Includes bibliographical references.