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.

Förarstödsystem har funnits länge, men tekniken och digitaliseringen fortsätter att utvecklas och så även förarstödsystemen. De system som utvecklas idag har större och mer fokuserad utveckling under kort tid och är för många okända system. Eftersom det finns begränsad kunskap om hur förarstödsystem fungerar när det kommer till detektering av vilt syftar denna studie till att skapa en fördjupad förståelse för vilka funktioner som finns i förarstödsystemen idag. Studien har skett genom en nulägesanalys baserad på hur systemen kan minska kollision med vilt samt vilka framtidsutsikter det finns beträffande utveckling av dessa system och funktioner. För att uppfylla syftet har intervjuer genomförts med ledande biltillverkarna och underleverantörer till fordonsindustrin och branschexperter. Insamlad empiri från intervjuer har kompletterats med ett urvalresultat i tidigare forskning. För att bearbeta insamlad empiri används en tematisk analys. Studiens bearbetade empiri presenteras i följande teman: Presentation av företag och respondenter; Nulägesanalys; Utmaningar och framtida möjligheter; Kommersiella aspekter; och Framtidsprojektioner. Det råder en samstämmig bild i resultatet kring att stödsystem för viltdetektion är i sin linda och att de främsta vinsterna med dessa är en tidig detektion av vilt, vilket kan minska risken för allvarliga olyckor. Tekniska framsteg görs vars syfte främst är att göra föraren mer medveten i sin körning och samtidigt utöka kommunikationen mellan trafikanter och infrastruktur. Hinder för utveckling ligger i marknadsmässiga faktorer och otydliga nationella och internationella regler. / Driver support systems have been around for a long time, but technology and digitization continue to evolve daily. Technology development is in constant motion. The systems that are being developed today have, in relation to the remaining vehicle technology, been given a significantly large and conditional development in a short time and are still new to humans. As there is limited knowledge about how driver support systems work when it comes to game detection, this study aims to create an in-depth understanding of what functions exist in driver support systems today, through a kind of current situation analysis, which detects game, how these can reduce collision with game and what prospects there are regarding the development of these systems and functions. To fulfil the purpose, interviews are conducted with leading car manufacturers and subcontractors to the automotive industry and industry experts. A thematic analysis is used to process collected empirical data. The study's processed empirics are presented in the following themes: Presentation of companies and respondents; Current situation analysis; Challenges and future opportunities; Commercial aspects; and Future projections. There is a consistent picture in the results that support systems for game detection are in their infancy and that the main benefits of these are an early detection of game, which can reduce the risk of serious accidents. Technical advances are being made whose main purpose is to make the driver more involved in their driving and at the same time expand the communication between road users and infrastructure. Obstacles to development lie in market factors and unclear national and international rules.

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.

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. / Intersection crashes account for over 5,000 fatalities each year in the U.S., which places them among the most lethal crash modes. Highly automated vehicles are a rapidly emerging technology, which has the potential to greatly reduce all traffic fatalities. This work evaluated the capacity of intersection advanced driver assistance systems (I-ADAS) to prevent U.S. intersection crashes and mitigate associated injuries. I-ADAS is an emerging technology used by highly automated vehicles to help drivers safely navigate intersections. This technology utilizes onboard sensors to detect oncoming vehicles. If an imminent crash is detected, I-ADAS can respond by (a) warning the driver and/or (b) autonomously braking. Another function of I-ADAS may be to prevent intersection violations altogether, such as running a red light or a stop sign. Preventing and/or mitigating crashes and injuries that occur in intersection crashes are among the highest priority for designers, evaluators, and regulatory agencies. This dissertation has three main components. The first aim of this research was to describe how individuals drive through intersections. This included examining how drivers approach, traverse, and take crash avoidance actions at intersections. The second aim was to develop a dataset of intersection crashes that could be used to examine I-ADAS effectiveness. This was completed by extracting crashes that occurred throughout the U.S., and reconstructing vehicle positions before and after impact. The third aim was to use the extracted dataset of intersection crashes, and consider a scenario where one of the vehicles had been equipped with I-ADAS. Estimates of IADAS effectiveness were then generated based on these results.

The aim of this PhD thesis was to investigate traffic safety and mobility for individuals with hearing loss (HL). Three studies were conducted: 1. a questionnaire survey aimed to evaluate differences in choice of transportation that might be related to HL, 2. a driving simulator study that looked into compensatory strategies and evaluated the efficiency of a tactile signal to alert the driver, and 3. a field study to evaluate these effects in real traffic and to evaluate a navigation system with a supportive tactile signal. The effects of HL discovered in this thesis add to the knowledge and understanding of the influence of HL on traffic safety and mobility. Differences found consistently point to a generally more cautious behavior. Compensatory and coping strategies associated with HL are bound to driving complexity and appear when complexity increases. These strategies include driving at lower speeds, using a more comprehensive visual search behavior and being less engaged in distracting activities. Evaluation of a tactile signal showed that by adding a tactile modality, some driver assistance systems can also be made accessible to drivers with HL. At the same time, the systems might be more effective for all users, since the driver can be more focused on the road. Based on the results in this thesis, drivers with HL cannot be considered an increased traffic safety risk, and there should be no need for adjustments of the requirements of hearing for a license to drive a car. / Syftet med den här doktorsavhandlingen var att undersöka trafiksäkerhet och mobilitet för individer med hörselnedsättning (HN). Tre studier har genomförts: 1. en enkätstudie för att undersöka skillnader i transportvanor relaterade till HN, 2. en körsimulatorstudie for att titta på kompensatoriska strategier och utvärdera effektiviteten i en taktil signal för att påkalla förarens uppmärksamhet och 3. en fältstudie för att undersöka effekterna i riktig trafik samt utvärdera ett navigationssystem med en taktil signal som stöd för navigering. Effekterna av HN som kom fram i denna avhandling bidrar till kunskapen och förståelsen för hur HN påverkar trafiksäkerhet och mobilitet. De funna skillnaderna pekar konsistent mot ett generelltmera försiktigt beteende. Kompensatoriska - och copingstrategier förknippade med HN beror på körkomplexitet och observeras när komplexiteten ökar. Dessa strategier innebär körning med lägre hastighet, mera heltäckande visuell avsökning och mindre engagemang i distraherande uppgifter. Utvärdering av en taktil signal visade att genom att lägga till en taktil modalitet kan vissa förarstödsystem bli tillgängliga även för förare med HN. Samtidigt kan systemen bli mera effektiva för alla användare eftersom föraren då kan fokusera mera på vägen. Baserat på resultaten i den här avhandlingen kan inte förare med HN betraktas som någon förhöjd risk och det bör därmed inte finnas något behov av att justera hörselkraven när det gäller körkortsinnehav.

Le travail de cette thèse a été consacré au développement d’une nouvelle méthode de détection pour un système anticollision par la mesure de trajectographie, ce qui pourrait contribuer aux systèmes d’aide à la conduite. Pour obtenir une haute probabilité de détection, nous avons choisi la solution de vidéo stéréoscopique coopérative : la coopération entre véhicules rend la détection plus facile et fiable. Il y a deux participants dans le système : les véhicules « porteurs du système » aussi bien que les « suiveurs », sont équipés de caméras stéréoscopiques, c’est à dire de deux capteurs d’image, appartenant à des familles technologique à haute cadence; les véhicules « cibles » sont équipés des feux à Leds modulés, dont la fréquence de modulation est déjà connue par les véhicules « suiveurs ». Après filtrage dans l’espace temporel, le système ne détecte que des signaux issus des feux modulés, ce qui réduit fortement l’information à traiter par rapport aux calculs de trajectographie traditionnels. La détection de feux modulés est donc réalisée par le filtrage par traitement numérique des images, qui est adapté à la fréquence de modulation recherchée. Pour cela, nous avons proposé 3 types de filtres adaptés à la fréquence de modulation et conçus de façon à rejeter au mieux les signaux de fond.Pour évaluer les performances tant en détection qu’en réjection des fausses alarmes, nous avons d’abord effectué des simulations numériques en prenant en compte des signaux artificiels, puis des calculs sur vrais signaux obtenus dans les expérimentations avec véhicule d’essai statique, puis roulant. Les roulages étaient de différentes vitesses, de 30km/h jusqu’à 100km/h, ce qui nous a permis d’analyser le signal issu du feu ainsi que le comportement de nos filtres à des vitesses angulaires de feu nulles, faibles ou élevées. Le résultat de ces expérimentations montre que le filtrage permet de détecter les feux à Leds de type DRL jusqu’à 140m sans aucune fausse détection sur le fond. Ces expérimentations sont une étape essentielle pour définir de façon plus précise un tel système, en particulier dans le choix du seuil. Nous avons aussi évalué des technologies qui peuvent améliorer la performance du système, mais qui ne sont pas encore prêtes à industrialiser. Par exemple, les « rétines » artificielles nous permettent d’utiliser les filtres analogiques intégrés, et ainsi de réduire leurs bandes passantes. / This thesis was devoted to the development of a new detection method for vehicular collision avoidance system based on trajectory measurement, which could contribute to driver assistance systems.In order to obtain high detection probability, we have chosen the cooperative stereoscopic video solution: the cooperation between vehicles makes it easier and more reliable when they aim to detect each other. There are two participants in the system: the “system carriers" vehicles, or the " followers" are equipped with stereoscopic cameras (two image sensors), who belong to high speed technology families; the "targets" vehicles are equipped with modulated LED lights, with the modulation frequency being already known by the "followers". After space-time filtering, the system detects the signals emitted bymodulated lights sources, which greatly reduces the amount of information to be processed comparing to traditional trajectory calculations methods. The detection of modulated light is achieved by filtering based on digital image processing, which is adapted to the desired modulation frequency. We have proposed three types of filters suitable for detecting the modulation at this frequency and at the same time for rejecting the background as well as possible.In order to be able to evaluate the performances of both detecting signals and rejecting false alarms, we first performed numerical simulations based on the model signals, then calculations on real signals acquired in static and driving experiments. The tested speeds were from 30km/h up to 100km/h, which allowed us to analyze the signals emitted from vehicle lights as well as the behavior of our filters under different angular velocities of the lights (zero, low and high). The result of these experiments showed that our method of filtering could detect LED-type DRL lights up to 140m without any false alarm. This is essential to define more precisely the values of thresholds of such systems. We have also evaluated technologies that are possible to improve system performance in the future, which are not yet ready to be used in industry productions. For example, artificial "retinas" could allow us to integrate analog filters in the chips, and thus to reduce bandwidth of the filters.

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>