Academic literature on the topic 'Automobile systems'

Thesis (S.M. in System Design and Management)--Massachusetts Institute of Technology, Engineering Systems Division, System Design and Management Program, 2010.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (p. 111-112).<br>Electrical and electronic components have a prominent role in today's vehicles. Particularly during the last two decades, functionality has been added at an exponential rate, resulting in increased complexity, especially of the Electrical Distribution System (EDS), which is the backbone of the Electrical and Electronic System (EES). Increased content and complexity of electrical systems, together with pressure to reduce the design cycle time - to bring a larger variety of products to the market and at a faster pace - are forcing car companies to re-evaluate their existing electrical development processes. One of the ways that car makers have devised to accomplish this is a common EES architecture strategy, which consists in combining communization, standardization, reusability and best practices to create flexible EES architectural concepts that will be used in a higher number of derivative vehicles. This common architecture has several benefits, the most important being: reduction of development costs and time, which translates in less time for putting the products in the market; architecture, concepts and components reuse; rapid platform modifications, to adapt to market changes and regional preferences. The EES architecture choice for a vehicle is the result of the implementation of the desired functions in hardware and software. Many considerations need to be taken into account: costs, network capabilities, modularity, manufacturing, energy management, weight, among several others. The present work aims to explain these considerations, as well as the elements of the common EES, and in particular their impact on the EDS. Another important aspect for the successful implementation of the common architecture is the EDS development process. Despite the availability of a wide range of software tools, the current EDS approach is intensely manual, relying on design experts to define and maintain the interrelationships and complexities of the core design definition. There is a need to redefine the process, from concept to manufacture using a systems engineering approach, which would yield key benefits, like shorten development time, produce accurate harness manufacturing prints, reduce wiring costs by synchronizing all input and output data. An analysis of the tools and methods for design and validation of wire harnesses will be presented in the last two chapters of this thesis.<br>by Marcia E. Azpeitia Camacho.<br>S.M.in System Design and Management

A dual, double-acting propulsion system is analyzed to determine how efficiently it can convert the potential energy available from liquid nitrogen into useful work. The two double-acting pistons (high- and low-pressure) were analyzed by using a Matlab-Simulink computer simulation to determine their respective mechanical efficiencies. The flow circuit for the entire system was analyzed by using flow circuit analysis software to determine pressure losses throughout the system at the required mass flow rates. The results of the piston simulation indicate that the two pistons analyzed are very efficient at transferring energy into useful work. The flow circuit analysis shows that the system can adequately maintain the mass flow rate requirements of the pistons but also identifies components that have a significant impact on the performance of the system. The results of the analysis indicate that the nitrogen propulsion system meets the intended goals of its designers.

Cette thèse a été développé grâce à une Conventions Industrielles de Formation par la Recherche (CIFRE). Cette convention fait partie d’un programme de l’Association nationale de la recherche et de la technologie (ANRT), coordonné par le Centre nationale de la recherche scientifique (CNRS). L’accord CIFRE subventionne les entreprises françaises qui engagent un thésard pour conduire un projet scientifique dans l’entreprise, en partenariat avec un laboratoire publique de recherche. Pour cette thèse, l’accord CIFRE a été signé par Renault et les laboratoires GIPSA Lab de Grenoble et PRISME d’Orléans.Cette thèse se focalise sur la modélisation 0D, en particulier sur une description plus détaillé du processus de la combustion et l’estimation des masses enfermées dans la chambre de combustion d’un moteur à allumage commandé (Spark Ignited (SI) engine). Les principaux développements comportent des points suivants :- L’impact flamme parois pendant la combustion : un nouveau modèle pour prendre en compte ce phénomène dans le cadre d’un modèle de combustion 0D à deux zones a été développé. Ce modèle permet de prendre en compte la géométrie de la chambre de combustion et la proportion de flamme que brûle proche des parois du cylindre. Plusieurs études ont montré qu’une grand proportion (20% au 30%) du mélange frais brûle dans ce mode de combustion ce qui montre l’importance de prendre en compte ce phénomène. - L’estimation de la mass totale enfermée dans la chambre de combustion après la fermeture des soupapes est un phénomène très intéressant qui présente un Challenger pour les chercheurs motoristes. Une estimation plus précise de la mass enfermée dans la chambre de combustion permet d’avoir un meilleur contrôle de l’injection du carburant et une amélioration dans le traitement des polluants.- Le dernier point à traiter dans cette thèse est la commande d’un système d’injection “common rail”. Ce point a pour but de compléter la modélisation de la combustion en ajoutant une thématique liée à l’injection, lequel est un paramètre crucial dans le processus de la combustion. L’objectif d’un système d’injection common rail est de contrôler l’avance de l’injection, la durée et la pression, de façon indépendante dans chaque cylindre, pour avoir un meilleur contrôle de la combustion, en dépendant des conditions d’opération. Cette injection permet de réguler le carburant en quantités très petites, ce qu’aide à réduire la consommation, les émissions polluantes, et aussi à améliorer la performance du moteur<br>This thesis has been developed thanks to a Conventions Industrielles de Formation par la Recherche (CIFRE)1 agreement, that is a program of the french agency Association nationale de la recherche et de la Technologie(ANRT), coordinated by the Centre nationale de la recherche scientifique (CNRS). The CIFRE program grants the Franch companies who engage a PhD student to carry out a research project of the company within a public research lab. For this thesis, a CIFRE agreement has been accorded between the automobile company Renault France and the scientific laboratories Gipsa Lab in Grenoble and PRISME in Orléans.This thesis is focused on the modeling of a detailed description of the 0D combustion process and the estimation of the enclosed mass in the combustion chamber for a Spark Ignited (SI) engine. The main developments are summarized as follows:- The combustion process is frequently modeled as growing flame inside of the combustion chamber. Many 0D thermodynamical Engine models mostly focus on the laminar characteristics of such a free developing ame, but they lack of a suitable approximation of the combustion when the ame reaches the cylinder walls. In this thesis, a flame-wall interaction model is proposed as a complement of a 0D two zones thermodynamical model.- The estimation of the total mass enclosed in the combustion chamber is an interesting and challenging task for the engine control community. In this thesis, two nonlinear observers are synthesized for the enclosed mass estimation: a classical nonlinear high gain observer and an extended linear parameter varying (LPV) high gain observer.- A controller for a common rail injection system is developed in this thesis. First, an input state linearization of a common rail model is performed, in order to overcome the strong nonlinearities and build a virtual linear model. Using the virtual model, two linear control strategies are implemented to regulate the common rail pressure: an optimal linear quadratic regulator LQR with integral action and an optimal LQR tracking (feedforward) with integral action strategy

Due to concerns about the negative impacts of powering vehicles using fossil fuel and the future availability of fossil fuel, there has been an increased focus on electric vehicles. However, current electric vehicle energy efficiency is a key problem as these vehicles are not as efficient as fossil-fueled vehicles. One way of decreasing a vehicle’s energy consumption is to reduce the weight of the vehicle, while still ensuring the safety and reliability of the vehicle. Controller Area Network (CAN) systems have been used in vehicles to realize real-time applications, however the low peak data rates of CAN have begun to limit the applications that can be realized. This bachelor’s thesis project focuses on secure communication within a vehicle using Ethernet. Additionally, the use of Power over Ethernet can be used for powering some of the network attached devices within the vehicle. The goal is to reduce the number of components and the weight of the vehicle while continuing to ensure the security and reliability of the communication – even when the network grows in size (either in physical size or in number of connected devices). This thesis shows that an Ethernet based system can serve as a possible replacement candidate for the CAN system due to its low latencies and high bandwidth. Ethernet is also a very scalable system with none of the limitations that a CAN system have.<br>Den negativa påverkan av fossila bränslen har de senaste årtionden haft en negativ på planeten, mängden fossila bränslen över världen konsumeras även i en högre takt än vad som produceras. Därför har fokusen för att finna förnybara energi källor som både är effektiva och inte påverkar miljön på ett negativt sätt ökat. Därför är elbilar en viktig del i konverteringen av enheter som drivs av fossila bränslen till förnybara energikällor. Ett av problemen i en elbil är att energi konsumptionen är inte lika effektiv som fossila bränslen inom bil industrin. Ett sätt att sänka energi konsumptionen är att minska mängden komponenter inom en bil för att minska på vikten, utan att påverka säkerheten och tillförlitligheten. Tidigare har man använt sig av ett CAN system för att försäkra sig om systemet fungerar felfritt i realtid, problematiken med detta system är att när nätverket ökar i storlek så sätter de fysiska begränsningarna av detta system stop för den garanterade säkerheten. Detta kandidatexamensarbete kommer att fokusera på den interna kommunikationen i en elbil med hjälp av ett ethernet baserat kommunkations system över CAN systemet. Power over Ethernet tekinken kommer att tillämpas för de systemen som kan drivas av detta system. Målet är att reducera antalet komponenter som behövs och att garantera säkerheten och tillförlitligheten av den interna kommunikationen när nätverket av komponenter ökar i storlek. Det här kandidatarbetet visar att Ethernet kan ersätta det nuvarande CAN systemet ef-tersom att Ethernet erbjuder låga latenser och hög bandbredd. Detta arbete visar även att Et-hernet är väldigt skalbart och har inte begränsingarna som ett CAN system har.

Thesis (S.M.)--Massachusetts Institute of Technology, Engineering Systems Division, Technology and Policy Program, 2006.<br>Includes bibliographical references (p. 160-167).<br>Intelligent driver warning systems can be found in many high-end vehicles on the road today, which will likely rapidly increase as they become standard equipment. However, introducing multiple warning systems into vehicles could potentially add to the complexity of the driving task, and there are many critical human factors issues that should be considered, such as how the interaction between alarm alerting schemes, system reliabilities, and distractions combine to affect driving performance and situation awareness. In addition, there are also questions with respect to whether there should be any minimum safety standards set to ensure both functional and usage safety of these systems, and what these standards should be. An experiment was conducted to study how a single master alert versus multiple individual alerts of different reliabilities affected drivers' responses to different imminent collision situations while distracted. A master alert may have advantages since it reduces the total number of alerts, which could be advantageous especially with the proliferation of intelligent warning systems. However, a master alert may also confuse drivers, since it does not warn of a specific hazard, unlike a specific alert for each warning systems.<br>(cont.) Auditory alerts were used to warn of imminent frontal and rear collisions, as well as unintentional left and right lane departures. Low and high warning reliabilities were also tested. The different warning systems and reliability factors produced significantly different reaction times and response accuracies. The warning systems with low reliability caused accuracy rates to fall more than 40% across the four warning systems. In addition, low reliability systems also induced negative emotions in participants. Thus, reliability is one of the most crucial determinants of driving performance and the safety outcome, and it is imperative that warning systems are reliable. For the master versus distinct alarms factor, drivers responded statistically no different to the various collision warnings for both reaction times and accuracy of responses. However, in a subjective post-experiment assessment, participants preferred distinct alarms for different driver warning systems, even though their objective performance showed no difference to the different alerting schemes. This study showed that it was essential to design robust and reliable intelligent warning systems. However, there are no existing safety standards today to ensure that these systems are safe before they are introduced into vehicles, even though such systems are already available in high-end cars.<br>(cont.) Even though there are tradeoffs in having standards, such as increased time-to-market and possible loss of innovation, I recommend that safety standards be set nonetheless, since standards will ensure the safety performance of warning systems, to an extent. In terms of functional safety, safety standards should be performance-based, and should specify a minimum level of reliability. In terms of usage safety, the standards should also be performance-based, where driving performance can be indicated by measures such as reaction time, lane position, heading distance and accuracy of responses. In addition, multiple threat scenarios should also be tested. In terms of design guidelines, the various human factors guidelines from different countries should be harmonized internationally to ensure that manufacturers have access to a consistent set of guidelines. Finally, it is also important that these standards, especially for usage safety, specify tests with not just the average driver, but also with peripheral driving populations including novice and elderly drivers.<br>by Angela Wei Ling Ho.<br>S.M.

Safety belt reminder systems are ubiquitously present in most, if not alI automobiles sold in the United States. Past research has found that the effectiveness of these reminder systems have shown minimal social benefit in the effort to increase safety belt use. The current investigation was conducted to determine if modified reminder systems could improve safety belt use. This research used an electronically equipped research vehicle sponsored by General Motors Corporation. The vehicle's research equipment allowed for the manipulation of different auditory reminder stimuli (i.e., chime, buzzer, and voice), temporal factors (e.g., presentation delays and second reminders) I and the measurement of the driver's safety belt use. Three modifications were explored: the presentation of a Delayed Reminder, Second Reminder, and comparisons of different auditory stimuli. The vehicle also permitted a single subject repeated measure design and methodology that provided process analysis. The results showed that the Delayed Reminder appeared ineffective at increasing belt use, whereas the Second Reminder was found to increase two out of nine subjects' safety belt response rates. The differential effects between the three auditory stimuli (i.e., Chime, Buzzer, & Voice) were inconclusive, though for two subjects the Buzzer and Voice were associated with safety belt increases.<br>Master of Science