Search Results

The Ford GT Program Team was allocated just 22 months from concept to production to complete the Electrical and Electronics systems of the Ford GT. This reduced vehicle program timing - unlike any other in Ford's history -- demanded that the team streamline the standard development process, which is typically 54 months. This aggressive schedule allowed only 12 weeks to design the entire electrical and electronic system architecture, route the wire harnesses, package the components, and manufacture and/or procure all components necessary for the first three-vehicle prototype build.

Two oxygenated fuels were evaluated on a single-cylinder diesel engine and compared to three hydrocarbon diesel fuels. The oxygenated fuels included canola biodiesel (canola methyl esters, CME) and CME blended with dibutyl succinate (DBS), both of which are or have the potential to be bio-derived. DBS was added to improve the cold flow properties, but also reduced the cetane number and net heating value of the resulting blend. A 60-40 blend of the two (60% vol CME and 40% vol DBS) provided desirable cold flow benefits while staying above the U.S. minimum cetane number requirement. Contrary to prior vehicle test results and numerous literature reports, single-cylinder engine testing of both CME and the 60-40 blend showed no statistically discernable change in NOx emissions relative to diesel fuel, but only when constant intake oxygen was maintained.

A method of predicting brake specific fuel consumption characteristics from limited specifications of engine design has been investigated. For spark ignition engines operating on homogeneous mixtures, indicated specific fuel consumption based on gross indicated power is related to compression ratio and spark timing relative to optimum values. The influence of burn rate is approximately accounted for by the differences in spark timings required to correctly phase combustion. Data from engines of contemporary design shows that indicated specific fuel consumption can be defined as a generic function of relative spark timing, mixture air/fuel ratio and exhaust gas recirculation rate. The additional information required to generate brake specific performance maps is cylinder volumetric efficiency, rubbing friction, auxiliary loads, and exhaust back pressure characteristics.

Thermal comfort in automotive seating has been studied and discussed for a long time. The available research, because it is focused on the components, has not produced a model that provides insight into the human-seat system interaction. This work, which represents the beginning of an extensive research program, aims to establish the foundation for such a model. This paper will discuss the key physiological, psychological, and biomechanical factors related to perceptions of thermal comfort in automotive seats. The methodology to establish perceived thermal comfort requirements will also be presented and discussed.

The world urbanization is growing rapidly, bringing many challenges for people to move in dense metropolitan regions. Public transportation is not able to attend the whole demand, and individual transportation modes are struggling with traffic congestion and stringent regulations to reduce its attractiveness, such as the license plate restriction in São Paulo. On the other hand, enablers like smartphones mass penetration, GPS connected services and shared economy have opened space to a whole new range of possible solutions to improve people perception on urban mobility. This work aims to evaluate the modal choice behavior models and understand the success factor of current mobility solutions in the city of São Paulo. The data available through origin/destination researches will be used to validate the models used in this work.

The development and implementation of a new structure for data-driven models for NOX and soot emissions is described. The model structure is a linear regression model, where physically relevant input signals are used as regressors, and all the regression parameters are defined as grid-maps in the engine speed/injected fuel domain. The method of using grid-maps in the engine speed/injected fuel domain for all the regression parameters enables the models to be valid for changes in physical parameters that affect the emissions, without having to include these parameters as input signals to the models. This is possible for parameters that are dependent only on the engine speed and the amount of injected fuel. This means that models can handle changes for different parameters in the complete working range of the engine, without having to include all signals that actually effect the emissions into the models.

Recently, papers have been published purporting to study the effect of rear axle tramp during tread separation events, and its effect on vehicle handling [1, 2]. Based on analysis and physical testing, one paper [1] has put forth a mathematical model which the authors claim allows vehicle designers to select shock damping values during the development process of a vehicle in order to assure that a vehicle will not experience axle tramp during tread separations. In the course of their work, “lumpy” tires (tires with rubber blocks adhered to the tire's tread) were employed to excite the axle tramp resonance, even though this method has been shown not to duplicate the physical mechanisms behind an actual tread belt separation. This paper evaluates the theories postulated in [1] by first analyzing the equations behind the mathematical model presented. The model is then tested to see if it agrees with observed physical testing.

Reductions of hardware costs as well as implementations of new innovative functions are the main drivers of today's automotive electronics. Indeed more and more resources are spent on adapting existing solutions to different environments. At the same time, due to the increasing number of networked components, a level of complexity has been reached which is difficult to handle using traditional development processes. The automotive industry addresses this problem through a paradigm shift from a hardware-, component-driven to a requirement- and function-driven development process, and a stringent standardization of infrastructure elements. One central standardization initiative is the AUTomotive Open System ARchitecture (AUTOSAR). AUTOSAR was founded in 2003 by major OEMs and Tier1 suppliers and now includes a large number of automotive, electronics, semiconductor, hard- and software companies.

The pre EGR valve pressure is an important measurement for the Diesel engine air handling system. It is commonly used for the EGR flow calculation during engine transient operation. Due to the erosive exhaust gas, an EGR pressure sensor will eventually have gold corrosion resulting in drive-ability issues. Therefore, a software replacement for the EGR pressure sensor is desirable. However, when the EGR valve is on the cold side of the EGR cooler, the accuracy of the EGR pressure estimation deteriorates because of the variability of the pressure drop across the EGR cooler due to EGR cooler fouling. In this paper, an adaptive scheme is developed to improve the accuracy of pre EGR valve pressure estimation in the presence of EGR cooler fouling for diesel engines. The pressure drop across the EGR cooler is shown to be proportional to the velocity pressure of the EGR flow through the cooler.

Electrically assisted turbochargers are a promising technology for improving boost response of turbocharged engines. These systems include a turbocharger shaft mounted electric motor/generator. In the assist mode, electrical energy is applied to the turbocharger shaft via the motor function, while in the regenerative mode energy can be extracted from the shaft via the generator function, hence these systems are also referred to as regenerative electrically assisted turbochargers (REAT). REAT allows simultaneous improvement of boost response and fuel economy of boosted engines. This is achieved by optimally scheduling the electrical assist and regeneration actions. REAT also allows the exhaust turbine to operate within a narrow range of optimal vane positions relative to the unassisted variable geometry turbocharger (VGT). The ability to operate within a narrow range of VGT vane positions allows an opportunity for a more optimal turbine design for a REAT system.

Thermal effectiveness of Exhaust Gas Recirculation (EGR) coolers used in diesel engines can progressively decrease and stabilize over time due to inner fouling layer of the cooler tubes. Thermophoretic force has been identified as the major cause of diesel exhaust soot fouling, and models are proposed in the literature but improvements in simulation are needed especially for the long-term trend of soot deposition. To describe the fouling stabilization behavior, a removal mechanism is required to account for stabilization of the soot layer. Observations from previous experiments on surrogate circular tubes suggest there are three primary factors to determine removal mechanisms: surface temperature, thickness, and shear velocity. Based on this hypothesis, we developed a 1D CFD fouling model for predicting the thermal effectiveness reduction of real EGR coolers. The model includes the two competing mechanisms mentioned that results in fouling balance.

Static seating bucks have long been used as the only means to subjectively appraise the vehicle interior packages in the vehicle development process. The appraisal results have traditionally been communicated back to the requesting engineers either orally or in a written format. Any design changes have to be made separately after the appraisal is completed. Further, static seating bucks lack the flexibility to accommodate design iterations during the evolution of a vehicle program. The challenge has always been on how to build a seating buck quickly enough to support the changing needs of vehicle programs, especially in the early vehicle development phases. There is always a disconnect between what the seating buck represents and what is in the latest design (CAD), since it takes weeks or months to build a seating buck and by the time it is built the design has already been evolved. There is also no direct feedback from seating buck appraisal to the design in CAD.

Tests are conducted to improve the use of exhaust gas recirculation on a single cylinder diesel engine with EGR stream treatment techniques that include intake heating, combustible substance oxidation, catalytic fuel reforming, and partial bypass-flow control. In parallel with the empirical work, theoretical modeling analyses are performed to investigate the effectiveness of the reforming process and the combined effects on the overall system efficiency. The research is aimed at stabilizing and expanding the limits of heavy EGR during steady and transient operations so that the individual limiting conditions of EGR can be better identified. Additionally, the heavy EGR is applied to enable in-cylinder low temperature combustion. The effectiveness of EGR treatment on engine emission and operating characteristics are therefore reported.

Simulink is a very successful and popular method for modelling and auto-coding embedded automotive features, functions and algorithms. Due to its history of success, university feeder programs, and large third party tool support, it has, in some cases, been applied to areas of the software system where other methods, principles and strategies may provide better options for the software and systems engineers and architects. This paper provides approaches to determine when best to apply UML and when best to apply Simulink to a typical automotive feature. Object oriented software design patterns as well as general guidelines are provided to help in this effort. This paper's intent is not to suggest a replacement for Simulink but to provide the software architects and designers additional options when decomposing high level requirements into reusable software components.

This paper presents a comparison of aqueous corrosion rates in 5% NaCl solution for eight experimental creep-resistant magnesium alloys considered for automotive powertrain applications, as well as three reference alloys (pure magnesium, AM50B and AZ91D). The corrosion rates were measured using the techniques of titration, weight loss, hydrogen evolution, and DC polarization. The corrosion rates measured by these techniques are compared with each other as well as with those obtained with salt-spray testing using ASTM B117. The advantages and disadvantages of the various corrosion measurement techniques are discussed.

This paper takes a look at one of the problems associated with the concept of autonomous control of vehicles in the current traffic environment, namely the changing of lanes. Given the increase in traffic density on highways and interstate roads over the past few decades, safe navigation of individual vehicles has required increased driver attention and diligence to an increased number of visual information cues. The concept of autonomous vehicles operating without driver intervention in the present traffic system appears daunting. One aspect of traffic maneuvering involves changing lanes to a position between two other vehicles. Although this aspect appears straightforward, it is the lack of accurate knowledge of other vehicle maneuvering which makes the task difficult. Using Model Predictive Control (MPC) techniques, the task is addressed in an optimization problem framework.

Considering that the most part of commercial vehicles are equipped with air brakes it is very important assure specific technical requirements for air brake system and its components. In addition, the effects of brake system failure are more critical for commercial vehicles which require more attention on their requirements details. Historically, the development of air brakes technology started on North America and Europe and consequently two strong and distinct resolutions were structured: FMVSS 121 and ECE R.13, respectively. For passenger cars were developed the ECER.13H to harmonize North American and European resolutions. However, for commercial vehicles regional applications, culture and implementation time must be considered. These commercial vehicles peculiarities must be understood and their specific requirements harmonized to attend the global marketing growth.

It is very important and unquestionable that we need to have a clear technical requirement for Air Brake Systems and its components, since it is one of most important regarding safety. Looking to heavy commercial vehicles and possible air brake system failures, everything becomes clearly to pay total attention for these normative and regulatory requirements. Historically, the development of Brakes technology has started on EUA and Europe and consequently two strong and distinct requirements were structured: FMVSS 121 and ECE-R13. From decades people are trying to harmonize these requirements and for passenger cars, the evolution was faster. However, for commercial vehicles there are more peculiarities considering regional applications and some of them cultural and implementation time. As globally market is growing so fast as well new markets around the world, become fundamental the clearly understanding of these similarities, variants, peculiarities and correlated requirements.

The growing competition of the automotive market makes more and more necessary the reduction of development time and consequently, the increase of the capacity to quickly respond to the launching of the competitors. One of the most costly phases on the vehicle development process is the field durability test, both in function of the number of prototypes employed and the time needed to its execution. More and more diffused, the fatigue life prediction methods have played an important part in the durability analysis via CAE. Nevertheless, in order they can be reliable and really being able to reduce the development time and cost, they need to be provided with load cases that can accurately represent the field durability tests. This work presents a CAE approach used for light trucks in order to get a reasonable understanding of component durability behavior due to payload increase. In general, road load data is not available for a new payload condition.

This paper describes the CFD modeling work conducted for the development and research of a Vortex Induced Stratification Combustion (VISC) system that demonstrated superior fuel economy benefits. The Ford in-house CFD code and simulation methodology were employed. In the VISC concept a vortex forms on the outside of the wide cone angle spray and transports fuel vapor from the spray to the spark plug gap. A spray model for an outward-opening pintle injector used in the engine was developed, tested, and implemented in the code. Modeling proved to be effective for design optimization and analysis. The CFD simulations revealed important physical phenomena associated with the spray-guided combustion system mixing preparation.