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This paper first reports on the benchmarking of a gasoline- fueled vehicle currently for sale in California that is certified to ULEV standards. Emissions data from this vehicle indicate the improvements necessary over current technology to meet SULEV tailpipe standards. Tests with this vehicle also show emissions levels with current technology under off-cycle conditions representative of real-world use. We then present Delphi's strategy of on-board partial oxidation (POx) reforming with gasoline-fueled, spark-ignition engines. On-board reforming provides a source of hydrogen fuel. Tests were run with bottled gas simulating the output of a POx reformer. Results show that an advanced Engine Management System with a small on-board reformer can provide very low tailpipe emissions both under cold start and warmed-up conditions using relatively small amounts of POx gas. The data cover both normal US Federal Test Procedure (FTP) conditions as well as more extreme, off-cycle operation.

The lateral runout of disc brake corner components can lead to the generation of brake system pulsation. Emphasis on reducing component flatness and lateral runout tolerances are a typical response to address this phenomenon. This paper presents the results of an analytical study that examined the effect that the attachment of the wheel to the brake corner assembly could have on the lateral distortion of the rotor. An analysis procedure was developed to utilize the finite element method and simulate the mechanics of the assembly process. Calculated rotor distortions were compared to laboratory measurements. A statistical approach was utilized, in conjunction with the finite element method, to study a number of wheel and brake corner parameters and identify the characteristics of a robust design.

A method of canceling unknown angular rate effects in impact immunity measurement for angular rate sensors is presented. A pair of the same type of testing sensors is arranged such that the sensing axes of the sensor pair are 180° out of phase. While an angular rate produces anti-phase component in the sensor outputs, a linear acceleration produces in-phase response from the sensors due to similar mechanical symmetry. This phase difference is used to cancel the angular rate component even though the actual angular rate may still be unknown. This cancellation can be derived from the sensor output transfer function and is supported with our experimental data.

Hybrid electric vehicles have the potential to reduce air pollution and improve fuel economy without sacrificing the present conveniences of long range and available infrastructure that conventional vehicles offer. Hybrid vehicles are generally classified as series or parallel hybrids. A series hybrid vehicle is essentially an electric vehicle with an on-board source of power for charging the batteries. In a parallel hybrid vehicle, the engine and the electric motor can be used to drive the vehicle simultaneously. There are various possible configurations of parallel hybrid vehicles depending on the role of the electric motor/generator and the engine. In this paper, a comparative study of the drivetrains of five different hybrid vehicles is presented. The underlying design architectures are examined, with analysis as to the tradeoffs and advantages represented in these architectures.

Since the late 1980s, Delphi Automotive Systems has been very involved with the practical development of a variety of Collision Avoidance products for the near- and long-term automotive market. Many of these complex collision avoidance products will require the integration of various vehicular components/systems in order to provide a cohesive functioning product that is seamlessly integrated into the vehicle infrastructure. One such example of this system integration process was the development of an Adaptive Cruise Control system on an Opel Vectra. The design approach heavily incorporated system engineering processes/procedures. The critical issues and other technical challenges in developing these systems will be explored. Details on the hardware and algorithms developed for this vehicle, as well as the greater systems integration issues that arose during its development will also be presented.

The objective of this paper is to impart the challenges presented and the solutions derived to transform an artist's rendering into a production driver's door switch to be used in the interior of a high profile sports car. The challenges took many forms throughout the process, from data translation and packaging, to the final decorative issues. The results are a finished product providing a new approach to automotive interior switch design. It incorporates a low profile, continuous plane keypad with “soft touch” feel, tactile feedback, and integrated back lighting.

The interdependence of consumer features, new electronic and electrical architectures and hybrid propulsion systems are examined. There are two major forces driving future vehicle electronic and electrical systems, one is consumer demand for comfort and safety, and two is the demand for reduced fuel consumption and emissions. These forces are linked by the use of electronics to control vehicle energy generation and usage while providing managed solutions to these demands. Automobile consumer features are discussed and the case is made that these features will require more electric power to be installed on the vehicle. The presence of this increased electric power will then enable the hybrid vehicle functions that will benefit fuel economy and emissions performance.

Recent advances in dependable embedded system technology, as well as continuing demand for improved handling and passive and active safety improvements, have led vehicle manufacturers and suppliers to actively pursue development programs in computer-controlled, by-wire subsystems. These subsystems include steer-by-wire and brake-by-wire, and are composed of mechanically de-coupled sets of actuators and controllers connected through multiplexed, in-vehicle computer networks; there is no mechanical link to the driver. This paper addresses fundamental benefits and issues of steer-by-wire, especially those related to automated vehicle control and steering feel quality as perceived by the driver.

It is estimated that in the United States, nearly one quarter of all fatal automobile accidents involve a vehicle rollover. [1] In order to reduce fatalities and serious injuries, it is desirable to develop a sensing system that can detect an imminent rollover condition with sufficient time to activate occupant safety protection devices. The goals of a Rollover Sensing Module (RSM) are; 1 To accurately estimate vehicle roll and pitch angles 2 To reliably predict in a timely manner an imminent rollover 3 To eliminate false activation of safety devices 4 To function properly during airborne conditions 5 To be as autonomous as possible, not requiring information from other vehicle subsystems.

Electric power steering (EPS) is an advanced steering system that uses an electric motor to provide steering assist. Being a new technology it lacks the extensive operational history of conventional steering systems. Also conventional systems cannot be used to command an output independent of the driver input. In contrast EPS, by means of an electric motor, could be used to do so. As a result EPS systems may have additional failure modes, which need to be studied. In this paper we will consider the requirements for successful EPS operation. The steps required to develop diagnostics based on the requirements are also discussed. The results of this paper have been implemented in various EPS-based programs.

In recent years, the desire for improved vehicle performance, reliability and safety have increased the electrical content and its complexity in vehicles. Advanced automotive systems integrate sensors, controllers, actuators and communication networks. To maintain safety and reliability, a comprehensive system of diagnostics and physical and analytic redundancy are used. In some cases, diagnostic strategies based on analytical redundancy can provide detection, as well as fault-tolerance, and may provide benefits in cost, packaging, flexibility and reusability. This paper discusses a range of diagnostic methods and their applicability to advanced automotive systems such as X-by-Wire. It will also show the reduction to practice of an advanced analytical technique for an automotive application.

The purpose of this paper is to investigate occupant injuries which may be sustained during a single-event crash with known roll mechanism. The data was obtained from the weighted National Automotive Sampling System/ Crashworthiness Data System (NASS-CDS) for calendar years 1992 to 1996. The effect of number of rollover turns, roll direction, ejection and belt usage on driver injury responses was analyzed in single-event trip-overs. Trip-overs were chosen for the analysis because they account for over 50% of rollover crashes. The number of rollovers was divided in 3 categories: ¼ to ½ turn, ¾ to 1 turn and above 1 turn. Roll direction was either roll-left or a rollright along the longitudinal axis of the vehicle. Roll-left represents a roll with the driver side leading, while a roll right is with the right front passenger side leading. In the database used in this study, there were three times more belted drivers than unbelted.

The present paper reports on a study of the HVAC energy usage for an EREV (extended range electric vehicle) implementation of a localized cooling/heating system. Components in the localized system use thermoelectric (TE) devices to target the occupant's chest, face, lap and foot areas. A novel contact TE seat was integrated into the system. Human subject comfort rides and a thermal manikin in the tunnel were used to establish equivalent comfort for the baseline and localized system. The tunnel test results indicate that, with the localized system, HVAC energy savings of 37% are achieved for cooling conditions (ambient conditions greater than 10 °C) and 38% for heating conditions (ambient conditions less than 10 °C), respectively based on an annualized ambient and vehicle occupancy weighted method. The driving range extension for an electric vehicle was also estimated based on the HVAC energy saving.

Spot, or distributed, cooling and heating is an energy efficient way of delivering comfort to an occupant in the car. This paper describes an approach to distributed cooling in the vehicle. A two passenger CFD model of an SUV cabin was developed to obtain the solar and convective thermal loads on the vehicle, characterize the interior thermal environment and accurately evaluate the fluid-thermal environment around the occupants. The present paper focuses on the design and CFD analysis of the energy efficient HVAC system with spot cooling. The CFD model was validated with wind tunnel data for its overall accuracy. A baseline system with conventional HVAC air was first analyzed at mid and high ambient conditions. The airflow and cooling delivered to the driver and the passenger was calculated. Subsequently, spot cooling was analyzed in conjunction with a much lower conventional HVAC airflow.

In vehicular mobility context, it is extremely important for the environmental sustainability that the available energy will be used as efficiently as possible, both in the use of internal combustion engines (ICE) as powertrain, as well in the application of Hybrid and Electric Vehicle Motors (HEV/EV). In this comparison, ICE has a lower efficiency when compared to electric motors, wasting much of the potential energy of the fuel in form of heat and noise. On the other hand, the electric vehicles face limitation in autonomy and recharge time, demanding for a more efficient use of energy stored in batteries. This study aims to present emerging technologies for reuse of energy within the automotive context, originally known as “Energy Harvesting” and “Renewable Energies”.

This paper describes the development and implementation of an Engine Drag Control algorithm to improve vehicle stability performance. Engine drag can occur on low and high coefficient surfaces when the driver suddenly releases the throttle. If the engine drag force becomes larger than the frictional force between the tire and the road, the tires will break loose from the surface and slip. This could induce vehicle instability especially with rear drive vehicles on low-coefficient surfaces. The EDC algorithm has been developed to provide accurate control of the wheels. EDC will help reduce the yaw rate of the vehicle and thus achieve greater vehicle stability. The paper also presents methods used to test the robustness of such a system. The purpose of the testing was to ensure that there would be no false activations of EDC under normal driving conditions and also to ensure that, when the system is active, it is mostly transparent to the driver.

An algorithm for estimation of vehicle yaw rate and side slip angle using steering wheel angle, wheel speed, and lateral acceleration sensors is proposed. It is intended for application in vehicle stability enhancement systems, which use controlled brakes or steering. The algorithm first generates two initial estimates of yaw rate from wheel speeds and from lateral acceleration. A new estimate is subsequently calculated as a weighted average of the two initial ones, with the weights proportional to confidence levels in each estimate. This preliminary estimate is fed into a closed loop nonlinear observer, which generates the final estimate of yaw rate along with estimates of lateral velocity and side slip angle. Parameters of the observer depend on the estimated surface coefficient of adhesion, thus providing adaptation to changes in road surface coefficient of adhesion.

This paper summarizes the results of an investigation of high risk, high potential technologies for hybrid vehicle drive applications and investigate potential solutions for the technical risk items associated with these technologies. The study consisted of the design, build, and test of different types of electric machines to understand their performance, efficiency, and manufacturability to develop hybrid vehicles with cost and performance similar to the present day IC engine based vehicles, but with lower emissions and better fuel economy. Machine technologies examined include synchronous reluctance, permanent magnet, and switched reluctance. Test data for various machine technologies is presented along with a discussion of the technical risk associated with each technology.

Continuous Improvement activities are often based on a list of top concerns, such as highest RPN (Risk Priority Number) on the PFMEA (Process Failure Modes and Effects Analysis), warranty items, or scrap rates. But a company is in business to make a profit for its stockholders. Therefore, money should be considered, rather than just technical engineering tools and RPNs. Current PFMEA methodology (See references 1 and 2) focuses on delivering quality parts to the customer. The financial impact of various potential process problems is not considered directly. A new and extended technique called FMERA (pronounced Fuh-MAIR-uh) can identify and prioritize the process part of potential problems that have the most financial impact on an operation. Alternatives can be evaluated to maximize the financial benefits. FMERA is a method for getting the voice of the stockholder into process decisions.

CFD analysis was performed using the FLUENT software to design the thermal system for a hybrid vehicle battery pack. The battery pack contained multiple modular battery elements, called bricks, and the inlet and outlet bus bars that electrically connected the bricks into a series string. The simulated thermal system was comprised of the vehicle cabin, seat cavity, inlet plenum, battery pack, a downstream centrifugal fan, and the vehicle trunk. The fan was modeled using a multiple reference frame approach. A full system analysis was done for airflow and thermal performance optimization to ensure the most uniform cell temperatures under all operating conditions. The mesh for the full system was about 13 million cells run on a 6-node HP cluster. A baseline design was first analyzed for fluid-thermal performance. Subsequently, multiple design iterations were run to create uniform airflow among all the individual bricks while minimizing parasitic pressure drop.