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Technical Paper

Model Reference Adaptive Control of a Pneumatic Valve Actuator for Infinitely Variable Valve Timing and Lift

2007-04-16
2007-01-1297
Electro-pneumatic valve actuators are used to eliminate the cam shaft of a traditional internal combustion engine. They are used to control the opening timing, duration, and lift of both intake and exhaust valves. A physics based nonlinear mathematical model called the level one model was built using Newton's law, mass conservation and thermodynamic principles. A control oriented model, the level two model, was created by partially linearizing the level one model for model reference parameter identification. This model reduces computational throughput and enables real-time implementation. A model reference adaptive control system was used to identify the nonlinear parameters that were needed for generating a feedforward control signal. The closed-loop valve lift tracking, valve opening and closing timing control strategies were proposed.
Technical Paper

Control Method of Dual Motor-Based Steer-by-Wire System

2007-04-16
2007-01-1149
This paper describes a front road wheel steer-by-wire system with two actuator motors on the rack and pinion assembly to move the road wheels. Dual actuators are used to provide actuator redundancy and to enhance the fault tolerance capability. When one actuator faults or fails, the other actuator is designed to work independently and maintain full system performance. The paper emphasizes control method to implement the motion control for the front road wheel steer-by-wire system with two actuators on the common load. The proposed dual servo synchronization motion control implements the angle tracking for the road wheel reference input by controlling two actuators synchronously and cooperatively. It includes two servo feedback control loops to track the common reference input. The angular position error between two feedback loops is compensated using a synchronized compensator.
Technical Paper

Fuel Economy Improvements through Improved Automatic Transmission Warmup - Stand Alone Oil to Air (OTA) Transmission Cooling Strategy with Thermostatic Cold Flow Bypass Valve

2001-05-14
2001-01-1760
The stand alone oil to air (OTA) transmission cooling strategy with thermostatic cold flow bypass valve has been shown to be an effective means of improving the warmup of an automatic transmission. Improving the system warmup rate of an automatic transmission significantly improves its efficiency by reducing losses resulting from extremely viscous transmission fluid and can allow for calibration changes that improve overall transmission performance. Improved transmission efficiency in turn allows for improved engine efficiency and performance. The improvements obtained from increased transmission and engine efficiency result in an overall increase in vehicle fuel economy. Fuel economy and consumption are important parameters considered by the vehicle manufacturer and the customer. Fuel economy can be considered as important as reliability and durability.
Technical Paper

Modeling of Human Thermal Comfort

2001-06-26
2001-01-2117
Current vehicle climate control systems are dramatically overpowered because they are designed to condition the cabin air mass in a specified period of time. A more effective and energy efficient objective is to directly achieve thermal comfort of the passengers. NREL is developing numerical and experimental tools to predict human thermal comfort in non-uniform transient thermal environments. These tools include a finite element model of human thermal physiology, a psychological model that predicts both local and global thermal comfort, and a high spatial resolution sweating thermal manikin for testing in actual vehicles.
Technical Paper

Oxygenates screening for AdvancedPetroleum-Based Diesel Fuels: Part 2. The Effect of Oxygenate Blending Compounds on Exhaust Emissions

2001-09-24
2001-01-3632
Adding oxygenates to diesel fuel has shown the potential for reducing particulate (PM) emissions in the exhaust. The objective of this study was to select the most promising oxygenate compounds as blending components in diesel fuel for advanced engine testing. A fuel matrix was designed to consider the effect of molecular structure and boiling point on the ability of oxygenates to reduce engine-out exhaust emissions from a modern diesel engine. Nine test fuels including a low-sulfur (∼1 ppm), low-aromatic hydrocracked base fuel and 8 oxygenate-base fuel blends were utilized. All oxygenated fuels were formulated to contain 7% wt. of oxygen. A DaimlerChrysler OM611 CIDI engine for light-duty vehicles was controlled with a SwRI Rapid Prototyping Electronic Control System. The base fuel was evaluated in four speed-load modes and oxygenated blends only in one mode. Each operating mode and fuel combination was run in triplicate.
Technical Paper

Analysis of Coatings Appearance and Durability Testing Induced Surface Defects Using Image Capture/Processing/Analysis

2001-03-05
2001-01-3798
This paper describes the applicability of optical imaging techniques to the analysis of the scratch resistance of automotive interior plastic materials. The evaluation of so-called “finger testing” has traditionally relied upon human vision for detection of the initial scratch position. Commonly performed under uniform and defined illumination conditions, the relative contrast difference signified by whitening on a surface as determined by unaided human vision is a highly variable subjective perception; thus individual inspectors may determine the “whitening” point differently. This paper compares test data obtained from both visual and instrumental evaluation methods and discusses the advantages of optical imaging techniques for surface defect analysis.
Technical Paper

High Efficient LED Headlamp Design-Styling versus Light Performance

2007-04-16
2007-01-0874
First LED headlamps will be released into the market in 2007. Special permissions allow this introduction although the official regulation is still under discussion in ECE. The LED technology for front lighting has entered into a new phase from theoretical, prototype status to real and practical applications. Additionally in Europe the legislation, which is under preparation, defines LED modules with one or more LED chips in a row which should be replaceable. With this boundary conditions headlamp suppliers needs to balance between an attractive and innovative styling, demanded by car manufacturers and the light performance to gurantee good visibility at night. The paper describes the methods how to design an LED headlamp with high efficiency by keeping in mind the parameters: packaging, weight, styling and light perfromance. Results with specific design proposals are shown.
Technical Paper

Design Parameter Tradeoffs for LED Headlamp Applications

2007-04-16
2007-01-0871
High-power LEDs and LED headlamps have become a serious consideration for the automotive industry. White LEDs have achieved the required performance for initial automotive headlamp applications. However tradeoffs among several attributes such as efficiency, cost, weight and performance profoundly affect LED headlamp development and need to be addressed by vehicle manufacturers, lamp set makers and LED source suppliers in order for LED headlamps to be effective. The solutions to these tradeoffs relates to the behavior of the LED sources, the thermo-mechanical integration of LEDs in a headlamp environment and input from the vehicle manufacturer regarding styling and packaging for an LED headlamp on the respective targeted vehicles.
Technical Paper

Towards Development of Thermal Standards for the Design of LED Lamps

2007-04-16
2007-01-1037
Even though the use of LED's in automotive industry is continuously increasing, the test standards used for the thermal design of the lamps do not address the unique needs of LED based lamps. The challenge becomes more significant because LED's are semiconductor devices with lower maximum operating temperatures and photometric properties that depend on temperature. This paper presents sunload test results and lamp thermal data measured on vehicles undergoing simulated driving conditions in a lab environment. The data clearly indicates substantial differences in the measured data versus the test conditions to which the lamps are designed today. It is recommended to modify test standards that the lamps must meet to more closely emulate the field conditions.
Technical Paper

Construction and Application of Near Field (TIR Type) Lenses for Automotive Lighting Functions

2007-04-16
2007-01-1040
Light Emitting Diodes (LEDs) are fast becoming the preferred light sources for automotive lighting applications. They emit light at cone angles equal (hemispherical) or less (conical) than 2Π radians. One way for efficiently collecting and collimating light from LED light sources is to use Near Field Lenses (NFLs). NFLs are collimators using refraction and total internal reflection (TIR) to efficiently collect and direct light. They tend to have thick sections and therefore require challenging molding techniques, and they may have the LED source optically coupled directly into them. Beside these functional aspects, NFLs offer unique styling for different lighting functions such as those in rear combination lamps (RCLs), front turn signal lamps, daytime running lamps (DRLs) and headlamps.
Technical Paper

A Reusable Control System Architecture for Hybrid Powertrains

2002-10-21
2002-01-2808
System integration is the path to successful entry of hybrid electric vehicle (HEV) technology into the marketplace. A modular solution capable of meeting varying customer requirements is needed. The controller must possess a flexible hierarchical architecture that insures cross-platform compatibility and provides adaptability for various engine, motor, transmission, and battery configurations. A hybrid powertrain supervisory controller (PSC) has been designed for an advanced parallel-type HEV prototype, which uses a continuously variable transmission (CVT). The controller schedules torque commands for the engine and motor and chooses the transmission ratio to meet driver demanded acceleration. The controller is organized around a state machine, which determines how best to employ powertrain components to satisfy the driver while maximizing fuel economy.
Technical Paper

Impact of Engine Operating Conditions on Low-NOx Emissions in a Light-Duty CIDI Engine Using Advanced Fuels

2002-10-21
2002-01-2884
The control of NOx emissions is the greatest technical challenge in meeting future emission regulations for diesel engines. In this work, a modal analysis was performed for developing an engine control strategy to take advantage of fuel properties to minimize engine-out NOx emissions. This work focused on the use of EGR to reduce NOx while counteracting anticipated PM increases by using oxygenated fuels. A DaimlerChrysler OM611 CIDI engine for light-duty vehicles was controlled with a SwRI Rapid Prototyping Electronic Control System. Engine mapping consisted of sweeping parameters of greatest NOx impact, starting with OEM injection timing (including pilot injection) and EGR. The engine control strategy consisted of increased EGR and simultaneous modulation of both main and pilot injection timing to minimize NOx and PM emission indexes with constraints based on the impact of the modulation on BSFC, Smoke, Boost and BSHC.
Technical Paper

GENPAD® - Ergonomic Packaging

2002-03-04
2002-01-1241
GENPAD® is a knowledge-based, three-dimensional modeling computer tool developed by Visteon to create occupant-friendly interiors. GENPAD quickly and easily produces zones to evaluate ergonomic aspects of vehicle interiors such as reach, clearance, vision, and reflection. These zones are produced from automated design studies based on experience and engineering standards accepted by the automotive industry. Without GENPAD, a single study requires an experienced engineer 4-6 hours to complete. Multiple studies require several engineers weeks to perform. The methods used are also error-prone due to complex instructions. To overcome these challenges, GENPAD provides over 50 ergonomic packaging studies that produce accurate results in minutes, not weeks, every time.
Technical Paper

Heavy Vehicle Auxiliary Load Electrification for the Essential Power System Program: Benefits, Tradeoffs, and Remaining Challenges

2002-11-18
2002-01-3135
Intelligent management of vehicle auxiliary power can reduce fuel consumed by Class 8 tractor-trailers. Through the U.S. Department of Energy's Essential Power System (EPS) Program, the National Renewable Energy Laboratory is investigating electrification of major mechanically driven auxiliary loads in heavy vehicles. This paper describes the benefits and tradeoffs of a managed EPS and quantifies the potential energy savings of component electrification. Simulations predict that maximum fuel economy increases of 9%-15% (urban drive cycle) and 5%-8% (constant 65 mph) are possible. Future EPS work will require a systems approach with a better understanding of duty cycles and auxiliary needs.
Technical Paper

The Mobile Wireless Ether - Finding Its Way Into the Automobile

2002-10-21
2002-21-0046
The application and usage of various wide-area (long range) to personal-area (short range) wireless technologies and associated services in automobiles has arrived. It is essential for implementers to understand the parameters and capabilities of these technologies, many of which utilize and depend upon remote data/information transport services across one or more physical and logical entities within an automobile. This dependence, coupled with unique and typically diverse operational characteristics and requirements of the various wireless technologies, presents significant integration challenges to the automotive OEM and systems/components providers. Investigating and providing insight into managing this complexity for currently and soon to be deployed wireless technologies is addressed in this paper.
Technical Paper

Degree of Hybridization Modeling of a Fuel Cell Hybrid Electric Sport Utility Vehicle

2001-03-05
2001-01-0236
An ADVISOR model of a large sport utility vehicle with a fuel cell / battery hybrid electric drivetrain is developed using validated component models. The vehicle mass, electric traction drive, and total net power available from fuel cells plus batteries are held fixed. Results are presented for a range of fuel cell size from zero (pure battery EV) up to a pure fuel cell vehicle (no battery storage). The fuel economy results show that some degree of hybridization is beneficial, and that there is a complex interaction between the drive cycle dynamics, component efficiencies, and the control strategy.
Technical Paper

New Designs and Concepts for Vehicle Entertainment Systems

2006-11-21
2006-01-2828
The need for entertainment is a constant desire since human beans started to use vehicles for short and long distance travel. The radio, a home entertainment revolution, was the first one to be incorporated. The information and entertainment that initially brought the radio to the vehicles also started a major change on the interior and electrical systems. This revolution will require changes in vehicle design to accommodate the new concepts and features.
Technical Paper

Energy Management Strategies for Plug-In Hybrid Electric Vehicles

2007-04-16
2007-01-0290
Plug-in hybrid electric vehicles (PHEVs) differ from hybrid vehicles (HEVs) with their ability to use off-board electricity generation to recharge their energy storage systems. In addition to possessing charge-sustaining HEV operation capability, PHEVs use the stored electrical energy during a charge-depleting operating period to displace a significant amount of petroleum consumption. The particular operating strategy employed during the charge-depleting mode will significantly influence the component attributes and the value of the PHEV technology. This paper summarizes three potential energy management strategies, and compares the implications of selecting one strategy over another in the context of the aggressiveness and distance of the duty cycle over which the vehicle will likely operate.
Technical Paper

Platform Engineering Applied to Plug-In Hybrid Electric Vehicles

2007-04-16
2007-01-0292
Plug-in hybrid electric vehicle (PHEV) technology will provide substantial reduction in petroleum consumption as demonstrated in previous studies. Platform engineering steps including, reduced mass, improved engine efficiency, relaxed performance, improved aerodynamics and rolling resistance can impact both vehicle efficiency and design. Simulations have been completed to quantify the relative impacts of platform engineering on conventional, hybrid, and PHEV powertrain design, cost, and consumption. The application of platform engineering to PHEVs reduced energy storage system requirements by more than 12%, offering potential for more widespread use of PHEV technology in an energy battery supply-limited market. Results also suggest that platform engineering may be a more cost-effective way to reduce petroleum consumption than increasing the energy storage capacity of a PHEV.
Technical Paper

Software Validation a Vital Activity for a Mature Product Development Organization

2005-11-22
2005-01-4168
Software is today one of the most important components of electronic products. The capture and validation of the requirements makes a difference if the product will fulfill the customer's expectations or generate enormous frustration. The correct implementation of software validation makes the Product Development Organization more mature and reliable. Software validation is an opportunity for the product development team to identify if the requirements and customer expectations were achieved. It is also used to identify the risks and possible improvements to the product. Software testing is one element of a brooder topic that is often referred to as verification and validation (V&V). Verification refers to the set of activities that ensure that software correctly implements a specific function. Validation refers to a different set of activities that ensure that the software that has been built is traceable to customer requirements.
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