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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

A High Speed Flow Visualization Study of Fuel Spray Pattern Effect on Mixture Formation in a Low Pressure Direct Injection Gasoline Engine

2007-04-16
2007-01-1411
In developing a direct injection gasoline engine, the in-cylinder fuel air mixing is key to good performance and emissions. High speed visualization in an optically accessible single cylinder engine for direct injection gasoline engine applications is an effective tool to reveal the fuel spray pattern effect on mixture formation The fuel injectors in this study employ the unique multi-hole turbulence nozzles in a PFI-like (Port Fuel Injection) fuel system architecture specifically developed as a Low Pressure Direct Injection (LPDI) fuel injection system. In this study, three injector sprays with a narrow 40° spray angle, a 60°spray angle with 5°offset angle, and a wide 80° spray angle with 10° offset angle were evaluated. Image processing algorithms were developed to analyze the nature of in-cylinder fuel-air mixing and the extent of fuel spray impingement on the cylinder wall.
Technical Paper

Design Considerations & Characterization Test Methods for Activated Carbon Foam Hydrocarbon Traps in Automotive Air Induction Systems

2007-04-16
2007-01-1429
As OEMs race to build their sales fleets to meet ever more stringent California Air Resources Board (CARB) mobile source evaporative emissions requirements, new technologies are emerging to control pollution. Evaporative emissions emanating from sources up-stream in the induction flow and venting through the ducts of the engine air induction system (EIS) need to be controlled in order classify a salable vehicle as a Partial Zero Emissions Vehicle (PZEV) in the state of California. As other states explore adopting California's pollution control standards, demand for emissions control measures in the induction system is expected to increase. This paper documents some of the considerations of designing an adsorbent evaporative emissions device in to a 2007 production passenger car for the North American and Asian markets. This new evaporative emissions device will be permanently installed in the vehicle's air cleaner cover without requiring service for 150K miles (expected vehicle life).
Technical Paper

Investigating Cleaning Procedures for OEM Engine Air Intake Filters

2007-04-16
2007-01-1431
Most new passenger vehicles on the road today are equipped with a disposable OEM engine intake filter made of cellulose paper or synthetic non-woven media. Engine intake filters have an expected and recommended service life (by OEMs) of approximately 45K to 75K kilometers under normal driving conditions [ref. 2, 3, 4 & 5]. Majority of air filter element manufacturers do not recommend any type of cleaning to be performed on their OEM products. However, cleaning OEM and aftermarket air filters is common for end-customers in areas such as Asia, Middle East and South America. Vehicle owners in some regions would like to service and clean their own air filter elements in an effort to reduce vehicle operating costs. As a result, a number of OEMs selling passenger vehicles in these regions are requesting their suppliers explore solutions and the effects of whether cleaning air filter elements is appropriate for proper engine operation.
Technical Paper

US 2010 Emissions Capable Camless Heavy-Duty On-Highway Natural Gas Engine

2007-07-23
2007-01-1930
The goal of this project was to demonstrate a low emissions, high efficiency heavy-duty on-highway natural gas engine. The emissions targets for this project are to demonstrate US 2010 emissions standards on the 13-mode steady state test. To meet this goal, a chemically correct combustion (stoichiometric) natural gas engine with exhaust gas recirculation (EGR) and a three way catalyst (TWC) was developed. In addition, a Sturman Industries, Inc. camless Hydraulic Valve Actuation (HVA) system was used to improve efficiency. A Volvo 11 liter diesel engine was converted to operate as a stoichiometric natural gas engine. Operating a natural gas engine with stoichiometric combustion allows for the effective use of a TWC, which can simultaneously oxidize hydrocarbons and carbon monoxide and reduce NOx. High conversion efficiencies are possible through proper control of air-fuel ratio.
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

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

Development of Truck Engine Technologies for Use with Fischer-Tropsch Fuels

2001-09-24
2001-01-3520
The Fischer-Tropsch (FT) process can be used to synthesize diesel fuels from a variety of energy sources, including coal, natural gas and biomass. Diesel fuels produced from the FT process are essentially sulfur-free, have very low aromatic content, and have excellent ignition characteristics. Because of these favorable attributes, FT diesel fuels may offer environmental benefits over transportation fuels derived from crude oil. Previous tests have shown that FT diesel fuel can be used in unmodified engines and have been shown to lower regulated emissions. Whereas exhaust emissions reductions from these previous studies have been impressive, this paper demonstrates that far greater exhaust emissions reductions are possible if the diesel engine is optimized to exploit the properties of the FT fuels. A Power Stroke 7.3 liter turbocharged diesel engine has been modified for use with FT diesel.
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

Emission Reductions and Operational Experiences With Heavy Duty Diesel Fleet Vehicles Retrofitted with Continuously Regenerated Diesel Particulate Filters in Southern California

2001-03-05
2001-01-0512
Particulate emission control from diesel engines is one of the major concerns in the urban areas in California. Recently, regulations have been proposed for stringent PM emission requirements from both existing and new diesel engines. As a result, particulate emission control from urban diesel engines using advanced particulate filter technology is being evaluated at several locations in California. Although ceramic based particle filters are well known for high PM reductions, the lack of effective and durable regeneration system has limited their applications. The continuously regenerated diesel particulate filter (CRDPF) technology discussed in this presentation, solves this problem by catalytically oxidizing NO present in the diesel exhaust to NO2 which is utilized to continuously combust the engine soot under the typical diesel engine operating condition.
Technical Paper

Class 8 Trucks Operating On Ultra-Low Sulfur Diesel With Particulate Filter Systems: A Fleet Start-Up Experience

2000-10-16
2000-01-2821
Previous studies have shown that regenerating particulate filters are very effective at reducing particulate matter emissions from diesel engines. Some particulate filters are passive devices that can be installed in place of the muffler on both new and older model diesel engines. These passive devices could potentially be used to retrofit large numbers of trucks and buses already in service, to substantially reduce particulate matter emissions. Catalyst-type particulate filters must be used with diesel fuels having low sulfur content to avoid poisoning the catalyst. A project has been launched to evaluate a truck fleet retrofitted with two types of passive particulate filter systems and operating on diesel fuel having ultra-low sulfur content. The objective of this project is to evaluate new particulate filter and fuel technology in service, using a fleet of twenty Class 8 grocery store trucks. This paper summarizes the truck fleet start-up experience.
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

Combustion Characteristics Detection for Low Pressure Direct Injection Engines Using Ionization Signal

2006-10-16
2006-01-3317
It is well-known that in-cylinder ionization signals can be used for detecting combustion characteristics of IC (Internal Combustion) engines. For example, engine misfire, incomplete combustion (or partial-burn), knock, MBT (Minimum spark advance for Best Torque) timing and combustion stability can be detected using in-cylinder ionization signals. In addition, closed loop combustion spark timing control strategies have been developed to control engine MBT timing and to manage spark timing advance (knock) and retard (incomplete combustion) limits. In-cylinder ionization signals can also be used for closed loop control of maximum equivalence ratio (lean limit) at a desired combustion stability level. Up to now, most of the ionization applications have been for PFI (Port Fuel Injection) engines. This paper presents ionization detection for gasoline Direct Injection (DI) engines.
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.
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