Search Results

This paper addresses the longstanding problems of residual gas measurement during engine dynamometer testing, and of real-time residual modeling for engine control applications. A new method is described which is simple to apply, requiring only currently standard calibration test cell instrumentation. Experimental validation against measurements using direct in-cylinder CO2 sampling is presented, and a comprehensive error sensitivity analysis is included. A real-time capable, controls-oriented model is also described. Its accuracy is assessed by comparison to engine-simulation-generated residual values after using these values to determine the model parameters.

Safety is a key element in new vehicle design and active safety, together with driver distraction prevention, has become one of the most talked about issues in the mobility industry. This book features 20 SAE technical papers, originally published in 2009 and 2010, which showcase how the mobility industry is considering all aspects of safety in designing and producing safer vehicles. These papers were selected by SAE International's 2010 President Dr. Andrew Brown Jr., Executive Director and Chief Technologist for Delphi Corporation. The contents of this book explore a variety of safety issues in the areas of market and consumer preferences; driver assistance and modeling; active safety system, crash sensing and sensor fusion; communications; and road safety. The publication also includes a number of articles authored by renowned experts in the field of active safety.

Wall-wetting due to liquid fuel film motion and fuel droplet impingement on combustion chamber walls is a major source of unburned hydrocarbons (UBHC), and is a concern for oil dilution in PFI engines. An experimental study was carried out to investigate the effects of injection timing, a charge motion control device, and the matching of injector with port geometry, on the “footprints” of liquid fuel inside the combustion chamber during the PFI engine starting process. Using a gasoline-soluble dye and filter paper deployed on the cylinder liner and piston top land surfaces to capture the liquid fuel footprints, the effects of the mixture formation processes on the wetted footprints can be qualitatively and quantitatively examined by comparing the wetted footprint locations and their color intensities. Real-time filming of the development of wetted footprints using a high-speed camera can also show the time history of the fuel wetting process inside an optically accessible engine.

Estimation of vehicle roll angle, lateral velocity and side slip angle for the purpose of crash sensing is considered. Only roll rate sensor and the sensors readily available in vehicles equipped with ESC (Electronic Stability Control) systems are used in the estimation process. The algorithms are based on kinematic relationships, thus avoiding dependence on vehicle and tire models, which minimizes tuning efforts and sensitivity to parameter variations. The estimate of roll angle is obtained by blending two preliminary estimates, each valid in different conditions, in such a manner that the final estimate continuously favors the more accurate one. The roll angle estimate is used to compensate the gravity component in measured lateral acceleration due to vehicle roll or road bank angle. This facilitates estimation of lateral velocity and side slip angle from fundamental kinematic relationships involving the gravity-compensated lateral acceleration, yaw rate and longitudinal velocity.

A gasoline compression-ignition combustion system is being developed for full-time operation over the speed-load map. Low-temperature combustion was achieved using multiple late injection (MLI), intake boost, and moderate EGR for high efficiency, low NOx, and low particulate emissions. The relatively long ignition delay and high volatility of RON 91 pump gasoline combined with an advanced injection system and variable valve actuation provided controlled mixture stratification for low combustion noise. Tests were conducted on a single-cylinder research engine. Design of Experiments and response surface models were used to evaluate injection strategies, injector designs, and various valve lift profiles across the speed-load operating range. At light loads, an exhaust rebreathing strategy was used to promote autoignition and maintain exhaust temperatures. At medium loads, a triple injection strategy produced the best results with high thermal efficiency.

This book features 20 SAE technical papers, originally published in 2009 and 2010, which showcase how the mobility industry is developing greener products and staying responsive - if not ahead of - new standards and legal requirements. These papers were selected by SAE International's 2010 President Dr. Andrew Brown Jr., Executive Director and Chief Technologist for Delphi Corporation. Authored by international experts from both industry and academia, they cover a wide range of cutting-edge subjects including powertrain electrification, alternative fuels, new emissions standards and remediation strategies, nanotechnology, sustainability, in-vehicle networking, and how various countries are also stepping up to the "green challenge".

This paper is an overview of the current state (calendar year 2010) of in-vehicle multiplexing and what pertinent technologies are emerging. Usage and trends of in-vehicle networking protocols will be presented and categorized. The past few years have seen a large growth in the number and type of communication buses used in automobiles, trucks, construction equipment, and military, among others. Development continues even into boating and recreation vehicles. Areas for discussion will include SAE Class A, B, C, Diagnostics, SafetyBus, Mobile Media, Wireless, and X-by-Wire. All existing mainstream vehicular multiplex protocols (approximately 40) are categorized using the SAE convention as well as categories previously proposed by this author. Top contenders will be pointed out along with a discussion of the protocol in the best position to become the industry standard in each category.

Gasoline direct injection (GDi) engines have become popular due to their inherent potential for reduction of exhaust emissions and fuel consumption to meet increasingly stringent environmental standards. These engines require high-pressure fuel injection in order to improve the fuel atomization process and accelerate mixture preparation. To achieve a lower-cost system, a single-piston high-pressure fuel pump design is often employed due to its relative simplicity. However, pumps of this design are acknowledged as the source of high levels of fuel pressure fluctuations which can lead to audible noise, variations in the amount and spray quality of fuel delivery from cylinder to cylinder, compromised durability and consumer dissatisfaction. In this paper, the design process for a high-pressure fuel rail assembly using Robust Engineering methodology is presented.

It is rare for a single technology to have the power to dramatically influence almost every major industry in the world. Nanotechnology falls into this category and offers fundamentally new capabilities to architect a broad array of novel materials, composites and structures on a molecular scale. This technology has the potential to drastically re-define the methods used for developing lighter, stronger, and high-performance structures and processes with unique and non-traditional properties. This paper focuses on some of the automotive applications for nanotechnology and showcases a few of them that are believed to have the highest probability of success in this highly competitive industry. No discussion of nanotechnology is complete without touching upon its health and environmental implications.

Modern automatic transmissions use various methods to estimate fluid line pressures in order to improve shift quality and reduce energy losses. These estimations lead to improvements in fuel economy, customer satisfaction and reduced exhaust emissions. The further addition of pressure feedback switches improves operational knowledge by verifying when clutches have received their commanded pressures. Product reliability above the industry standard for transmission pressure switches was developed through the use of multiple FEA platforms combined with advanced design optimization software, robust optimization and Shainin® tools. In this optimized design, ferromagnetic non-contact pressure switches operate by translating fluid pressure into piston motion, isolated by a sealed proprietary diaphragm.

During the past decade, there has been a steady increase in studies addressing rollover crashes and injuries. Though rollovers are not the most frequent crash type, they are significant with respect to serious injury and interest in rollovers has grown with the introduction of SUVs, vans, and light trucks. A review of Occupant and Vehicle Responses in Rollovers examines relevant conditions for field roll overs, vehicle responses, and occupant kinetics in the vehicle. This book edited by Dr. David C. Viano and Dr. Chantal S. Parenteau includes 62 technical documents covering 15 years of rollover crash safety, including field crash statistics, pre- and rollover dynamics, test procedures and dummy responses.