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In a previous study (Song et al. 2017), an adjustable generic simplified vehicle buck was developed; eleven PMHS were impacted by the buck representing a SUV, a van and a sedan successively; and biofidelity corridors were established. The objectives of the current study were 1) to develop the computational model of the buck, and 2) to simulate these PMHS tests with the buck model and to assess the biofidelity of the GHBMC 50th percentile male pedestrian simplified model (GHBMC M50-PS). First, coupon tensile tests and static and dynamic compression tests were performed on the steel tubes representing the bonnet leading edge (BLE), the bumper and the spoiler used in the above PMHS tests. Based on these tests, the computational models of the above components were then developed and validated. Next, the buck model was built with the component models, and used to simulate the PMHS tests with the GHBMC M50-PS model.

For higher mileage vehicles, noise from contaminant ingress is one of the largest durability issues for wheel bearings. The mileage that wheel bearing sealing issues increase can vary due to multiple factors, such as the level of corrosion for the vehicle and the mating components around the wheel bearing. In general, sealing issues increase after 20,000 to 30,000 km. Protecting the seals from splash is a key step in extending bearing life. Benchmarking has shown a variety of different brake corner designs to protect the bearing from splash. This report examines the effect of factors from different designs, such as the radial gap between constant velocity joint (CVJ) slinger and the knuckle, knuckle labyrinth height and varying slinger designs to minimize the amount of splash to the bearing inboard seal. This report reviews some of the bearing seal failure modes caused by splash.

Finite Element Human Body Models (HBM) have become powerful tools to study the response to impact. However, they are typically only developed for a limited number of sizes and ages. Various approaches driven by control points have been reported in the literature for the non-linear scaling of these HBM into models with different geometrical characteristics. The purpose of this study is to compare the performances of commonly used control points based interpolation methods in different usage scenarios. Performance metrics include the respect of target, the mesh quality and the runability. For this study, the Kriging and Moving Least square interpolation approaches were compared in three test cases. The first two cases correspond to changes of anthropometric dimensions of (1) a child model (from 6 to 1.5 years old) and (2) the GHBMC M50 model (Global Human Body Models Consortium, from 50th to 5th percentile female).

Low-pressure, Cooled Exhaust Gas Recirculation (LPC EGR) brings significant fuel economy, NOx reduction and knock suppression benefits to a modern, boosted, downsized Spark Ignition (SI) engine. As a prerequisite to design an engine control system for LPC EGR, this paper presents development of a set of estimation algorithms to accurately estimate the flow rate, pressure states and thermal states of the LPC EGR-related components.

This paper describes a method to estimate the engine stop position using any production style crank position sensor, while accounting for possible engine rock-back. The approach is based on modeling the engine speed state, achieving robustness and ease of calibration by adapting the rubbing friction model component during the first part of engine coast-down, followed by open-loop modeling when the engine speed has dropped below the sensor signal validity threshold.

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.

Several statistical methods are currently used to build injury risk curves in the biomechanical field. These methods include the certainty method (Mertz et al. 1996), Mertz/Weber method (Mertz and Weber 1982), logistic regression (Kuppa et al. 2003, Hosmer and Lemeshow 2000), survival analysis with Weibull distribution (Kent et al. 2004, Hosmer and Lemeshow 2000), and the consistent threshold estimate (CTE) (Nusholtz et al. 1999, Di Domenico and Nusholtz 2005). There is currently no consensus on the most accurate method to be used and no guidelines to help the user to choose the more appropriate one. Injury risk curves built for the WorldSID 50th side impact dummy with these different methods could vary significantly, depending on the sample considered (Petitjean et al. 2009). As a consequence, further investigations were needed to determine the fields of application of the different methods and to recommend the best statistical method depending on the biomechanical sample considered.

Gasoline Direct injection (GDi) systems offer performance and /or fuel consumption advantages compared to the traditional lower pressure port fuel injected technology. One disadvantage of GDi is the higher level of audible noise produced by the high pressure GDi system components. Powertrain noise is a known warranty complaint across the automotive industry. This paper presents an objective comparison of acoustic noise emitted by eight solenoid actuated fuel injector designs during their normal operation, including at engine idle, where powertrain noise is more noticeable to the customer. Taguchi Robust Engineering methods will be used to conduct an assessment of the noise generated by various GDi fuel injector designs. Injector fixturing, measurement procedures, and their impact on reducing test-to-test measurement variation are discussed.

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.

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".

Stability is an essential indicator of proper system operation. To this end, it is often of interest to predict the Region of Asymptotic Stability (RAS) associated with an equilibrium point of interest. In the case of the presence of constraints that need to be satisfied, one is faced with the problem of estimating a Restricted RAS (RRAS). Practical methods for estimating RRASs have been proposed and demonstrated for relatively high-order systems. These methods are based on Lyapunov's second method. However, they do not address the problem of constructing an optimal Lyapunov function. In this paper, a method of finding a Lyapunov function that yields improved estimates of the restricted region of asymptotic stability is set forth. In addition, a new method for estimating RRASs based on the average of the Lyapunov derivative is also set forth. Numerical examples illustrate the utility of the proposed methods.

A complete system approach to power semiconductor analysis and selection is set forth in this paper. In order to address design overkill, a suitable power profile across the desired drive schedule is obtained through vehicle simulation in lieu of worse case operating conditions. The representative profile is then applied to detailed models of the inverter, power device, and power device thermal stack-up in order to predict worse case, silicon junction temperature rise. The simulation stream includes a closed silicon thermal loop that leads to more accurate power loss and junction temperature calculations. The models are combined and exercised in a single platform for ease of integration and fast simulation. Herein, the methods will be applied to a working example of an inverter for motor drives, and analytical results will be reviewed.

Intake camshaft retard beyond that necessary for reliable cold start-ability is shown to improve part-load fuel economy. By retarding the intake camshaft timing, engine pumping losses can be reduced and fuel economy significantly improved. At high engine speeds, additional intake cam retard may also improve full-load torque and power. To achieve these benefits, an intake camshaft phaser with intermediate lock pin position (ILP) and increased phaser authority was developed. ILP is necessary to reliably start at the intermediate phase position for cold temperatures, while providing increased phaser retard under warm conditions. The phaser also provides sufficient intake advance to maximize low-speed torque and provides good scavenging for boosted engine applications. Design and development of the intermediate locking phaser system is described. The pros and cons of various methods of accomplishing locking and unlocking a phaser are illustrated.

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.

Gasoline Direct Injection (GDi) system is a relatively new technology. In early implementations, its major components, i.e. high pressure fuel pump, injectors, and fuel rails, emit objectionable acoustic noise during normal operation. This paper will focus on making an objective comparison (assessment) of acoustic noise emitted by several cam-driven high pressure fuel pumps during their normal operation, especially at engine idle. Taguchi robust engineering methods will be used to conduct the robust assessment study of six GDi high-pressure pumps. A-weighted total sound pressure level (SPL), processed from two free-field microphones around each pump, will be used as the main function in the Taguchi design of experiments (DOE).

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.

Brazilian ethanol vehicles are typically equipped with an auxiliary gasoline sub-tank fuel system which aids cold starting and drivability for low ambient temperatures. Port fuel injectors capable of rapidly heating ethanol have been developed to eliminate this auxiliary system. These injectors also enable reductions in emissions. Computational Fluid Dynamics (CFD) is used in conjunction with Taguchi Robust Engineering methods to optimize the heat exchanging geometry of these heated injectors. Simulation results are confirmed with experimental hardware and engine cold start testing. Modeling results, experimental hardware, and engine cold start performance is presented and discussed.

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.

Signal processing incorporating Artificial Neural Networks (ANN) has been shown to be well suited for modeling engine-related performance indicators [ 1 , 2 , 3 ] that require multi-dimensional parametric calibration space. However, to obtain acceptable accuracy, traditional ANN implementation may require processing resources beyond the capability of current engine controllers. This paper explores the practicality of implementing an ANN-based algorithm performing real-time calculations of the volumetric efficiency (VE) for an engine with variable valve actuation (phasing and lift variation). This alternative approach was considered attractive since the additional degree of freedom introduced by variable lift would be cumbersome to add to the traditional multi-dimensional table-based representation of VE.

The US Environmental Protection Agency (EPA)’s heavy duty diesel emission standard was tightened beginning from 2007 with the introduction of ultra-low-sulfur diesel fuel. Most heavy duty diesel applications were required to equip Particulate Matter (PM) after-treatment systems to meet the new tighter, emission standard. Systems utilizing Diesel Oxidation Catalyst (DOC) and Catalyzed-Diesel Particulate Filter (DPF) are a mainstream of modern diesel PM after-treatment systems. To ensure appropriate performance of the system, periodic cleaning of the PM trapped in DPF by its oxidation (a process called “regeneration”) is necessary. As a result, of this regeneration, DOC’s and DPF’s can be exposed to hundreds of thermal cycles during their lifetime. Therefore, to understand the thermo-mechanical performance of the DOC and DPF is an essential issue to evaluate the durability of the system.