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Auburn Hills, MI, United States

Gao Y.,University of Georgia | Ginart A.,University of Georgia | Ginart A.,Sonnenbatterie | Duan C.,FEV North America Inc. | And 2 more authors.
Electronics Letters

The switching frequency of inductive power transfer may change along with the air gap between two coils due to mutual inductance variation. The mutual inductance is conventionally estimated through experimental measurement or finite element analysis. To simplify this process, a frequency-gap model for series-series compensated inductive power transfer is proposed to calculate the unity-gain frequency based on known air gap and coil geometric parameters. Neumann's formula is applied to compute the mutual inductance of the primary and secondary coils. The experimental results show that the unity-gain frequency can be predicted with varying loads and air gaps (75-250 mm), and a demonstrated unity-gain error of <6%. © The Institution of Engineering and Technology 2016. Source

Venkitachalam H.,RWTH Aachen | Schlosser A.,FEV GmbH | Richenhagen J.,FEV GmbH | Kupper M.,FEV GmbH | Tasky T.,FEV North America Inc.
SAE Technical Papers

Electrification is a key enabler to reduce emissions levels and noise in commercial vehicles. With electrification, Batteries are being used in commercial hybrid vehicles like city buses and trucks for kinetic energy recovery, boosting and electric driving. A battery management system monitors and controls multiple components of a battery system like cells, relays, sensors, actuators and high voltage loads to optimize the performance of a battery system. This paper deals with the development of modular control architecture for battery management systems in commercial vehicles. The key technical challenges for software development in commercial vehicles are growing complexity, rising number of functional requirements, safety, variant diversity, software quality requirements and reduced development costs. Software architecture is critical to handle some of these challenges early in the development process. The commercial vehicle domain is characterized by low production volumes and large number of variants. The existence of multiple vehicle level requirements, control strategies, sensors and actuators contribute towards variant diversity in software development for battery management systems. The vehicle manufacturer or the supplier has to ensure that the software fulfils certain quality characteristics based on standards. Due to increased functional complexity and cost pressure, the development process has to ensure early detection of the deviations in software quality and provide an objective feedback to the developers. Variability of the battery management system was improved by systematically representing the system topology and the functional features in a product feature model. Software architecture was derived from these functional features based on architectural design guidelines. Early detection of the deviations in software quality was ensured by verification and validation of software architecture using metrics. Metrics enabled automatic evaluation of the software architecture thereby reducing development costs, improving software quality and development efficiency. © Copyright 2015 SAE International. Source

Caffrey C.,U.S. Environmental Protection Agency | Bolon K.,U.S. Environmental Protection Agency | Kolwich G.,FEV North America Inc. | Johnston R.,EDAG Inc | Shaw T.,Munro and Associ. Inc.
SAE Technical Papers

The United States Environmental Protection Agency contracted with FEV North America, Inc. to conduct a whole vehicle analysis of the potential for mass reduction and related cost impacts for a future light-duty pickup truck. The goal was to evaluate the incremental costs of reducing vehicle mass on a body on frame vehicle at levels that are feasible in the 2020 to 2025 model year (MY) timeframe given the design, material, and manufacturing processes likely to be available, without sacrificing utility, performance, or safety. The holistic, vehicle-level approach and body-structure CAE modeling that were demonstrated in a previous study of a mid-sized crossover utility vehicle were used for this study. In addition, evaluations of closures performance, durability, and vehicle dynamics that are unique to pickup trucks are included. Secondary mass reduction was also analyzed on a part by part basis with consideration of vehicle performance requirements. This paper presents an overview of the study "Vehicle Mass Reduction and Cost Analysis-Light-duty Pickup Truck Model Years 2020-2025", by FEV North America, Inc. This study indicates that when mass reduction strategies are considered using a full-vehicle approach, significant mass reduction can be achieved relative to a 2011 light-duty pickup while maintaining vehicle functional objectives. The incremental results are assembled into a curve for mass reduction costs (in $/kg), as a function of the vehicle mass reduction level. Results from the study show that relative to the baseline vehicle (2011MY), mass reduction levels below 9% can result in a cost savings (cumulative net incremental direct manufacturing costs) with cumulative costs increasing to $4.36/kg, or $2,228 per vehicle, at 21.4% (510.9 kg) mass reduction. Copyright © 2015 SAE International. Source

Wellmann T.,FEV North America Inc. | Wellmann T.,Fevs North American Technical Center | Govindswamy K.,FEV North America Inc. | Orzechowski J.,FCA U.S. LLC | And 2 more authors.
SAE International Journal of Engines

Integration of automatic engine Stop/Start systems in “conventional” drivetrains with 12V starters is a relatively cost-effective measure to reduce fuel consumption. Therefore, automatic engine Stop/Start systems are becoming more prevalent and increasing market share of such systems is predicted. A quick, reliable and consistent engine start behavior is essential for customer acceptance of these systems. The launch of the vehicle should not be compromised by the Stop/Start system, which implies that the engine start time and transmission readiness for transmitting torque should occur within the time the driver releases the brake pedal and de-presses the accelerator pedal. Comfort and NVH aspects will continue to play an important role for customer acceptance of these systems. Hence, the engine stop and re-start behavior should be imperceptible to the driver from both a tactile and acoustic standpoint. This paper describes the details of various powertrain calibration factors for the engine start process. The key phases of an engine start event are described in detail, and their influence on the vehicle vibration investigated. The engine stop behavior is analyzed with respect to crank position and possible engine “roll back” and its influence on vehicle vibration. Unconventional start systems such as assisted direct starts are investigated with respect to engine start time and associated NVH behavior. Case studies are utilized to illustrate the influence of cylinder pressure, spark, and injection system parameters on the engine start process. In addition, key parameters of torque converted equipped planetary automatic transmissions with respect to the engine start behavior are analyzed. Comparisons of different Stop/Start systems are conducted and their influence on engine start, launch delay, and “change-of-mind” engine re-start are summarized. Copyright © 2015 SAE International. Source

Arvanitis A.,FCA U.S. LLC | Orzechowski J.,FCA U.S. LLC | Tousignant T.,FEV North America Inc. | Govindswamy K.,FEV North America Inc.
SAE International Journal of Passenger Cars - Mechanical Systems

Automotive companies are studying to add extra value in their vehicles by enhancing powertrain sound quality. The objective is to create a brand sound that is unique and preferred by their customers since quietness is not always the most desired characteristic, especially for high-performance products. This paper describes the process of developing a brand powertrain sound for a high-performance vehicle using the DFSS methodology. Initially the customer's preferred sound was identified and analyzed. This was achieved by subjective evaluations through voice-of-customer clinics using vehicles of similar specifications. Objective data were acquired during several driving conditions. In order for the design process to be effective, it is very important to understand the relationship between subjective results and physical quantities of sound. Several sound quality metrics were calculated during the data analysis process. A House of Quality (HOQ) matrix was created to characterize this correlation using the new metrics. Multiple sample candidate sounds were designed using sound design and simulation tools. A unique and preferred target sound was identified after an extensive double-elimination round of paired-comparison analysis of candidate sounds using an in-vehicle audio system. Final optimization was executed, with live jury, to demonstrate and verify the new unique and preferred sound. Copyright © 2015 SAE International. Source

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