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Viewing 1 to 30 of 1539
2017-10-08
Technical Paper
2017-01-2202
Shiyou Yang
This work presents an application of two sub-models relative to chemical-kinetics-based turbulent pre-mixed combustion modeling approach on the simulation of burn rate and emissions of spark ignition engines. In present paper, the justification of turbulent pre-mixed combustion modeling directly based on chemical kinetics plus a turbulence model is given briefly. Two sub-models relative to this kind of pre-mixed combustion modeling approach are described generally, including a practical PRF (primary reference fuel) chemical kinetics mechanism which can correctly capture the laminar flame speed under a wide range of Ford SI (spark ignition) engines/operating conditions, and an advanced spark plug ignition model which has been developed by Ford recently.
2017-10-08
Technical Paper
2017-01-2446
Pengchuan Wang, Nikolaos Katopodes, Yuji Fujii
Wet clutch packs are the key component for gear shifting in the step-ratio automatic transmission system. They are coupled or de-coupled to alter gear ratios based on driver’s demand and vehicle operating conditions. The frictional interfaces between clutch plates are lubricated with automatic transmission fluid (ATF) for both thermal and friction management. In a 10-speed transmission, there may be as many as 6 clutch packs. Under any driving conditions, 2 to 3 clutch packs are typically open, shearing ATF and contributing to energy loss. There is an opportunity to improve fuel economy by reducing this viscous drag. One main factor that directly affects clutch drag is the clearance between rotating plates. The axial position of clutch plates changes continually at every instance. It is empirically known that not only the total clearance, but also its distribution between the plates affects the viscous drag.
2017-10-08
Technical Paper
2017-01-2343
Nicolas Champagne, Nicolas Obrecht, Arup Gangopadhyay, Rob Zdrodowski, Z Liu
The oil and additive industry is challenged to meet future automotive legislations aimed at reducing worlwide CO2 emissions levels. The most efficient solution used to date has been to decrease oil viscosity leading to the introduction of new SAE grades such as SAE 0W-8. However this solution may soon reach its limit due to potential issues related to wear with lower engine oil viscosities. In this paper, an innovative solution is proposed that combines the use of a new tailor-made polyalkylene glycol with specific anti-wear additives. Valvetrain wear measurements using radionuclide technique demonstrates the robustness of this solution. The wear performance was also confirmed in normalized GF-5 testings. An extensive tribological evaluation (film formation, wear testing and tribofilm surface analysis) of the interactions between the base oil and the anti-wear additives lead us to propose an underlying mechanism that can explain this performance benefit.
2017-09-17
Technical Paper
2017-01-2534
Silvia Faria Iombriller, Wesley Bolognesi Prado
It is very important and unquestionable that we need to have a clear technical requirement for Air Brake Systems and its components, since it is one of most important regarding safety. Looking to heavy commercial vehicles and possible air brake system failures, everything becomes clearly to pay total attention for these normative and regulatory requirements. Historically, the development of Brakes technology has started on EUA and Europe and consequently two strong and distinct requirements were structured: FMVSS 121 and ECE-R13. From decades people are trying to harmonize these requirements and for passenger cars, the evolution was faster. However, for commercial vehicles there are more peculiarities considering regional applications and some of them cultural and implementation time. As globally market is growing so fast as well new markets around the world, become fundamental the clearly understanding of these similarities, variants, peculiarities and correlated requirements.
2017-09-04
Technical Paper
2017-24-0065
Helmut Ruhland, Thomas Lorenz, Jens Dunstheimer, Albert Breuer, Maziar Khosravi
An integral part of combustion system development for previous NA gasoline engines was the optimization of charge motion towards the best compromise in terms of full load performance, part load stability, emissions and, last but not least, fuel economy. This situation might have changed with the introduction of GTDI engines. While it is generally accepted that an increased charge motion level improves the mixture preparation of a direct injection gasoline engine, the tradeoff in terms of performance seems to become less dominant as the boosting systems of modern engines are typically sound enough to compensate the flow losses generated by the more restrictive ports. Certainly the increased boost level does not come for free. Increased charge motion generates higher pumping- and wall heat losses. Hence it is questionable and engine dependent, whether more charge motion is always better.
2017-06-05
Technical Paper
2017-01-1798
Jiri Navratil, Warren Seeley, Peng Wang, Shriram Siravara
Abstract The ability to accurately predict exhaust system acoustics, including transmission loss (TL) and tailpipe noise, based on CAD geometry has long been a requirement of most OEM’s and Tier 1 exhaust suppliers. Correlation to measurement data has been problematic under various operating conditions, including flow. This study was undertaken to develop robust modelling technique, ensuring sensible correlation between the 1-D models and test data. Ford use Ricardo WAVE as one of their 1-D NVH tools, which was chosen for the purpose of this benchmark study. The most commonly used metrics for evaluating the acoustical performance of mufflers are insertion loss (IL), TL, and noise reduction (NR). TL is often the first step of analysis, since it represents the inherent capability of the muffler to attenuate sound if both the source and termination are assumed to be anechoic. It can also be reliably measured and numerically simulated without having to connect to an engine.
2017-06-05
Technical Paper
2017-01-1781
Joshua Wheeler
Abstract The design and operation of a vehicle’s heating, ventilation, and air conditioning (HVAC) system has great impact on the performance of the vehicle’s Automatic Speech Recognition (ASR) and Hands-Free Communication (HFC) system. HVAC noise provides high amplitudes of broadband frequency content that affects the signal to noise ratio (SNR) within the vehicle cabin, and works to mask the user’s speech. But what’s less obvious is that when the airflow from the panel vents or defroster openings can be directed toward the vehicle microphone, a mechanical “buffeting” phenomenon occurs on the microphone’s diaphragm that distresses the ASR system beyond its ability to interpret the user’s voice. The airflow velocity can be strong enough that a simple windscreen on the microphone is not enough to eliminate the problem. Minimizing this buffeting effect is a vital key to building a vehicle that meets the customer’s expectations for ASR and HFC performance.
2017-06-05
Technical Paper
2017-01-1864
Joshua Wheeler
Abstract The performance of a vehicle’s Automatic Speech Recognition (ASR) system is dependent on the signal to noise ratio (SNR) in the cabin at the time a user voices their command. HVAC noise and environmental noise in particular (like road and wind noise), provide high amplitudes of broadband frequency content that lower the SNR within the vehicle cabin, and work to mask the user’s speech. Managing this noise is a vital key to building a vehicle that meets the customer’s expectations for ASR performance. However, a speech recognition engineer is not likely to be the same person responsible for designing the tires, suspension, air ducts and vents, sound package and exterior body shape that define the amount of noise present in the cabin.
2017-06-05
Journal Article
2017-01-1796
Rick D. Dehner, Ahmet Selamet, Michael Steiger, Keith Miazgowicz, Ahsanul Karim
Abstract Ported shroud compressor covers recirculate low momentum air near the inducer blade tips, and the use of these devices has traditionally been confined to extending the low-flow operating region at elevated rotational speeds for compressors on compression-ignition (CI) engines. Implementation of ported shrouds on compressors for spark-ignition (SI) engines has been generally avoided due to operation at pressure ratios below the region where ported shrouds improve low-flow range, the slight efficiency penalty, and the perception of increased noise. The present study provides an experimental investigation of performance and acoustics for a SI engine turbocharger compressor both with a ported shroud and without (baseline). The objective of implementing the ported shroud was to reduce mid-flow range broadband whoosh noise of the baseline compressor over 4-12 kHz.
2017-04-11
Journal Article
2017-01-9175
Yitao Zhu, Makarand Datar, Kalyan Addepalli, Natalie Remisoski
Nowadays, the vehicle design is highly ruled by the increasing customer demands and expectations. In addition to ride comfort and vehicle handling, the Noise, Vibration and Harshness (NVH) behavior of the powertrain is also a critical factor that has a big impact on the customer experience. To evaluate the powertrain NVH characteristics, the NVH error states should be studied. A typical NVH event could be decoupled into 3 parts: source, path, and receiver. Take-off shudder, which evaluates the NVH severity level during vehicle take-off, is one of the most important NVH error states. The main sources of Front Wheel Drive (FWD) take-off shudder are the plunging Constant Velocity Joints (CVJ) on the left and right half shafts. This is because a plunging CVJ generates a third order plunging force with half shaft Revolution Per Minute (RPM), which is along the slip of the plunging CVJ.
2017-03-28
Technical Paper
2017-01-0690
Maziar Khosravi, Helmut Ruhland, Thomas Lorenz, Carsten Weber
Abstract The performance of boosted gasoline engines is limited at high loads by knock, stochastic Low Speed Pre-Ignition, and Megaknock. An investigation has been carried out on the occurrence of abnormal combustion and megaknock in a 1.6 L GTDI engine with the aim to determine the causes of such phenomena. A classification of abnormal combustion events and causes is presented in order to facilitate a consistent terminology. The experiments specifically focus on the effects of exhaust residual gas on occurrence of megaknock in multi-cylinder engines. The results showed that while a misfire will not lead to megaknock, a very late combustion in one cycle, in one cylinder may lead to megaknock in the following cycle in the same or adjacent cylinder. Additionally, a recently developed multi-zone model was used to analyze the role of residual gas on auto-ignition.
2017-03-28
Technical Paper
2017-01-0672
Yanyu Wang, Jiongxun Zhang, Paul Dice, Xin Wang, Mahdi Shahbakhti, Jeffrey Naber, Michael Czekala, Qiuping Qu, Garlan Huberts
Abstract The effect of flow direction towards the spark plug electrodes on ignition parameters is analyzed using an innovative spark aerodynamics fixture that enables adjustment of the spark plug gap orientation and plug axis tilt angle with respect to the incoming flow. The ignition was supplied by a long discharge high energy 110 mJ coil. The flow was supplied by compressed air and the spark was discharged into the flow at varying positions relative to the flow. The secondary ignition voltage and current were measured using a high speed (10MHz) data acquisition system, and the ignition-related metrics were calculated accordingly. Six different electrode designs were tested. These designs feature different positions of the electrode gap with respect to the flow and different shapes of the ground electrodes. The resulting ignition metrics were compared with respect to the spark plug ground strap orientation and plug axis tilt angle about the flow direction.
2017-03-28
Technical Paper
2017-01-0776
Ulrich Kramer, Thomas Lorenz, Christian Hofmann, Helmut Ruhland, Rolf Klein, Carsten Weber
Abstract A fundamental requirement for natural gas (NG) and renewable methane (e.g. bio-methane or power-to-gas methane) as automotive fuel is reliable knock resistance; to enable optimization of dedicated NG engines with high compression ratio and high turbocharger boost (which enables considerable engine downsizing factors). In order to describe the knock resistance of NG, the Methane Number (MN) has been introduced. The lowest MN which generally can be found in any NG is 65, and the vast majority of NG (~ 99.8%) is delivered with a MN above 70. The MN of bio-methane and power-to-gas methane is usually far above 80. Thus, from an automotive point of view any methane fuel should at least provide a minimum Methane Number of 70 at any point of sale. But the European draft standard describing the automotive CNG fuel quality so far proposes a minimum MN limit of 65.
2017-03-28
Technical Paper
2017-01-1474
Raed E. El-Jawahri, Agnes Kim, Dean Jaradi, Rich Ruthinowski, Kevin Siasoco, Cortney Stancato, Para Weerappuli
Abstract Sled tests simulating full-frontal rigid barrier impact were conducted using the Hybrid III 5th female and the 50th male anthropomorphic test devices (ATDs). The ATDs were positioned in the outboard rear seat of a generic small car environment. Two belt configurations were used: 1) a standard belt with no load limiter or pre-tensioner and 2) a seatbelt with a 4.5 kN load-limiting retractor with a stop function and a retractor pre-tensioner (LL-PT). In the current study, the LL-PT belt system reduced the peak responses of both ATDs. Probabilities of serious-to-fatal injuries (AIS3+), based on the ATDs peak responses, were calculated using the risk curves in NHTSA’s December 2015 Request for Comments (RFC) proposing changes to the United States New Car Assessment Program (US-NCAP). Those probabilities were compared to the injury rates (IRs) observed in the field on point estimate basis.
2017-03-28
Technical Paper
2017-01-1694
Victor Silva, Renato Veiga
Abstract Demand for enhanced infotainment systems with features like navigation, real-time traffic, music streaming service, mirroring and others is increasing, forcing automakers to develop solutions that fulfill customer needs. However, many of those systems are too expensive to be fitted to an entry-level vehicle leaving a gap in the market that fails customer’s expectation. This gap is usually filled by a smartphone which may have all the features the customer wants but in many cases it cannot be properly fitted in the vehicle due to lack of specific storage space. This paper describes how the engineering team developed an innovative, flexible and effective solution that holds a smartphone in an ergonomic location.
2017-03-28
Technical Paper
2017-01-1706
Sandeep Bhattacharya, Daniel Green, Raj Sohmshetty, Ahmet Alpas
Abstract Automobile body panels made from advanced high strength steel (AHSS) provide high strength-to-mass ratio and thus AHSS are important for automotive light-weighting strategy. However, in order to increase their use, the significant wear damage that AHSS sheets cause to the trim dies should be reduced. The wear of dies has undesirable consequences including deterioration of trimmed parts' edges. In this research, die wear measurement techniques that consisted of white-light optical interferometry methods supported by large depth-of-field optical microscopy were developed. 1.4 mm-thick DP980-type AHSS sheets were trimmed using dies made from AISI D2 steel. A clearance of 10% of the thickness of the sheets was maintained between the upper and lower dies. The wear of the upper and lower dies was evaluated and material abrasion and chipping were identified as the main damage features at the trim edges.
2017-03-28
Technical Paper
2017-01-1660
Huaxin Li, Di Ma, Brahim Medjahed, Qianyi Wang, Yu Seung Kim, Pramita Mitra
Abstract Nowadays, the automotive industry is experiencing the advent of unprecedented applications with connected devices, such as identifying safe users for insurance companies or assessing vehicle health. To enable such applications, driving behavior data are collected from vehicles and provided to third parties (e.g., insurance firms, car sharing businesses, healthcare providers). In the new wave of IoT (Internet of Things), driving statistics and users’ data generated from wearable devices can be exploited to better assess driving behaviors and construct driver models. We propose a framework for securely collecting data from multiple sources (e.g., vehicles and brought-in devices) and integrating them in the cloud to enable next-generation services with guaranteed user privacy protection.
2017-03-28
Technical Paper
2017-01-1515
Neil Lewington, Lauri Ohra-aho, Olav Lange, Klaus Rudnik
Abstract Industry trends towards lighter, more aerodynamically efficient road vehicles have the potential to degrade a vehicle’s response to crosswinds. In this paper, a methodology is outlined that indirectly couples a computational fluid dynamics (CFD) simulation of the vehicle’s aerodynamic characteristics with a multi-body dynamics simulation (MBD) to determine yaw, roll and pitch response characteristics during a severe crosswind event. This one-way coupling approach mimics physical test conditions outlined in open loop test procedure ISO 12021:2010 that forms part of the vehicle sign-off criterion at Ford Motor Company. The methodology uses an overset mesh CFD method to drive the vehicle through a prescribed crosswind event, providing unfiltered predictions of vehicle force and moment responses that are used as applied forces in the MBD model. The method does not account for changes in vehicle attitude due to applied aerodynamic forces and moments.
2017-03-28
Technical Paper
2017-01-1572
Wesley Kerstens
Abstract The detection and diagnosis of sensor faults in real-time is necessary for satisfactory performance of vehicle Electronic Stability Control (ESC) and Roll Stability Control (RSC) systems. This paper presents an observer designed to detect faults of a roll rate sensor that is robust to model uncertainties and disturbances. A reference vehicle roll angle estimate, independent of roll-rate sensor measurement, is formed from available ESC inertial sensor measurements. Residuals are generated by comparing the reference roll angle and roll rate, with the observer outputs. Stopping rules based on the current state of the vehicle and the magnitude of the residuals are then used to determine if a sensor fault is present. The system’s low order allows for efficient implementation in real-time on a fixed-point microprocessor. Modification of the roll rate sensor signal during in vehicle experiments shows the algorithm’s ability to detect faults.
2017-03-28
Technical Paper
2017-01-1556
Jianbo Lu, Li Xu, Daniel Eisele, Stephen Samuel, Matthew Rupp, Levasseur Tellis
Abstract This paper presents an advanced yaw stability control system that uses a sensor set including an inertial measurement unit to sense the 6 degrees-of-freedom motions of a vehicle. The full degree of the inertial measurement unit improves and enhances the vehicle motion state estimation over the one in the traditional electronic stability controls. The addition of vehicle state estimation leads to the performance refinement of vehicle stability control that can improve performance in certain situations. The paper provides both detailed system description and test results showing the effectiveness of the system.
2017-03-28
Technical Paper
2017-01-1339
Anselm Hopf, Günter Bartsch, Frank Krämer, Carsten Weber
Abstract Modern cylinder-head designs for gasoline engines are guiding the exhaust gas to the turbocharger system via an integrated exhaust manifold (IEM) which has several advantages like weight and cost reduction. On the other hand, the exhaust ports are running through a package labyrinth and are heavily bent within smallest space. Increased pressure drop, reduced mass flow rate, and deteriorated port flow efficiency could be the consequences leading to higher emissions, increased fuel consumption, and higher knock sensitivity. The optimization of the individual ports by computational fluid dynamics (CFD) is a proper means to minimize or even delete these drawbacks. Meanwhile, there are several powerful optimization methods for three-dimensional flows on the market. In this paper, a combined optimization strategy using CFD topology optimization followed by a shape optimization is presented.
2017-03-28
Technical Paper
2017-01-1342
Nicolas Zagorski, Eric Nelson, Ari Caliskan, Allen Li
Abstract The use of structural optimization in the design of automotive structures is increasingly common. However, it is often challenging to apply these methods simultaneously for different requirements or model configurations. Multi-model optimization (MMO) aims to simplify the iterative design process associated with optimizing multiple parts or configurations with common design variables especially when conflicting requirements exist. In this paper, the use of MMO is demonstrated to evaluate the feasibility of an automotive door concept using an alternative material.
2017-03-28
Technical Paper
2017-01-1383
Satheesh Kumar Chandran, James Forbes, Carrie Bittick, Kathleen Allanson, Fnu Brinda
Abstract There is a strong business case for automotive interfaces to undergo usability testing throughout their product development lifecycle. System Usability Scale (SUS) is a simple and standard measure of usability. To meet the timing needs for product development, usability testing needs to be performed in a quick, cost effective manner. Hence the required sample size of participants for a usability study is one of the critical factors. To determine an acceptable sample size, a Monte Carlo simulation using SUS scores from eleven different in-vehicle automotive interface usability studies was used to create 500,000 subsamples of different sample sizes. The percentage of subsamples with mean scores within the confidence interval of the population mean was calculated. At a subsample size of thirty-five, 95% of the subsamples have a mean SUS score within the 95% confidence interval of the population mean.
2017-03-28
Technical Paper
2017-01-1381
Satheesh Kumar Chandran, James Forbes, Carrie Bittick, Shimul Bhuva
Abstract There is a strong business case for automotive companies to improve by understanding what consumers want, like and dislike. Various aspects of ergonomics such as reach, visibility, usability, feel are dependent on measuring consumer’s ability, opinions and satisfaction. Rating scales (such as adjective, continuous, logarithmic, etc.) are used to measure these complex attitudes. It is essential the correct rating scale and appropriate analysis methods are used to capture these attitudes. Previous psychology research has been conducted on the performance of different rating scales. This ratings scale research focused on scales and their reliability and validity for various applications. This paper will summarize past research, discuss the use of rating scales specific to vehicle ergonomics, and analyze the results of an automotive interface study that correlates the seven-point adjective rating scale to the system usability score (SUS).
2017-03-28
Technical Paper
2017-01-1388
S. M. Akbar Berry, Michael Kolich, Johnathan Line, Waguih ElMaraghy
Abstract Thermal comfort in automotive seating has been studied and discussed for a long time. The available research, because it is focused on the components, has not produced a model that provides insight into the human-seat system interaction. This work, which represents the beginning of an extensive research program, aims to establish the foundation for such a model. This paper will discuss the key physiological, psychological, and biomechanical factors related to perceptions of thermal comfort in automotive seats. The methodology to establish perceived thermal comfort requirements will also be presented and discussed.
2017-03-28
Technical Paper
2017-01-1385
Satheesh Kumar Chandran, James Forbes, Carrie Bittick, Kathleen Allanson, Santosh Erupaka, Fnu Brinda
Abstract Measurement of usability with the System Usability Scale (SUS) is successfully applied to products in many industries. The benefit of any measurement scale, however, is limited by the repeatability of the associated testing process. For SUS, these factors can include sample size, study protocol, previous experience, and pre study exposure to the system being tested. Differences in user exposure can influence the usability assessment of interfaces which could affect the validity of SUS scores.
2017-03-28
Technical Paper
2017-01-1372
Bo Wang, Smruti Panigrahi, Mayur Narsude, Amit Mohanty
Abstract Increasing number of vehicles are equipped with telematics devices and are able to transmit vehicle CAN bus information remotely. This paper examines the possibility of identifying individual drivers from their driving signatures embedded in these telematics data. The vehicle telematics data used in this study were collected from a small fleet of 30 Ford Fiesta vehicles driven by 30 volunteer drivers over 15 days of real-world driving in London, UK. The collected CAN signals included vehicle speed, accelerator pedal position, brake pedal pressure, steering wheel angle, gear position, and engine RPM. These signals were collected at approximately 5Hz frequency and transmitted to the cloud for offline driver identification modeling. A list of driving metrics was developed to quantify driver behaviors, such as mean brake pedal pressure and longitudinal jerk. Random Forest (RF) was used to predict driver IDs based on the developed driving metrics.
2017-03-28
Technical Paper
2017-01-1378
Gianna F. Gomez-Levi, Ksenia Kozak, Nanxin Wang, Jian Wan, Linas Mikulionis
Abstract Researchers report an estimated 35.7 million of vehicles with touchscreens will be sold in 2019 worldwide [1]. As the use of touchscreens grows in the automotive industry, there is a need to study how driver’s arm and hand moves to access the touchscreen as well as how the driver utilizes the hardware around the touchscreen. In order to aid drivers while using the touchscreen and to minimize distractions, the drivers’ hand must be able to freely move to perform a task on the touchscreen without the trim interfering with the task. At the same time some trim may be used to support the hand and fingers while accessing the touchscreen particularly during tasks that take a longer period of time to complete. A study was performed to understand the effect of the size and the angle of a shelf placed under a touchscreen. Motion capture (Mocap) data of the hand of subjects performing two different tasks on the touchscreen was collected in the Human Occupant Package Simulator (HOPS).
2017-03-28
Technical Paper
2017-01-1375
Louis Tijerina, Danielle Warren, Sang-Hwan Kim, Francine Dolins
Abstract This study investigated the effects of three navigation system human-machine interfaces (HMIs) on driver eye-glance behavior, navigational errors, and subjective assessments. Thirty-six drivers drove an unfamiliar 3-segment route in downtown Detroit. HMIs were 2D or 3D (level-of-detail) electronic map display + standard voice prompts, or 3D map-display augmented by photorealistic images + landmark-enhanced voice prompts. Participants drove the same three route segments in order but were assigned a different HMI condition/segment in a 3-period/3-treatment crossover experimental design. Results indicate that drivers’ visual attention using the advanced navigation systems HMIs were within US Department of Transportation recommended visual distraction limits. More turns missed in the first route segment, regardless of HMI, were attributable to greater route complexity and a late-onset voice prompt.
2017-03-28
Technical Paper
2017-01-0382
Oscar Hernandez Cervantes, Antonio Espiritu Santo Rincon
Abstract The development of an automatic control system for a towing dynamometer used for testing is described in this paper. The process involved the deployment of new power electronics circuit boards, a TELMA retarder, instrumentation and a human machine interface (HMI) achieved through an open source platform. The purpose of this platform is to have a low cost system that allows further function development, data acquisition and communication with other devices. This system is intended as a novel solution that will allow closed loop and automated tests integrated with PCM data for engine calibration. It is projected to be part of a flexible calibration system with direct communication to the interfaces used during development (ATI, ETAS), which will be used to achieve lean test and development schedules.
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