1,471 results
Search Results
2. Evaluation of the Stability and Ignition Quality of Diesel-Biodiesel-Butanol Blends
- Author
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Fanourios Zannikos, Chrysovalanti E. Tsesmeli, Dimitrios Karonis, George S. Dodos, Theodora Tyrovola, and Iraklis Zahos Siagos
- Subjects
Biodiesel ,Materials science ,020209 energy ,media_common.quotation_subject ,Butanol ,02 engineering and technology ,Pulp and paper industry ,law.invention ,Ignition system ,chemistry.chemical_compound ,Diesel fuel ,020303 mechanical engineering & transports ,0203 mechanical engineering ,chemistry ,law ,0202 electrical engineering, electronic engineering, information engineering ,Quality (business) ,media_common - Published
- 2017
3. Evaluation of Anti-Knock Quality of Dicyclopentadiene-Gasoline Blends
- Author
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Mohannad Al-Khodaier, Bengt Johansson, Nimal Naser, Mani Sarathy, Muhammad Umer Waqas, and Vijai Shankar Bhavani Shankar
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Materials science ,020209 energy ,media_common.quotation_subject ,02 engineering and technology ,Pulp and paper industry ,chemistry.chemical_compound ,020401 chemical engineering ,chemistry ,Dicyclopentadiene ,0202 electrical engineering, electronic engineering, information engineering ,Quality (business) ,0204 chemical engineering ,Gasoline ,media_common - Published
- 2017
4. Effects of Fuel Ethanol Quality on Vehicle System Components
- Author
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Jill M. Cummings
- Subjects
chemistry.chemical_compound ,Ethanol ,chemistry ,media_common.quotation_subject ,Environmental science ,Quality (business) ,Pulp and paper industry ,media_common - Published
- 2011
5. Combined Experimental and Numerical Investigation of the ECN Spray G under Different Engine-Like Conditions
- Author
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Gianluca D'Errico, Roberto Ianniello, Alessandro Montanaro, Luigi Allocca, Tommaso Lucchini, Angelo Onorati, and Davide Paredi
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Risk ,Pollution ,Materials science ,020209 energy ,media_common.quotation_subject ,02 engineering and technology ,Industrial and Manufacturing Engineering ,Automotive engineering ,Automotive Engineering ,Safety, Risk, Reliability and Quality ,ECN Spray G ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Reliability and Quality ,0202 electrical engineering, electronic engineering, information engineering ,OpenFOAM ,Safety ,CFD ,media_common - Abstract
A detailed understanding of Gasoline Direct Injection (GDI) techniques applied to spark-ignition (SI) engines is necessary as they allow for many technical advantages such as increased power output, higher fuel efficiency and better cold start performances. Within this context, the extensive validation of multi-dimensional models against experimental data is a fundamental task in order to achieve an accurate reproduction of the physical phenomena characterizing the injected fuel spray. In this work, simulations of different Engine Combustion Network (ECN) Spray G conditions were performed with the Lib-ICE code, which is based on the open source OpenFOAMtechnology, by using a RANS Eulerian-Lagrangian approach to model the ambient gas-fuel spray interaction. Foremost, the main scope of the activity was to identify the most accurate numerical set-up in terms of atomization ad secondary break-up models, thanks to a validation of the computed results against experimental data available for the ECN Spray G baseline condition. Specifically, attention was focused on spray penetration along with an analysis of spray morphology and effects of plume-to-plume interaction. Afterwards, the reference set-up was tested and validated under different operating conditions, characterized by detailed experimental measurements specifically provided for this work. In particular, Mie scattering and Schlieren techniques allowed the quasi-simultaneous acquisition of both vapor and liquid penetrations, while a customized image-processing procedure, developed in Matlab environment, was used for the outline of the spray contours of both fuel phases to measure the parameters characterizing the jet development. A robust reference numerical set-up was identified, capable to reproduce with good accuracy the injection process of a multi-hole GDI spray under the wide range of tested operating conditions
- Published
- 2018
6. Development and Validation of a Submodel for Thermal Exchanges in the Hydraulic Circuits of a Global Engine Model
- Author
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Broatch, A., Olmeda, P., Martín, J., and Salvador-Iborra, Josep
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Engineering ,Government ,business.industry ,020209 energy ,02 engineering and technology ,7. Clean energy ,Engineering management ,020303 mechanical engineering & transports ,0203 mechanical engineering ,13. Climate action ,MAQUINAS Y MOTORES TERMICOS ,0202 electrical engineering, electronic engineering, information engineering ,media_common.cataloged_instance ,European union ,business ,Mallet ,media_common - Abstract
[EN] To face the current challenges of the automotive industry, there is a need for computational models capable to simulate the engine behavior under low-temperature and low-pressure conditions. Internal combustion engines are complex and have interconnected systems where many processes take place and influence each other. Thus, a global approach to engine simulation is suitable to study the entire engine performance. The circuits that distribute the hydraulic fluids -liquid fuels, coolants and lubricants- are critical subsystems of the engine. This work presents a 0D model which was developed and set up to make possible the simulation of hydraulic circuits in a global engine model. The model is capable of simulating flow and pressure distributions as well as heat transfer processes in a circuit. After its development, the thermo-hydraulic model was implemented in a physical based engine model called Virtual Engine Model (VEMOD), which takes into account all the relevant relations among subsystems. In the present paper, the thermo-hydraulic model is described and then it is used to simulate oil and coolant circuits of a diesel engine. The objective of the work is to validate the model under steady-state and transient operation, with focus on the thermal evolution of oil and coolant. For validation under steady-state conditions, 22 operating points were measured and simulated, some of them in cold environment. In general, good agreement was obtained between simulation and experiments. Next, the WLTP driving cycle was simulated starting from warmed-up conditions and from ambient temperature. Results were compared with the experiment, showing that modeled trends were close to those experimentally measured. Thermal evolutions of oil and coolant were predicted with mean errors between 0.7 °C and 2.1 °C. In particular, the warm-up phase was satisfactorily modeled., This research has been partially funded by the European Union’s Horizon 2020 Framework Programme for research, technological development and demonstration under grant agreement 723976 (“DiePeR”) and by the Spanish government under the grant agreement TRA2017-89894-R. Josep SalvadorIborra was supported by Universitat Politècnica de València through the contract FPI-S2-2016-1357 of the program PAID01-16. The authors wish to thank Renault SAS, especially P. Mallet and E. Gaïffas, for supporting this research. Jaime Monfort San Segundo is acknowledged for his helpful collaboration in the code implementation
- Published
- 2018
7. Further knowledge on effects of fuels quality changes on emission potential of common-rail D.I. diesel engine
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C. Bertoli, N. Del Giacomo, Chiara Guido, and Carlo Beatrice
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fuel quality ,Common rail ,Waste management ,media_common.quotation_subject ,Diesel combustion ,Environmental science ,Quality (business) ,Diesel engine ,common rail ,Automotive engineering ,media_common - Abstract
This paper reports some results on the emission performance of a CR DI diesel engine burning five model diesel fuels. The fuels were prepared by Agip Petroli S.p.A within the PNRA research program, sponsored by Italian Ministry of Environment and were a base fuel, a synthetic fuel and three oxygenated fuels. The engine employed in the tests was a prototype derived from Fiat M724 1910 cc, installed on Fiat Group class C Cars (1350 kg of mass). The prototype complies with EURO3 regulations. Two test points representative of two zones of ECE15+EUDC test cycle were chosen. Thermodynamic variables, emissions and injection systems parameters were recorded. Tests show the further potential of advanced fuels, obtained by blends of reformulated and oxygenated components, in reducing pollutants emissions.
- Published
- 2001
8. On the Definition of Resource Sharing Levels to Understand and Control the Impact of Contention in Multicore Processors
- Author
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Hamid Tabani, Leonidas Kosmidis, Enrico Mezzetti, Jaume Abella Ferrer, Francisco Javier Cazorla Almeida, and Barcelona Supercomputing Center
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Multi-core processor ,Software timing ,Horizon (archaeology) ,Operations research ,Computer science ,Freedom from interference ,European research ,Control (management) ,Real-time data processing ,Multicore timing analysis ,Interference channel ,Multiprocessadors ,Multicore contention ,Shared resource ,Work (electrical) ,Multiprocessors ,media_common.cataloged_instance ,European union ,Embedded systems (Computer systems) ,Informàtica::Hardware [Àrees temàtiques de la UPC] ,media_common - Abstract
The trend toward the adoption of a multiprocessor system on a chip (MPSoC) in critical real-time domains, like avionics or automotive, responds to the demand for increased computing performance to support advanced software functionalities. The other side of the coin is that MPSoCs challenge software timing analysis. This is so as co-running applications affect each other’s timing behavior on account of the interference incurred when accessing shared hardware resources, with the latter steadily increasing in number and complexity in every new generation of MPSoCs. For a solid and cost-contained software-timing validation approach, we contend that a taxonomy has to be developed to capture the different levels at which processors’ resources can be shared. Those levels are to be related to the conventional run-time software abstractions (e.g., task, thread, runnable) and the particular abstraction used to carry out contention analysis. From the standpoint of contention analysis, only the resources in those levels shared by the different run-time software entities need to be mastered and addressed by timing analysis, whereas the remaining resources can be safely disregarded. We tailor this approach to two of NVIDIA’s embedded platforms, TX2 and AGX Xavier, of particular relevance for the automotive domain. For the identified shared resources, we also characterize the contention that tasks can suffer and discuss the limitations and early approaches for modeling timing interference in shared hardware resources. This work has been partially supported by the SpanishMinistry of Science and Innovation under grants PID2019-107255GB and FJCI-2017 -34095; and the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 878752 (MASTECS) and the European Research Council (ERC) grant agreement No. 772773 (SuPerCom).
- Published
- 2021
9. Analysis of Fuel Properties on Combustion Characteristics in a Narrow-Throat Pre-Chamber Engine
- Author
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Manuel Alejandro Echeverri Marquez, Moez Ben Houidi, Bengt Johansson, Ponnya Hlaing, Emre Cenker, and Paula Burgos
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Engineering ,Supervisor ,business.industry ,media_common.quotation_subject ,Gratitude ,Combustion chamber ,Engine knocking ,business ,Combustion ,Fuel injection ,Research center ,Manufacturing engineering ,media_common - Abstract
The paper is based upon the work supported by Saudi Aramco Research and Development Center FUELCOM3 program under Master Research Agreement Number 6600024505/01. FUELCOM (Fuel Combustion for Advanced Engines) is a collaborative research undertaking between Saudi Aramco and KAUST intended to address the fundamental aspects of hydrocarbon fuel combustion in engines, and develop fuel/engine design tools suitable for advanced combustion modes. The authors would like to thank King Abdullah University of Science and Technology (KAUST) and the Clean Combustion Research Center (CCRC) for lab facilities and research support. Finally, the authors would like to convey gratitude towards the IC Engine Lab Safety Supervisor Adrian I. Ichim and the lab technician Riyad H. Jambi for their kind input and assistance in performing the experiments. The authors would like to express gratitude toward
- Published
- 2021
10. Introduction to Successful Predicting of Product Performance (Reliability, Durability, Safety, Quality, Recalls, Profit, Life Cycle Cost, and Others)
- Author
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Lev Klyatis
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Government ,Engineering ,Profit (accounting) ,business.industry ,media_common.quotation_subject ,Automotive industry ,Durability ,Product (business) ,Quality (business) ,Operations management ,Objective information ,business ,Reliability (statistics) ,media_common - Abstract
This paper will discuss the problem with successful predicting of product performance (reliability, quality, durability, safety, recalls, profit, life cycle cost, and other interconnected technical and economic components of performance). The best component for analysing the performance situation during service life, including predicting, is recalls, because, first, recall accumulates the safety , reliability, durability, quality, profit, and total economic situation. And second, there is open official and objective information about the number of recalls from Government (National Highway Trafic Safety Administration and others), as well as companies-producers. Therefore, for analyzing the situation with the product performance, including predicting, this paper considers the situation with recalls. First, it will demonstrate how dangerous the current situation is with recalls, safety, reliability, and durability, especially in automotive, including in the USA for last thirty years. Then it will be demonstrated that recalls directly connect with profit.
- Published
- 2015
11. Transporting NV Standardized Testing from the Lab to the Production Environment
- Author
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Paul Goodes and G. Pietila
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Engineering ,Scope (project management) ,business.industry ,media_common.quotation_subject ,Automotive industry ,Steering wheel ,Original equipment manufacturer ,Reliability engineering ,Tier 1 network ,Axle ,Tier 2 network ,Quality (business) ,business ,Simulation ,media_common - Abstract
NVH labs at Tier 1 and Tier 2 suppliers have in the past 15 years implemented testing techniques to validate the NV performance of their products. Validation tests are most often conducted to check compliance of the product to vehicle OEM specifications, less often to truly assess NV performance. Vehicle OEM specifications are sometimes outdated, narrow in scope and require labtype of conditions, i.e. anechoic or hemi-anechoic environment, fixed microphone position and specific operating conditions. Tier 1 and 2 suppliers often find themselves in a situation in which they have to transport lab tests to the plant floor, as they are requested by their customer to ensure 100% shipped quality. In order to do so, they are faced with several technical and commercial challenges as vehicle OEM specifications often have no provisions for plant-floor boundary conditions and cycle time requirements. For cost reasons, the component manufacturer typically aims at adding NV performance checks to an existing test station, which poses additional challenges over using a completely redesigned test station. This paper will discuss the challenges encountered by Tier 1 and Tier 2 suppliers having to implement end-of-line NV testing for quality control. The paper will discuss these challenges for a few different automotive components, namely steering wheel clock springs, sunroofs, axles and shock absorbers. The authors will describe some of the challenges faced and the solution implemented at the end of the line as it relates to boundary conditions, absolute levels at feedback sensor and pass/fail criteria
- Published
- 2009
12. Simulating Headlamp Illumination Using Photometric Light Clusters
- Author
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William Neale and David Hessel
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Engineering ,business.industry ,Headlamp ,media_common.quotation_subject ,Cluster (physics) ,Contrast (vision) ,Computer vision ,Artificial intelligence ,business ,Visibility ,Luminance ,Simulation ,media_common - Abstract
Assessing the ability of a driver to see objects, pedestrians, or other vehicles at night is a necessary precursor to determining if that driver could have avoided a nighttime crash. The visibility of an object at night is largely due to the luminance contrast between the object and its background. This difference depends on many factors, one of which is the amount of illumination produced by a vehicle’s headlamps. This paper focuses on a method for digitally modeling a vehicle headlamp, such that the illumination produced by the headlamps can be evaluated. The paper introduces the underlying concepts and a methodology for simulating, in a computer environment, a high-beam headlamp using a computer generated light cluster. In addition, the results of using this methodology are evaluated by comparing light values measured for a real headlamp to a simulated headlamp.
- Published
- 2009
13. Pervasive Computing applied to Cars
- Author
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Aislan Gomide Foina, Javier Ramirez-Fernandez, and Ahmed El-Deeb
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Engineering ,Ubiquitous computing ,Health management system ,business.industry ,Emerging technologies ,media_common.quotation_subject ,Node (networking) ,Reliability (computer networking) ,Computer security ,computer.software_genre ,Architecture ,business ,Function (engineering) ,Set (psychology) ,computer ,media_common - Abstract
This paper presents an architecture called PeSoV using new emerging technologies to increase the security, reliability and connectivity of motorized vehicles. Many people die because of car accidents caused by lack of attention and imprudence of car drivers. Some technologies like the standard IEEE 1609, Zigbee and a network of ranging sensors can be used as tools to help the driver to avoid accidents. PeSoV is composed of three subsystems: a car health management subsystem responsible to care about the good function of the car; a car-car communication subsystem responsible to allow the communication between cars; and a collision predict subsystem that will warn the driver in case of an possible collision. INTRODUCTION In the end of the century 19th the modern car started to take its shape. Since that time, the automobile was always dependent of a human driver, and like everything that needs a person, it is susceptible to human fails. In the year of 2006, 822 USA citizens died in Iraq war [1], but 42 thousand people died in USA because of car accidents. 75% of the deaths were vehicle occupants, 13% of these people were pedestrians and 12% were motorcyclists [2]. Most of these accidents happened because the driver was not paying attention to the environment around him, and the human mind is not fast enough to avoid some kinds of obstacles. These deaths could be avoided or at least reduced by a computer driver. Communication between cars and other facilities on the road was not conceived as something easy. It is until the time that IEEE has established the family of standards 1609. This family of standards encompasses a bundle of standards for vehicle communications from vehicle-to-vehicle to vehicle-to-roadside signs while providing other standards that handles security issues, networking, and data transmission issues. Such standards are adopted in the proposed system in this paper that serves as an overview of what we can do with vehicles with these set of standards from increasing safety to smoothing traffic problems. The best model that can take opportunity of these standards in vehicles is Ubiquitous Computing. For its philosophy of seamless integration of technology and computing in daily life [3], pervasive computing fit as the best model for inventing and developing systems for cars that help increase safety margins and handle traffic problems while minimizing road accidents. We will adapt the pervasive computing paradigm in such proposed system as a mean to seamlessly enable cars to be intelligent in monitoring and tracking their own health condition and act on it; to be able to communicate with other cars on the road for information; to be able to discover the road ahead. In other words, according to the proposed system with the aid of IEEE 1609 family of standards, cars became like a network of computers in which a car is like a computer node on a network that is able to communicate with other nodes. Not only this, each car’s internal parts are treated as a network of mechanical parts similar to a network of computers in which a car’s mechanical parts can communicate and synchronize matters among each other. This paper is organized by stating some other related work in the next section; subsequently, the proposed system details shall be discussed in its three subsystems; and finally, challenges and future research directions ended by conclusions are discussed.
- Published
- 2008
14. Triple Safety: Lightweighting Automobiles to Improve Occupant, Highway, and Global Safety
- Author
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Laura Schewel
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Transport engineering ,Engineering ,Human health ,Risk analysis (engineering) ,business.industry ,media_common.quotation_subject ,Climate change ,business ,Welfare ,Environmental degradation ,media_common - Abstract
Automobilesʼ negative impact on human health and welfare includes traffic-related deaths and injuries as well as the deaths and injuries caused by automobilesʼ contribution to climate change and other global environmental degradation. This paper explores solutions that both enhance vehicle performance and reduce environmental impacts, and focuses on demonstrating the ability of lightweight vehicles to provide such a solution. Some controversy exists around the question of whether lighter and more fuel-efficient vehicles can be as safe as traditional vehicles. Recent research reviewed in this paper indicates that several solutions exist that can both improve efficiency and thereby global safety, and maintain (or even improve) highway safety.
- Published
- 2008
15. The Influence of Vehicle-to-Ground Impact Conditions on Rollover Dynamics and Severity
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Nathan A. Rose, Gray Beauchamp, and Stephen J. Fenton
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Engineering ,business.industry ,media_common.quotation_subject ,Dynamics (mechanics) ,Crash ,Structural engineering ,Rollover ,Inertia ,Automotive engineering ,Center of gravity ,Orientation (geometry) ,Impact model ,business ,Roll moment ,media_common - Abstract
This paper explores the influence of the impact conditions on the dynamics and the severity of rollover crashes. It describes how causal connections are sought between the impact conditions and the crash attributes to which they lead. The paper begins by extending previously presented equations that describe the dynamics of an idealized vehicle-to-ground impact. It then considers the behavior of these equations under a variety of impact conditions that occur during real-world rollovers. Specifically, the equations of this impact model are used to explore the ways in which and the extent to which rollover dynamics and severity are influenced by the following factors: (1) the vehicle's shape and its orientation at impact; (2) its weight, center-of-mass location, and roll moment of inertia; (3) its translational speed; (4) its downward velocity; and (5) its roll velocity. Throughout this discussion, data from real-world and staged rollover crashes are used to give the parameter study an empirical basis.
- Published
- 2008
16. Simulation and Its Contribution to Evaluate Highly Automated Driving Functions
- Author
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Thomas Kuehbeck, Sebastian Wagner, Alois Knoll, and Korbinian Groh
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Ground truth ,Measure (data warehouse) ,Odometry ,Computer science ,media_common.quotation_subject ,Real-time computing ,Process (computing) ,Key (cryptography) ,Differential GPS ,Representation (mathematics) ,Function (engineering) ,media_common - Abstract
A key criterion for launching autonomous vehicles on real roads is the knowledge of their capability to ensure traffic safety. In contrast to ADAS, deriving this measure of safety is difficult to achieve as the functional scope of an autonomous driving function exceeds by far the one of ADAS. As a consequence, real-world testing solely is not sufficient enough to cover the required test volume. This assessment problem imposes new requirements on a valid test concept for automated driving. A possible solution represents simulation by enabling it to generate reliable test kilometers. As a first step, we discuss in this paper the feasibility of simulation frameworks to re- simulate a real-world test in certain scenarios. We will demonstrate that even with ground truth information of the vehicle odometry and corresponding environment model an acceptable accordance of functional behavior is not guaranteed. Hence, to yield a reliable degree of confidence in a risk assessment a single scenario has to be represented by an ensemble generated from a local variation considering both, ground truth information and odometry including the environment model. In order to achieve these statements we first introduce a valid representation of traffic scenarios acting as a test case description for an autonomous driving function. Afterwards, the description based on the vehicle odometry and created environment model as well as the description based on the ground truth measured via Differential GPS are re-simulated using the same autonomous driving function as deployed in the test vehicle. The reprocessed traces are compared to the corresponding real-world data to illustrate resulting behavior changes in the autonomous driving function. To make the behavior changes interpretable for the assessment process a sensitive risk value is deployed containing information about the reprocessing quality of the chosen description and simulation.
- Published
- 2019
17. An Initial Study on Monetary Cost Evaluation for the Design of Automotive Electrical Architectures
- Author
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Sri Kanajan, Arkadeb Ghosal, Alberto Sangiovanni-Vincentelli, and Randall J. Urbance
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Engineering ,Cost estimate ,business.industry ,COCOMO ,media_common.quotation_subject ,Automotive industry ,Cost driver ,Systems engineering ,Cost engineering ,Relevant cost ,business ,Function (engineering) ,Enterprise software ,media_common - Abstract
One of the many challenges facing electronic 1 system architects is how to provide a cost estimate related to design decisions over the entire life-cycle and product line of the architecture. Various cost modeling techniques may be used to perform this estimation. However, the estimation is often done in an ad-hoc manner, based on specific design scenarios or business assumptions. This situation may yield an unfair comparison of architectural alternatives due to the limited scope of the evaluation. A preferred estimation method would involve rigorous cost modeling based on architectural design cost drivers similar to those used in the manufacturing (e.g. process-based technical cost modeling) or in the enterprise software domain (e.g. COCOMO). This paper describes an initial study of a cost model associated with automotive electronic system architecture. The model's intended use is to evaluate system cost drivers in response to various architectural decisions (e.g. choosing a communication bus topology or mapping a function to hardware). The primary cost driver categories explored are design and development, part fabrication, assembly and in-service costs. The preliminary version of this cost model focuses on describing the key influences on cost, but not the entire mathematical model. The paper presents the cost model with the help of influence diagrams and illustrates the use of the cost modeling methodology through an automotive case study – a steer-by-wire system. As future work, we propose to build a cost model and supporting methodology that accounts for architecture evolution to address the issue of evolving architecture requirements as well as when and where to employ new technology in the architecture.
- Published
- 2007
18. Angular Velocity Perception Threshold and Sense of Presence for a Three Degrees of Freedom (DOF) Driving Simulator in Virtual Environment
- Author
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Baris Aykent, Jean-Rémy Chardonnet, Andras Kemeny, and Frédéric Merienne
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Synthèse d'image et réalité virtuelle [Informatique] ,Computer science ,Driving simulation ,media_common.quotation_subject ,Degrees of freedom ,Driving simulator ,Sense of presence ,Angular velocity ,Modélisation et simulation [Informatique] ,Virtual reality ,computer.software_genre ,Vehicle dynamics ,Virtual machine ,Control theory ,Perception ,Presence ,computer ,media_common - Abstract
Angular velocity perception plays an important role for a better sense of presence in driving simulators. This paper deals with the angular velocity perception threshold and sense of presence. A three degrees of freedom (DOF: roll, pitch, and heave) driving simulator, a motion tracking sensor, a driving simulation software, and self-prepared questionnaires were used. Due to the subjective assessments, there were no significant differences between static and dynamic platform types. Eight different cases were investigated with respect to visual and inertial factors (field of view (FOV) and motion platform). Subjective evaluations showed that there were no significant differences between static and dynamic conditions. Lower FOV, static platform, stereo vision condition has provided the best condition (best realism depending on objective-subjective measure relationship). FUI SI²M
- Published
- 2018
19. NASA Personal Air Transportation Technologies
- Author
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Mark D. Moore
- Subjects
System of systems ,Computer science ,Aviation ,business.industry ,media_common.quotation_subject ,Certification ,Avionics ,NASA spin-off technologies ,Transport engineering ,Aeronautics ,Service (economics) ,Portfolio ,Niche market ,business ,media_common - Abstract
The ability to personalize air travel through the use of an on-demand, highly distributed air transportation system will provide the degree of freedom and control that Americans enjoy in other aspects of their life. This new capability, of traveling when, where, and how we want with greatly enhanced mobility, accessibility, and speed requires vehicle and airspace technologies to provide the equivalent of an internet PC ubiquity, to an air transportation system that now exists as a centralized hub and spoke mainframe NASA airspace related research in this new category of aviation has been conducted through the Small Aircraft Transportation (SATS) project, while the vehicle technology efforts have been conducted in the Personal Air Vehicle sector of the Vehicle Systems Program. The PAV sector technology research conducted over the past several years is described, including intelligent avionics for ease of use, integrated low noise propulsion, advanced internal combustion engines, low cost variable pitch ducted propellers, lean design structures, quality assurance based certification regulations, a laminar flow fuselage with integrated aero-propulsion, advanced vehicle concepts, and high density airspace simulations. INTRODUCTION This paper provides the technology development portion of a trilogy of papers that report out the results of the Personal Air Vehicle (PAV) Sector of the NASA Vehicle Systems Program (VSP). The NASA VSP was cancelled over the past year as part of the Aeronautics Enterpr ise restructur ing, being replaced by the Fundamental Aeronautics Program. Since no further investment is currently planned relating to small aircraft, transitioning this research to industry is imperative to maximize the potential societal benefit. These three papers present the project research, incorporating the overarching system of systems perspective of th is vehicle sector (The Third Wave of Aeronautics: OnDemand Mobility SAE paper 2006-01-2429), the technology portfolio investment required to enable PAV sector capabilities (NASA Personal Air Transportation Technologies – SAE Paper 2006-01-2413), and the integrated vehicle concept development required to achieve a balanced and complementary technology portfolio (Next Generation NASA GA Aircraft Concept – SAE Paper 2006-01-2430). The PAV Sector was the smallest of the six VSP vehicle sectors, with a full cost investment of $10 million dollars over the 3 years. While not the solution to all travel, PAVs would provide a new, better choice for mid range trip distances of 50 to 500 miles where airlines and automobiles provide poor block speed service. Since this travel market accounts for almost half of all person trip miles in the U.S, it is more than a niche market that deserves effective cost to uti l i ty solutions to provide societal benefit. This supplemental personal air transportation network would do what car, airline, or rail could never do; combine ondemand access with high speed to yield a direct extension of the wireless, fax, and internet on-demand service age. At the same time, this new capability could maximize transportation capacity, robustness, and productivity. The f irst figure indicates how specific technology investments could yield integrated solutions which would offer increasingly distributed air operation capability. An analogy is presented to the computer industry which has transformed itself over the past 30 years from a highly centralized market solution, into an incredibly distributed market solution. This computer market revolution was driven by a combination of performance, packaging and cost technologies, which when combined with ease of use technologies (the Windows and Mac operating systems), the result was a much broader market with greatly increased revenues, while serving the customer better. The current aviation market offers an ‘innovator’s dilemma’ of trying to meet entrenched market needs through ever smal ler incremental improvements to existing customers, instead of developing disruptive technologies that create new value networks. A detailed discussion of this potential ‘Third Wave of Aeronautics: On-Demand Mobility’ is presented in SAE paper 2006-01-2429. At the commencement of the PAV sector efforts, an industry/academia/government working group was established to provide guidance on technology content and priorities. In addition, an independent review panel o f i n dustry ‘grey-beards’ provided continuous improvement of the technology project efforts. These meetings established a PAV sector GOTChA (Goals, Objectives, Technology Challenges, and Approaches – see Appendix) documentation set which decomposed efforts into a capabil i ty-based research plan with tracking metrics. These desired end state capabilities are listed below in Table 1, and are discussed in more detail within each technology approach section. The technology approaches were prioritized into near-term 5year and far-term 15-year efforts, with available funding limiting current research to primarily the near-term set except for a few exploratory far-term efforts. A n important distinction which occurred at the start of the research planning was defining the PAV as a selfoperated vehicle meeting personal transportation needs; therefore a PAV is not necessarily personally owned or maintained, since fractional ownership offers dramatic benefits in cost through increased utilization. A n important realization from this capability set is that the PAV technology efforts are not centered around achieving improved performance, but instead focus on improving the ‘ilities’ of the operational experience. In fact, as with most disruptive technologies, the focus is no t on improv ing ex is t ing cus tomer demands (established pilots) for improved performance, but instead meeting new customer requirements that would permit the current market to greatly expand, and reach greater economies of scale for all. Required Capability SOA 5-Years 15-Years Ease of Use (equiv. safety) SEP-IFR* Haptic Auto-like Community/Cabin Noise SEP Motorcycle Auto Emissions (HC/NOX/Lead g/mile) .5/1.0/.2 .05/.10/0 .03/.06/0 Acquisition Cost (2004 $ K) 450 150 100 Safety (accidents/100K hr) 6.5 2.0 .5 Cruise speed (mph) 200 200 150 Range (statute miles) 600 600 300 Efficiency (mpg) 13 16 40 Field Length (feet to clear obstacle) 250
- Published
- 2006
20. The HUMOSIM Ergonomics Framework: A New Approach to Digital Human Simulation for Ergonomic Analysis
- Author
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Bernard J. Martin, Matthew P. Reed, Julian J. Faraway, and Don B. Chaffin
- Subjects
Inverse kinematics ,business.industry ,Computer science ,media_common.quotation_subject ,Fidelity ,Kinematics ,Workspace ,Motion (physics) ,Variety (cybernetics) ,Software ,Human–computer interaction ,Systems engineering ,business ,Representation (mathematics) ,media_common - Abstract
The potential of digital human modeling to improve the design of products and workspaces has been limited by the time-consuming manual manipulation of figures that is required to perform simulations. Moreover, the inaccuracies in posture and motion that result from manual procedures compromise the fidelity of the resulting analyses. This paper presents a new approach to the control of human figure models and the analysis of simulated tasks. The new methods are embodied in an algorithmic framework developed in the Human Motion Simulation (HUMOSIM) laboratory at the University of Michigan. The framework consists of an interconnected, hierarchical set of posture and motion modules that control aspects of human behavior, such as gaze or upper-extremity motion. Analysis modules, addressing issues such as shoulder stress and balance, are integrated into the framework. The framework encompasses many individual innovations in motion simulation algorithms, but the primary innovation is in the development of a comprehensive system for motion simulation and ergonomic analysis that is specifically designed to be independent of any particular human modeling system. The modules are developed as lightweight algorithms based on closed-form equations and simple numerical methods that can be communicated in written form and implemented in any computer language. The modules are independent of any particular figure model structure, requiring only basic forward-kinematics control and public-domain numerical algorithms. Key aspects of the module algorithms are “behavior-based,” meaning that the large amount of redundancy in the human kinematic linkage is resolved using empirical models based on laboratory data. The implementation of the HUMOSIM framework in human figure models will allow much faster and more accurate simulation of human interactions with products and workspaces using high-level, task-based control. INTRODUCTION Digital human figure models (DHM) are now widely used for ergonomic analysis of products and workplaces. In many organizations, DHM software is a tool of first resort for answering questions relating to physical interaction between people and objects. Yet any objective appraisal of the technology would conclude that the current reality of DHM software capability is far from the promise of a “digital human” that can interact realistically with products and environments. This paper is focused on efforts to improve the ability of DHM software to simulate physical posture and motion. Nearly every other aspect of DHM functionality also warrants improvement, including body shape representation, strength simulation, and cognitive function, but posture and motion are critical to the primary applications of DHM to the assessment of physical tasks. Posture simulation is as old as computerized manikins, because the manikin must be postured before an analysis can be conducted. Important early work was performed by Ryan for the U.S. Navy (Ryan 1970). Porter et al. (1993) summarized applications of digital human models in vehicle ergonomics during the early years of personal computers, at which time few of the current commercial DHM software tools were in use. Chaffin (2001) presented case studies of the expanding use of DHM for both product and workplace design and assessment. As evidence of the importance of posture and motion simulation, dozens of papers in the SAE literature and in other forums have presented a wide variety of methods for human simulating postures and motions, including multiple-regression (Snyder et al. 1972); analytic and numerical inverse kinematics (Jung et al. 1995; Tolani et al. 2000); optimization-based inverse kinematics (Wang and Verriest 1998); differential inverse kinematics (Zhang and Chaffin, 2000); functional regression on stretch-pivot parameters (Faraway 2000); scaling, warping, and blending of motion-capture data (Park et al. 2002; Faraway 2003; Monnier et al. 2003; Park et al. 2004; Dufour and Wang 2005); and many 2006-01-2365 The HUMOSIM Ergonomics Framework: A New Approach to Digital Human Simulation for Ergonomic Analysis Matthew P. Reed, Julian Faraway, Don B. Chaffin and Bernard J. Martin University of Michigan
- Published
- 2006
21. Security Needs for the Future Intelligent Vehicles
- Author
-
Michael Jenkins and Syed Masud Mahmud
- Subjects
biology ,Computer science ,Event (computing) ,business.industry ,media_common.quotation_subject ,Active safety ,Internal communications ,Computer security ,computer.software_genre ,Payment ,Microcontroller ,Toll ,biology.protein ,Telematics ,Electronics ,business ,computer ,media_common - Abstract
The need for active safety, highway guidance, telematics, traffic management, cooperative driving, driver convenience and automatic toll payment will require future intelligent vehicles to communicate with other vehicles as well as with the road-side infrastructure. However, inter-vehicle and vehicle to roadside infrastructure communications will impose some security threats against vehicles’ safety and their proprietary information. To avoid collisions, a vehicle should receive messages only from other authentic vehicles. The internal buses and electronics of a vehicle must also be protected from intruders and other people with malicious intents. Otherwise, a person can inject incorrect messages into an authentic vehicle’s internal communication system and then make the vehicle transmit wrong information to the other vehicles within the vicinity. Such an event may have catastrophic consequences. Thus, a detailed study of the security needs of the future vehicles is very important. In this paper, we will present the results of a comprehensive study related to various types of security threats against a vehicle’s electronic communication system. The paper will identify various types of security attacks against a vehicle’s electronic system. The paper will also address various issues that are related to the design of secure microcontrollers, secure electronic modules, secure communications through the vehicle’s internal buses and privacy-protected secure peer-topeer communications.
- Published
- 2006
22. State of the Art in Sub-scale STOVL Hot Gas Ingestion Wind Tunnel Test Techniques
- Author
-
Peter Curtis, Richard Cook, and Peter Fenton
- Subjects
Engineering ,business.industry ,media_common.quotation_subject ,Scale (chemistry) ,Fidelity ,Propulsion ,Systems engineering ,Calibration ,State (computer science) ,business ,Wind tunnel test ,Simulation ,media_common ,Test data ,Wind tunnel - Abstract
This paper presents a detailed summary of the JSF STOVL Hot Gas Ingestion (HGI) sub-scale test program. It focuses on the System Demonstration and Development (SDD) phase of the JSF Program, where significant advances in the fidelity of testing have been made. It documents the improvements and refinements made to the dedicated test facility and powered wind tunnel model required for HGI testing. The paper covers an introduction to JSF and HGI, wind tunnel model hardware development, propulsion system calibrations, validation and understanding of the STOVL flow-field including comparison to full-scale data and test facility improvements. These improvements are also given perspective as the paper explains their practical effect in increasing the fidelity and confidence in the sub-scale test data, which will ultimately be used to support flight clearance for the F-35B aircraft. The improvements in test efficiency enable a more comprehensive database to be gathered within a given time frame.
- Published
- 2005
23. Cassette Factories and Robotic Bricks: A Roadmap for Establishing Deep Space Infrastructures
- Author
-
A. Scott Howe
- Subjects
Engineering ,business.industry ,media_common.quotation_subject ,Testbed ,Autonomous agent ,Mechanical engineering ,Control reconfiguration ,Modular design ,Revolute joint ,Variety (cybernetics) ,Computer-aided manufacturing ,Systems engineering ,business ,Function (engineering) ,media_common - Abstract
This paper proposes a roadmap for the development of a universal kit-of-parts construction system that can be delivered to a remote planetary surface and replicate copies of itself, while processing in-situ resources, assembling structures, and producing habitats and vehicles that are stockpiled and ready for habitation and use upon human crew arrival. The roadmap calls for four stages of system development: 1) Geometrical, configurational, and kinematic standard framework to achieve self-assembling structure, 2) Self-reconfiguration, self-repair, and cooperative autonomous agents to achieve self-replicability 3) Compartmentalization of manufacturing processes to achieve self-manufacturability, and 4) Achievement of self-sustainability with in-situ resource utilization. The four stages are discussed in depth. Challenges in the establishment of a configurational standard include the capacity to produce a wide variety of stable geometries that are useful in creating human habitable volumes and hierarchical spaces, and basic systematic revolute and prismatic actuation. The capacity for self-assembly will build on top of this standard, with coordinated modular robotic agents that work together to configure themselves into habitats and vehicles. Finally, simplification of manufacturing processes using digital methods, and the use of in-situ materials will be studied to establish "cassette factories" made out of the very modular elements that they themselves manufacture, to establish a sustainable construction system. The paper concludes with a discussion of some preliminary modular systems that may function as a testbed for exploring the nature of a universal kit-of-parts system (Howe & Colombano 2004).
- Published
- 2005
24. Towards Development of a Methodology to Measure Perception of Quality of Interior Materials
- Author
-
Vivek D. Bhise, James Dowd, Marc Hayes, Rashad Hammoudeh, and Radhakrishnan Nagarajan
- Subjects
Engineering ,Measure (data warehouse) ,Engineering drawing ,business.industry ,media_common.quotation_subject ,Automotive industry ,Semantics ,Industrial engineering ,Original equipment manufacturer ,Feeling ,Perception ,Quality (business) ,Semantic differential ,business ,media_common - Abstract
The automotive interior suppliers are challenged to develop materials, that not only perform functionally, but also provide the right combination sensory experience (e.g. visual appeal, tactile feeling) and brand differentiation at very competitive costs. Therefore, the objective of this research presented in this paper is to develop a methodology that can be used to measure customer perception of interior materials and to come up with a unique system for assessing value of different interior materials. The overall methodology involves the application of a number of psychophysical measurement methods (e.g. Semantic Differential Scaling) and statistical methods to assess: 1) overall customer perceived quality of materials, 2) elements (or attributes) of perception, and 3) value of materials from OEM's viewpoint in terms of the measurement of perception of quality divided by a measure of cost. This paper describes results of two pilot studies conducted for the following research phases: 1) Development of a list of adjective pairs to describe scales for overall evaluation/impression of the materials (e.g. Expensive-Cheap, Genuine-Fake, Quality-Shoddy, etc.), 2) Development of adjective pairs to measure elements of perception (e.g. Soft-Hard, Light-Dark, Smooth-Rough, Glossy-Flat, Slippery-Grippy, etc.), 3) Evaluation of a large number of materials of different types (e.g. woods, plastics/composites, fabrics, metallic, etc.) using the scales developed in earlier phases.
- Published
- 2005
25. Transfer Function Development in Design for Six Sigma Framework - Part I
- Author
-
Kai Yang and Matthew Hu
- Subjects
Engineering drawing ,Engineering ,business.industry ,media_common.quotation_subject ,Functional decomposition ,Transfer function ,Industrial engineering ,Axiomatic design ,New product development ,Design process ,Engineering design process ,Design for Six Sigma ,Function (engineering) ,business ,media_common - Abstract
Transfer functions, one of core components in Design for Six Sigma (DFSS), provide the needed relationships between design, process and materials parameters and the CTQs (Critical-to-Quality characteristics) in the product and process development cycle. Transfer function provides direct method for understanding and representing an over all product and process function. Transfer function also provides a strategy for customer voice cascade, function decomposition, physical modeling and concept generation. The concept of transfer function is not new. However, the development of transfer function is not trivial and is a creative and challenging task. In part I of this paper, we will discuss how to develop a transfer function in the DFSS framework. In part II of this paper, we devote our efforts in the discussion of selecting the best transfer function for design evaluation and optimization.
- Published
- 2005
26. Considerations of Bio-fidelity Corridors for Lateral Impacts
- Author
-
Timothy P. Hsu and Guy S. Nusholtz
- Subjects
Generation process ,Engineering ,Side impact ,Process (engineering) ,business.industry ,media_common.quotation_subject ,Fidelity ,Time alignment ,Mass scaling ,language.human_language ,Reliability engineering ,Maltese ,Time factor ,language ,business ,Simulation ,media_common - Abstract
Developing an effective side impact ATD for assessing vehicle impact responses requires a method for evaluating that ATD's bio-fidelity. ISO/TR9790 has been in existence for some years to serve that purpose. Recently, NHTSA sponsored a research project on the post-mortem human subjects (PMHS) responses subjected to side impact conditions. Based on those newly available PMHS data, Maltese generated a new approach for creating bio-fidelity corridors for human surrogates. The approach incorporates the time factor into the evaluation equation and automates the process (Maltese et al. 2002). This paper serves as the first attempt to look closely at the new bio-fidelity corridor generation process (hereafter referred as the Maltese approach) with respect to its validity, effectiveness, as well as its practicality. The effect of mass scaling was first examined in order to ensure the integrity of the data. The time alignment scheme and the formation of the corridors were then tested. The Maltese approach seems to represent the PMHS test responses. It appears to have some drawbacks due to the complexity of the PMHS responses. The approach works better for unimodal responses but does not produce unique solutions for all sets of time histories. This study also shows that the Maltese approach has merit by taking the time shift into account. The new approach statistically evaluates side impact ATDs for a large portion of the time period and has a well defined numerical procedure that reduces some of the subjectivity seen in ISO/TR9790. Some possible modifications aimed at further simplifying the procedure, improving the efficiency of the approach and eliminating the numerical problems are also studied and outlined in this paper.
- Published
- 2005
27. Gaseous Emissions Using Producer Gas as Fuel in Reciprocating Engines
- Author
-
Hari Sridhar, G Sridhar, N. K. S. Rajan, S. Dasappa, and P.J. Paul
- Subjects
Engineering ,Waste management ,Wood gas generator ,business.industry ,Producer gas ,Diesel cycle ,Diesel fuel ,Internal combustion engine ,media_common.cataloged_instance ,Coal gasification ,Gas engine ,European union ,business ,media_common - Abstract
In the recent times issues like the Green House Gas (GHG) emission reduction and carbon-trading through Clean Development Mechanism (CDM) have gained large prominence as a part of climate change. Biomass gasification is one such technology which is environmentally benign and holds large promise for the future. These technologies are currently being utilized for power generation applications at a number of industrial sites in India and abroad. This paper summarizes the work conducted using biomass derived producer gas in reciprocating internal combustion engines. The producer gas for the experimental work is derived from the well-established open top, re-burn, down draft gasification system, which is proven to generate consistent quality, ultraclean producer gas. This paper discusses the actual emission measurements in terms of NOx and CO on (a) dual–fuel engine (compression ignition engine) – using high speed diesel and producer gas fuel, (b) gas engine (spark ignited engine) – using 100% ultra clean producer gas. In the case of dual-fuel operation it is found that the NOx levels are lower compared to operations with pure diesel fuel on account of lower peak flame temperature, whereas the CO levels were higher due to combustion inefficiencies. In the case of gas alone operation it is found to be environmentally benign in terms of emissions; NOx and CO levels are found to be much lower than most of the existing emissions norms of various countries including the United States and European Union.
- Published
- 2005
28. Rapid Gasoline Powertrain System Design and Evaluation Using a Powertrain Starter Kit
- Author
-
Patrick Leteinturier and Simon Brewerton
- Subjects
Engineering ,Powertrain ,business.industry ,media_common.quotation_subject ,Reference design ,Automotive engineering ,Control theory ,Control system ,Systems design ,Quality (business) ,Gasoline ,business ,media_common ,Management control system - Abstract
Prototyping of a complete powertrain controller is not generally permissible due to the large number of subsystems involved and the resources required in making the design a reality. The availability of a complete control system reference design at an early stage in the lifecycle can greatly enhance the quality of the system definition and allows early ideas to be prototyped in the application environment. This paper describes the implementation of such a reference design for a gasoline engine and gearbox management control system, integrated into robust housing which can be used for development in a prototype vehicle. The paper also outlines the powertrain subsystems involved, discusses how the system partitioning is achieved, shows the implementation of the partitioning into the physical hardware, and concludes with presenting the system benefits which can be realized.
- Published
- 2005
29. Physical and Virtual Prototyping of Magnesium Instrument Panel Structures
- Author
-
Thomas Ruden, Suresh Lanka, and John Z. Lin
- Subjects
Rapid prototyping ,Engineering ,business.industry ,media_common.quotation_subject ,Noise, vibration, and harshness ,Virtual reality ,Finite element method ,New product development ,Systems engineering ,Quality (business) ,business ,Engineering design process ,Simulation ,Virtual prototyping ,media_common - Abstract
This paper reviews the current strategies for physical prototyping of Magnesium instrument panel (I/P) structures. Bottlenecks in the traditional physical prototype based product development process are discussed. As demand for fast-to-market and cost-reduction mounts, virtual prototyping becomes increasingly important in meeting the timing and performance goals. A virtual prototyping methodology is presented in this paper to enable high performance Magnesium I/P structures in Safety, NVH, and initial part quality aspects. Examples of Finite Element Analysis (FEA) results and correlations are included.
- Published
- 2005
30. European Standards and Regulations and Car Manufacturers Needs for Quality Fuels
- Author
-
Rodica Faucon
- Subjects
Engineering ,Waste management ,Standardization ,business.industry ,media_common.quotation_subject ,Environmental economics ,Green vehicle ,Diesel fuel ,Biofuel ,media_common.cataloged_instance ,Quality (business) ,European union ,Gasoline ,business ,Air quality index ,media_common - Abstract
There has been tremendous fuel standardization and regulatory activity in the European Union since 1993, in response to the increasingly severe vehicle emissions regulations. The paper reviews the E.U. political process aimed at improving the Community's targets for air quality that led to the joint publication of the Emissions and Fuel Directives in 1998 and their later up-dated versions. It further explains how the standardization contributed to support the E.U. policy, by up-dating the existing EN 228 (Unleaded Gasoline) and EN 590 (Diesel fuel) standards and by developing new standards such as EN 14274 on Fuel Quality Monitoring and EN 14214 on Biofuels. Lastly, the paper reviews car manufacturer ways to meet 2005 and beyond emissions limits and proposes new fuels parameters such as particulate contamination, gasoline and diesel fuel deposit control capability and anti-corrosion performance of diesel fuel, to be included in further developments of standards and directives.
- Published
- 2004
31. Clutch Lever Design Issues
- Author
-
Andrzej Szadkowski
- Subjects
Truck ,Lever ,Engineering ,business.product_category ,business.industry ,media_common.quotation_subject ,Mechanical engineering ,Kinematics ,Inertia ,Modeling and simulation ,Lift (force) ,Bolted joint ,Clutch ,business ,media_common - Abstract
Clutches possessing levers are prevalent in the North American market of medium and heavy duty trucks. The purpose of this paper is to investigate dynamic and kinematic problems related to clutch levers. Clutch designers are primarily concerned with the effects of levers on clamp load in the engaged state of the clutch, but neglect or downplay, consequences of dynamic effects on the release properties of clutches. The paper focuses on the release aspect of levers although the clamp load is also considered. The research method used in this paper was based on mathematical modeling and simulation of engagement and release processes. Main issues studied include: ○ Lever ratio varies both during the bearing departure and with wear of the clutch. The lever ratio variation affects both the lift of the pressure plate and the clutch clamp load. The simulation model can be utilized to optimize both lever shape and lever positioning during the entire clutch life. ○ Deflections of levers and other internal actuation components affect not only the pressure plate lift but also engagement quality of the clutch. ○ Centrifugal forces acting on levers affect the clamp load, release load and stability of lever location during clutch operation. Inertia forces of levers can affect the strap function and increase or decrease the clutch lift. ○ Improvements in stability of lever positioning during release can minimize clutch hysteresis. Some numerical examples are presented in order to illustrate clutch performance improvements made possible by simple design changes of levers. The main objective of this paper is to study kinematic and dynamic issues affecting the internal actuation process of the clutch and, subsequently, to derive mathematical models of clutch lever functions during actuations. The ultimate goal is to integrate these models into clutch design practice in order to improve important clutch characteristics.
- Published
- 2004
32. ULTIMATE: Metallic Thermal Protection System for Future RLV'S - Design and Thermo-mechanical Analyses –
- Author
-
Mark Mueller, Heiko Reinkober, and Wolfgang P. P. Fischer
- Subjects
Engineering ,business.industry ,Aerodynamic heating ,media_common.quotation_subject ,Space Shuttle ,ASTRA ,law.invention ,Orbiter ,law ,Space Shuttle thermal protection system ,Range (aeronautics) ,Aerospace engineering ,business ,Space Transportation System ,Function (engineering) ,media_common - Abstract
From the early beginning of space programs metallic Thermal Protection Systems (TPS) have been considered as promising technology to protect space vehicles against the severe aerodynamic heating encountered during re-entry into earth's atmosphere. The goal of "airplane-like" operations for future RLV's led to a renewed interest in TPS more durable than that developed for the space shuttle orbiter. This triggered developments of metallic TPS recently performed on the X-33. The same motivation is basis for the metallic TPS development within the frame of the German ASTRA ULTIMATE project since the thermal protection system contributes essentially to the overall mass and defines the operational cost of a space transportation system with its inspection, maintenance and repair capabilities. For these reasons the TPS dictates the overall economical operation of a future RLV. In Europe considerable effort has been spent to investigate future RLV concepts. One of these concepts named HOPPER has been chosen for further investigations and developments. Mission analyses performed so far for HOPPER identified large areas on the outer surface with moderate maximum temperatures during re-entry into Earth atmosphere. Nearly 80 per cent of the entire windward surface of this vehicle will experience maximum temperatures are in the range of 800 to 1200°C. Based on these boundaries HOPPER has been chosen as the reference vehicle for ULTIMATE metallic TPS development. The ULTIMATE TPS is intended for a max. temperature range of approx. 850 to 900 °C. The objective of this paper is to describe the TPS concept selected and the design of the single panels as well as the dedicated thermo-mechanical analyses to refine, optimize and verify design details. After establishing the overall requirements and needs for an advanced metallic TPS the ULTIMATE development has been started with a review of state-of-the-art technologies followed by an in-depth design trade-off and finally the selection of the most promising concept. Next, detailed thermo-mechanical analyses of the overall concept as well as design details/components have been performed to optimize the metallic TPS w.r.t its function and especially mass. During the subsequent detailed design phase emphasis has been given to operational aspects like inspection, maintenance, repair and panel exchange issues. This paper presents the results of the developments performed thus far and provides an overview of activities to be accomplished in the near future.
- Published
- 2003
33. Assessing and Modeling Direct Hydrogen and Gasoline Reforming Fuel Cell Vehicles and Their Cold-Start Performance
- Author
-
Danilo J. Santini, John S. Anderson, and Feng An
- Subjects
Engineering ,Cold start (automotive) ,Hydrogen ,business.industry ,media_common.quotation_subject ,Simulation modeling ,chemistry.chemical_element ,Environmental economics ,chemistry ,Greenhouse gas ,Range (aeronautics) ,Fuel cells ,Gasoline ,business ,Function (engineering) ,Simulation ,media_common - Abstract
This paper analyzes fuel economy benefits of direct hydrogen and gasoline reformer fuel cell vehicles, with special focus on cold-start impacts on these fuel cell based vehicles. Comparing several existing influential studies reveals that the most probable estimates from these studies differ greatly on the implied benefits of both types of fuel cell vehicles at the tank-to-wheel level (vehicle-powertrain efficiency and/or specific power), leading to great uncertainties in estimating well-to-wheel fuel energy and/or greenhouse gas (GHG) emission reduction potentials. This paper first addresses methodological issues to influence the outcome of these analyses. With one exception, we find that these studies consistently ignore cold-start and warm-up issues, which play important roles in determining both energy penalties and start-up time of fuel cell vehicles. To better understand cold-start and warm-up behavior, this paper examines approaches and results based on two available U.S. Department of Energy and USCAR funded National Laboratory vehicle simulation models -PSAT and ADVISOR. Our analysis reveals that the predicted cold-start effects are influenced by assumed choices concerning trade-offs between maximizing warm-up rate vs. minimizing wasteful energy during cold-starts, time to achievement of full power capability, and different modeling approaches. It appears that different cold-start warm-up strategies could result in a wide range of (1) vehicle performance capabilities as a function of time from start-up and (2) associated cold-start net energy penalties.
- Published
- 2003
34. Dynamic Characteristic Analysis of a Hydraulic Engine Mount with Lumped Model Based on Finite Element Analysis
- Author
-
Wen-Bin Shangguan and Lu Zhen-Hua
- Subjects
Engineering ,Computer simulation ,Hydraulic motor ,business.industry ,media_common.quotation_subject ,Mechanical engineering ,Computational fluid dynamics ,Inertia ,Finite element method ,law.invention ,Piston ,Vibration isolation ,Computer Science::Systems and Control ,law ,Fluid–structure interaction ,business ,media_common - Abstract
Hydraulic Engine Mount (HEM) is now widely used as a highly effective vibration isolator in automotive powertrain. A lumped parameter model is a traditional model for modeling the dynamic characteristics of HEM, in which the system parameters are usually obtained by experiments. In this paper, Computational Fluid Dynamics (CFD) method and nonlinear Finite Element Analysis (FEA) are used to determine the system parameters. A Fluid Structure Interaction (FSI) FEA technique is used to estimate the parameters of volumetric compliances, equivalent piston area, inertia and resistance of the fluid in the inertia track and decoupler of a HEM. A nonlinear FEA method is applied to determine the dynamic stiffness of rubber spring of the HEM. The system parameters predicated by FEA are compared favorably with experimental data and/or analytical solutions. A numerical simulation for an HEM with an inertia track and a free decoupler is performed based on the lumped model and using the estimated system parameters, and again the simulation results are compared with experimental data. The calculated time histories of some variables in the model, such as the pressure in the upper chamber, the displacement of the free decoupler and the volume flow through the inertia track and the decoupler, under different excitations, elucidate the working mechanism of the HEM. The work conducted in the paper demonstrates that the method for estimating the system parameters in the lumped model for HEM is effective, with which the dynamic characteristic analysis and design optimization of an HEM can be performed before its prototype development, and this can ensure its high quality and low cost for development.
- Published
- 2003
35. Development of 'All-Around View' System
- Author
-
Yasuhide Yamamoto, Ken Oizumi, Masato Inoue, and Masao Sakata
- Subjects
Engineering ,Photogrammetry ,business.industry ,Human–computer interaction ,Perception ,media_common.quotation_subject ,Computer vision ,Artificial intelligence ,System configuration ,business ,media_common - Abstract
This paper has described the “All-Around View” System that is proposed as one approach to monitoring the circumstances around a vehicle. This system uses multiple cameras used for photographing the situation around the host vehicle and presents that information to the driver the form of an easy-to-understand virtual plan view. It has been confirmed that the eye-point conversion system employed for the multiple cameras is feasible both technologically and in terms of compatibility with the car design. In continuing this research on visual aids for improving the driver’s awareness of the vehicle environment, this authors of this paper plan to investigate a system configuration that uses fewer cameras in future work.
- Published
- 2003
36. Methods of Testing Logical and Electrical Conformity of OBDII and EOBD Communication Bus Parameters Employed to Validate and Certify Diagnostic Scanner Tools
- Author
-
R. Grzeszczyk, Jerzy Merkisz, Stanisław Mazurek, and Piotr Boguś
- Subjects
Scanner ,business.industry ,Computer science ,media_common.quotation_subject ,Control (management) ,Process (computing) ,Conformity ,Software ,Logical conjunction ,Broadband ,Systems engineering ,Microsoft Windows ,business ,Simulation ,media_common - Abstract
This paper describes a framework of a system for examining OBD scanners, presenting that system's functionality and how to implement it in practice. There is a brief discussion of software designed for the Microsoft Windows environment to control and visualise the testing process. The paper also discusses additional software modules designed to examine specific properties of the OBD-equipped devices that are manufactured for the German market. These include examining the technical status of the two-state and broadband oxygen sensors based on analysing logged the temporal sequence of momentary current or voltage values.
- Published
- 2003
37. A New Calibration System for ECU Development
- Author
-
Jobst Richert, Andre Rolfsmeier, and Robert Leinfellner
- Subjects
Engineering ,Powertrain ,business.industry ,Process (engineering) ,media_common.quotation_subject ,Automotive industry ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,DSPACE ,Software ,Management system ,Systems engineering ,Fuel efficiency ,Function (engineering) ,business ,Simulation ,media_common - Abstract
Automotive manufacturers and suppliers of electronic control units (ECUs) will be challenged more and more in the future to reduce costs and the time needed for ECU development. At the same time, increasing requirements concerning exhaust gas emissions, drivability, onboard diagnostics and fuel consumption have led to the growing complexity of modern engines and the associated management systems. As a result, the number and complexity of control parameters and look-up tables in the ECU software is increasing dramatically. Thus, in powertrain applications especially, calibration development has become a time-consuming and cost-intensive stage in the overall ECU development process. This paper describes the current situation in calibration development and shows how the new dSPACE Calibration System will face this situation. It provides an overview of the main benefits of the tool, which has been designed in close cooperation with calibration engineers. A special focus will be on how the tool contributes to saving calibration costs and development time. Further emphasis will be placed on integration into the dSPACE tool chain, providing a complete environment for the development of ECU software. Interaction with tools for control design, function prototyping, target implementation and ECU testing will be detailed. In addition, the paper describes how international standards like ASAM/ASAP and NEXUS facilitate the calibration process and how these standards are supported by dSPACE.
- Published
- 2003
38. Development and Evaluation of a Kinematic Hood for Pedestrian Protection
- Author
-
Christoph Wilfling, Bernd Mlekusch, Ferdinand Dobida, Erwin Deutscher, and Martin Krenn
- Subjects
Transport engineering ,Engineering ,Aeronautics ,business.industry ,Head impact ,Vehicle safety ,Automotive industry ,media_common.cataloged_instance ,Kinematics ,Pedestrian ,European union ,business ,media_common - Abstract
This paper will present how the automotive industry is focusing more on the protection of pedestrians and cyclists. Approximately 6,000 out of every 35,000 persons killed in traffic accidents annually in the European Union are pedestrians. Therefore the development of passive measures to improve pedestrian safety is strongly supported by the European automotive industry. This paper describes in detail the mechanics and kinematics of an active hood. Furthermore the investigation of the integration and effects of the active hood in a feasible safety concept of modern cars is presented. Additionally, detailed evaluations of real hardware testing and simulation of pedestrian head impact are shown in this paper. The results are discussed, and some new information will be brought up for future strategies in safety concepts for new cars.
- Published
- 2003
39. Driving Simulator Validation Study
- Author
-
M. Kolich
- Subjects
Validation study ,Engineering ,business.industry ,media_common.quotation_subject ,New product development ,Driving simulator ,Fidelity ,Control engineering ,Virtual reality ,business ,Simulation ,media_common - Abstract
This paper describes how Johnson Controls, Inc. has a developed a driving simulator and there are no other simulators with the same capacity in the driving industry. Before this virtual reality tool could be applied to seat comfort development initiatives, it was necessary to demonstrate, through a series of investigations, an acceptable level of fidelity (sensory realism) and validity (as compared to real world driving). This paper describes this study and demonstrates that there are no significant differences between an actual and simulated ride and drive using a 23-item survey. Based on this evidence, the driving simulator was incorporated into the product development process.
- Published
- 2003
40. Evaluating the Uncertainty in Various Measurement Tasks Common to Accident Reconstruction
- Author
-
Bruno Schmidt, Frank Navin, W. J. Wright, Al Baxter, Oren Masory, Terry Stanard, Raymond M. Brach, and Wade Bartlett
- Subjects
Accident (fallacy) ,Engineering ,Operations research ,business.industry ,media_common.quotation_subject ,Sample (statistics) ,Crash data ,Data mining ,computer.software_genre ,Function (engineering) ,business ,computer ,media_common - Abstract
When performing calculations pertaining to the analysis of motor vehicle accidents, this paper describes how investigators must often select appropriate values for a number of parameters. The uncertainty of the final answer is a function of the uncertainty of each parameter involved in the calculation. This paper presents the results of recent tests that were conducted to obtain sample distributions of some common parameters, including measurements made with tapes, measurements made with roller-wheels, skidmark measurements, yawmark measurements, estimation of crush damage from photographs, and drag factors, that can be used to evaluate the uncertainty in an accident reconstruction analysis. The paper also reviews the distributions of some pertinent data reported by other researchers.
- Published
- 2002
41. The Development of a Sound Quality-Based End-of-Line Inspection System for Powered Seat Adjusters
- Author
-
L. Braner, Mark A. Ann Arbor Jay, Jianrong Dong, G. Cerrato-Jay, T. Bernard, D. J. Pickering, and R. Davidson
- Subjects
Engineering ,geography ,geography.geographical_feature_category ,business.industry ,media_common.quotation_subject ,Control (management) ,Reliability engineering ,Noise ,Consistency (database systems) ,New product development ,Quality (business) ,Line (text file) ,Sound quality ,business ,Sound (geography) ,Simulation ,media_common - Abstract
In recent years, the perceived quality of powered seat adjusters based on their sound during operation has become a primary concern for vehicle and seat manufacturers. Historical noise targets based on overall dB(A) at the occupant’s ear have consistently proved inadequate as a measure of the sound quality of a seat adjuster. Significant effort has been devoted to develop alternative sound quality metrics that can truly discriminate between “good” and “bad” seat adjusters. These new metrics have been successfully applied for some years by product development engineers in test labs. However, in the assembly plant the sound quality of the seat adjuster is still assessed subjectively by an operator at the end of the assembly line. The main problem with this approach is not only the lack of consistency and repeatability across large samples of seat tracks, but also the fact that the only feedback provided from the end-of-line to the product development team is of subjective nature. This subjective information is of little help for the engineers who have to diagnose and remedy the problem. Additionally, since sound quality has become one of the main reasons for rejection at the end of the assembly line, there is the need for integrating sound quality performance checks with the standard quality control or functional checks in the manufacturing environment. Therefore, the new challenge for the seat adjuster manufacturer is to implement at the end of the assembly line an automated Sound Quality-based inspection system that relies exclusively on objective parameters. The authors of this paper have devoted a lot of effort toward developing such a system, and this paper will describe and discuss the main issues related to its design, implementation and validation.
- Published
- 2001
42. The BMW Active Cruise Control ACC
- Author
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Thomas Sauer, Joachim Dr. Steinle, Willibald Prestl, and Oliver Tschernoster
- Subjects
Electronic speed control ,Engineering ,Adaptive control ,business.industry ,media_common.quotation_subject ,Control (management) ,Control unit ,Control engineering ,Automotive engineering ,Control function ,Headway ,business ,Function (engineering) ,Cruise control ,media_common - Abstract
This paper describes the BMW Active Cruise Control (ACC) system which adds a headway control function to the speed control function of conventional cruise control systems. The functions of the ACC are described, including the system capabilities, limits, function design and system philosophy. This is followed by a description of the system, its components, and its control functions. The paper concludes with a discussion regarding the safety concepts of the combined sensor control unit and of the entire system network.
- Published
- 2000
43. Life-Cycle Emissions of Alternative Fuels for Transportation: Dealing with Uncertanties
- Author
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Robert M. Moore, Daniel Sperling, J. Fernando Contadini, and Meena Sundaresan
- Subjects
Upstream (petroleum industry) ,Engineering ,Operations research ,business.industry ,media_common.quotation_subject ,Principal (computer security) ,Air pollution ,Environmental engineering ,Probabilistic logic ,medicine.disease_cause ,Alternative fuels ,Greenhouse gas ,Value (economics) ,medicine ,Function (engineering) ,business ,media_common - Abstract
Author(s): Contadini, J. Fernando; Moore, Robert M.; Sperling, Daniel; Sundaresan, Meena | Abstract: A principal motivation for introducing alternative fuels is to reduce air pollution and greenhouse gas emissions. A comprehensive evaluation of the reductions must include all Life Cycle activities from the vehicle operation to the feedstock extraction. This paper focuses on the fuel upstream activities only. We compare the results and methods of the three most comprehensive existing fuel upstream models in the U.S.A. and we explore the differences and uncertainties of these types of analyses. To explicitly include the impact of uncertainties, we create a new model using the following approaches:- Instead of using a single value as input, the new model deals with ranges around the most probable value- Ranges are discussed and calibrated by an expert network, in terms of their relative probability.- Probabilistic function techniques are applied to study the impact of the uncertainties on the model output.The paper also presents the rationale and benefits of using each of the alternative approaches that are discussed and reviewed.
- Published
- 2000
44. Initial Evaluation of Limited Delegation of Separation Assurance to the Cockpit
- Author
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Jean-Pierre Nicolaon, Karim Zeghal, Anne Cloerec, Isabelle Grimaud, and Eric Hoffman
- Subjects
Flexibility (engineering) ,Operations research ,Delegation ,Control theory ,Computer science ,Maneuvering area ,media_common.quotation_subject ,Key (cryptography) ,Workload ,Set (psychology) ,Cockpit ,media_common ,Reliability engineering - Abstract
This paper presents the initial evaluation of the EACAC study, which is investigating delegation by the controller to the pilot of some tasks related to separation assurance. The concept is applied in managed airspace for two classes of application: crossing and passing in en-route, and sequencing in Terminal Manoeuvring Area. The concept relies on two key points discussed in the paper: “limited delegation” and “flexible use of delegation”. The initial evaluation using a simplified ATC environment has been set up to get “feedback” from both controllers and pilots, and to assess the operational feasibility and potential interest of the concept. The overall feeling about the method is “promising” with a “great potential”, and could reduce workload. The notion of “flexible use of delegation” would enable the gradual growth of confidence and would also provide flexibility to use the method under different conditions (traffic, airspace, practice level). It has been highlighted and observed however that the conditions of applicability of the method must be respected, otherwise it could worsen the situations, resulting in an increase of workload and communication. The next step of the study will therefore be a “quantitative” experiment with the objective of evaluating expected gains of the method.
- Published
- 1999
45. Measured Vehicle Inertial Parameters-NHTSA’s Data Through November 1998
- Author
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J. Gavin Howe, W. Riley Garrott, Ronald A. Bixel, Dennis A. Guenther, Gary J. Heydinger, and Michael Pyne
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Engineering ,Inertial frame of reference ,business.industry ,media_common.quotation_subject ,Fictitious force ,Table (database) ,Listing (computer) ,business ,Inertia ,Simulation ,Marine engineering ,media_common - Abstract
This paper is primarily a printed listing of the National Highway Traffic Safety Administration’s (NHTSA) Light Vehicle Inertial Parameter Database. This database contains measured vehicle inertial parameters from SAE Paper 930897, “Measured Vehicle Inertial Parameters NHTSA’s Data Through September 1992” (1), as well as parameters obtained by NHTSA since 1992. The proceeding paper contained 414 entries. This paper contains 82 new entries, for a total of 496. The majority of the entries contain complete vehicle inertial parameters, some of the entries contain tilt table results only, and some entries contain both inertia and tilt table results. This paper provides a brief discussion of the accuracy of inertial measurements. Also included are selected graphs of quantities listed in the database for some of the 1998 model year vehicles tested.
- Published
- 1999
46. A Study on Attenuating Gear Teeth Oscillations at Low Engine Speeds Using Nonlinear Vibration Absorbers
- Author
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Ahmed Haris, Brett Friskney, Eliot Motato, Mahdi Mohammadpour, and Stephanos Theodossiades
- Subjects
Physics ,Vibration ,Nonlinear system ,Acoustics ,media_common.quotation_subject ,Noise, vibration, and harshness ,Natural frequency ,Dissipation ,Inertia ,Flywheel ,Damper ,media_common - Abstract
© 2018 SAE International. All Rights Reserved. Gear oscillations are one of the most common sources of Noise, Vibration and Harshness (NVH) issues manifested in automotive powertrains. These oscillations are generated mainly due to impacts of the meshing gear teeth over a broad frequency range. To mitigate NVH phenomena, automotive manufacturers traditionally couple linear tuned vibration absorbers to the driveline. Common palliatives used are clutch dampers and dual mass flywheels, which generally suppress vibrations effectively only over narrow frequency bands. Nonlinear Energy Sinks (NESs) are a class of vibration absorbers with essentially nonlinear characteristics that are designed for dissipating vibration energy over broad frequency ranges (due to the employed nonlinearity). The NES does not have a preferential natural frequency; this is rather characterized by the nonlinear stiffness. An NES functions on the principle of transferring energy between the primary system (e.g. driveline) and the absorber in two ways: (i) the NES induces a unidirectional transfer of the vibration energy excess from the primary system to the absorber and (ii) the NES induces a redistribution of the vibration energy excess in the modes of the primary structure, enhancing the energy dissipation capabilities of the primary structure. This paper presents a study on the use of NESs for reducing oscillations on gear pairs operating at low engine operating speeds. Numerical simulations were performed using a gear pair model equipped with an absorber with essentially cubic nonlinear stiffness, attached to the gear wheel. The stiffness and inertia properties of the absorber were varied with the objective of obtaining the parameter combination that induces significant attenuation of the oscillatory motion of the gear wheel. The occurring motion of the system using different sets of parameters is studied and presented.
- Published
- 2018
47. Experimental and Numerical Analysis of Diluted Combustion in a Direct Injection CNG Engine Featuring Post- Euro-VI Fuel Consumption Targets
- Author
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Frederic Ravet, Prashant Goel, Loïc Rouleau, Mirko Baratta, Betrand Lecointe, Danilo Laurenzano, Panagiotis Christou, and Daniela Anna Misul
- Subjects
Risk ,Pollution ,020209 energy ,media_common.quotation_subject ,Numerical analysis ,02 engineering and technology ,Combustion ,Industrial and Manufacturing Engineering ,Automotive engineering ,Automotive Engineering ,Safety, Risk, Reliability and Quality ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Reliability and Quality ,0202 electrical engineering, electronic engineering, information engineering ,Fuel efficiency ,Environmental science ,Safety ,media_common - Published
- 2018
48. A Low Order Model of SCR-in-DPF Systems with Proper Orthogonal Decomposition
- Author
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Thomas Steffen and Seun Olowojebutu
- Subjects
Model order reduction ,media_common.quotation_subject ,Fidelity ,02 engineering and technology ,Slip (materials science) ,021001 nanoscience & nanotechnology ,020303 mechanical engineering & transports ,Point of delivery ,High fidelity ,0203 mechanical engineering ,Control theory ,Control system ,Principal component analysis ,0210 nano-technology ,Galerkin method ,media_common - Abstract
© 2018 SAE International. All Rights Reserved. This paper presents a method to achieve a low order system model of the urea-based SCR catalyst coated filter (SCR-in-DPF or SCRF or SDPF), while preserving a high degree of fidelity. Proper orthogonal decomposition (POD), also known as principal component analysis (PCA), or Karhunen-Loeve decomposition (KLD), is a statistical method which achieves model order reduction by extracting the dominant characteristic modes of the system and devises a low-dimensional approximation on that basis. The motivation for using the POD approach is that the low-order model directly derives from the high-fidelity model (or experimental data) thereby retains the physics of the system. POD, with Galerkin projection, is applied to the 1D + 1D SCR-in-DPF model using ammonia surface coverage and wall temperature as the dominant system states to achieve model order reduction. The performance of the low-order POD model (with only a few basis modes) shows good agreement with the high fidelity model in steady and transient states analyses. This shows the promise of the application of POD in exhaust after-treatment system (EATS) modelling to achieve high fidelity low order models. In addition system control design is easier for the reduced order model using a modern approach. We demonstrate the performance of a model-based controller applied to the low-order POD model to minimize ammonia slip for a transient test cycle.
- Published
- 2018
49. CFD Investigation of the Impact of Electrical Heating on the Light-off of a Diesel Oxidation Catalyst
- Author
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Angelo Onorati, Tarcisio Cerri, Gianluca Montenegro, and Augusto Della Torre
- Subjects
Pollution ,Risk ,Diesel particulate filter ,Materials science ,business.industry ,020209 energy ,media_common.quotation_subject ,Metallurgy ,02 engineering and technology ,Computational fluid dynamics ,Industrial and Manufacturing Engineering ,Automotive Engineering ,Safety, Risk, Reliability and Quality ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Reliability and Quality ,0202 electrical engineering, electronic engineering, information engineering ,Safety ,business ,media_common - Published
- 2018
- Full Text
- View/download PDF
50. Computer Images and Animations in Court
- Author
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Richard J. Fay
- Subjects
Computer science ,Aside ,media_common.quotation_subject ,Common law ,Foundation (evidence) ,ComputingMilieux_LEGALASPECTSOFCOMPUTING ,Animation ,Discretion ,Computer security ,computer.software_genre ,Jury ,Need to know ,Law ,computer ,Computer animation ,media_common - Abstract
Computer imaging and animation can be extremely useful in analysing vehicle accidents and illustrating the results. However, the admissibility of computer images and animations in court is a concern. It is within the trial judge's discretion to decide whether a computer animation may be shown. Courts have accepted them in some cases and have rejected them in others. Aside from the legal issues, courts need to be sure that the images and motions are accurate, and are based on recognized principles. Juries need to know these same things. This paper discusses the requirements which should be met to make computer images acceptable in a court of law, and discusses methods for presenting an adequate foundation in court and the necessary explanations to a jury. The paper presents a systematic approach to laying the foundation for a court of law based on the author's own experience which employs the use of still images, photos, and diagrams. (A) For the covering abstract of the conference see IRRD 899758.
- Published
- 1997
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