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Viewing 1 to 30 of 516
2013-09-24
Journal Article
2013-01-2477
Gergis W. William, Samir Shoukry, Jacky Prucz, Thomas Evans
This paper presents 3D finite element analysis performed for a composite cylindrical tank made of 6061-aluminum liner overwrapped with carbon fibers subjected to a burst internal pressure of 1610 bars. As the service pressure expected in these tanks is 700 bars, a factor of safety of 2.3 is kept the same for all designs. The optimal design configuration of such high pressure storage tanks includes an inner liner used as a gas permeation barrier, geometrically optimized domes, inlet/outlet valves with minimum stress concentrations, and directionally tailored exterior reinforcement for high strength and stiffness. Filament winding of pressure vessels made of fiber composite materials is the most efficient manufacturing method for such high pressure hydrogen storage tanks. The complexity of the filament winding process in the dome region is characterized by continually changing the fiber orientation angle and the local thickness of the wall.
2004-10-26
Technical Paper
2004-01-2705
Jeffrey R. Stokes, Paul W. Claar
Data envelopment analysis (DEA) is used to examine the efficiency of 74 front wheel assist agricultural tractors from three U.S. manufacturers. The outputs of drawbar horsepower and power takeoff horsepower are modeled in a constant returns-to-scale framework using three productive performance inputs (fuel consumption, slip, and center of gravity), and one price input, namely, retail tractor price. The results suggest that by and large, John Deere tractors are more DEA efficient than their competitor's tractors. However, competitor's tractors that are DEA efficient are most often the top benchmarks for DEA inefficient tractors. These results suggest that while John Deere appears to produce many quality tractors, competitor's like CNH and AGCO produce a few tractors that may be of even higher quality.
2004-03-08
Technical Paper
2004-01-1768
Wolfram Hohmann
In this paper we will explore how 15 years after being introduced into avionics systems, “by-wire” technologies have entered the automotive world. The use of software within safety-relevant application areas like restraint systems, braking, steering and vehicle dynamics support and control systems, is requiring changes in the processes and methodologies used for embedded software development.
2011-04-12
Technical Paper
2011-01-0893
Keith Buford, Jonathan Williams, Matthew Simonini
Plug in hybrid electric vehicles (PHEV) and electric vehicles (EV) are using large lithium ion battery packs to store energy for powering electric traction motors. These batteries, or Rechargeable Energy Storage Systems (RESS), have a narrow temperature operating range and require thermal management systems to properly condition the batteries for use in automotive applications. This paper will focus on energy optimization of a RESS cooling system. The battery thermal management system for the General Motors Chevrolet Volt has three distinct modes for battery cooling: active cooling, passive cooling, and bypass. Testing was conducted on each individual thermal cooling mode to optimize, through control models, the energy efficiency of the system with the goal of maximizing electric vehicle range.
2011-09-13
Technical Paper
2011-01-2270
Andres Font
The continuously integration of electrics and electronics (EE) in the last decades is one of the main key drivers for innovation and business success of the Automotive OEMs. This is also applicable for truck manufacturers. On the other side factors like the rising vehicle complexity, number of variants and the warranty costs for EE issues are increasing the pressure on the engineering teams responsible for the mechatronic systems. To address these issues one of the key activities in the European market (focus on Germany) during the last decade was to introduce industry-wide standards for the data transfer of wiring harness data between OEM and harness supplier. In this paper the benefits and technical background of using the standards KBL and KOMP formats within the MB-Trucks brand will be presented. Moreover the role of the Information Technology (IT) will be explained in detail.
2011-09-13
Technical Paper
2011-01-2250
Farzad Ahmadkhanlou, Abas Goodarzi
Plug-In Hybrid Electric Vehicles (PHEV) require high power density energy storage system (ESS) for hybrid operation and high energy density ESS for EV mode range. The dual ESS allows the best utilization of battery technologies for both high power density and high energy density. In this paper, we have conducted vehicle level study and modeling to quantify the benefit of bi-directional DC-DC converter in dual battery systems for commercial heavy duty vehicles. The goal of this study is to increase the overall efficiency and fuel economy of PHEV. The simulation results show that PHEV with two sets of battery packs and a DC-DC converter has better performance and higher overall efficiency over the conventional PHEV.
2011-09-13
Journal Article
2011-01-2249
Ho Teng, Yue Ma, Kim Yeow, Marina Thelliez
Ideal operation temperatures for Li-ion batteries fall in a narrow range from 20°C to 40°C. If the cell operation temperatures are too high, active materials in the cells may become thermally unstable. If the temperatures are too low, the resistance to lithium-ion transport in the cells may become very high, limiting the electrochemical reactions. Good battery thermal management is crucial to both the battery performance and life. Characteristics of various battery thermal management systems are reviewed. Analyses show that the advantages of direct and indirect air cooling systems are their simplicity and capability of cooling the cells in a battery pack at ambient temperatures up to 40°C. However, the disadvantages are their poor control of the cell-to-cell differential temperatures in the pack and their capability to dissipate high cell generations.
2011-09-13
Journal Article
2011-01-2248
Ho Teng, Yue Ma, Kim Yeow, Marina Thelliez
The temperature distribution is studied theoretically in a battery module stacked with 12 high-power Li-ion pouch cells. The module is cooled indirectly with ambient air through aluminum heat-sink plates or cooling plates sandwiched between each pair of cells in the module. Each of the cooling plates has an extended cooling fin exposed in the cooling air channel. The cell temperatures can be controlled by changing the air temperature and/or the heat transfer coefficient on the cooling fin surfaces by regulating the air flow rate. It is found that due to the high thermal conductivity and thermal diffusivity of the cooling plates, heat transfer of the cooling plate governs the cell temperature distribution by spreading the cell heat over the entire cell surface. Influence of thermal from the cooling fins is also simulated.
2011-09-13
Technical Paper
2011-01-2247
Mohammad Rezvani, Mohamed AbuAli PhD, Seungchul Lee, Jay Lee, Jun Ni PhD
Batteries are widely used as storage devices and they have recently gained popularity due to their increasing smaller sizes, lighter weights and greater energy densities. These characteristics also render them suitable for powering electric vehicles. However, a key gap exists in that batteries are solely used as storage devices with a lack of information flow. Next-generation battery technologies will constitute the enabling tools that would lead to information-rich batteries, thus allowing the transparent assessment of a battery's health as well as the prediction of a battery's remaining-useful-life (RUL) and its subsequent impact on vehicle mobility. Various methods and techniques have been employed to predict battery RUL in order to improve the accuracy of the State of Charge (SoC) estimation.
2011-04-12
Technical Paper
2011-01-0882
Douglas R. Martin, Edward Badillo
Power Split Hybrids are unique when compared to conventional powertrains from the perspective that the engine speed is directly controlled by the motor/generator at all times. Therefore, traditional methods of detecting variations in fuel volatility do not apply for Power Split Hybrid based configurations. In their place, the Ratio-metric Fuel Compensation (RFC) method has been developed for Power Split Hybrid generator configurations to detect and compensate for engine hesitations within milliseconds of the first injection event. Furthermore, test results have shown that in the presence of low volatility fuel, RFC provides robust starts at the ideal lean air fuel ratio required for PZEV emissions compliance.
1999-11-15
Technical Paper
1999-01-3757
Konghui Guo, Qing Liu
One of the most essential factors causing automobile and aircraft shimmy is energy import from road to tires due to tire hysteresis characteristic. The magnitudes and direction of the energy import are close to frequency responses of tire cornering properties (TCP), which can be calculated directly according to the presented non-steady state TCP theoretical model. Selfexcited shimmy is the main type of wheel shimmy and behaves as negative equivalent damping characteristic of the tire-road vibration subsystem. The values of energy import or equivalent damping determine the tendency of wheel shimmy. Tire structural parameters have certain effects on frequency response of TCP and thereby result in influences on wheel shimmy. Based on the tire model, some valid ways to decrease shimmy tendency are concluded through proper variations of carcass stiffness, tire-width, kingpin caster, tire pneumatic trail, tire cornering stiffness and so on.
1999-11-15
Technical Paper
1999-01-3749
Samy Karuppana
Most heavy-duty vehicles including trucks, tractors, buses, ambulances, refrigerated trailers, passenger vehicles, electric vehicles and boats have high amp Direct Current systems. Unlike the majority of components and systems in such vehicles, DC electrical systems have undergone very few major improvements in recent years. The Intelligent Power Management System discussed in this paper can offer significant improvements in the DC power management of such vehicles. The primary benefits of this system include: improved reliability of all electrical components, early warning of impending failures, extended service life, optimized generation, storage and use of power, and reduced maintenance cost and vehicle downtime. This paper will describe the Intelligent Power Management System, its design, applications and benefits.
2004-10-26
Technical Paper
2004-01-2615
Michael Sevcovic, Jay Rotz
This paper describes the electrical system development for the headlight feature in an International High Performance Vehicle. Systems engineers developed several iterations of functional requirements, functional block diagrams, state diagrams, and body controller software requirements early in the development cycle at considerable engineering expense. The hardware design team found the functional block diagrams useful, however the software design team did not find the other artifacts useful. The software design teams chose to implement a design that was very similar to a current product offering and did not map to the system proposed by the systems engineering team. This paper provides examples of the Systems Engineering artifacts and shows when they were developed in the project timeline.
2012-09-24
Technical Paper
2012-01-2061
Gergis W. William, Samir Shoukry, Jacky Prucz
The hydrogen economy envisioned in the future requires safe and efficient means of storing hydrogen fuel for either use on-board vehicles, delivery on mobile transportation systems or high-volume storage in stationary systems. The main emphasis of this work is placed on the high -pressure storing of gaseous hydrogen on-board vehicles. As a result of its very low density, hydrogen gas has to be stored under very high pressure, ranging from 350 to 700 bars for current systems, in order to achieve practical levels of energy density in terms of the amount of energy that can be stored in a tank of a given volume. This paper presents 3D finite element analysis performed for a composite cylindrical tank made of 6061-aluminum liner overwrapped with carbon fibers subjected to a burst internal pressure of 1610 bars. As the service pressure expected in these tanks is 700 bars, a factor of safety of 2.3 is kept the same for all designs.
2012-09-24
Technical Paper
2012-01-2018
He Changming
The nonuniformity property of the temperature field distribution will not only affect on the battery charging and discharging performance but also its lifetime. In this paper the elementary structural design is implemented for Ni-Mh battery package and the corresponding test platform is constructed from the point of view of temperature difference control strategy, the test results show that the present structural design schemes can effectively restrain temperature difference enlargement among the battery stacks. Through the application of adopting the flow field uniformity method to control temperature difference, and flow field optimization inside the battery package, it is found that the flow field velocity change quantity ΔV is gradually reduced as the increase of the afflux hood angle Ak and air vent width Da, and the difference of battery temperature is relatively lower, which denoting that the corresponding relationship can be created based on test data.
2012-09-24
Journal Article
2012-01-2017
Ho Teng, Kim Yeow
Battery packs for plug-in hybrid electrical vehicle (PHEV) applications can be characterized as high-capacity and high-power packs. For PHEV battery packs, their power and electrical-energy capacities are determined by the range of the electrical-energy-driven operation and the required vehicle drive power. PHEV packs often employ high-power lithium-ion (Li-ion) pouch cells with large cell capacity in order to achieve high packing efficiency. Lithium-ion battery packs for PHEV applications generally have a 96SnP configuration, where S is for cells in series, P is for cells in parallel, and n = 1, 2 or 3. Two PHEV battery packs with 355V nominal voltage and 25-kWh nominal energy capacity are studied. The first pack is assembled with 96 70Ah high-power Li-ion pouch cells in 96S1P configuration. The second pack is assembled with 192 35Ah high-power Li-ion pouch cells in 96S2P configuration.
2012-09-24
Technical Paper
2012-01-2019
Enders Dickinson, Philippe Westreich, Vani Dantam
As fuel costs and anti-idling legislation become more prevalent, the life cycle cost of the energy storage component of no-idle systems is becoming a critical consideration. Current systems employ up to four AGM lead-acid batteries, with a one year standard warranty. OEMs have reported higher than acceptable warranty claim levels and are interested in examining the potential advantages of alternative storage technologies. The use lead-carbon asymmetric hybrid battery/supercapacitor energy storage in the no-idle system application is examined through modified SAE J2185 cycle testing and other means - as these battery products have significantly improved rechargeability (charge acceptance) and longer life (up to 4x higher cycle life in deep cycle applications). The performance improvement is expected to provide shorter recharge times and reduced warranty claims. The technology could potentially offer means to a lower capacity alternator, thus reducing cost.
2016-09-27
Technical Paper
2016-01-8096
Ilya A. Kulikov, Alexander Shorin, Sergey Bakhmutov, Alexey Terenchenko, Kirill Karpukhin
Abstract The paper proposes a method to analyze a trade-off between IC engine and electric battery sizes which is the essential issue of plugin hybrid and range extended electric vehicle design. This method implies a set of maps to be elaborated from batch simulations of hybrid vehicle running a driving cycle. Said maps establish relationships between ICE power, fuel consumption, electric energy consumption, and driving range of a vehicle. From these, one can choose a combination of ICE power and battery energy content meeting specific requirements for fuel economy and driving range. Mathematical model of the vehicle and the hybrid powertrain adopted for driving cycle simulations is described. Besides vehicle dynamics and drivetrain’s powerflows, it addresses battery’s current and voltage restrictions, which define performance of an electric drivetrain and have to be taken into account when selecting ICE power.
2015-09-29
Technical Paper
2015-01-2849
Hariharan Venkitachalam, Axel Schlosser, Johannes Richenhagen, Mirco Küpper, Thomas Tasky
Abstract Electrification is a key enabler to reduce emissions levels and noise in commercial vehicles. With electrification, Batteries are being used in commercial hybrid vehicles like city buses and trucks for kinetic energy recovery, boosting and electric driving. A battery management system monitors and controls multiple components of a battery system like cells, relays, sensors, actuators and high voltage loads to optimize the performance of a battery system. This paper deals with the development of modular control architecture for battery management systems in commercial vehicles. The key technical challenges for software development in commercial vehicles are growing complexity, rising number of functional requirements, safety, variant diversity, software quality requirements and reduced development costs. Software architecture is critical to handle some of these challenges early in the development process.
2015-09-29
Technical Paper
2015-01-2845
Qi Chen
Abstract Recent years have witnessed an increase in the number of electrical loads being driven by semiconductor devices in the body control module (or BCM) rather than by electro-mechanical relays in a typical truck with a 24V vehicle power net. This paper presents the major challenges caused by the higher voltage class of the truck supply and the longer wire harness cables, followed by an analysis of some key issues related to the design of truck BCMs to drive different loads. It offers some general guidance on practical design issues to BCM designers, such as an understanding of the advantages and disadvantages of different BCM architectural topologies, how to make a choice between a relay or a semiconductor driver, knowledge of the requirements of semiconductors used in truck applications etc.
2015-01-14
Technical Paper
2015-26-0042
Suresh Kumar Gurusamy, Chandrasekar Rajagopalan, R Sateesh Kumar, B Ashok
Abstract In present commercial vehicles, the cranking torque required for a heavy duty compression ignition engine is very high. This results in higher durability and reliability requirement of cranking system components and also makes it cumbersome to implement start-stop micro hybrid feature which requires more number of cranking cycles in lifetime. Hence higher capacity starter motor and battery is being used for implementing start-stop feature. However this would result in cost and packaging issues. In order to implement start-stop feature maintaining the same starter motor and battery capacity, the cranking energy demand of the engine needs to be reduced. Studies conducted shows that the major source of breakaway torque is the work done in compression stroke during a starting cycle.
2015-09-29
Technical Paper
2015-01-2855
Massimiliano Ruggeri, Giorgio Massarotti, Pietro Marani, Carlo Ferraresi
Abstract Losses reduction and oil flow optimization management in construction machines and, in general, in heavy duty vehicles are two of the most challenging missions of today fluid power research. One of the most promising ideas is to implement multiple hydraulic power sources but this requires a flexible pump switch system; in fact, depending on flow request and machine mode, one or more pumps can be switched to serve each actuator. To put into practice these concepts it is necessary to in-depth design the distribution system, through which hydrostatic transmissions supply the different loads. The new component here presented realizes the pump switch management, creating a matrix framework of the hydraulic flow connections. Putting this concept it into practice the new architecture is able to connect alternatively a pump to one actuator at a time providing also for cross connections, enabling different sources flow summation.
2016-09-27
Technical Paper
2016-01-8071
Igor Gritsuk, Vladimir Volkov, Yurii Gutarevych, Vasyl Mateichyk, Valeriy Verbovskiy
Abstract The article discusses the use of the combined heating system with phase-transitional thermal accumulator. The peculiarity of the presented system is that it uses thermal energy of exhaust gas, coolant and motor oil, and emissions of the internal combustion engine during its operation to accumulate the thermal energy. The results of experimental studies of the combined heating system are shown. A system and methods for pre-start and after-start heating of the vehicular engine in the investigated system are developed. The structure of the "combined heating” system to study the impact of its structural and adjustment parameters on the performance of thermal development of the vehicular engine is described. The use of the combined heating system within phase-transitional thermal accumulators is compared with the use of standard systems for a truck engine 8FS 9.2 / 8. It reduces the time of coolant and motor oil thermal development by 22.9-57.5% and 25-57% accordingly.
2016-04-05
Technical Paper
2016-01-1289
Francis Assadian, Kevin R. Mallon, Bo Fu
Abstract Heavy-duty electric powertrains provide a potential solution to the high emissions and low fuel economy of trucks, buses, and other heavy-duty vehicles. However, the high-capacity batteries needed to power these vehicles are both cost and weight prohibitive. One possible method of supplementing battery power is to mount flexible solar panel modules to the roof of these vehicles, thereby allowing for a smaller battery (reducing battery cost and weight) or extended vehicle range. Electric buses identified as the type of vehicle that would derive the most benefit from roof-mounted solar panels due to their low operating speed (including frequent idling) and large available surface area. In this paper, the performance of an electric bus with combined battery and photovoltaic power sources is simulated on the Orange County Bus Cycle for average weather in Davis, CA.
2016-10-25
Technical Paper
2016-36-0159
Mauro Iurk Rocha, Ivna Oliveira da Cruz, Maria Clara Kremer Faller, Antônio Carlos Scardini Villela, Sergio Roberto Amaral, Frederico Braz Silva, Sillas Oliva Filho
Abstract Vehicles manufacturers, in search of cost reduction, fill the tanks of recently manufactured vehicles with the least volume of fuel necessary for future commercialization. The adoption of such practice, depending on the diesel fuel storage conditions, may lead to oxidation products formation in the fuel system and to problems during the first start of these vehicles. Some vehicles manufacturers, trying to minimize the occurrence of these problems, replace the diesel fuel in the vehicle tank with new fuel when vehicle storage time reaches 90 days. As a result of such occurrences, the opportunity for a first fill diesel fuel development, that presented better oxidation stability during storage, was identified.
2016-10-25
Technical Paper
2016-36-0176
Fábio Coelho Barbosa
Abstract Environmental concerns and limited fossil fuels reserves have fostered an increased interest in alternative propulsion systems. In this scenario, electric traction, with its inherent zero local emissions, high efficiency and improved operational performance (acceleration and hill climbing potential), emerges as a desired option for public transport systems. Transit buses, the prevailing transport system in cities, and, hence, strong contributors to traffic environmental impact on urban areas, can reduce considerably their environment burden with the use of electric traction. This means less local pollutants, specially particulate matter - PM and nitrogen oxides - NOx, currently the “Achilles heel” of diesel engines, as well as CO2 greenhouse emissions - GHG.
1949-01-01
Technical Paper
490197
L. C. WOLCOTT
ALTHOUGH the wiring systems of trucks are relatively simple and rather accessible for repair and replacement, the author explains that the amount of wire used on buses is much larger and, furthermore, the wires have to run all over the vehicle, thus becoming an inseparable component of the bus. Wires could be readily replaced if conduits and junction boxes were used but, the author says, their cost would be prohibitive. Rather, he looks to the use of insulating materials having longer life, which would give trouble-free wiring systems at a reasonable cost.
2005-11-01
Technical Paper
2005-01-3638
Stéphane Bilodeau
In severe - hot and humid - climates, Vehicles Air Conditioning Systems (AC systems) in use today suffers from a lack of performance and on a difficulty to efficiently meet the cooling load without causing a significant reduction in the performance of the internal combustion engine. This is especially true in applications where vehicles have long idling period and a lot of passengers, such as buses and passenger shuttles. An integrated cooling system has been implemented and tested in an Airport Passenger shuttle in order to improve fuel economy and cooling effectiveness in severe environment (up to 120 °F). The cooling system integrates a high-efficiency thermal storage technology (based on phase change materials) coupled to high performance compressors. Comprehensive performance analyses and testing of the high-performance system have highlighted many benefits of using the technology in such applications.
2005-11-01
Technical Paper
2005-01-3616
Nabil Hammad, Sameh. M. Metwalley, A. M. A. A. Abou-El-Nour, Shawki A. Abouel-Seoud
Reduction of alternator noise has become an increasingly important task in automotive industry as requirements for passenger compartment comfort increase, and other components such as the engine, exhaust system, etc. are made quieter. However, the aim of this study is to identify the noise sources of a numbers of alternator bands and to develop design guidelines to reduce the overall noise levels sacrificing the specified performance. With these guidelines, design engineers can reduce alternator noise effectively. To identify mechanical, aerodynamic and electromagnetic noise generation mechanisms, the alternator was reconfigured in many different ways, so as to separate each individual noise source. Noise generated by each configuration running at different speeds was measured, and its characteristics were analyzed. A special test stand was designed and fabricated, and tests were conducted in the automotive laboratory.
2009-05-13
Technical Paper
2009-01-1616
Dirk Adolph, Thorsten Schnorbus, Thomas Körfer, Oliver Hild, Ludger Ruhkamp, Matthias Lamping, Michael Lincks, Rene Linssen
The future worldwide emission regulations will request a drastic decrease of Diesel engine tailpipe emissions. Depending on the planned application and the real official regulations, a further strong decrease of engine out emissions is necessary, even though the utilized exhaust after-treatment systems are very powerful. To reduce NOx emissions internally, the external exhaust gas recirculation (EGR) is known as the most effective way. Due to the continuously increasing requirements regarding specific power, dynamic behavior and low emissions, future air path systems have to fulfill higher requirements and, consequently, become more and more complex, e.g. arrangements with a 2-stage turbo charging or 2-stage EGR system with different stages of cooling performance.
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