Browse Topic: Bus systems

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Factors Affecting the Willingness to Use Automated Buses: A Survey from China2020-01-514112/30/2020
With the development of autonomous driving technology, automated buses have begun trial operations in many cities around the world, and marketization has become an important issue. In order to explore the influencing factors of the public's willingness to use automated buses, two rounds of surveys were conducted. Firstly, the importance of the attributes of automated buses was studied, based on which questionnaires on willingness to use automated buses were designed. Using data from 266 questionnaires collected, a logistic regression model was established. Model results show that demographic variables and historical travel behavior characteristics will have a significant impact. Women are less willing to choose automated buses than men, and older people aged above 50 are more likely to use the mode. People who often use regular buses to travel have higher willingness to choose automated buses than people using other modes. Among people using other modes including private cars, subways
Xi, Haijiao, Wu, Zhongyi, Zhou, Hongmei, Yi, Maomao
Variability of driving conditions and its effect on charging time for urban battery electric buses2020-01-059804/14/2020
Due to growing environmental concerns and stringent vehicle emissions regulations, there is a constant urge in the automotive industry to move towards electrified propulsion systems. Public transportation plays a major role in contributing towards lowering the emission level. Battery electric buses are regarded as a type of promising green mass transportation as they provide the advantage of less greenhouse gas emissions per passenger. However, the electric bus poses a threat of limited range and is not able to drive throughout the day without being charged again. This research focuses on the current bus transit systems in the city of Ann Arbor and investigates the impact of different electrification levels on the final CO2 reduction. Utilizing models of a conventional diesel bus, hybrid electric bus, and battery electric bus, the CO2 emission for each type of transportation bus is estimated. Measured vehicle speed data from various routes under different driving conditions are used to
Paunikar, Anshul, Salehi, Rasoul
Hydrogen Fuel Cell Buses: Modelling and Analysing Suitability from an Operational and Environmental Perspective2020-01-117204/14/2020
In response to the need to decrease greenhouse gas emissions, the current trend in the transport sector is a greater focus on alternative powertrains. More recent air quality concerns have seen controlled zero emission zones within urban areas. As a result, there is growing interest in hydrogen fuel cell electric buses (FCEBs) as a zero local emission vehicle with superior range, operational flexibility and refuelling time than other clean alternatives e.g. battery electric buses (BEBs). This paper details the performance and suitability analysis of a proposed Wrightbus FCEB, using a quasistatic backwards-facing Simulink powertrain model. The model is validated against existing prototype vehicle data (Mk1), allowing it to be further leveraged for predictions of an advanced future production vehicle (Mk2) with next generation motors and fuel cell stack. The modelled outputs are used for a comparison of the FCEB performance to an equivalent BEB on industry standard drive cycles, as well
Doyle, Darryl, Harris, Andrew, Chege, Steve, Douglas, Lucinda, Early, Juliana, Best, Robert
Fiber Optics Mechanization of a Digital Time Division Command/Response Multiplex Data BusAS1773A (Current)03/14/2018
This document defines requirements for digital, command/ response time division multiplexing (data bus) techniques for fiber optic implementation. The concept of operation and information flow on the multiplex data bus and the functional formats to be employed are also defined.
AS-3 Fiber Optics and Applied Photonics Committee
Control Solutions Synchronize Operation of Space Launch System Heavy TransportersTBMG-2488806/01/2016
Control panels, embedded PCs, automation software, and servomotors and drives Beckhoff Automation Savage, MN 952-890-0000
Efficiency Improvement of Boost Converter for Fuel Cell Bus by Silicon Carbide Diodes2016-01-123404/05/2016
The adoption of silicon carbide (SiC) power semiconductors is regarded as a promising means of improving the fuel efficiency of all types of electrically powered vehicles, including plug-in, electric, fuel cell, and hybrid vehicles (PHVs, EVs, FCVs, and HVs). For this reason, adoption in a wide variety of vehicles is currently being studied, including in the fuel cell (FC) boost converter of an FC bus. The FC boost converter controls the output voltage of the FC up to 650 V. In this research, SiC Schottky barrier diodes (SiC-SBDs) were adopted in the upper arm of an FC boost converter. Since the forward voltage (Vf) of SiC-SBDs is smaller than conventional Si-PiN diodes (Si-PiNDs), the conduction loss of SiC-SBDs is correspondingly smaller. Recovery loss can also be reduced by at least 90% compared to Si-PiNDs since the recovery current of SiC-SBDs is substantially smaller. Lowering the recovery current of the upper arm has the effect of reducing the superimposed current when the
Sugiura, Toshikazu, Tanida, Atsushi, Tamura, Kazutaka
Tool to Analyze a Leaking Source of Saturated AmmoniaTBMG-2427004/01/2016
Containers of ammonia are used to supply cooling to different modules of the International Space Station. Each container has an attachment piece used to extract the ammonia. The attachment piece may allow ammonia to exit when not connected, and may also allow ammonia to exit to an outside area even when connected. The ammonia that has exited the container may accumulate in different compartments of the spacecraft. The ammonia is not desirable when accumulated in a compartment with a certain concentration.
Sensitivity Analysis of the Total Cost of Ownership for Electric Feeder Bus Using Various Types of Energy Storage2016-01-172103/27/2016
Urban Mobility is one of the most critical issues at the present. Public transport in connection with feeder bus system is proposed to be one of the main solution. Chulalongkorn University has a fleet of electric feeder bus in operation for a few years now. The fleet service is, however, to be improved because of current limitations in battery energy capacity and long battery charging time. This paper aims to examine the total cost of ownership (TCO) of the electric feeder buses using various types of energy storage. The results on the sensitivity analysis highlight the major parameters that exert strong influence in the TCOs. The fast charging system using supercapacitor battery bus shows the lowest TCO for the present bus fleet. The travel distance (km/year) and operational years were illustrated to be the top two parameters that exert major influence towards the TCO.
Nilprapunt, Wachira, Sripakagorn, Angkee
Electrification of Public Transport with Fast Charging in Traffic Congested Cities2016-01-171803/27/2016
The utility of energy efficiency and zero-emission of electric vehicles leads the way to electrify the urban public transport bus networks in many cities around the world. The purpose of this paper is to study the operational feasibility of transition the existing conventional combustion bus fleet to Electric bus fleet. The analysis is based on the data of the bus operation in Bangkok, Thailand. Traffic congestion as occurred in Bangkok is considered in the analysis. This research is focused on Fast charging technology of Electric vehicles. Instead of slow-charging overnight, Fast-charging is used during the regular layover time of the bus operation which is called Opportunity charging. The opportunity charging allows to extend the driving range of the electric buses which is a prominent problem of electric vehicles. The result stipulates the smallest number of batteries needed to meet the route requirement which come up with outstanding efficiency in energy consumption and more
Thitacharee, Thitipat, Sripakagorn, Angkee
Optimizing Drive Systems for Energy SavingsTBMG-2394602/01/2016
Energy savings are an extremely important topic in virtually every segment of industry today. In general, the largest consumer of power in a converting line or machine is the drive system. As energy costs continue to increase and energy conservation becomes a greater priority, are there technologies or methods that can be implemented to reduce the energy consumption on converting machinery?
Evaluation of Biogas Use in Transit Bus Fleets2015-36-022709/22/2015
Current massive urbanization process concentrates high amount of population and impose an increased demand on transport systems. In this context, transit bus system plays an important role, as the most dynamic and less capital intensive transit option available. At the same time, it is strongly dependant on fossil fuels, predominantly diesel fuel, with its intrinsic polluting and greenhouse (climate change) effects. This has boosted research and investments for alternative and renewable fuels. One solution currently receiving widespread recognition is biogas use in transit bus fleets, as it allows the use of a renewable fuel, made from substrates derived basically from waste and sewage that otherwise would produce methane released to the atmosphere. Biogas contains basically methane, carbon dioxide, trace amounts of hydrogen sulfides and water, and to be used as engine fuel need to be upgraded, which means increasing the methane content up to 97% and removing water and other gases
Barbosa, Fábio Coelho
Scoping the Human-Centred Design Led 2020 Vision for Malaysia Electric Buses (EV)2015-01-003103/10/2015
The Malaysia National Automotive Policy (NAP 2014) focuses on the systemic changes needed for the country to develop a competitive and sustainable automotive manufacturing sector. Alternative electric vehicles (EV) -including the public transport sector, in particular buses - forms part of this strategy. This also features in the Transport Scenarios for the Kuala Lumpur Structure Plan for 2020. Kuala Lumpur's population is expected to reach 10 million by 2020, the current public transport system is beset by problems, e.g. route congestion, a growing trend of private car ownership among a rising middle-class, and a range of environmental and infrastructure issues which must be challenged. A human-centred design approach to public transport focuses on developing (future) scenarios to accommodate the 2020 economic, environmental and social considerations building on Design for Sustainability (DfS), user needs, behaviour change and inclusivity principles. This provides a design framework
Kuys, Jung-Ok (Jo), Melles, Gavin, Thompson-Whiteside, Scott, Kapoor, Ajay
Virtualization Technology and Using Virtual CPU in the Context of ISO26262: The E-Gas Case Study2013-01-019604/08/2013
A new development environment is required where conflict between control systems is minimized, where processing can be executed while maintaining independence between systems, and where quality can be assured easily. This environment must enable flexibility in software layouts to accommodate software changes during the development process and the parallel development of multiple derivative systems. We have developed virtualization technology (virtual CPU), which allows the execution of system control with a single CPU without conflict between systems. An outstanding virtual CPU architecture that we have developed allows us to execute multiple real-time control tasks with the hardware scheduler, and we have developed hardware that extends the management of address space and interrupt handling, making it possible for a single CPU to be configured as multiple CPUs. Also, we have implemented a bus system that reduces interference between threads. By combining the above three technologies
Niimi, Yukihide, Ono, Takayuki, Arai, Soichiro, sugimoto, Hideki, Mariani, Riccardo
Hybrid Transit Bus Technology Assessment - A Feasibility Approach2012-36-013910/02/2012
Stricter environmental regulation and the increasing concern about fuel economy and emissions have driven transit agencies and operators toward environmental and economic concerns when selecting transit bus technology. In this scenario, hybrid bus, that combines two or more distinct propulsion systems (generally combustion engine and electric motor), has been seen as a choice that balances both the need for better environmental and efficiency performance and capital expenditures for introducing new technology-based transit bus fleets. The source of better performance of hybrid buses is the ability to i) optimize the operating point of combustion engine to achieve best fuel economy; ii) store energy generated during braking at storage devices (batteries, supercapacitors or flywheels), to be used to power the vehicle when needed, and, hence, iii) downsizing engine due to reduced average power requirements. Most significant gains in efficiency and environmental performance of hybrid
Barbosa, Fabio Coelho
Internet Protocol over Ethernet in Powertrain - Comparison with Current Applications and Future Trends2012-01-019504/16/2012
The increasing number of electronic control units (ECUs) in vehicles leads to more and more complex systems with a steadily growing demand for data exchange. This growth includes the number of bus participants, the amount of data and hence the data transfer rates. In addition, the trend towards car-to-x connectivity reinforces the need for new in-vehicle communication solutions. Since the early 1990s Controller Area Network (CAN) is the most widely used powertrain bus system. Since 2000 FlexRay is used in addition to CAN in the premium segment. For classic powertrain applications, the data transfer rates of these bus systems are sufficient; however the utilization is sometimes difficult and gateways are often required. For new applications like hybrid and electric vehicles and the next generation of external communication applications (e.g. telematics services) new concepts based on the existing bus systems or completely new solutions are needed. Looking outside of automotive business
Schneider, Stefan, Dang, Liem, Schlottmann, Eckart, Baque, Siegbert, Franke, Joern
Development of a City Bus Driving Cycle in Seoul Based on the Actual Patterns of Urban Bus Driving2009-01-291410/06/2009
Studies of driving cycles for buses have been published in a number of papers, e.g., the Central Business District (CBD) and New York Bus (NY Bus) driving cycles. Such studies, however, cannot represent the actual driving environment of Seoul because of differences in road conditions and the volume of traffic. Thus, this study presents the development of a driving cycle for the city bus system of Seoul, the capital city of Korea. A representative route is selected by means of a statistical analysis of the city bus routes in Seoul. Experiments are performed to measure velocity, road grade, engine speed, load conditions, gear-shift patterns, and vehicle acceleration in actual Seoul traffic. A simulation model is developed to evaluate a driving cycle on the basis of the measured data obtained. The coupling effect between velocity and acceleration is analyzed, as well as the coupling effect between road grade and vehicle acceleration. A driving cycle is then proposed based upon an analysis
Wi, Hyoseong, Park, Jinil, Lee, Jong-hwa, Kim, Wooseok, Kim, Yukyeom
Fiber Optics Mechanization of a Digital Time Division Command/Response Multiplex Data BusAS1773 (Historical)05/19/2008
This document defines requirements for digital, command/ response time division multiplexing (data bus) techniques for fiber optic implementation. The concept of operation and information flow on the multiplex data bus and the functional formats to be employed are also defined.
AS-3 Fiber Optics and Applied Photonics Committee
Using CompactPCI to Build Rugged Embedded SystemsTBMG-615002/29/2008
The task-specific nature of an embedded system application typically defines a narrow scope of performance requirements. But the range of options for achieving those requirements are broad — from multicore processors and rugged single board computers (SBCs) to I/O devices and the bus systems that tie everything together. And the choices to be made are critical in their impact on cost, on performance efficiency in computeintensive operations, and on the ability to function reliably in hot, cold, dusty or wet environments.
Buses and Networks for Contemporary Avionics2007-01-380109/17/2007
MIL-STD-1553 has served the needs of military system integrators for over 30 years, particularly in the area of command and control applications. Nevertheless, contemporary applications such as high-speed digitized sensors, file transfers, processor clusters, and displays require much higher data rates than 1553's 1 Mb/s. For some environments, particularly for legacy aircraft, the optimal solution is to transmit faster data rates over existing 1553 buses. However, there are other applications that can accommodate and benefit by the deployment of gigabit or multi-gigabit copper or optical switched fabric networks. In addition to MIL-STD-1553, this paper presents and comments about several avionics networking technologies including High-Speed 1553, Fibre Channel, Gigabit Ethernet, and ARINC 664, a form of profiled Ethernet.
Glass, Mike
Intelligent Automotive System Services Requirements, Architectures and Implementation Issues2004-21-004110/18/2004
The paper introduces an integrated view on the emerging domain of system services as important part of an automotive IT infrastructure. System services are essential to allow an adequate administration and reliable operation of complex automotive IT systems during production, operation or maintenance of a vehicle. System services are vehicle-wide services. They range from software installation and configuration services, safety and security services, system diagnosis services, communication, connectivity and network services, up to vehicle status or engergy management services. The paper will discuss requirements, architecture and implementation issues as well as organisational implications, based on lessons learned from a prototypical implementation at BMW Car IT GmbH.
Saad, Alexandre, Weinmann, Ulrich
Advanced Detection Systems for AFV Transit Vehicle Maintenance, Storage, & Fueling Facilities2002-01-308911/18/2002
As alternative-fueled vehicle (AFV) municipal transit bus systems continue to evolve and grow, the maintenance, storage and refueling facilities for AFV buses and vehicles will also require upgrade to ensure adequate and proper flammable vapor and fire detection systems are provided. The evolution of alternative-fuel engines, from diesel to natural gas to hydrogen, presents the facility fire protection engineer with a unique challenge: ensure that the facility and its contents are adequately protected against a potential variety of invisible, odorless fire risks. Proper application of modern flammable gas and optical flame detectors is a key consideration when designing a facility protection system intended to detect and prevent a devastating gas explosion and fire. This paper will provide an overview of AFV facility hazards, the optimum gas and flame detection technologies, and the benefits delivered by these new detection technologies.
Opheim, Dave
A 42V Inverter/Rectifier for ISA using Discrete Semiconductor Components2001-01-249708/20/2001
A demonstration inverter has been built to illustrate the feasibility of implementing an ISA inverter in a 42V automotive powernet using discrete semiconductor switches. The high current carrying capability of the package (300A) enables the component count to be reduced to a minimum of two per switch. For a 10kW inverter, the current carrying requirements of each switch is about 400A peak. With careful layout and design, this solution could be a viable alternative to a module solution, which typically would have the same FET component count.
Murray, Anthony F. J., Wood, Peter, Keskar, Neeraj, Chen, Jingdong, Guerra, Alberto
FlexRay - The Communication System for Advanced Automotive Control Systems2001-01-067603/05/2001
BMW, DaimlerChrysler, Motorola and Philips present their joint development activity related to the FlexRay communication system that is intended for distributed applications in vehicles. The designated applications for powertrain and chassis control place requirements in terms of availability, reliability and data bandwidth that cannot be met by any product currently available on the market under the testing conditions encountered in an automobile. A short look back on events so far is followed by a description of the protocol and its first implementation as an integrated circuit, as well as its incorporation into a complete tool environment.
Berwanger, Josef, Ebner, Christian, Schedl, Anton, Belschner, Ralf, Fluhrer, Sven, Lohrmann, Peter, Fuchs, Emmerich, Millinger, Dietmar, Sprachmann, Michael, Bogenberger, Florian, Hay, Gary, Krüger, Andreas, Rausch, Mathias, Budde, Wolfgang O., Fuhrmann, Peter, Mores, Robert
Car Multimedia Bus Development2000-01-306008/21/2000
The following paper will discuss the latest developments that are taking place in the automobile industry pertaining to the development of a high-speed data bus standard. By 2005, it is likely that we will see the introduction of numerous high-speed, real time multimedia applications proliferating into the vehicle. These applications will provide the car owner access to information, entertainment, communication, and safety as well as the Internet. These systems will also drive the need to have a high-speed data bus serving as a backbone for data traffic between different applications. Currently, the minimum bus speed being considered for such applications is 100 Mbps, which is suitable for transmitting a compressed video and audio data stream. Concerns about electromagnetic interference (EMI) and weight have driven the physical media requirement to be plastic optical fiber (POF). Worldwide working groups and consortiums have been attempting to achieve the goal of developing one high
Little, Brad, Desjarlais, Frank
A Novel Battery Chrager-Discharger of the Regulated-Peak-Power-Tracking-System1999-01-244508/02/1999
A novel battery charger/discharger converter for the series-parallel regulated peak-power-tracking system is proposed. This converter shares the common magnetic component in both the charger mode and the discharge mode to minimize the size and weight of the system. To reduce the number of the additional semiconductor component, a tapped-inductor topology is proposed and design procedures for the converter is presented. The hardware experiments of the proposed converter are presented. The software simulations for the various system mode of operation including the transition modes are performed
Cho, Y.J., Cho, B.H.
Potassium AMTEC Cell Performance1999-01-270208/02/1999
AMTEC systems have historically been operated with sodium as the working fluid, in large part because fabrication of beta”-alumina solid electrolyte (BASE) membranes has been substantially easier with sodium than with potassium or other alkali metals1. It has been anticipated that because potassium has a substantially higher vapor pressure for a given temperature, and because the best K-BASE conductivity falls only marginally below that for Na-BASE, potassium AMTEC cells could produce higher power at a given temperature or comparable power at a lower temperature than similar sodium cells. Operation at lower temperatures can reduce materials lifetime or compatibility problems, and for severely heat input constrained systems it could enhance efficiency by reducing parasitic thermal conduction losses. Recently K-BASE tubes have become available as a commercial product2 and conventional experiments to evaluate the performance of complete KAMTEC cells have become much more feasible
Barkan, A., Hunt, T. K., Thomas, B.
Bus System for Wiring Actuators of Restraint Systems97105302/24/1997
The continuing increase in the performance of restraint systems has led to a drastic increase in the number of actuator devices. The individual wiring of the igniters becomes more and more problematic through the accompanied large number of plug connections and cables. Along with demands for weight and volume reduction, there are requirements for EMI and short circuit protection to eliminate erroneous deployment and misuse. As a solution, a new multi-protocol dual wire bus system is described that has the capability to supply energy and address multiple peripheral output stages to simultaneously fire any combination of actuators.
Bauer, Joachim, Mehler, Gerhard, Nitschke, Werner
Rapid Bus Project96166508/01/1996
Rapid bus applies rapid transit thinking to bus operation. Designed to revitalize bus services, rapid bus is targeted at corridors where conventional bus service has reached saturation, while investment in high capacity rail transit cannot be justified for financial reasons. Rapid bus uses new technology and rail based marketing to grow ridership in medium density markets.
Leicester, Glen
The Development of the Interactive Pioneer Bus (IP-BUS)96012202/01/1996
The current trend towards the Multimediazation in the car cabin is remarkable. Adding to the existing car audio systems, Navigation, RBDS (Radio Brordecast Data System), DAB(Digital Audio Brordcasting), Cellular phone and other digital media are likely to be incorporated into the new car entertainment system, which shall also provide expandability for new media in the future. The recently proposed control bus systems are mainly designed for car operations which are not suitable for audio systems in terms of transfer rate, datalength, and cost. And the mainstream concept is that the audio control bus line should be separate from the standpoint of safety. However, there is still no standard car entertainment bus, car and car audio makers continue developing their own format. This causes over investment in development of audio systems, inefficiency of designing, and difficulty in cost reductions. We also have to consider cost merit for component units as a larger scale of car
Ikata, Yoshikatsu, Kurosaki, Masanori
The Next Decade: The Role of Russia in the Global Automotive Industry95278112/01/1995
Developed automotive nations reached the stage where any further growth of vehicle population is colliding with the interests of society. This problem can not be resolved through the effort of the automotive industry alone. The controlled development of transportation systems offers a trade-off between the adverse effects of vehicle population growth and meeting the demand of society in mobility. In Russia, the theory and the methodology of the land transportation development control has envolved in the seventies. An attempt has been undertaken at the Technical Center of VAZ to formulate the concept of the Next Generation Transportation System (NGTS). The main feature of this system is the limited urban motor vehicle population in combination with alternative kinds of transportation. This activity may be of interest to the world community.
Moskalyuk, Anatoly N., Kovalchuk, Anatoly V.
Robust Adaptive Data-Compression for Peak-Load Reduction in Low-Speed Automotive Multiplex Systems94165809/01/1994
The improvement of low-speed MUX-systems in car-body areas gets important in a scenario where on one hand, the possible number of integrated local control units (LCU's) gets larger and on the other hand, the possible versions of a car range from basic to top-of-the-line. Cost and developement time can be reduced if the same MUX-System is used throughout this whole range. A possibility to realize this is the use of data-compression (DC) for data-transmission. Basic configurations integrating only a small number of LCU's of a car-MUX can communicate without using data-compression, whereas for the top-of-the-line versions, the performance can be enhanced using DC only for communication processes between additional control units causing critical peak load situations. Specifically, the use of adaptive algorithms in automotive multiplex systems is a promising way to improve the MUX's capacity performance by minimizing redundant symbols/information in peak-load situations. The main problem in
Kempf, Gero G., Strenzl, Karl
Using Proven Advanced Wiring Techniques to Make a Smart Transit Bus an Operational Reality93296611/01/1993
The purpose of this paper is to document the development of the Los Angeles County Metropolitan Transportation Authority's (MTA) “SMART” Bus Program that uses a distributed computer network as a electronic control system. Current bus wiring methods use an ever increasing multitude of mechanical relays, circuit breakers, and heavy wiring bundles which provide little communication between electronic subsystems. On October 20, 1992, the MTA's first SMART vehicle, a 1984 Neoplan bus, was completed. In early 1993, the two additional buses were selected for modification; the first methanol SMART bus, a 1993 TMC, and a 1989 Flxible Metro bus. The Neoplan represents the first known “SMART” mass transit vehicle released into service. As of the first week in June 1993, the Neoplan bus continues to accumulate revenue service mileage. The TMC bus was completed in April 1993 and is now undergoing extensive road testing. The Flxible bus is in the early stages of design and modification and is
Haynes, Skip, Banks, Dave, Beauchamp, Mark, Grabowski, Joe, Johnson, Jeff
Urban Transportation Development in the Developing Countries93192711/01/1993
In developing countries with large populations and the demand for environmental protection, there is a need for the urban traffic development. These countries could implement Mass Transit, develop less polluting power sources, restrict the production of passenger cars and motorcycles and promote legislation for emission systems.
Choh, Octa, Zhu, Lulu J.
Rapid Traffic System - Preliminary Study For A Ground Transport System93170310/01/1993
This paper summarizes a preliminary study of some alternatives for construction of Rapid Transit System - RTS. For studies approach it was considered an area in the Vale do Paraiba particularly the São José dos Campos City and Jacareí Town. The final conclusion includes a proposal for implementation on the Urban Passengers Transportation System on this zone. The proposal is based on the success of “Step by Step” Program with immediate introduction of Guided Buses and/or Guided Trolley buses. With evolution of urban growing the system can be converted to a Light Rail Vehicle System.
Franco, Odilon C., Dias, Joaquim A. P., Greca, Ronaldo M.
A Status Report on South Coast Air Quality Management District Alternative Fuels Demonstrations93183308/01/1993
The Technology Advancement program at the South Coast Air Quality Management District was established in 1989. A number of demonstrations of the use of alternative fuels in light-, medium- and heavy-duty vehicles have been initiated since that time. The results of completed demonstrations will be reported, along with the status of current projects and plans for future activities.
Sullivan, Cindy, Leonard, Jon
The Evolution of Bus Design - A European Perspective92160108/01/1992
For the 1992 SAE/I.Mech.E. exchange lecture, the Chairman of the Automobile Division of the Institution of Mechanical Engineers reviews the background to the major evolutions in bus design in Europe over the past decade or so. This includes a review of the bus and its environment, together with the effect of legislation. An overview of European bus operations is included, with comments on the climate of change within the industry in Great Britain. Trends in bus production levels in Europe are also examined. Considered in the bus design evolution are: the changing nature of vehicle configurations with a movement towards low floor one step entry products, changes in engine design to achieve diesel exhaust emission standards, and innovations in transmission design yielding benefits in fuel economy and improved foundation brake life. Views are expressed on future design needs, including alternative fuels and vehicle electrics. The progress towards a European bus is reviewed.
McKnight, James
Guideway Bus in Practical Use - Seeking for a Pleasant Car Society92156208/01/1992
Japan is the largest automobile producing nation in the world, and its automobile holding has been ranked at the second place, next to the United States (U.S.). The automotive vehicle population has dramatically increased, and it has created overcrowded-situations in urban areas. An increased number of highways has somewhat improved the traffic conditions. However, a deterioration of transportation efficiency has caused poor fuel economy and air quality and it has caused serious concern for the human life in Japanese cities from the perspectives of energy conservation and environmental safety. The Guideway Bus System has been developed as an alternative transportation system to solve the Japanese urban traffic problem. The system reduces the number of cars in the city and retains the convenience of bus transportation systems currently being used in most cities in Japan. The guideway bus system uses a hybrid powerplant consisting of a diesel engine and an electric motor. The system is
Ariga, Hajime
Optimization of Urban Public Transportation Systems for Engergy Conservation91174409/01/1991
Herzog, Claus, Derderian, Philip
Development of the Small-Size CD Changer90004202/01/1990
While the market acceptance and the demand for car CD players is growing, the CD Changer has very high potential for automotive use because of its easy handling by the driver. This paper describes the analysis of the market, the creation of the product concept, the technical themes for the development, and the result. As technical themes, we focused on miniaturization of the mechanism and vibration performance.
Suzuki, Shoji, Hamazaki, Hank
The Guideway Bus System At the Asian-Pacific Exposition: Fukuoka 8989131211/01/1989
The Guideway Bus (GB) system is a kind of guideway transit system using conventional buses fitted with mechanical guidance equipment. This paper presents a general overview of the GB at the Asian-Pacific Exposition: FUKUOKA '89. This is the first commercial application under license of the Japanese authorities. This system consists of 4 vehicles, 4 stations, a 900 m long double-track guideway with only a single-track section between intermediate stations, a control center, and a maintenance yard. It is capable of carrying 975 pass./h/direction at the minimum headway of 4 minutes. The vehicles are diesel-engine buses, on which the driver operates both brake and accelerator, but does not steer the wheel except for driving in the yard. A vehicle protection subsystem has been developed for avoiding collision or deadlock on the single-track. In order to insure safe passage through the merge and demerge zones at either end of the single- track, an on-board switching subsystem, controlled in
Matsumoto, Norio, Fukumoto, Yozo
Conceptual Design of the Space Station Polar Platform Thermal Control Subsystem89146107/01/1989
NASA's Space Station Freedom Program encompasses unmanned polar-orbiting platforms (POPs) in low-earth orbit (LEO) designed to support a variety of scientific and earth-observation missions. The platforms are modular in design, permitting in-orbit maintenance and replacement of limited-life subsystem and payload components. Such in-orbit servicing can extend the platform's useful life to 15 years or more, far exceeding that of a typical LEO spacecraft. The long life and modular design has forced a new approach to thermal control subsystem (TCS) design. The platform's TCS must be readily adaptable to, and compatible with, the physical reconfiguration and resultant heat load changes. NASA has, in fact, identified thermal management as a critical factor in the overall platform design. A dual approach was used for the current polar platform TCS design. Platform thermal control is maintained using a distributed network of heat pipe panels, while payload thermal control is maintained via a
Bond, H. E., Benko, D. J., Chalmers, D. R., Pergament, S. D.
A Multiplex Protocol for Medium Scale Systems89054302/01/1989
For a self-running decentralized bus network, the CSMA-CD (Collision Detection) approach has been suggested, however one of the drawbacks with such an approach is the high cost incurred due to the large amount of hardware required for implementation. We have investigated a medium scale system utilizing Collision Avoidance CSMA transmission method. Evaluation boards were then constructed and tested. With 16 nodes operating at 62.5Kbaud, it was confirmed that for each node transmitting 2 bytes of data, an access time of approximately 17ms was achievable. Furthermore, we have considered the effects of EMC when equipped within a wiring harness.
Nagasawa, Kazumi, Uda, Makoto
Investigations Into The Electromagnetic Compatibility And Performance Evaluation Of Databus Systems In Motor Vehicles88508309/01/1988
Databus systems in motor vehicles allow communication between electronic control devices. Among the factors of particular interest for the development of a bus system are electromagnetic compatibility (EMC) and, especially for realtime applications, performance. This paper deals with EMC measurements conducted on a bus system for multiplex applications which is currently undergoing testing at Daimler-Benz. The second half of the paper presents a comparison of performance of ABUS and CAN data-bus protocols, these being well suited for controlling time-critical operations, in respect of data rate, bus access time, bit error probability and message priority.
Dudeck, Ingo, Hipp, Ulrich, Raith, Thomas
LCD for Automotive Instrumentation88022202/01/1988
Liquid crystal displays combine a multitude of desirable display characteristics for the automobile dashboard. Rapidly advancing technology in displays, packaging and electronics is making LCD ever more attractive to the instrumentation designer. This paper describes areas of LCD development relevant to automotive application at Philips.
Fenger, Carl
Hybrid MIL-STD-1553B/1773 Electrical/Optical Buses87248210/01/1987
Hybrid buses, which use MIL-STD-1553B transmission on wire cable as well as DOD-STD-1773 transmission on fiber optic cable, are relatively easy to implement because of the similarity of the two standards. There are a number of applications where the use of a hybrid bus offers significant advantages. Some examples are where a cable passes through a high electromagnetic interference area, the cable passes through an area where the fire or explosion hazard needs to be reduced, or long cable runs are required. This paper describes a number of possible hybrid bus configurations and test results are given on two hybrid buses which were designed, built, and tested. The hybrid buses utilized gateway circuits which provide the interface required for bidirectional transmission of signals between a MIL-STD-1553B bus and a DOD-STD-1773 bus.
Briscoe, William G.
Advanced MIL-STD-1553 UHF/WHF Radio86084004/24/1986
The paper describes an advanced MIL-STD-1553-controlled UHF/VHF radio. In previous UHF/VHF radio subsystems, each UHF/VHF radio had a dedicated control head which stored and controlled all radio modes and data. In an advanced architecture, independent multipurpose data entry units are used to control any number of radios, simultaneously, with the aid of a bus control-processor as a data base and mode command controller for the radios and display units. To integrate the system properly, the bus control-processor must have dynamic control of each radio's modes and provide the data to generate each of the display unit's data formats. Processors with advanced software can reconfigure radio parameters to circumvent failures, and also generate valid command modes when receiving conflicting data from the independent data entry unit or associated data inputs. The processor can also determine which antenna is best suited for communication in any particular phase of the mission, primarily useful
Christiano, Paul F.
Development for a Future Bus Transport System84168811/01/1984
A general survey on the bus transport system shows the direction and the necessity of further developments. The components especially considered are the vehicle size (from small buses to double-articulated high-capacity buses), the vehicle drive (diesel, dual power, electric, methanol, gases, energy recovery) and guiding systems (mechanically and electronic track guided buses). Most of the development components are available.
Drewitz, Hans, Hipp, Eberhard
Digital Flight Control System EMI/EMP Testing-Lessons Learned83141110/03/1983
A laboratory test facility has been developed to apply full-scale lightning and EMP fields to safety-critical digital flight control systems early in the development process. Such testing enables relatively low-cost evaluation of system susceptibility, allows in-depth study of the effects of disturbances, and provides essential feedback to system engineers attempting to harden the design. Results indicate that: ○ Proper design practice results in systems that can tolerate fields associated with lightning strikes or EMP to levels projected within a metal-skinned aircraft. ○ Lightning/EMP tests do uncover design faults and are of value early in the development process. ○ Optical data bus mechanization outperformed a conventional wire bus in high-level transient fields, as expected.
Bailey, D. G., Graves, G. L.
Recent Activities of the APTA Bus Technology liaison Board83118708/08/1983
The American Public Transit Association (APTA) supports the Bus Technology Liaison Board (BTLB) under contract to the Urban Mass Transportation Administration (UMTA) of the U.S. Department of Transportation. The function of the Board is to provide the transit industry's viewpoint and advice in the form of reviews and evaluations of UMTA's bus and paratransit technology projects. Recent activities of the BTLB related to product improvements, regulations, and procurement policies in the urban transit bus industry are examined.
Cihak, Frank J., Jones, Patrick D.
Chrome Plating Simplified: The Two Bus Bar System83068502/01/1983
We will be discussing the age of the two bar hard chrome plating system and comparing the time and work produced using the two bar system versus the three bar system. In concluding, we hope to bring out the advantages of work produced, amount of space needed in a shop, quantity of power sources needed and the overall savings to a company by replacing the three bar hard chrome plating system with the two bar system.
Doshier, J. W.
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