Browse Topic: Public transportation systems

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Augusta Regional Airport Preparation for Transformative VTOL Air Vehicle OperationsF-0081-2025-01325/20/2025
The emergence of electric Vertical Takeoff and Landing (eVTOL) air vehicles is transforming how people and freight are moved in short distances. This transformation has a profound impact on surrounding infrastructure necessary to provide Aircraft On Ground support for eVTOLs. The hover capabilities of eVTOLs have similar operating characteristics within terminal and uncontrolled airspace. However, the need to conserve battery energy via rapid approaches and departures affects terminal airspace management. To attract eVTOL operators, existing airports, landing zones, and vertiports are modifying their infrastructure to include fixed electric charging stations, additional taxiways, upgraded fire suppression systems, separate hangers, and capable MRO facilities. Augusta Regional Airport (KAGS) is the base airport for the annual Masters Golf Tournament which experiences five times the normal airport traffic and some 40,000 commuting patrons. eVTOLs can offset land traffic issues associated with commuters and supplies. Since KAGS is centroid to 32,000 square miles of territory void of major highways, basing eVTOLs can offer expedited transit services for people and goods which will have a profound impact on the economic viability and quality of life in the area.
Stanzione, Kaydon, Johnston, Diane
Roll Take-Off Model for Tiltrotor Preliminary DesignF-0081-2025-02455/20/2025
In the last years, new rotorcraft configurations have increased the attention among industries, through which the tiltrotor one due to its capability of combining both rotorcraft and aircraft advantages. However, there are situations where the vertical take-off mode could be enhanced in hard environmental and flight conditions. Therefore, to address this challenge, this work aims to develop a methodology to characterize a roll take-off model for a general tiltrotor configuration in such situations. By combining the integration of the equation of motion and geometrical assumptions, the runway distance is determined for an acceptable range of nacelle tilting angles. The process is developed by meeting the requirements defined by the regulations, combining the aircraft certification standards (CS23 and CS25) with the available tiltrotor certification basis from the FAA project #TC3419RC-R. Following the Nominal application, a sensitivity analysis is carried out, which studies the main effects on the results by varying one variable at a time in terms of weight, wing-loading, and disk-loading.
Passarelli D'Onofrio, Anna Sofia, Pecoraro, Matteo
History and Future of VTOL Air FreightF-0080-2024-13775/7/2024
Transporting cargo has been a goal of helicopter operations since the earliest days of development. The concept of carrying passengers and cargo from and to remote locations without a runway was originally exploited by the US military in times of peace and war. Early helicopter designs were limited in fixed useful load after onboarding crew and fuel. The 1940's saw helicopters transporting small, lightweight packages on an as-needed basis. The decade of the 1960's started seeing heavy lift helicopters transporting specialty loads in construction and logistics supply, again on an as-needed basis. Today, several Part 135 helicopter operators offer as needed VTOL cargo services. Blade Air Mobility has developed a successful public company business model in Part 135 passenger transport and is also expanding in carrying parcels. With the advent of transformative VTOL air vehicle designs, there has been increasing emphasis on examining parcel delivery on a regular basis. As omni-channel ecommerce drives the ever-increasing need for same day delivery post order. Retails and distributors need to compete with big box retailers and warehouse companies such as Walmart and Amazon, respectively. This results in reducing or eliminating over-the-road transport delivery. The future of parcel and cargo distribution is proposed to be with VTOL air vehicles. To understand the future of such distribution, it is imperative to examine the development of helicopter size, performance, and operational uses.
Stanzione, Kaydon, Schrage, Daniel
An Airport & Vertiport/Aircraft Compatibility Approach of Electric Vertical Takeoff & Landing Aircraft DesignF-0079-2023-180605/16/2023
ABSTRACT
Bris, Gaël, Nguyen, Loup-Giang
Safety Considerations on the Operation of Electric Vertical and Takeoff Landing (VTOL) Aircraft at Airports and VertiportsF-0078-2022-176105/10/2022
ABSTRACT
Bris, Gaël, Nguyen,  Loup-Giang
Carbon Neutrality, Reduction and Offset-Aviation Solutions in the 21st Century2021-01-00393/2/2021
Begun in 2016, the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) was developed and agreed by International Civil Aviation Organization (ICAO) 191 Member States, while the Airport Carbon Accreditation was developed by the Airports, Council International Europe as a carbon management system and certification. The aviation industry has its own offsetting scheme to measure aviation emissions and carbon offsetting and it has become the first industry sector which leads the world making commitments to reduce emissions. CORSIA and the Airport Carbon Accreditation are programs that impose carbon management obligations on the aviation industry. The training product to be presented, will clarify for the first time how to go beyond mere compliance and exceed the carbon reduction requirements of these instruments by achieving carbon neutrality in operations, to decrease costs, boost revenue, productivity and customer experience for airlines, airports and ground service providers. The methodology that will be explained for achieving carbon neutrality involves gains in operational efficiency and the use of sustainable aviation fuels (SAFs) to reduce carbon in operations, and investment in reforestation and conservation projects (forest carbon credits) to offset emissions. Innovative practices and benefits of communicating with customers and the public about carbon neutral goals, milestones and achievements will be shared and explained. This training will describe how carbon neutrality when done right decreases operational costs, reduces health and safety risks, lowers environmental risks, and generates new revenue and sales through brand trust, customer loyalty and revenue science. For the very first time, tools, technologies and solutions on how to transition to a low-cost, high-revenue producing carbon neutral operations model for airlines, airports and ground service providers will be presented.
Nyamdorj, Bolormaa, Anaka, Wayne, Stoica, Andrei, Sushant, Sushant, Ortega, Joshua, Helm, Brittney, Moreira, Paula
House Noise-Reduction Measurements for Use in Studies of Aircraft Flyover NoiseAIR1081A (Current)12/22/2020
A-21 Aircraft Noise Measurement Aviation Emission Modeling
ITIS Phrase Lists (International Traveler Information Systems)J2540/2_202012 (Current)12/6/2020
This standard provides a table of textual messages meeting the requirements for expressing International Traveler Information Systems (ITIS) phrases commonly used in the ITS industry. The tables provided herein follow the rules of SAE J2540 and therefore allow a local representation in various different languages, media expressions, etc., to allow true international use of these phrases. The phrases are predominantly intended for use in the description of traffic-related events of interest to travelers and other traffic practitioners. Other phrases exist for other specific specialty areas of ITS, and all such phrases follow a set of encoding and decoding rules outlined in SAE J2540 to ensure that the use of these phrases in messages remain interoperable between disparate types of user equipment. Implementers are cautioned to obtain the most recent set of tables by means of the ITS data registry, a process which involves SAE and other standards-setting organizations, and which is intended to maintain and enhance the level of harmonization among ITS standards set by each of the organizations. This standard defines the normative index values to be used to provide phrases needed by ITS practitioners. This standard provides non-normative textual phrases which MAY be used by implementers to ensure intelligible results. This standard follows the formats and rules established in SAE J2540 in the expressions, manipulations, and use of such tables. It should be pointed out that within the rules established by this standard, a variety of final tables are all considered “conformant” with the standard, and may vary as fits the needs of implementers.
V2X Core Technical Committee
A Life-Cycle Economic Study of eVTOL Air Taxi Service in the U.S. North-East RegionF-0076-2020-1641010/5/2020
The Urban/Advanced Air Mobility (UAM/AAM) transportation concept has been studied and shown to offer advantages in travel time-savings to individuals over the automobile, mass transit, and in many cases, commercial air transport alternatives. This paper presents a study of this new market using a parametric approach that accounts for the performance of Electric Vertical Takeoff and Landing (eVTOL) aircraft, takeoff and landing infrastructure (vertiports), and the demand for ridership given a ticket price and time saved. One of the key mode choice drivers in switching from existing transportation options to an AAM service is the value gained in saving time, which is also tightly correlated with people's income level. The analysis framework can facilitate market feasibility analysis by considering various scenarios and constraints. The results suggest that near-term profitability is possible even though vertiport throughput capacities are limited by existing footprint and operational constraints. Vertiport expansion can increase throughput and demand up to a point of maximum aircraft utilization. This new limit is due in part to ground turnaround time and battery charging requirements. Improvement in battery charging rates or implementing battery swap strategies could dramatically improve profitability while maximizing vehicle utilization. As operations increase to hundreds of flights at certain vertiports, local airspace congestion and aircraft vertiport mobility become the next bottleneck.
Sirirojvisuth, Nate, Justin, Cedric, Briceno, Simon
Streamlined Tails - The Effects of Truncation on Aerodynamic Drag2020-01-06734/14/2020
Significant aerodynamic drag reduction is obtained on a bluff body by tapering the rear body. In the 1930’s it was found that a practical low drag car body could be achieved by cutting off the tail of a streamlined shape. The rear end of a car with a truncated tail is commonly referred to as a Kamm back. It has often been interpreted as implying that the drag of this type of body is almost the same as that for a fully streamlined shape. From a review of the limited research into truncated streamlined tails it is shown in this paper that, while true for some near axisymmetric bodies, it is not the case for many more car-like shapes. For these shapes the drag reduction from an elongated tail varies almost linearly with the reduction in cross section area. A CFD simulation to determine the drag reduction from a truncated streamlined tail of variable length on the simple Windsor Body is shown by way of confirmation.
Howell, Jeff, Rajaratnam, Eleanor, Passmore, Martin
A New Network Design for the “Internet from Space”20AERP02_062/1/2020
Satellites do not yet play a major role in the world's Internet infrastructure; however, this may soon change. Within the next decade, a new generation of satellites could lay the foundations for an “Internet from space,” according to Ankit Singla, a professor at ETH Zurich's Network Design & Architecture Lab. His team is investigating how to improve the performance of large-scale computer networks including the Internet. Exploiting advances in cost-cutting technologies in the space sector, the new satellite systems would use thousands of satellites instead of the tens of satellites used in past systems. These satellites could then be linked to each other via laser light to form a network. The coverage provided by these satellites would reach remote regions that currently have no or very limited access to the Internet, since they are not connected or are only poorly connected to the intercontinental fiber optic cables that power today's Internet.
A New Network Design for the “Internet from Space”TBMG-360662/1/2020
Satellites do not yet play a major role in the world’s Internet infrastructure; however, this may soon change. Within the next decade, a new generation of satellites could lay the foundations for an “Internet from space,” according to Ankit Singla, a professor at ETH Zurich’s Network Design & Architecture Lab. His team is investigating how to improve the performance of large-scale computer networks including the Internet.
Unsettled Impacts of Integrating Automated Electric Vehicles into a Mobility-as-a-Service Ecosystem and Effects on Traditional Transportation and Ownership 1235 1999EPR201900412/20/2019
This is London editing to see how removing all formatting works in this rich text editor: USA The current business model of the automotive industry is based on individual car ownership, yet new ridesharing companies such as Uber and Lyft are well capitalized to invest in: Large, commercially operated, on-demand mobility service vehicle fleets. Bribes for government officials Insane robots! cyborgs demented roombas H2O and e=mc2 Car manufacturers like Tesla want to incorporate personal car owners into part-time fleet operation by utilizing the company’s fleet service. These robotaxi fleets can be operated profitably when the technology works in a reliable manner and regulators allow driverless operation. Although Mobility-as-a-Service (MaaS) models of private and commercial vehicle fleets can complement public transportation models, they may contribute to lower public transportation ridership and thus higher subsidies per ride. This can lead to inefficiencies in the utilization of existing public transportation infrastructure. MaaS platforms can also cause a reduced reliance on parking infrastructure (e.g., street parking lanes and parking garages) which can contribute to an improvement in overall traffic flow, and a reduction in capital investment for commercial and residential real-estate development. Urban planning can be better centered around the true mobility needs of the citizens without sacrificing valuable space for vehicles that are inactive most of the time. A key challenge is the transition phase where traditional forms of car ownership and transportation coexist with new forms of mobility services (before true MaaS platforms are fully optimized). Another fundamental issue is determining the true cost of car ownership and establishing ideal cost structures for on-demand mobility services in order to replace the need of owning a car. This needs to occur without compromising subsidized public transportation which provides affordable transportation for low-income groups. NOTE: SAE EDGE™ Research Reports are intended to identify and illuminate key issues in emerging, but still unsettled, technologies of interest to the mobility industry. The goal of SAE EDGE™ Research Reports is to stimulate discussion and work in the hope of promoting and speeding resolution of identified issues. SAE EDGE™ Research Reports are not intended to resolve the issues they identify or close any topic to further scrutiny. Click here to access the full SAE EDGETM Research Report portfolio. [It appears that the text needs highlighted to select it, which is good. This will prevent accidentally removing all formatting with a stray click.] [It appears that the underline and color change of the hyperlink remains, though it is no longer a hyperlink.] [If TM is a symbol and not a superscript, it is unchanged, which is good.] For reference, the original formatting: USA The current business model of the automotive industry is based on individual car ownership, yet new ridesharing companies such as Uber and Lyft are well capitalized to invest in: Large, commercially operated, on-demand mobility service vehicle fleets. Bribes for government officials Insane robots! cyborgs demented roombas H2O and e=mc2 Car manufacturers like Tesla want to incorporate personal car owners into part-time fleet operation by utilizing the company’s fleet service. These robotaxi fleets can be operated profitably when the technology works in a reliable manner and regulators allow driverless operation. Although Mobility-as-a-Service (MaaS) models of private and commercial vehicle fleets can complement public transportation models, they may contribute to lower public transportation ridership and thus higher subsidies per ride. This can lead to inefficiencies in the utilization of existing public transportation infrastructure. MaaS platforms can also cause a reduced reliance on parking infrastructure (e.g., street parking lanes and parking garages) which can contribute to an improvement in overall traffic flow, and a reduction in capital investment for commercial and residential real-estate development. Urban planning can be better centered around the true mobility needs of the citizens without sacrificing valuable space for vehicles that are inactive most of the time. A key challenge is the transition phase where traditional forms of car ownership and transportation coexist with new forms of mobility services (before true MaaS platforms are fully optimized). Another fundamental issue is determining the true cost of car ownership and establishing ideal cost structures for on-demand mobility services in order to replace the need of owning a car. This needs to occur without compromising subsidized public transportation which provides affordable transportation for low-income groups. NOTE: SAE EDGE™ Research Reports are intended to identify and illuminate key issues in emerging, but still unsettled, technologies of interest to the mobility industry. The goal of SAE EDGE™ Research Reports is to stimulate discussion and work in the hope of promoting and speeding resolution of identified issues. SAE EDGE™ Research Reports are not intended to resolve the issues they identify or close any topic to further scrutiny. Click here to access the full SAE EDGETM Research Report portfolio.
Letter from the Editors-in-Chief12-02-04-001412/18/2019
Watzenig, Daniel, Fruehling, Terry
ZF's Tech Portfolio is Ready for Level 4 Autonomy19AVEP09_119/1/2019
Well aware of the relentless hype that comes with automated driving development, ZF's autonomy boss knows cost will be crucial-and customer persuasion required. “We are constantly asking this question: Who is the customer likely to buy an SAE Level 4 autonomous vehicle in the consumer passenger market?” This is one of the key queries that drives the thinking of Torsten Gollewski, head of autonomous mobility systems at ZF. The global Tier 1 is playing a crucial role in enabling the next generation of mobility. A technology pragmatist, Gollewski is well aware of the hype that surrounds autonomous vehicles (AVs). There's a commonly held belief outside the industry that all vehicles will soon be automated and electric.
Birch, Stuart
Photogrammetric Frost Roughness Measurements in Cold-Soaked Conditions2019-01-19706/10/2019
Cold-soaked fuel frost (CSFF) is a form of aircraft wing contamination that occurs when a vehicle caries sufficient fuel for multiple trips or take-offs and landings. Following the first trip, which may reach altitudes above 10,000 m (33,000 ft), the fuel for the subsequent trips is carried in the wing tanks and may reach temperatures below -25 °C. In certain times of the year at some airports, temperatures and humidity levels will form CSFF on the aircraft wing surfaces over the fuel tanks. Unless an exemption is granted for the specific aircraft model, aircraft are not allowed to takeoff if the wing surfaces are contaminated by frost. Because aircraft operators desire to minimize vehicle time spent at airports, aircraft manufacturers are expected to pursue designs that safely operate with CSFF at takeoff and to pursue certification exemptions for aircraft models enabling CSFF takeoffs. To assist manufacturers in the design of future aircraft and to assist regulators in evaluating certification exemption requests, more information about frost roughness characteristics and evolution in CSFF conditions is required. However, because of the material and optical properties of frost, measuring CSFF properties using traditional roughness measurement presents challenges. For this investigation, a photogrammetric approach based on “structure-from-motion” algorithms traditionally employed in aerial surveying was developed to characterize the evolution of CSFF roughness. Using the approach, measurements of frost roughness evolution were performed in the Baylor Frost Tunnel (BFT) for two basic air temperature, humidity, surface temperature, and velocity conditions with frost time up to two hours. An analysis of variance approach was used to determine the sensitivity frost growth rates to the environmental conditions. The resulting measurements demonstrate different evolution histories with air velocity and air temperature being the most important factors governing roughness growth.
Miyauchi, Taber, McClain, Stephen T., Zhang, Tongxin, O'Neal, Dennis L., Riley, James T.
Runway Deicing Product Anti/Deicing Performance Assessment: Review and Future Directions2019-01-19746/10/2019
Every winter, northern airport operations are disrupted by heavy snowstorms and freezing precipitations. A simple snow accumulation or a thin layer of ice can affect aircraft operations (take-off, landing and taxi), and increase the risk for passengers and crew members, by rendering the runway slippery. Any deficits in deicing operations can also lead to flight delays and even cancellations that cost a lot to the industry. In order to maintain the runway and taxiway in a safe and useable condition, airport authorities use mechanical tools, but also chemical products. Chemical products available on the market for use in airports are principally in solid forms and liquid form, and are denominated as Runway Deicing Product (RDP). All of the products used in airport should meet the technical requirements of one of the two Aerospace Materials Specifications (AMS) documents: the AMS1431D Compound, Solid Runway and taxiway Deicing/Anti-icing and the AMS1435C Fluid, Generic, Deicing/Anti-icing Runways and Taxiways. Most of the products are used as freezing point depressants and are applied on snow, ice or packed snow covers to create holes and facilitate the mechanical removal. Over the past ten years, efforts have been brought along to adapt and to develop methods in order to assess the deicing and the anti-icing performance of the products. Some of those methods are included in actual SAE documents and some are in development. This paper will present a review of those methods and also cover the future directions of the research and development in the field.
Brassard, Jean-Denis, Laforte, Caroline, Tremblay, Marc Mario, Volat, Christophe
First Smile, Last Smile19AVEP05_095/1/2019
May Mobility is building a unique business model around AV shuttle services, explains COO and co-founder Alisyn Malek. Entering the busy headquarters of May Mobility, my eyes fix almost immediately on a huge red Corvette brake caliper sitting on a tool cart beside an engineer's work station. “You guys must be planning some really fast self-driving shuttles,” I quip to COO and co-founder Alisyn Malek moments later, when she greets me for our interview. “In order to have a safe and reliable system we have to know the hardware as well as the software,”- Malek explained. “And to gain that knowledge we do the systems-level design and development on both. From brakes, to sensor suite integration, to wire harness design-all are done in house. We have to make sure we get the checks and balances between both systems.”
Brooke, Lindsay
Power RACe2019-01-13453/19/2019
Ever increasing process applications inspire us to design innovative and modular manufacturing cells in compliance with modern specifications. The result is the new highly flexible Aerospace application specific robot introduced as the “POWER RACe”. This paper describes how benchmarks for flexible automated drilling and fastening are being achieved with the Power RACe technology platform.
Dillhoefer, Thorsten, Erdinc PhD, Fatih
Prediction of Weather Impacts on Airport Arrival Meter Fix Capacity2019-01-13503/19/2019
This paper introduces a data driven model for predicting airport arrival capacity with 2-8 hour look-ahead forecast data. The model is suitable for air traffic flow management by explicitly investigating the impact of convective weather on airport arrival meter fix throughput. Estimation of the arrival airport capacity under arrival meter fix flow constraints due to severe weather is an important part of Air Traffic Management (ATM). Airport arrival capacity can be reduced if one or more airport arrival meter fixes are partially or completely blocked by convective weather. When the predicted airport arrival demands exceed the predicted available airport’s arrival capacity for a sustained period, Ground Delay Program (GDP) operations will be triggered by ATM system. Severe imbalances between demand and capacity occur most frequently when the airport capacity is severely degraded due to either bad airport terminal surface weather or inclement convective weather around airport arrival fixes. A model that predicts the weather-impacted airport arrival meter fix throughput may help ATM personnel to plan GDP operations more efficiently. This paper identifies the characteristics of air traffic flow across arrival meter fixes at Newark Liberty International Airport (EWR). The proposed approach, based on machine-learning methods, is developed to predict the weather impacted EWR arrival Meter Fix (MF) throughput. Sector forecast coverage is used to envision the weather impact on airport arrival MF flow, and the validation is accomplished by using Convective Weather Avoidance Model (CWAM) 0.5 to 2-hour and Collaborative Convective Forecast Product (CCFP) 4 to 8-hour look-ahead forecast data for the period of April-September in 2014. Furthermore, the regression tree ensemble learning of random forests approach for translating a sector forecast coverage model to EWR arrival meter fix throughput is examined. The results suggest that ATM decision makers in charge of MF flow control and GDP planning may benefit from adopting the airport arrival meter capacity prediction models to estimate the inclement weather impacts.
Wang, Yao
“Light-Written” Photonic Memory DevicesTBMG-339113/1/2019
Light is the most energy-efficient way to move information; however, light shows one big limitation: it is difficult to store. Data centers, for example, rely primarily on magnetic hard drives in which information is transferred at an energy cost that is increasing. A hybrid technology was developed that shows advantages of both light and magnetic hard drives.
Ideas for multi-modal mobility18AUTP10_0410/1/2018
Silicon Valley often gets credit for ideas that have been percolating elsewhere for a long time. Great ideas that are not yet fully refined and need a tweak or two to make them viable. Case in point: micro mobility. Last March, I was in San Jose for the Nvidia GPU Technology Conference when a flock of Bird electric scooters magically appeared all over the sidewalks of downtown. Within days, there were thousands more in San Francisco and other cities from Bird, Lime and several other startups. Some critics of this sudden flood called it “scootermaggeddon.”
Abuelsamid, Sam
Effects of Clamping Force on the Operating Behavior of PEM Fuel Cell2018-01-17189/10/2018
Proton exchange membrane (PEM) fuel cell is widely recognized as an outstanding portable power plant and expected to be possibly commercialization in the near future. As is well known, mechanical stresses implemented on the bipolar plates during the assembly procedure should have prominent influences on mass and heat transfer behavior inside the cell, as well as the resultant performance. In this study, an analytical model is proposed to comprehensively investigate the influence of clamping force on the mass transport, electrochemical properties and overall cell output capability of a PEM fuel cell. The results indicate that proper clamping force not only benefits the gas leakage prevention but also increases the contact area between the neighboring components to decrease the contact ohmic resistance. However, deformation always takes place simultaneously, changing the local physical structures of the cell components, which possibly leads to the decrement of porosity and permeability of the gas diffusion layer (GDL) and catalyst layer (CL), hinders the gas species and liquid water transport in GDL, and also decreases the cross-sectional flow area in the channel. The combined effect of the aforementioned factors finally contributes to the cell performance fluctuation. Moreover, although the contact resistance decreases with increasing stresses, more significant mass transfer losses, e.g. lower membrane water content and larger gradient in liquid saturation, results in more serious concentration voltage losses and weaker proton conductivity in the membrane, further impairing the cell voltage output. Therefore, cell performance should be optimized by the balancing among the transport properties and the contact resistance involved in the fuel cell. By using this analytical model, optimal cell design parameters and clamping pressure exerted on the fuel cell can be quickly predicted accordingly. Proper discussions are carried out and suggestions are proposed.
Chen, Rouxian, Qin, Yanzhou, Du, Qing, Peng, Jun
NITROS: An Innovative Training Program to Enhance Rotorcraft SafetyF-0074-2018-128725/14/2018
ABSTRACT Helicopters are currently used in important applications providing a valuable contribution to society and economic growth. Thanks to their operational flexibility it is possible to accomplish increasingly complex missions. If the expansion of the usage of rotorcraft is to follow the pace of growth achieved by the fixed-wing public transport in the last years, several issues need to be urgently addressed to increase the use and the public acceptance of rotorcraft. Aspects related to complexity of the operations and safety are of primary importance, since in the last 20 years helicopter accident rates, worldwide, remained unacceptably high, when compared to fixed-wing aircraft. The complexity of the phenomena involved in rotorcraft flight calls for the training of engineers with a genuine multidisciplinary background. This paper presents the doctoral research and training program NITROS, which is set up under the Marie Skłodowska-Curie Action of the European Union to address complex solutions to rotorcraft safety.
Quaranta, Giuseppe, Barakos, George, White, Mark, Pavel, Marilena, Mulder, Max
Correlation Model of Subjective and Objective Evaluation Based on Grey GM(0,N) for Automobile Sound Quality02-11-02-00084/18/2018
Correlation analysis of subjective and objective evaluation for automobile sound quality is an important topic in automobile technology fields. In view of the deficiency of multi-dimensional linear regression analysis and the theoretical merits of grey system method, grey comprehensive relational degree was calculated to analyze the contribution of objective evaluation data to subjective evaluation. The main objective variables affecting the subjective feeling were determined. The variables include loudness, sharpness and shaking degrees. Grey GM(0,4) model was established as a quantitative expression for describing the subjective and objective evaluation correlation. The results of residual test and posterior-variance-test show that the established model was accurate and the model can be used to analyze and predict subjective and objective evaluation data of automobile sound quality.
Zhao, Zhendong
Mission-based Design Space Exploration for Powertrain Electrification of Series Plugin Hybrid Electric Delivery Truck2018-01-10274/3/2018
Hybrid electric vehicles (HEV) are essential for reducing fuel consumption and emissions. However, when analyzing different segments of the transportation industry, for example, public transportation or different sizes of delivery trucks and how the HEV are used, it is clear that one powertrain may not be optimal in all situations. Choosing a hybrid powertrain architecture and proper component sizes for different applications is an important task to find the optimal trade-off between fuel economy, drivability, and vehicle cost. However, exploring and evaluating all possible architectures and component sizes is a time-consuming task. A search algorithm, using Gaussian Processes, is proposed that simultaneously explores multiple architecture options, to identify the Pareto-optimal solutions. The search algorithm is designed to carefully select the candidate in each iteration which is most likely to be Pareto-optimal, based on the results from previous candidates, to reduce computational time. The powertrain of a medium-sized series plugin hybrid electric delivery truck with a range extender is optimized for different driving missions. Three different powertrain architectures are included in the design space exploration and the fuel economy is evaluated using a simulation model of the powertrain and Dynamic Programming. Results from the analysis show which ranges of powertrain component sizes are recommended for the different types of driving scenarios.
Jung, Daniel, Ahmed, Qadeer, Zhang, Xieyuan, Rizzoni, Giorgio
Development, Performance Analysis and Optimization of Parallel Hydraulic Hybrid System for City Bus Application2018-01-04194/3/2018
One of the key requisites for a sustained mobility development is to have an efficient public transport system. Fuel efficiency and emission control are extremely important in this respect. By the very nature of city driving, it is obvious that city traffic results in frequent vehicle start and stops; which involves huge waste of vehicle kinetic energy. Every time vehicle moving from idle, needs a bigger input of power and every time the brakes are applied, all energy built up disappears again, wasted in the brake pads as heat. An effort has been taken to recuperate vehicle kinetic energy, hydraulically during braking events and utilize it to assist the vehicle during acceleration. Hydraulic based hybrid vehicle working on the principle of regenerative braking is one of the most fuel-efficient technologies for city application. Parallel hydraulic hybrid vehicle has been developed and optimized for fuel efficiency gain at vehicle level. Objective of this paper is to study behavior, performance and optimization of hydraulic hybrid vehicle in city application. This paper deals with evaluation of simulation, integration, calibration and performance tests carried out at real world usage conditions. As a final proof of concept and performance, the hydraulic hybrid bus was tested back to back with conventional city bus of same configuration and results were analyzed and compared. This paper also deals on the scope of engine downsizing and major challenges faced in developing hydraulic hybrid system for extremely hot weather conditions such as South Asian countries.
Yaser, K U Syed Taj, Bakatwar, Rupesh, Bhargava, Aashish, Tiwari, Sanjay
Fiber Optics Mechanization of a Digital Time Division Command/Response Multiplex Data BusAS1773A (Current)3/14/2018
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
A Review of Modal Choice Models: Case Study for São Paulo2017-36-027911/7/2017
The world urbanization is growing rapidly, bringing many challenges for people to move in dense metropolitan regions. Public transportation is not able to attend the whole demand, and individual transportation modes are struggling with traffic congestion and stringent regulations to reduce its attractiveness, such as the license plate restriction in São Paulo. On the other hand, enablers like smartphones mass penetration, GPS connected services and shared economy have opened space to a whole new range of possible solutions to improve people perception on urban mobility. This work aims to evaluate the modal choice behavior models and understand the success factor of current mobility solutions in the city of São Paulo. The data available through origin/destination researches will be used to validate the models used in this work.
Steckelberg, Danilo, Barretto, Guira, Morales, Nicolás
The Impact of the Autonomous Vehicle in Society and in the Urban Mobility in the City of São Paulo2017-36-038611/7/2017
The safety, reliability and efficiency in the progress of the autonomous vehicle have increased in recent years. In parallel, companies in the segment of people transportation, either individually or shared, took the world leadership using smartphone app into a new concept of urban mobility with conventional vehicles with drivers, starting consequently a change of habit of the population, and defying the laws of local transport. These services for urban mobility are related as tendencies of driving forces in the face of the relevance of the limitations of resources, population density, greater awareness toward the environment and traffic congestion. The acquisition of the “own vehicle” as currently, conceived and successful by Alfred Sloan in the 1920s, has become a question for future generations. This study shows that the provision of a more secure service, reliable, and efficient, will enable a significant reduction in total cost of ownership to the increasingly sophisticated and highly informed generation Z, who continually seeks to optimize its resources, availability and quality of life in real time. It also shows how the autonomous vehicles will transform urban mobility in the next 20 years and the impact generated in the city of São Paulo, the largest city in Latin America and with more than 12 million inhabitants.
Briganti, Murilo Cesar Perin, de Mello Filho, Luiz Vicente Figueira, Cardamoni, Raquel, Iano, Yuzo
Power RACe2017-01-20939/19/2017
Ever increasing process applications inspire us, as suppliers of aircraft, structural-assembly, and equipment to design innovative and modular, manufacturing cells in compliance with modern specification. The result is the new highly flexible Aerospace application specific robot identified as “POWER RACe”. This paper describes how benchmarks for flexible automated drilling and fastening are being achieved with the Power RACe technology platform.
Dillhoefer, Thorsten
CPAC Bulkhead Riveting System2017-01-20749/19/2017
Ever increasing process applications inspire us, as suppliers of aircraft, structural-assembly, and equipment to design innovative and modular, manufacturing cells in compliance with modern specifications. The result is the new flexible C-Frame Panel Assembly Cell (CPAC) Bulkhead riveting System. This paper describes how benchmarks for flexible automated drilling and fastening are being achieved with the CPAC.
Dillhoefer, Thorsten, Erdinc, Fatih
Characterization and Discrimination of Aircrafts and Runways Winter Maintenance Anti-Icing Fluids2017-01-21409/19/2017
Aircrafts and runways de-icing operations with anti-icing fluids are still the most commonly used methods. In the specific case of aircrafts, they do contain glycols. Nevertheless, since two decades now, major environmental concerns are raised, along with important associated costs. Furthermore, once applied either on aircrafts or on runways, these fluids are diluted because of water brought from adverse weather conditions (rain, snow, icy conditions), conducting to increasing the freezing point from a subzero level to 0°C. The characterization of the freezing points of these fluids is indeed crucial for safety reasons. For years now, Raman spectroscopy is used for the characterization of these fluids, specifically the freezing point. But the presence of dyes did perturb the usual spectroscopic characterization. Three fluids, from their pure commercial form to highly diluted rate, were then studied by means of Raman spectroscopy at a new laser wavelength, and with the support of multivariate data analysis (MDA). Each fluid belonged to a specific type of aircraft anti-icing fluid (I, II and IV). The discrimination of the fluids between each other was obtained. Spectroscopic data was organized through MDA in such a way that neither the presence of a dye nor the dilution would allow any confusion. The identification of the evolution of freezing temperatures with dilution was elaborated, with their rapid increase as dilution increased too. MDA allowed also the elaboration of prediction models, and such tool conducted to the forecast of concentration in anti-icing, or of its freezing temperature on the basis of the Raman signature of the considered fluid, with a given degree of confidence.
Marchetti, Mario, Casteran, Guillaume, Jobard, Celine, Saintot, Bruno, Bourson, Patrice, Fontana, Marc
The Seat Interference Potential as an Indicator for the Aircraft Boarding Progress2017-01-21139/19/2017
Passenger boarding is always part of the critical path of the aircraft turnaround: both efficient boarding and online prediction of the boarding progress are essential for a reliable turnaround progress. However, the boarding progress is mainly controlled by the passenger behavior. A fundamental scientific approach for aircraft boarding enables the consideration of individual passenger behaviors and operational constraints in order to develop a sustainable concept for enabling a prediction of the boarding progress. A reliable microscopic simulation approach is used to model the passenger behavior, where the individual movement is defined as a one-dimensional, stochastic, and time/space discrete transition process. The simulation covers a broad range of behaviors and boarding strategies as well as the integration of new technologies and procedures. Future cabin management systems will provide an enabling infrastructure to further improve the overall turnaround process and to allow for on-line prediction of specific handling processes. The paper provides a method to indicate the progress of the aircraft boarding. In this context, the aircraft seats are used as a sensor network with the capability to detect the status (free or occupied) of each seat. These individual seat statuses are used to derive an aggregated interference potential of the current seating condition with regards to the passenger seating process. The interference potential is a major indicator for the expected aircraft boarding time. In combination with an integrated airline/airport information management (e.g. sequence of boarding passengers) the boarding progress will be transformed from a black box to a transparent progress with the operator’s online ability to react to significant deviations from the planned progress.
Schultz, Michael
The Analysis of the Stiffness-Damping Parameters of a H-Bahn Vehicle2017-01-18906/5/2017
H-Bahn ("hanging railway") refers to the suspended, unmanned urban railway transportation system. Through the reasonable platform layout, H-Bahn can be easily integrated into the existing urban transit system. With the development of urban roads, the associated rail facilities can be conveniently disassembled, moved and expanded. The track beam, circuits, communication equipment, and sound insulation screen are all installed in a box-type track beam so that the system can achieve a high level of integration and intelligence. The carriage of the modern H-banh vehicle is connected with the bogies by two hanging devices. The vehicle is always running in the box-type track beam; therefore there are less possibilities of derailment. Consequently, the key work focuses on the running stability evaluation and curve negotiation performance analysis. In order to study the factors affecting running stability, the different stiffness and damping parameters in the primary and secondary suspension system are assigned to calculate the running stability index. To begin with, the vertical and lateral mathematic -dynamics models of the vehicle are established. Moreover, based on the USA VI rail spectrum, the vertical and lateral input displacements of the rail can be developed. In addition, the time-domain acceleration responses calculated by the dynamics model are converted to the amplitude-frequency characteristic curves by the Fourier transform. Finally, the weighted Sperling index calculated by the corresponding frequency and amplitude can evaluate the vehicle running stability. From the results of the vertical running stability analysis, the vertical indexes Wz are less than 2.5 almost, so that the running stability belongs to Level 1. For analyzing the lateral vibration, the hanging device is regarded as a fixed rigid body connecting the vehicle body and bogies. From the results of lateral running stability analysis, the lateral index Wy increases with the lateral stiffness of the air spring (< 2.5 × 105), and Wy is more than 3.0 at some points. In order to analyze the curve negotiation performance, the statics model describing the lateral rolling condition is established. By solving the nonlinear equations describing the statics model, the rolling angles of vehicle body are calculated in different conditions. The stiffness of air spring and centrifugal acceleration should be controlled in the limited values for improving the curve negotiation performance.
Zhang, Xingyu, Yang, Bo, Zhang, Manchuang, Hu, Sanbao
Interior Noise and Vibration Reduction of BRT - Premium Segment Bus2017-01-18666/5/2017
Urbanisation has led to an increased need for mobility in public transportation. Sensing the unfolding worrisome scenario, many countries have taken up different mass rapid transit solutions to alleviate the problem and restore the free flowing traffic. BRT should have been the logical choice particularly considering the lower capital costs involved and faster implementation. Comprehensibly the expectations of this class of vehicles will be high in term of quality and comfort to the passengers. Level of vibration and noise is an important indicator to evaluate vehicle's ride comfort. The challenges are to design the high powered Powertrain and Air Conditioning system nonetheless low interior noise, vibration and harshness correspondents to personal cars. This paper is an invention of, development work done in interior noise refinement of a bus. A prototype bus manufactured to meet all the requirement of BRT - premium segment urban bus. The prototype was almost meeting the entire required specifications, excluding interior noise and vibrations. The rear zone of the interior was the major concern of NVH levels, which demands to carry out the root cause analysis. There were various structure-borne and air-borne sources contributing to increase in NVH levels. Design and development iterations were conducted on the vehicle to achieve the well significant noise and vibration reduction and increased comfort to the passengers.
Jawale, Pradeep, Karanth, Nagesh
Runway Independent High Speed CarterCopter BizJetF-0073-2017-123015/9/2017
ABSTRACT Carter Aviation Technologies, LLC has spent over 20 years developing aircraft concepts utilizing its Slowed Rotor/Compound (SR/C™) technology, a technology that offers VTOL capability with fixed-wing cruise performance in a much simpler and less expensive method than other high speed VTOL approaches, with a rotor always in autorotation in case of emergency. Key to this technology is a rotor and related control system that can be dramatically slowed in flight while remaining stable. Multiple manned demonstrators have demonstrated the feasibility of the technology, as well as provided solid experimental flight test data on performance potential. Carter is now utilizing this technology for a new aircraft concept, the CarterCopter BizJet, to provide runway independent operation with business jet cruise performance, carrying up to nine people at top speeds exceeding 500 mph (435+ ktas or 805+ km/hr). This paper will focus on this new platform, its features, and capabilities.
Jr., Jay, Lewis, Jeffrey
New Approach of Tools Application for Systems Engineering in Automotive Software Development2017-01-16013/28/2017
This paper outlines the modeling process in SysML (Systems Modeling Language) in context of MBSE (Model Based Software Engineering) as well as the MBD (Model-Based Design) in Simulink and we compare the models to get useful information into software. For this goal, we propose the use of an RM/SM tool (Requirements Management and Systems Modeling) (3SL Cradle) and Matlab/Simulink to model the system, do the system validations, and finally embed the generated code. For automotive systems, the development process is visualized through the V-Model, which leads to the right choice of components, the integration of the system and the project realization. The first step in V-Model handles the requirements management for the development, i.e., the requirements for a project will be collected in respect to the stakeholder’s needs and system limitations. Then, the next steps consist of modeling the system based on its requirements, going through simulation, system validation through Model-In-the-Loop (MIL), Software-In-the-Loop (SIL), Processor-In-the-Loop (PIL), and Hardware-In-the-Loop (HIL) tests. For this paper, the chosen modeling language was SysML for the MBSE point of view because it aims to standardize Modeling Design, by unifying diverse modeling languages used by engineers. This language also supports specification, analysis, design, verification, and validation of systems. To get executable models, we use Matlab/Simulink models that are largely used by the Original Equipment Manufacturers (OEMs) to develop new products. Our approach addresses the V-Model through SysML and MBD in Matlab/Simulink towards software validation. To achieve that, we use the commercial RM/SM tool that is used to collect stakeholder’s and system requirements. It provides a SysML design section as well where SysML models can be developed according to project requirements. One of the objectives in using the commercial tool is that it will be possible to analyze the transition from models in RM/SM tools to models for simulation, such as Simulink and offer a new possibility for OEM’s and suppliers to abstract system models into executable models. The main contribution of this paper is that the automotive software development process is showed from its concept to its realization in real systems.
Santos, Max Mauro, Mendes, Celso, Banik, Taysa, Franco, Felipe, Neme, João, Prado, Wanderley, Cerri, Fernando, Nunes, Lauro
Shared Autonomous Vehicles as a Sustainable Solution to the Last Mile Problem: A Case Study of Ann Arbor-Detroit Area2017-01-12763/28/2017
The problem of accessibility to public transit is well-documented in transportation theory and network literature, and is known as the last mile problem. A lack of first and last mile transit services impairs access to public transit causing commuters to opt for private modes of transit over public modes. This paper analyzes the implications of a shared autonomous vehicle (AV) taxi system providing last mile transit services in terms of environmental, cost, and performance metrics. Conventional public transit options and a hypothetical last-mile shared autonomous vehicle (SAV) system are analyzed for transit between Ann Arbor and Detroit Wayne County Airport for life cycle energy, emissions, total travel time, and travel costs. In the case study, energy savings from using public transit options with AV last mile service were as high as 37% when compared to a personal vehicle option. Energy and greenhouse gas burdens were very sensitive to vehicle powertrain and ridership parameters. The results suggest that an AV taxi service providing last-mile transit services could enhance the sustainability of transit by influencing a mode shift from private modes to public modes of transit. Wait times associated with public transit options, as well as high AV technology costs, could be obstacles for a last mile service.
Moorthy, Aditi, De Kleine, Robert, Keoleian, Gregory, Good, Jeremy, Lewis, Geoff
The Effect Factors and Location Planning Method Study of a Novel Car-Sharing Network2017-01-02493/28/2017
With the development of the Internet for vehicles, the Car-sharing has been developed rapidly in recent years. This paper focuses on the network programming and distribution for Car-sharing, which helps to clarify the characteristics and basic law of Car-sharing network development, as well as the main approaches to construct it. Firstly, by analyzing the effect factors and expanding ways of Car-sharing network, characteristics of the development of Car-sharing industry and its network, as well as main Car-sharing users and services, the influence factors of Car-sharing demand and the main demand points in a city are summarized. Secondly, in order to better evaluate the network programming and distribution for Car-sharing, this paper proposes an optimization decision method of the car-sharing network planning by evaluating the possible alternatives in a same scale. The assessment index of Car-sharing network planning is constructed. Then the Analytic Hierarchy Process (AHP) and grey correlation analysis system are utilized to select the best scheme. Finally, by using the two-dimensional space analytical method, the paper constructs a Car-sharing network location sitting model which can make a balance between supply and demand. Then, the model is applied in the city of Wuhan and the results show that the model is practicable. So, the theory and method of Car-sharing network and location planning can be applied to any city by using the same ways introduced in this paper, which are useful for the network programming and distribution for Car-sharing.
Mi, Jia, Jie, Hu, Zhu, Hao, Liu, Hao, Zhang, Yuzhou
Fast Charging Lithium-Ion Batteries2017-01-12043/28/2017
We try to understand the fast recharge capability of automotive lithium-ion batteries and its effect of fast charge on capacity degradation. We find out that 5 Ah prismatic Li-ion cells can be fully recharged in 3 minutes under a constant rate of 20C, or in 2 min (25.5C) from 0% to 85% state of charge (SOC) without undue stresses. We cycle the battery at 16C charge rate from 0 to 100%SOC and do not see any unexpected battery capacity loss in 50 cycles, where half of the cycles are charged at1C-rate as a reference capacity check. We realize that the batteries under the fast charge tests do not experience any negative impacts related to mass transport in either solid electrodes or the electrolyte system. In the paper, we propose a new procedure to measure the ac and dc resistances of the battery under continuous operation. Electrochemical impedance analyses on the whole battery and the individual electrodes are also conducted.
Yang, Xiao, Miller, Ted
FRAC (Frame Riveter Assembly Cell)2016-01-20799/27/2016
The industry wide requirement of new highly flexible automated fastening systems in aircraft production has created the need for developing new fastening systems. This paper will focus on the development of the Frame Riveting Assembly Cell (FRAC) by BROETJE-Automation to meet this need. The new FRAC machine configuration is built for automated drilling and fastening of different aircraft type parts. It is highly flexible with a high speed positioning system mounted multifunction end effector. System travel is limited only by installed track length. The FRAC integrates well with conventional and reconfigurable automated fastening work holding tools.
Janssen, Alexander, Dillhoefer, Thorsten
Delphi launches driverless pilot program in Singapore, aims for SAE Level 4 operation by 201916AUTP09_099/1/2016
Delphi Automotive on August 1 announced an extensive autonomous-vehicle pilot program in Singapore, aimed at demonstrating cloud-based fully automated mobility on demand (AMoD) capability “at the [SAE] Level 4 performance level” by late 2019, said Glen DeVos, Vice President of Delphi's Business Services Unit based in Mountain View, CA. Operational capability is expected by 2022. Delphi is partnering with the Singapore government's Land Transport Authority (LTA) on the multi-phase project. The initial phase, to be conducted through 2019, will involve a fleet of six modified production vehicles operating at low speed on fixed routes in the island nation's “one north” area, a business park that is currently serving as a test bed for autonomous-vehicle development, DeVos explained in a recent media briefing.
Brooke, Lindsay
Fluid, Deicing/Anti-Icing, Runways and Taxiways Glycol BaseAMS1426D (Current)8/15/2016
This specification covers a glycol-base deicing/anti-icing material in the form of a liquid.
G-12 Runway Deicing Product Committee
Control Solutions Synchronize Operation of Space Launch System Heavy TransportersTBMG-248886/1/2016
Control panels, embedded PCs, automation software, and servomotors and drives Beckhoff Automation Savage, MN 952-890-0000
Biomimetics: nature leads the way on design16MEIP06_186/1/2016
That bird flight inspired Leonardo da Vinci to conceptualize “flying machines,” only to be developed centuries later by the Wright brothers by observing pigeons in flight, is quite well known. Such imitation of the models, systems, and elements of nature for the purpose of solving complex problems, otherwise known as biomimetics or biomimicry, is not new. Mother Nature is a great engineer that over the years has fascinated engineers and scientists alike, who have borrowed and applied its time-tested patterns and strategies. Technological advancements and continuous endeavors to push the limits of engineering have led to transformational innovations, as can be seen in some of the recent trends to catch up with nature's best assets. Velcro is perhaps the best known and commercially successful example of a nature-inspired design. After a hunting trip in the Alps in 1941, Swiss engineer Mestral's socks and dog were covered in burdock burrs. Intrigued by it, Mestral studied them under a microscope to understand the simple system of interlocking hooks and spent the next few years developing Velcro. Such mimicking of nature's precise and efficient shapes, structures, and geometries is referred to as the basic level of biomimicry, by American biologist Janine Benyus.
Rapidly Pulsed Reductants in Diesel NOx Reduction by Lean NOx Traps: Effects of Mixing Uniformity and Reductant Type2016-01-09564/5/2016
Lean NOx Traps (LNTs) are one type of lean NOx reduction technology typically used in smaller diesel passenger cars where urea-based Selective Catalytic Reduction (SCR) systems may be difficult to package . However, the performance of lean NOx traps (LNT) at temperatures above 400 C needs to be improved. The use of Rapidly Pulsed Reductants (RPR) is a process in which hydrocarbons are injected in rapid pulses ahead of a LNT in order to expand its operating window to higher temperatures and space velocities. This approach has also been called Di-Air (diesel NOx aftertreatment by adsorbed intermediate reductants) by Toyota. There is a vast parameter space which could be explored to maximize RPR performance and reduce the fuel penalty associated with injecting hydrocarbons. In this study, the mixing uniformity of the injected pulses, the type of reductant, and the concentration of pulsed reductant in the main flow were investigated. We found that all of these parameters are important for the RPR system performance. To obtain a uniformity of flow with the injected species to approach that of a plug flow, we developed a design using specific mixers to maximize the performance of RPR. The initial hypothesis for the required mixing process was to uniformly mix the injected reductants with the main flow in the radial direction, while keeping the axial mixing as low as possible. This goal was achieved by incorporating different mass transport processes, i.e. advection in the radial direction, and diffusion in the axial direction. Numerical investigation of the mixing of high frequency pulsed gaseous hydrocarbons into the main exhaust flow was performed to design an effective mixer to satisfy the desired mixing conditions. This mixing process and a fast injection system (down to 1ms pulse duration) was shown to have uniform radial mixing and axially separated pulses of reductants that gave the optimal mixing condition and achieved the highest RPR NOx conversion performance. Employing the designed mixer, a range of reductants (H2, CO, C2H4, C3H6, and C3H8) were tested under similar operating conditions over a Pt/Rh LNT. The effectiveness of different reductants for NOx conversion in different temperature regimes was found to be as follows: T < 270°C: H2 > CO > C3H6 > C2H4; 270°C < T < 500°C: C3H6 > H2 > CO > C2H4; T > 500°C: C3H6 > C2H4 >H2 ∼ CO. In terms of the selectivity of converted NOx, H2 resulted in significant ammonia formation at low temperatures, but overall, the N2 selectivity was as follows: CO ∼ C3H6 > C2H4 >> H2. Generally, it was concluded that hydrocarbon reductants provided higher NOx conversion in the mid-range and especially higher temperature ranges with relatively high nitrogen selectivity. However, it was observed that the reactivity of hydrocarbons and the availability of oxygen had a significant influence on their performance, especially as the pulsing frequency was increased and reduction reaction time became more limited. In this study we have shown that the use of rapidly pulsed reductants (RPR) can be studied in the laboratory with the equipment and methods presented here. In studies with a LNT catalyst, the variations in NOx performance with several reductants at reasonably high frequencies were shown. This suggests that this system should be able to provide useful information for optimizing the performance of LNT catalysts at high temperatures.
Reihani, Amin, Corson, Benjamin, Hoard, John W., Fisher, Galen B., Smirnov, Evgeny, Roemer, Dirk, Theis, Joseph, Lambert, Christine
Efficiency Improvement of Boost Converter for Fuel Cell Bus by Silicon Carbide Diodes2016-01-12344/5/2016
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 silicon insulated gate bipolar transistors (Si-IGBTs) in the lower arm turn on. As a result, the turn-on loss of the lower arm can be reduced by approximately 70%. It was confirmed that installing SiC-SBDs in the upper arm of the FC boost converter improved efficiency by 0.5% in the load range over 50%.
Sugiura, Toshikazu, Tanida, Atsushi, Tamura, Kazutaka
Locating Wire Short Fault for In-Vehicle Controller Area Network with Resistance Estimation Approach2016-01-00654/5/2016
Wire shorts on an in-vehicle controller area network (CAN) impact the communication between electrical control units (ECUs), and negatively affects the vehicle control. The fault, especially the intermittent fault, is difficult to locate. In this paper, an equivalent circuit model for in-vehicle CAN bus is developed under the wire short fault scenario. The bus resistance is estimated and a resistance-distance mapping approach is proposed to locate the fault. The proposed approach is implemented in an Arduino-based embedded system and validated on a vehicle frame. The experimental results are promising. The approach presented in this paper may reduce trouble shooting time for CAN wire short faults and may enable early detection before the customer is inconvenienced.
Du, Xinyu, Jiang, Shengbing, Nagose, Atul, Zhang, Yilu, Wienckowski, Natalie
Tool to Analyze a Leaking Source of Saturated AmmoniaTBMG-242704/1/2016
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.
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