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1

Vehicle systems design optimization study  

SciTech Connect

The optimization of an electric vehicle layout requires a weight distribution in the range of 53/47 to 62/38 in order to assure dynamic handling characteristics comparable to current production internal combustion engine vehicles. It is possible to achieve this goal and also provide passenger and cargo space comparable to a selected current production sub-compact car either in a unique new design or by utilizing the production vehicle as a base. Necessary modification of the base vehicle can be accomplished without major modification of the structure or running gear. As long as batteries are as heavy and require as much space as they currently do, they must be divided into two packages - one at front under the hood and a second at the rear under the cargo area - in order to achieve the desired weight distribution. The weight distribution criteria requires the placement of batteries at the front of the vehicle even when the central tunnel is used for the location of some batteries. The optimum layout has a front motor and front wheel drive. This configuration provides the optimum vehicle dynamic handling characteristics and the maximum passsenger and cargo space for a given size vehicle.

Gilmour, J. L.

1980-04-01

2

Conceptual design for aerospace vehicles  

NASA Technical Reports Server (NTRS)

The designers of aircraft and more recently, aerospace vehicles have always struggled with the problems of evolving their designs to produce a machine which would perform its assigned task(s) in some optimum fashion. Almost invariably this involved dealing with more variables and constraints than could be handled in any computationally feasible way. With the advent of the electronic digital computer, the possibilities for introducing more variable and constraints into the initial design process led to greater expectations for improvement in vehicle (system) efficiency. The creation of the large scale systems necessary to achieve optimum designs has, for many reason, proved to be difficult. From a technical standpoint, significant problems arise in the development of satisfactory algorithms for processing of data from the various technical disciplines in a way that would be compatible with the complex optimization function. Also, the creation of effective optimization routines for multi-variable and constraint situations which could lead to consistent results has lagged. The current capability for carrying out the conceptual design of an aircraft on an interdisciplinary bases was evaluated to determine the need for extending this capability, and if necessary, to recommend means by which this could be carried out. Based on a review of available documentation and individual consultations, it appears that there is extensive interest at Langley Research Center as well as in the aerospace community in providing a higher level of capability that meets the technical challenges. By implication, the current design capability is inadequate and it does not operate in a way that allows the various technical disciplines to participate and cooperately interact in the design process. Based on this assessment, it was concluded that substantial effort should be devoted to developing a computer-based conceptual design system that would provide the capability needed for the near-term as well as framework for development of more advanced methods to serve future needs.

Gratzer, Louis B.

1989-01-01

3

Delta Clipper vehicle design for supportability  

NASA Astrophysics Data System (ADS)

The paper describes the Single Stage Rocket Technology (SSRT) Delta Clipper vehicle design. As a means of reducing vehicle processing and turnaround times, the SSRT Delta Clipper design, contrary to past practices, incorporates support ability engineering features into its initial set of design requirements. The engineering process used to 'design-in' supportability into the Delta Clipper vehicle is described in detail and is illustrated using diagrams.

Smiljanic, Ray R.; Klevatt, Paul L.; Steinmeyer, Donald A.

1993-02-01

4

Vehicle systems design optimization study  

NASA Technical Reports Server (NTRS)

The optimum vehicle configuration and component locations are determined for an electric drive vehicle based on using the basic structure of a current production subcompact vehicle. The optimization of an electric vehicle layout requires a weight distribution in the range of 53/47 to 62/38 in order to assure dynamic handling characteristics comparable to current internal combustion engine vehicles. Necessary modification of the base vehicle can be accomplished without major modification of the structure or running gear. As long as batteries are as heavy and require as much space as they currently do, they must be divided into two packages, one at front under the hood and a second at the rear under the cargo area, in order to achieve the desired weight distribution. The weight distribution criteria requires the placement of batteries at the front of the vehicle even when the central tunnel is used for the location of some batteries. The optimum layout has a front motor and front wheel drive. This configuration provides the optimum vehicle dynamic handling characteristics and the maximum passenger and cargo space for a given size vehicle.

Gilmour, J. L.

1980-01-01

5

Optimization methods applied to hybrid vehicle design  

NASA Technical Reports Server (NTRS)

The use of optimization methods as an effective design tool in the design of hybrid vehicle propulsion systems is demonstrated. Optimization techniques were used to select values for three design parameters (battery weight, heat engine power rating and power split between the two on-board energy sources) such that various measures of vehicle performance (acquisition cost, life cycle cost and petroleum consumption) were optimized. The apporach produced designs which were often significant improvements over hybrid designs already reported on in the literature. The principal conclusions are as follows. First, it was found that the strategy used to split the required power between the two on-board energy sources can have a significant effect on life cycle cost and petroleum consumption. Second, the optimization program should be constructed so that performance measures and design variables can be easily changed. Third, the vehicle simulation program has a significant effect on the computer run time of the overall optimization program; run time can be significantly reduced by proper design of the types of trips the vehicle takes in a one year period. Fourth, care must be taken in designing the cost and constraint expressions which are used in the optimization so that they are relatively smooth functions of the design variables. Fifth, proper handling of constraints on battery weight and heat engine rating, variables which must be large enough to meet power demands, is particularly important for the success of an optimization study. Finally, the principal conclusion is that optimization methods provide a practical tool for carrying out the design of a hybrid vehicle propulsion system.

Donoghue, J. F.; Burghart, J. H.

1983-01-01

6

Airbreathing hypersonic vehicle design and analysis methods  

NASA Technical Reports Server (NTRS)

The design, analysis, and optimization of airbreathing hypersonic vehicles requires analyses involving many highly coupled disciplines at levels of accuracy exceeding those traditionally considered in a conceptual or preliminary-level design. Discipline analysis methods including propulsion, structures, thermal management, geometry, aerodynamics, performance, synthesis, sizing, closure, and cost are discussed. Also, the on-going integration of these methods into a working environment, known as HOLIST, is described.

Lockwood, Mary Kae; Petley, Dennis H.; Hunt, James L.; Martin, John G.

1996-01-01

7

HIFiRE-5 Flight Vehicle Design  

NASA Technical Reports Server (NTRS)

The Hypersonic International Flight Research Experimentation (HIFiRE) program is a hypersonic flight test program executed by the Air Force Research Laboratories (AFRL) and Australian Defence Science and Technology Organization (DSTO). HIFiRE flight 5 is devoted to measuring transition on a three-dimensional body. This paper summarizes payload configuration, trajectory, vehicle stability limits and roughness tolerances. Results show that the proposed configuration is suitable for testing transition on a three-dimensional body. Transition is predicted to occur within the test window, and a design has been developed that will allow the vehicle to be manufactured within prescribed roughness tolerances

Kimmel, Roger L.; Adamczak, David; Berger, Karen; Choudhari, Meelan

2010-01-01

8

Space vehicle meteoroid shielding design  

NASA Technical Reports Server (NTRS)

Design principles of spaced, multiwall meteoroid protection are investigated in the light of experimental data generated during the Apollo Program. The outer wall or shield is shown to be the most important element in the meteoroid-spacecraft interaction. The condition of the debris is primarily a function of the shock pressure, the melting points of the meteoroid and the shield, and the length of the meteoroid and thickness of the shield. Spacing between the walls is effective up to approximately 100 times the length of the meteoroid. The required thickness of the second wall is shown to be proportional to the meteoroid mass, velocity, and density, and to the spacing between the walls, taken with exponents dependent upon the condition of the debris. The effects of placing additional elements (insulation or honeycomb cells) between the two walls are discussed, and the efficiency of various protective configurations is presented. An analysis of the meteoroid protection proposed for the Comet Halley probe is included as an appendix.

Cour-Palais, B. G.

1979-01-01

9

Dynamic issues in launch vehicle design  

NASA Technical Reports Server (NTRS)

Launch vehicles, in general, have been defined using performance requirements and generic payload characteristics which dictated the propulsion system and the payload carrier. The vehicle concept is then selected using these requirements in conjunction with basic criteria and standards. During the design phase, the selected concept must be modified in order to cope with the numerous dynamic and other problems that occur during design and development. This is costly and is, to some extent, unnecessary. The purpose of this paper is to propose an approach for bringing the dynamic issues into focus during concept selection, where the greatest payoff exists. Delaying consideration of the issues to the design phases creates many problems, not the least of which are the impacts levied against the payload community. Volumes of information exist from prior programs on these dynamic issues and serve as the guidelines for this paper.

Ryan, Robert S.; Jewell, Ronald E.

1993-01-01

10

Design and control of Unmanned Ground Vehicle using SUV  

Microsoft Academic Search

This paper deals with a design and control of unmanned ground vehicle using SUV. The experimental vehicle was mounted smart motor and linear motor. Also, we were equipped with a lot of sensors to view the status of vehicle. Based on this, we have accomplished the research about control over longitudinal and lateral direction, transmission, and emergency stop. The vehicle

Jae-Hoon Jang; Myung-Wook Park; Jeong-yeob Lee; Ji-suk Lee

2009-01-01

11

Aircraft Conceptual Design Using Vehicle Sketch Pad  

NASA Technical Reports Server (NTRS)

Vehicle Sketch Pad (VSP) is a parametric geometry modeling tool that is intended for use in the conceptual design of aircraft. The intent of this software is to rapidly model aircraft configurations without expending the expertise and time that is typically required for modeling with traditional Computer Aided Design (CAD) packages. VSP accomplishes this by using parametrically defined components, such as a wing that is defined by span, area, sweep, taper ratio, thickness to cord, and so on. During this phase of frequent design builds, changes to the model can be rapidly visualized along with the internal volumetric layout. Using this geometry-based approach, parameters such as wetted areas and cord lengths can be easily extracted for rapid external performance analyses, such as a parasite drag buildup. At the completion of the conceptual design phase, VSP can export its geometry to higher fidelity tools. This geometry tool was developed by NASA and is freely available to U.S. companies and universities. It has become integral to conceptual design in the Aeronautics Systems Analysis Branch (ASAB) here at NASA Langley Research Center and is currently being used at over 100 universities, aerospace companies, and other government agencies. This paper focuses on the use of VSP in recent NASA conceptual design studies to facilitate geometry-centered design methodology. Such a process is shown to promote greater levels of creativity, more rapid assessment of critical design issues, and improved ability to quickly interact with higher order analyses. A number of VSP vehicle model examples are compared to CAD-based conceptual design, from a designer perspective; comparisons are also made of the time and expertise required to build the geometry representations as well.

Fredericks, William J.; Antcliff, Kevin R.; Costa, Guillermo; Deshpande, Nachiket; Moore, Mark D.; Miguel, Edric A. San; Snyder, Alison N.

2010-01-01

12

Habitability Designs for Crew Exploration Vehicle  

NASA Technical Reports Server (NTRS)

NASA's space human factors team is contributing to the habitability of the Crew Exploration Vehicle (CEV), which will take crews to low Earth orbit, and dock there with additional vehicles to go on to the moon's surface. They developed a task analysis for operations and for self-sustenance (sleeping, eating, hygiene), and estimated the volumes required for performing the various tasks and for the associated equipment, tools and supplies. Rough volumetric mockups were built for crew evaluations. Trade studies were performed to determine the size and location of windows. The habitability analysis also contributes to developing concepts of operations by identifying constraints on crew time. Recently completed studies provided stowage concepts, tools for assessing lighting constraints, and approaches to medical procedure development compatible with the tight space and absence of gravity. New work will be initiated to analyze design concepts and verify that equipment and layouts do meet requirements.

Woolford, Barbara

2006-01-01

13

Design Methodology for Unmannded Aerial Vehicle (UAV) Team Coordination  

E-print Network

1 Design Methodology for Unmannded Aerial Vehicle (UAV) Team Coordination F.B. da Silva S.D. Scott-mail: halab@mit.edu #12;2 Design Methodology for Unmannded Aerial Vehicle (UAV) Team Coordination by F.B. da Silva, S.D. Scott, and M.L. Cummings Executive Summary Unmanned Aerial Vehicle (UAV) systems, despite

Cummings, Mary "Missy"

14

Avionics systems design for cooperative unmanned air and ground vehicles  

E-print Network

This thesis summarizes the results of the design of avionics systems intended for use onboard unmanned air and ground vehicles, that are parts of a multi-vehicle system whose primary mission objective is to provide up-close ...

Omelchenko, Alexander, 1968-

2004-01-01

15

Wooden Spaceships: Human-Centered Vehicle Design for Space  

NASA Technical Reports Server (NTRS)

Presentation will focus on creative human centered design solutions in relation to manned space vehicle design and development in the NASA culture. We will talk about design process, iterative prototyping, mockup building and user testing and evaluation. We will take an inside look at how new space vehicle concepts are developed and designed for real life exploration scenarios.

Twyford, Evan

2009-01-01

16

Computational Aerothermodynamic Design Issues for Hypersonic Vehicles  

NASA Technical Reports Server (NTRS)

A brief review of the evolutionary progress in computational aerothermodynamics is presented. The current status of computational aerothermodynamics is then discussed, with emphasis on its capabilities and limitations for contributions to the design process of hypersonic vehicles. Some topics to be highlighted include: (1) aerodynamic coefficient predictions with emphasis on high temperature gas effects; (2) surface heating and temperature predictions for thermal protection system (TPS) design in a high temperature, thermochemical nonequilibrium environment; (3) methods for extracting and extending computational fluid dynamic (CFD) solutions for efficient utilization by all members of a multidisciplinary design team; (4) physical models; (5) validation process and error estimation; and (6) gridding and solution generation strategies. Recent experiences in the design of X-33 will be featured. Computational aerothermodynamic contributions to Mars Pathfinder, METEOR, and Stardust (Comet Sample return) will also provide context for this discussion. Some of the barriers that currently limit computational aerothermodynamics to a predominantly reactive mode in the design process will also be discussed, with the goal of providing focus for future research.

Gnoffo, Peter A.; Weilmuenster, K. James; Hamilton, H. Harris, II; Olynick, David R.; Venkatapathy, Ethiraj

1997-01-01

17

Computational Aerothermodynamic Design Issues for Hypersonic Vehicles  

NASA Technical Reports Server (NTRS)

A brief review of the evolutionary progress in computational aerothermodynamics is presented. The current status of computational aerothermodynamics is then discussed, with emphasis on its capabilities and limitations for contributions to the design process of hypersonic vehicles. Some topics to be highlighted include: (1) aerodynamic coefficient predictions with emphasis on high temperature gas effects; (2) surface heating and temperature predictions for thermal protection system (TPS) design in a high temperature, thermochemical nonequilibrium environment; (3) methods for extracting and extending computational fluid dynamic (CFD) solutions for efficient utilization by all members of a multidisciplinary design team; (4) physical models; (5) validation process and error estimation; and (6) gridding and solution generation strategies. Recent experiences in the design of X-33 will be featured. Computational aerothermodynamic contributions to Mars Path finder, METEOR, and Stardust (Comet Sample return) will also provide context for this discussion. Some of the barriers that currently limit computational aerothermodynamics to a predominantly reactive mode in the design process will also be discussed, with the goal of providing focus for future research.

Gnoffo, Peter A.; Weilmuenster, K. James; Hamilton, H. Harris, II; Olynick, David R.; Venkatapathy, Ethiraj

2005-01-01

18

Computational Aerothermodynamic Design Issues for Hypersonic Vehicles  

NASA Technical Reports Server (NTRS)

A brief review of the evolutionary progress in computational aerothermodynamics is presented. The current status of computational aerothermodynamics is then discussed, with emphasis on its capabilities and limitations for contributions to the design process of hypersonic vehicles. Some topics to be highlighted include: (1) aerodynamic coefficient predictions with emphasis on high temperature gas effects; (2) surface heating and temperature predictions for thermal protection system (TPS) design in a high temperature, thermochemical nonequilibrium environment; (3) methods for extracting and extending computational fluid dynamic (CFD) solutions for efficient utilization by all members of a multidisciplinary design team; (4) physical models; (5) validation process and error estimation; and (6) gridding and solution generation strategies. Recent experiences in the design of X-33 will be featured. Computational aerothermodynamic contributions to Mars Pathfinder, METEOR, and Stardust (Comet Sample return) will also provide context for this discussion. Some of the barriers that currently limit computational aerothermodynamics to a predominantly reactive mode in the design process will also be discussed, with the goal of providing focus for future research.

Olynick, David R.; Venkatapathy, Ethiraj

2004-01-01

19

Design and mobility evaluation of tracked lunar vehicle  

Microsoft Academic Search

Past lunar vehicles have had difficulty traveling through soft sand areas due to the thick, soft and dry regolith. This paper describes the design and evaluation results of a tracked lunar vehicle which aims at achieving greater mobility, particularly improved climbing ability on pure sand slopes, by reducing contact pressure with a crawler link. The tracked vehicle uses mesh crawler

Sachiko Wakabayashi; Hitoshi Sato; Shin-Ichiro Nishida

2009-01-01

20

Autonomous Controller Design for Unmanned Aerial Vehicles using  

E-print Network

Autonomous Controller Design for Unmanned Aerial Vehicles using Multi-objective Genetic Programming controllers were developed for fixed wing unmanned aerial vehicle (UAV) applications using multi well to real UAVs. 2 Unmanned Aerial Vehicle Simulation The focus of this research was the development

Fernandez, Thomas

21

Mechatronic design and control of hybrid electric vehicles  

Microsoft Academic Search

The work in this paper presents techniques for design, development, and control of hybrid electric vehicles (HEV). Toward these ends, four issues are explored. First, the development of HEV is presented. This synopsis includes a novel definition of degree of hybridization for automotive vehicles. Second, a load-leveling vehicle operation strategy is developed. In order to accomplish the strategy, a fuzzy

Bernd M. Baumann; Gregory Washington; Bradley C. Glenn; Giorgio Rizzoni

2000-01-01

22

Mechanical Design of Step-Climbing Vehicle with Passive Linkages  

Microsoft Academic Search

In our current research, we are developing a holonomic mobile vehicle which is capable of running over the irregular terrain. Our developing vehicle realizes omni-directional motion on at o or using special wheels and passes over non-at ground using the passive suspension mechanism. This paper proposes a mechanical design of passive linkages for increasing the vehicle's mobile performance on rough

Daisuke Chugo; Kuniaki Kawabata; Hayato Kaetsu; Hajime Asam; Taketoshi Mishima

2007-01-01

23

Accelerating the Design of Space Vehicles  

NASA Technical Reports Server (NTRS)

One of NASA's key goals is to increase the safety and reduce the cost of space transportation. Thus, a key element of NASA's new Integrated Space Transportation Plan is to develop new propulsion, structures, and operations for future generations of reusable launch vehicles (RLVs). As part of this effort to develop the next RLV, the ClCT Program's Computing, Networking, and Information Systems (CNIS) Project is developing and demonstrating collaborative software technologies that use the collective power of the NASA Grid to accelerate spacecraft design. One of these technologies, called AeroDB, automates the execution and monitoring of computational fluid dynamics (CFD) parameter studies on the NASA Grid. About the NASA Grid The NASA Grid, or Information Power Grid,. is being developed to leverage the distributed resources of NASA's many computers. instruments, simulators, and data storage systems. The goal is to use these combined resources to sdve difficult NASA challenges, such as iimulating the entire flight of a space vehicle from ascent to descent.To realize the vision of the NASA Grid, the CNIS Project is developing the software framework and protocols for building domain-specific environments and interfaces, new Grid services based on emerging industry standards, and advanced networking and computing testbeds to support new Grid-based applications such as AeroDB.

Laufenberg, Larry (Editor)

2003-01-01

24

Vehicle classes for pavement design and capacity analysis  

SciTech Connect

Transportation engineers working in Colorado were aware of a lack of published data at both the local and national level for vehicle classes on urban streets. Such vehicle class breakdowns are necessary for calculating equivalent daily loaded axle (EDLA) values for pavement design and conducting capacity analyses. A technical committee was formed to collect and analyze weekday vehicle class data on urban streets of various types. The major vehicle classes are passenger cars (70-75%), pickups (15-20%), single unit trucks (5-7%); tractor-trailers, buses, and recreational vehicles account for less than 1%. Using these data, a microcomputer spread sheet was set up to calculate EDLA values for pavement design for a range of design year volumes. This vehicle class data is also very useful in highway capacity calculations.

Kubala, J.; Asce, M.; Lalani, N.; O'Connell, R.; Petersen, C.

1986-11-01

25

Design diversity of HEVs with example vehicles from HEV competitions  

SciTech Connect

Hybrid Electric Vehicles (HEVS) can be designed and operated to satisfy many different operational missions. The three most common HEV types differ with respect to component sizing and operational capabilities. However, HEV technology offers design opportunities beyond these three types. This paper presents a detailed HEV categorization process that can be used to describe unique HEV prototype designs entered in college and university-level HEV design competitions. We explored possible energy management strategies associated with designs that control the utilization of the two on- board energy sources and use the competition vehicles to illustrate various configurations and designs that affect the vehicle`s capabilities. Experimental data is used to help describe the details of the power control strategies which determine how the engine and electric motor of HEV designs work together to provide motive power to the wheels.

Duoba, M.; Larsen, R.; LeBlanc, N.

1996-12-31

26

Winged cargo return vehicle. Volume 1: Conceptual design  

NASA Technical Reports Server (NTRS)

The Advanced Design Project (ADP) allows an opportunity for students to work in conjunction with NASA and other aerospace companies on NASA Advanced Design Projects. The following volumes represent the design report: Volume 1 Conceptual Design; Volume 2 Wind Tunnel Tests; Volume 3 Structural Analysis; and Volume 4 Water Tunnel Tests. The project chosen by the University of Minnesota in conjunction with NASA Marshall Space Flight Center for this year is a Cargo Return Vehicle (CRV) to support the Space Station Freedom. The vehicle is the third generation of vehicles to be built by NASA, the first two being the Apollo program, and the Space Shuttle program. The CRV is to work in conjunction with a personnel launch system (PLS) to further subdivide and specialize the vehicles that NASA will operate in the year 2000. The cargo return vehicle will carry payload to and from the Space Station Freedom (SSF).

1990-01-01

27

Department of Mechanical Engineering Spring 2012 Space Vehicle Water Drop Test and Vehicle Design  

E-print Network

PENNSTATE Department of Mechanical Engineering Spring 2012 Space Vehicle Water Drop Test to The Boeing Company Research other small scale water impact testing Research data acquisition systems to achieve adequate sampling rates Design a simplified water landing test vehicle on a small scale

Demirel, Melik C.

28

Design considerations for engineering Autonomous Underwater Vehicles  

E-print Network

Autonomous Underwater Vehicles (AUVs) have been established as a viable tool for Oceanographic Sciences. Being untethered and independent, AUVs fill the gap in Ocean Exploration left by the existing manned submersible and ...

Shah, Vikrant P. (Vikrant Pankaj)

2007-01-01

29

Two designs for an orbital transfer vehicle  

NASA Technical Reports Server (NTRS)

The Orbital Transfer Vehicle (OTV) and systems were researched in the following areas: avionics, crew systems, electrical power systems, environmental control/life support systems, navigation and orbital maneuvers, propulsion systems, reaction control systems (RCS), servicing systems, and structures.

Davis, Richard; Duquette, Miles; Fredrick, Rebecca; Schumacher, Daniel; Somers, Schaeffer; Stafira, Stanley; Williams, James; Zelinka, Mark

1988-01-01

30

Designing space vehicle shields for meteoroid protection: A new analysis  

Microsoft Academic Search

Dual-layer meteroid shields consisting of sacrificial bumper plates spaced some distance outboard from the vehicle hull are the most effective structures yet conceived for protecting space vehicles from supervelocity meteroid impacts. This paper presents a new analysis for designing dual-layer shields. The analysis is based upon energy and momentum conservation, fundamental electromagnetic radiation physics, and observation of results from extensive

H. F. Swift; R. Bamford; R. Chen

1982-01-01

31

Design of a fast crew transfer vehicle to Mars  

NASA Technical Reports Server (NTRS)

A final report is made on the trajectory and vehicle requirements for a fast crew transfer vehicle to Mars which will complete an Earth to Mars (and Mars to Earth) transfer in 150 days and will have a stay time at Mars of 40 days. This vehicle will maximize the crew's effectiveness on Mars by minimizing detrimental physiological effects such as bone demineralization and loss of muscle tone caused by long period exposure to zero gravity and radiation from cosmic rays and solar flares. The crew transfer vehicle discussed will complete the second half of a Split Mission to Mars. In the Split Mission, a slow, unmanned cargo vehicle, nicknamed the Barge, is sent to Mars ahead of the crew vehicle. Once the Barge is in orbit around Mars, the fast crew vehicle will be launched to rendezvous with the Barge in Mars orbit. The vehicle presented is designed to carry six astronauts for a mission duration of one year. The vehicle uses a chemical propulsion system and a nuclear power system. Four crew modules, similar to the proposed Space Station Common Modules, are used to house the crew and support equipment during the mission. The final design also includes a command module that is shielded to protect the crew during radiation events.

1988-01-01

32

Design and implementation of liquid cooling system for ArchiMITes vehicle  

E-print Network

MIT Vehicle Design Summit is building ArchiMITes, a lightweight hybrid vehicle with a modular auxiliary power unit. For testing purposes, the vehicle platform will first be built as an all-electric vehicle. It will be ...

Hui, Sam, S.B. Massachusetts Institute of Technology

2011-01-01

33

Mars reconnaissance lander: Vehicle and mission design  

NASA Astrophysics Data System (ADS)

There is enormous potential for more mobile planetary surface science. This is especially true in the case of Mars because the ability to cross challenge terrain, access areas of higher elevation, visit diverse geological features and perform long traverses of up to 200 km supports the search for past water and life. Vehicles capable of a ballistic 'hop' have been proposed on several occasions, but those proposals using in-situ acquired propellants are the most promising for significant planetary exploration. This paper considers a mission concept termed Mars Reconnaissance Lander using such a vehicle. We describe an approach where planetary science requirements that cannot be met by a conventional rover are used to derive vehicle and mission requirements. The performance of the hopper vehicle was assessed by adding estimates of gravity losses and mission mass constraints to recently developed methods. A baseline vehicle with a scientific payload of 16.5 kg and conservatively estimated sub-system masses is predicted to achieve a flight range of 0.97 km. Using a simple consideration of system reliability, the required cumulative range of 200 km could be achieved with a probability of around 80%. Such a range is sufficient to explore geologically diverse terrains. We therefore plot an illustrative traverse in Hypanis Valles/Xanthe Terra, which encounters crater wall sections, periglacial terrain, aqueous sedimentary deposits and a traverse up an ancient fluvial channel. Such a diversity of sites could not be considered with a conventional rover. The Mars Reconnaissance Lander mission and vehicle presents some very significant engineering challenges, but would represent a valuable complement to rovers, static landers and orbital observations.

Williams, H. R.; Bridges, J. C.; Ambrosi, R. M.; Perkinson, M.-C.; Reed, J.; Peacocke, L.; Bannister, N. P.; Howe, S. D.; O'Brien, R. C.; Klein, A. C.

2011-10-01

34

Preliminary subsystem designs for the Assured Crew Return Vehicle (ACRV)  

NASA Technical Reports Server (NTRS)

Described herein is a series of design studies concerning the Assured Crew Return Vehicle (ACRV). Study topics include a braking and landing system for the ACRV, ACRV growth options, and the design impacts of ACRV's role as a medical emergency vehicle. Four alternate designs are presented for the ACRV braking and landing system. Options presented include ballistic and lifting body reentries; the use of high-lift, high-payload aerodynamic decelerators, as well as conventional parachutes; landing systems designed for water landings, land landings or both; and an aerial recovery system. Uses of the ACRV or a similarly designed vehicle in several roles for possible future space missions are discussed, along with the required changes to the ACRV to allow it to perform these missions optimally. The impacts on the design of the ACRV due to its role as an emergency vehicle were studied and are presented here. This study included the design of a stretcher-like system to transport an ill or injured crewmember safely within the ACRV; a compilation of necessary medical equipment and decisions on how or where to store it; and recommendations about internal and external vehicle characteristics that will ease the transport of the ill or injured crewmember and allow for swift and easy ingress/egress of the vehicle.

1990-01-01

35

Control system design for a parallel hybrid electric vehicle  

E-print Network

This thesis addresses the design of control systems for a parallel hybrid electric drive train which is an alternative to conventional passenger vehicles. The principle components of the drive train are a small internal combustion engine...

Buntin, David Leighton

2012-06-07

36

Design of a vehicle based system to prevent ozone loss  

NASA Technical Reports Server (NTRS)

This project is designed to be completed over a three year period. Overall project goals are: (1) to understand the processes that contribute to stratospheric ozone loss; (2) to determine the best scheme to prevent ozone loss; and (3) to design a vehicle based system to carry out the prevention scheme. The 1993/1994 design objectives included: (1) to review the results of the 1992/1993 design team, including a reevaluation of the key assumptions used; (2) to develop a matrix of baseline vehicle concepts as candidates for the delivery vehicle; and (3) to develop a selection criteria and perform quantitative trade studies to use in the selection of the specific vehicle concept.

Talbot, Matthew D.; Eby, Steven C.; Ireland, Glen J.; Mcwithey, Michael C.; Schneider, Mark S.; Youngblood, Daniel L.; Johnson, Matt; Taylor, Chris

1994-01-01

37

Preliminary design data package, appendix C. [hybrid electric vehicles  

NASA Technical Reports Server (NTRS)

The data and documentation required to define the preliminary design of a near term hybrid vehicle and to quantify its operational characteristics are presented together with the assumptions and rationale behind the design decisions. Aspects discussed include development requirements for the propulsion system, the chassis system, the body, and the vehicle systems. Particular emphasis is given to the controls, the heat engine, and the batteries.

1979-01-01

38

Intelligent controller design for electric vehicle  

Microsoft Academic Search

In some electric vehicle the power supplied by the battery is DC in nature and is inappropriate to operate a variable speed DC motor. The battery power is converted to the required regulated supply for the motor by using an electronic power converter. The exact nature and timing of the current and voltage waveforms that are fed to the motor

S. Poorani; K. U. Kumar; S. Renganarayanan

2003-01-01

39

Design considerations for a contactless electric vehicle battery charger  

Microsoft Academic Search

This paper overviews theoretical and practical design issues related to inductive power transfer systems and verifies the developed theory using a practical electric vehicle battery charger. The design focuses on the necessary approaches to ensure power transfer over the complete operating range of the system. As such, a new approach to the design of the primary resonant circuit is proposed,

Chwei-Sen Wang; Oskar H. Stielau; Grant A. Covic

2005-01-01

40

Jig of passenger vehicle chassis design and welding process simulation  

Microsoft Academic Search

Based on the design theory of jig welding and installing chassis wiring. The welding fixture and the weld install main line of the various locations of the passenger vehicle after floor are planed and designed, using CATIA V5R17 to modelling and assembling the jig, Conforms to the request jig chart is designed and produces the engineering plat. Then using the

Yinhu Qiao; Jiang Han; Chunyan Zhang

2010-01-01

41

ME 409: Flight Vehicle Design I: Information Sheet  

E-print Network

) Piazza: See below for description of Piazza TEXTBOOKS: Required: Aircraft Design: A Conceptual Approach, Daniel Raymer, AIAA, 2006 Reference:* Design of Aircraft, Thomas Corke, Prentice Hall, 2003 AirplaneME 409: Flight Vehicle Design I: Information Sheet 1 INSTRUCTOR: Prof. Don Wroblewski OFFICE HRS: M

42

ME 410 Flight Vehicle Design II Spring 2011 Information Sheet  

E-print Network

E-MAIL Don Wroblewski ENG 415 TBA 3-9739 dew11@bu.edu TEXT: Recommended: Aircraft Design in this class will be a preliminary design of an aircraft, to be accomplished in teams. The idea is to have eachME 410 Flight Vehicle Design II Spring 2011 Information Sheet INSTRUCTOR: OFFICE: OFFICE HRS: PHONE

43

Design and analysis of a gyroscopically controlled micro air vehicle  

NASA Astrophysics Data System (ADS)

Much of the current research on micro air vehicle design relies on aerodynamic forces for attitude control. The aerodynamic environment in which micro air vehicles operate is characterized by a low Reynolds number and is not fully understood, resulting in decreased performance and efficiency when compared to large-scale vehicles. In this work, we propose a new rotary-wing micro air vehicle design that utilizes gyroscopic dynamics for attitude control. Unlike traditional micro air vehicles where attitude control moments are generated by aerodynamic control surfaces, the proposed vehicle will leverage the existing angular momentum of its rotating components to generate gyroscopic moments for controlling attitude. We explore this paradigm in an effort to reduce mechanical complexity that is inherent in blade pitch modulation mechanisms such as the swashplate, and to increase agility and possibly even efficiency when compared to state-of-the-art micro vertical-take-off-and-landing vehicles. The evolution of the mechanical design, including the evaluation of three prototypes that explore the use of gyroscopic attitude control, is presented along with a comprehensive dynamic and aerodynamic model of the third prototype. Two controllers that utilize gyroscopic moments are developed and tested in simulation. In addition, several experiments were performed using a VICON motion tracking system and off-board control. These results will also be presented.

Thorne, Christopher Everett

44

Precipitation. [and space vehicle design criteria  

NASA Technical Reports Server (NTRS)

Precipitation is usually defined as all forms of hydrometeors, liquid or solid, which are free in the atmosphere and which reach the ground. In this report the definition is extended to those hydrometeors which do not reach the ground, but impinge on a flying surface, such as space vehicles. Accumulation is reported in depth over a horizontal surface; i.e., millimeters or inches for the liquid phase and in depth or equivalent depth of water equivalent for the frozen phase.

1973-01-01

45

Aerospace Vehicle Design, Spacecraft Section. Volume 3  

NASA Technical Reports Server (NTRS)

Research results are presented for the following groups: Project Mars Airplane Vehicle and Reconnaissance Instrument Carrier (MAVRIC), ACME, ARES, Project ACRONYM, Mars Aircraft Recepticle with Technical Instruments, Aerobraking, and Navigation (MARTIAN), and NOMADS. Each project is described by the following areas of focus: mission planning and costs; aerobraking systems; structures and thermal control systems; attitude and articulation control systems; comman and data control systems; science instrumentation; and power and propulsion systems.

1988-01-01

46

Development of Integrated Programs for Aerospace-Vehicle Design (IPAD)  

NASA Technical Reports Server (NTRS)

Integrated Programs for Aerospace Vehicle Design (IPAD) system design requirements are given. The information is based on the IPAD User Requirements Document (D6-IPAD-70013-D) and the Integrated Information Processing Requirements Document (D6-IPAD-70012-D). General information about IPAD and a list of the system design requirements that are to be satisfied by the IPAD system are given. The system design requirements definition is to be considered as a baseline definition of the IPAD system design requirements.

Anderson, O. L.; Calvery, A. L.; Davis, D. A.; Dickmann, L.; Folger, D. H.; Jochem, E. N.; Kitto, C. M.; Vonlimbach, G.

1977-01-01

47

Conceptual design of flapping-wing micro air vehicles.  

PubMed

Traditional micro air vehicles (MAVs) are miniature versions of full-scale aircraft from which their design principles closely follow. The first step in aircraft design is the development of a conceptual design, where basic specifications and vehicle size are established. Conceptual design methods do not rely on specific knowledge of the propulsion system, vehicle layout and subsystems; these details are addressed later in the design process. Non-traditional MAV designs based on birds or insects are less common and without well-established conceptual design methods. This paper presents a conceptual design process for hovering flapping-wing vehicles. An energy-based accounting of propulsion and aerodynamics is combined with a one degree-of-freedom dynamic flapping model. Important results include simple analytical expressions for flight endurance and range, predictions for maximum feasible wing size and body mass, and critical design space restrictions resulting from finite wing inertia. A new figure-of-merit for wing structural-inertial efficiency is proposed and used to quantify the performance of real and artificial insect wings. The impact of these results on future flapping-wing MAV designs is discussed in detail. PMID:22498507

Whitney, J P; Wood, R J

2012-09-01

48

Application of optimization techniques to vehicle design: A review  

NASA Technical Reports Server (NTRS)

The work that has been done in the last decade or so in the application of optimization techniques to vehicle design is discussed. Much of the work reviewed deals with the design of body or suspension (chassis) components for reduced weight. Also reviewed are studies dealing with system optimization problems for improved functional performance, such as ride or handling. In reviewing the work on the use of optimization techniques, one notes the transition from the rare mention of the methods in the 70's to an increased effort in the early 80's. Efficient and convenient optimization and analysis tools still need to be developed so that they can be regularly applied in the early design stage of the vehicle development cycle to be most effective. Based on the reported applications, an attempt is made to assess the potential for automotive application of optimization techniques. The major issue involved remains the creation of quantifiable means of analysis to be used in vehicle design. The conventional process of vehicle design still contains much experience-based input because it has not yet proven possible to quantify all important constraints. This restraint on the part of the analysis will continue to be a major limiting factor in application of optimization to vehicle design.

Prasad, B.; Magee, C. L.

1984-01-01

49

Airbreathing Hypersonic Vision-Operational-Vehicles Design Matrix  

NASA Technical Reports Server (NTRS)

This paper presents the status of the airbreathing hypersonic airplane and space-access vision-operational-vehicle design matrix, with emphasis on horizontal takeoff and landing systems being, studied at Langley, it reflects the synergies and issues, and indicates the thrust of the effort to resolve the design matrix including Mach 5 to 10 airplanes with global-reach potential, pop-up and dual-role transatmospheric vehicles and airbreathing launch systems. The convergence of several critical systems/technologies across the vehicle matrix is indicated. This is particularly true for the low speed propulsion system for large unassisted horizontal takeoff vehicles which favor turbines and/or perhaps pulse detonation engines that do not require LOX which imposes loading concerns and mission Flexibility restraints.

Hunt, James L.; Pegg, Robert J.; Petley, Dennis H.

1999-01-01

50

Airbreathing Hypersonic Vision-Operational-Vehicles Design Matrix  

NASA Technical Reports Server (NTRS)

This paper presents the status of the airbreathing hypersonic airplane and space-access vision-operational-vehicle design matrix, with emphasis on horizontal takeoff and landing systems being studied at Langley; it reflects the synergies and issues, and indicates the thrust of the effort to resolve the design matrix including Mach 5 to 10 airplanes with global-reach potential, pop-up and dual-role transatmospheric vehicles and airbreathing launch systems. The convergence of several critical systems/technologies across the vehicle matrix is indicated. This is particularly true for the low speed propulsion system for large unassisted horizontal takeoff vehicles which favor turbines and/or perhaps pulse detonation engines that do not require LOX which imposes loading concerns and mission flexibility restraints.

Hunt, James L.; Pegg, Robert J.; Petley, Dennis H.

1999-01-01

51

Design of a Smart Unmanned Ground Vehicle for Hazardous Environments  

E-print Network

A smart Unmanned Ground Vehicle (UGV) is designed and developed for some application specific missions to operate predominantly in hazardous environments. In our work, we have developed a small and lightweight vehicle to operate in general cross-country terrains in or without daylight. The UGV can send visual feedbacks to the operator at a remote location. Onboard infrared sensors can detect the obstacles around the UGV and sends signals to the operator.

Chakraborty, Saurav

2010-01-01

52

Design of multiple-input power converter for hybrid vehicles  

Microsoft Academic Search

This paper deals with designing and sizing of a multiple-input power electronic converter (MIPEC) to be used in an electric vehicle propulsion system that includes a fuel cell (FC) generator and a combined storage unit. The combined storage unit is composed by an ultracapacitors tank (UC) and a battery unit (BU). MIPEC is responsible for power-flow management on-board the vehicle

Luca Solero; Alessandro Lidozzi; Josè Antenor Pomilio

2005-01-01

53

Control Design for Autonomous Vehicles: A Dynamic Optimization Perspective  

Microsoft Academic Search

Control design for autonomous vehicles involves a number of issues that are not satisfactorily addressed in classical control systems theory. There is typically the need for prescribing and commanding a collection of interacting dynamic control systems in order to meet the desired requirements for overall behavior, whereas conventional control design has only one system to govern. This context requires a

Fernando Lobo Pereira

2001-01-01

54

Powertrain Communication System Design of Hybrid Electric Vehicle  

Microsoft Academic Search

In the automotive system design flow, protocol design is an essential step which mainly includes message allocation, message priority assignment and message period assignment. This work provides an approach in the message period assignment through experiment and validation. The experiment and validation takes the powertrain system of hybrid electric vehicle as the platform. Under the baud rate of 500 Kbps,

Lifang Wang; Fang Li; Chenglin Liao

2009-01-01

55

Design and evolution of a piezoelectrically actuated miniature swimming vehicle  

Microsoft Academic Search

This work details the design of a miniature swimming vehicle that propels itself through oscillations of a flexible fin mounted in the stern. The fin is driven through a mechanism that is actuated by two curved-beam bending piezoelectric actuators. An optimization routine is used to design the mechanism for rigid body guidance. The actuators are modeled statically using the Bernoulli-Euler

Michael G. Borgen; Gregory N. Washington; Gary L. Kinzel

2003-01-01

56

Advanced lead acid battery designs for hybrid electric vehicles  

Microsoft Academic Search

In this paper, the authors present a high power, lead acid battery design that has demonstrated long life. The design uses horizontal plates with multiple lug connectors to deliver high power for hybrid electric vehicle applications. The horizontal plate configuration helps improve life by allowing for better thermal management and mechanical compression. They use computer models that were previously developed

Dean B. Edwards; Charles Kinney

2001-01-01

57

Design study of flat belt CVT for electric vehicles  

NASA Technical Reports Server (NTRS)

A continuously variable transmission (CVT) was studied, using a novel flat belt pulley arrangement which couples the high speed output shaft of an energy storage flywheel to the drive train of an electric vehicle. A specific CVT arrangement was recommended and its components were selected and sized, based on the design requirements of a 1700 KG vehicle. A design layout was prepared and engineering calculations made of component efficiencies and operating life. The transmission efficiency was calculated to be significantly over 90% with the expected vehicle operation. A design consistent with automotive practice for low future production costs was considered, together with maintainability. The technology advancements required to develop the flat belt CVT were identified and an estimate was made of how the size of the flat belt CVT scales to larger and smaller design output torques. The suitability of the flat belt CVT for alternate application to an electric vehicle powered by an electric motor without flywheel and to a hybrid electric vehicle powered by an electric motor with an internal combustion engine was studied.

Kumm, E. L.

1980-01-01

58

Performance and design analysis of ballistic reusable SSTO launch vehicles  

NASA Astrophysics Data System (ADS)

Based on previous system studies of MBB on single-stage ballistic launch vehicles with vertical take-off and landing (VTOL) from 1969 and 1986, a review is presented of the performance and design criteria of such advanced launch systems with respect to the present 'state of the art'. This type of launch vehicle is a prime candidate for an economical future space transportation system in the medium-size payload class. Ascent trajectory optimization, which is more difficult than for a multistage rocket, reveals the requirement for a careful thrust variation (reduction) during ascent as well as a high takeoff acceleration in order to achieve the minimum velocity requirement and maximum payload. Further, the impact of vehicle net mass and average specific impulse are presented as well as the design options for the single-stage to orbit (SSTO) propulsion system and other specific design features.

Koelle, Dietrich E.

59

Fire hazard considerations for composites in vehicle design  

NASA Technical Reports Server (NTRS)

Military ground vehicles fires are a significant cause of system loss, equipment damage, and crew injury in both combat and non-combat situations. During combat, the ability to successfully fight an internal fire, without losing fighting and mobility capabilities, is often the key to crew survival and mission success. In addition to enemy hits in combat, vehicle fires are initiated by electrical system failures, fuel line leaks, munitions mishaps and improper personnel actions. If not controlled, such fires can spread to other areas of the vehicle, causing extensive damage and the potential for personnel injury and death. The inherent fire safety characteristics (i.e. ignitability, compartments of these vehicles play a major roll in determining rather a newly started fire becomes a fizzle or a catastrophe. This paper addresses a systems approach to assuring optimum vehicle fire safety during the design phase of complex vehicle systems utilizing extensive uses of composites, plastic and related materials. It provides practical means for defining the potential fire hazard risks during a conceptual design phase, and criteria for the selection of composite materials based on its fire safety characteristics.

Gordon, Rex B.

1994-01-01

60

Systems design analysis applied to launch vehicle configuration  

NASA Technical Reports Server (NTRS)

As emphasis shifts from optimum-performance aerospace systems to least lift-cycle costs, systems designs must seek, adapt, and innovate cost improvement techniques in design through operations. The systems design process of concept, definition, and design was assessed for the types and flow of total quality management techniques that may be applicable in a launch vehicle systems design analysis. Techniques discussed are task ordering, quality leverage, concurrent engineering, Pareto's principle, robustness, quality function deployment, criteria, and others. These cost oriented techniques are as applicable to aerospace systems design analysis as to any large commercial system.

Ryan, R.; Verderaime, V.

1993-01-01

61

ME 410 Flight Vehicle Design II Spring 2012 Information Sheet  

E-print Network

E-MAIL Don Wroblewski ENG 415 M 4-5 W 9-10 3-9739 dew11@bu.edu TEXT: Recommended: Aircraft Design in this class will be a preliminary design of an aircraft, to be accomplished in teams. The idea is to have eachME 410 Flight Vehicle Design II Spring 2012 Information Sheet INSTRUCTOR: OFFICE: OFFICE HRS: PHONE

62

Analysis Method for Quantifying Vehicle Design Goals  

NASA Technical Reports Server (NTRS)

A document discusses a method for using Design Structure Matrices (DSM), coupled with high-level tools representing important life-cycle parameters, to comprehensively conceptualize a flight/ground space transportation system design by dealing with such variables as performance, up-front costs, downstream operations costs, and reliability. This approach also weighs operational approaches based on their effect on upstream design variables so that it is possible to readily, yet defensively, establish linkages between operations and these upstream variables. To avoid the large range of problems that have defeated previous methods of dealing with the complex problems of transportation design, and to cut down the inefficient use of resources, the method described in the document identifies those areas that are of sufficient promise and that provide a higher grade of analysis for those issues, as well as the linkages at issue between operations and other factors. Ultimately, the system is designed to save resources and time, and allows for the evolution of operable space transportation system technology, and design and conceptual system approach targets.

Fimognari, Peter; Eskridge, Richard; Martin, Adam; Lee, Michael

2007-01-01

63

MIT Electric Vehicle Team Porsche designing a cooling system for the AC24 electric motor  

E-print Network

In this thesis I worked on the design and analysis of a cooling system for the electric motor of the MIT Electric Vehicle Team's Porsche 914 Battery Electric Vehicle. The vehicle's Azure Dynamics AC24 motor tended to ...

Meenen, Jordan N

2010-01-01

64

A design approach for small vision-based autonomous vehicles  

NASA Astrophysics Data System (ADS)

This paper describes the design of a small autonomous vehicle based on the Helios computing platform, a custom FPGA-based board capable of supporting on-board vision. Target applications for the Helios computing platform are those that require lightweight equipment and low power consumption. To demonstrate the capabilities of FPGAs in real-time control of autonomous vehicles, a 16 inch long R/C monster truck was outfitted with a Helios board. The platform provided by such a small vehicle is ideal for testing and development. The proof of concept application for this autonomous vehicle was a timed race through an environment with obstacles. Given the size restrictions of the vehicle and its operating environment, the only feasible on-board sensor is a small CMOS camera. The single video feed is therefore the only source of information from the surrounding environment. The image is then segmented and processed by custom logic in the FPGA that also controls direction and speed of the vehicle based on visual input.

Edwards, Barrett B.; Fife, Wade S.; Archibald, James K.; Lee, Dah-Jye; Wilde, Doran K.

2006-10-01

65

Design Fires for Vehicles in Road Tunnels  

Microsoft Academic Search

Fire in road tunnels is a unique design problem which can lead to serious consequences if not addressed appropriately. Observations from full scale tunnel fire experiments have indicated the heat release rate depends on the ventilation conditions, tunnel geometry and fuel load. Although these experiments have provided valuable information, they are generally very expensive to conduct and the data are

M. K. Cheong; M. J. Spearpoint; C. M. Fleischmann

66

Launch Vehicle Design Process: Characterization, Technical Integration, and Lessons Learned  

NASA Technical Reports Server (NTRS)

Engineering design is a challenging activity for any product. Since launch vehicles are highly complex and interconnected and have extreme energy densities, their design represents a challenge of the highest order. The purpose of this document is to delineate and clarify the design process associated with the launch vehicle for space flight transportation. The goal is to define and characterize a baseline for the space transportation design process. This baseline can be used as a basis for improving effectiveness and efficiency of the design process. The baseline characterization is achieved via compartmentalization and technical integration of subsystems, design functions, and discipline functions. First, a global design process overview is provided in order to show responsibility, interactions, and connectivity of overall aspects of the design process. Then design essentials are delineated in order to emphasize necessary features of the design process that are sometimes overlooked. Finally the design process characterization is presented. This is accomplished by considering project technical framework, technical integration, process description (technical integration model, subsystem tree, design/discipline planes, decision gates, and tasks), and the design sequence. Also included in the document are a snapshot relating to process improvements, illustrations of the process, a survey of recommendations from experienced practitioners in aerospace, lessons learned, references, and a bibliography.

Blair, J. C.; Ryan, R. S.; Schutzenhofer, L. A.; Humphries, W. R.

2001-01-01

67

GPS Receiver Design for Spin-Stabilized Launch Vehicles  

Microsoft Academic Search

This paper describes the design and development of a dedicated GPS receiver for spin stabilized launch vehicles. The receiver is built around a commercially available low cost GPS chip set and operates an enhanced firmware specifically adapted for high dynamics applications. In order to keep tracking a sufficient number of GPS signals even during the spinning motion, we use multiple

Takuji Ebinuma; Tomomichi Kusu; Toshio Abe; Hirobumi Saito

2009-01-01

68

Integrating vehicle design and human factors: minimizing elderly driving constraints  

Microsoft Academic Search

With a projected rise in the number of elderly, most of whom have also relied primarily on the private automobile for their mobility, it is likely that future adaptations in vehicle design will be linked in some part to the physical infirmities often faced by the elderly. This paper offers a bridge between medical research on the physical impairments of

Susan A. Shaheen; Debbie A. Niemeier

2001-01-01

69

Infantry mobility hybrid electric vehicle performance analysis and design  

Microsoft Academic Search

Optimal energy flux analysis and design of a power plant for infantry mobility hybrid diesel-electric vehicle is dealt with in this paper. Control strategy management and propulsion system sizing is done on the basis of minimizing total fuel consumption. A quasi-static system model has allowed analyzing the most restrictive operations; moreover the simulation has been used in expected real driving

Francisco José Jimenez-Espadafor; Juan José Ruiz Marín; José A. Becerra Villanueva; Miguel Torres García; Elisa Carvajal Trujillo; Francisco José Florencio Ojeda

2011-01-01

70

Design of a long endurance Titan VTOL vehicle  

Microsoft Academic Search

Saturn's moon Titan promises insight into numerous key scientific questions, many of which can be investigated only by in situ exploration of its surface and atmosphere. This paper presents research on a vertical takeoff and landing (VTOL) vehicle designed to conduct a scientific investigation of Titan's atmosphere, clouds, haze, surface, and any possible oceans. Multiple options for vertical takeoff and

Ravi Prakash; Robert D. Braun; Luke S. Colby; Scott R. Francis; Mustafa E. Gündüz; Kevin W. Flaherty; Jarret M. Lafleur; Henry S. Wright

2006-01-01

71

Design of a Small Solar-Powered Unmanned Aerial Vehicle  

Microsoft Academic Search

This thesis reports on a conceptual design of a solar-powered unmanned aerial vehicle (UAV) with a mass no more than 10 kg. This UAV will have the necessary equipment to study wildfires in California, including a Global Positioning System (GPS) and infrared cameras. Using similar aircraft in the same weight class, the geometry of the aircraft was calculated. A weight

Christopher Hartney

2011-01-01

72

Emerging CFD technologies and aerospace vehicle design  

NASA Technical Reports Server (NTRS)

With the recent focus on the needs of design and applications CFD, research groups have begun to address the traditional bottlenecks of grid generation and surface modeling. Now, a host of emerging technologies promise to shortcut or dramatically simplify the simulation process. This paper discusses the current status of these emerging technologies. It will argue that some tools are already available which can have positive impact on portions of the design cycle. However, in most cases, these tools need to be integrated into specific engineering systems and process cycles to be used effectively. The rapidly maturing status of unstructured and Cartesian approaches for inviscid simulations makes suggests the possibility of highly automated Euler-boundary layer simulations with application to loads estimation and even preliminary design. Similarly, technology is available to link block structured mesh generation algorithms with topology libraries to avoid tedious re-meshing of topologically similar configurations. Work in algorithmic based auto-blocking suggests that domain decomposition and point placement operations in multi-block mesh generation may be properly posed as problems in Computational Geometry, and following this approach may lead to robust algorithmic processes for automatic mesh generation.

Aftosmis, Michael J.

1995-01-01

73

MDO approach for early design of aerobraking orbital transfer vehicles  

NASA Astrophysics Data System (ADS)

This paper presents a new multidisciplinary design optimization (MDO) methodology for preliminary design of an aeroassisted orbital transfer vehicle (AOTV) performing a two-way transfer between a low-Earth "parking" orbit and a high-energy orbit. This work has been performed in the frame of Onera's CENTOR [N. Bérend, C. Jolly, F. Jouhaud, D. Lazaro, Y. Mauriot, C. Monjaret, J.M. Moschetta, M. Parlier, J.L. Pastre, Y. Servouze, J.L. Vérant, Project CENTOR: Preparing the design of future orbital transfer vehicles; IAC-07-D.2.3.07, in: 58th International Astronautical Congress, 24-28/09/2007, Hyderabad, India] project whose objective is to prepare tools and methodology for studying and designing future space transportation systems for new kinds of missions such as on-orbit servicing (OOS), payload ferrying, or in-situ observation of space-debris. Using simplified models and an appropriate low-dimension formulation for the optimization problem the method makes possible to obtain rapidly and easily a global view of the trade-off between the payload mass and the total mass. It also makes possible to discuss the feasibility of the vehicle with regard to different multidisciplinary constraints and technology hypotheses for the heat shield. This approach is illustrated by eight different AOTV design studies, considering two different missions (LEO-MEO and LEO-GEO), two different propulsion technologies (LOX-LH2 and LOX-CH4) and two different thermal protection system (TPS) characteristics. In each case, we discuss the feasibility and characteristics of the lightest vehicle carrying a prescribed 100 kg payload, and, conversely, a heavy vehicle with a prescribed 18 ton total mass, carrying the heaviest possible payload.

Bérend, N.; Bertrand, S.

2009-12-01

74

IPAD: Integrated Programs for Aerospace-vehicle Design  

NASA Technical Reports Server (NTRS)

Early work was performed to apply data base technology in support of the management of engineering data in the design and manufacturing environments. The principal objective of the IPAD project is to develop a computer software system for use in the design of aerospace vehicles. Two prototype systems are created for this purpose. Relational Information Manager (RIM) is a successful commercial product. The IPAD Information Processor (IPIP), a much more sophisticated system, is still under development.

Miller, R. E., Jr.

1985-01-01

75

MDO approach for early design of aerobraking orbital transfer vehicles  

Microsoft Academic Search

This paper presents a new multidisciplinary design optimization (MDO) methodology for preliminary design of an aeroassisted orbital transfer vehicle (AOTV) performing a two-way transfer between a low-Earth “parking” orbit and a high-energy orbit. This work has been performed in the frame of Onera's CENTOR [N. Bérend, C. Jolly, F. Jouhaud, D. Lazaro, Y. Mauriot, C. Monjaret, J.M. Moschetta, M. Parlier,

N. Bérend; S. Bertrand

2009-01-01

76

Analysis and Design of Launch Vehicle Flight Control Systems  

NASA Technical Reports Server (NTRS)

This paper describes the fundamental principles of launch vehicle flight control analysis and design. In particular, the classical concept of "drift-minimum" and "load-minimum" control principles is re-examined and its performance and stability robustness with respect to modeling uncertainties and a gimbal angle constraint is discussed. It is shown that an additional feedback of angle-of-attack or lateral acceleration can significantly improve the overall performance and robustness, especially in the presence of unexpected large wind disturbance. Non-minimum-phase structural filtering of "unstably interacting" bending modes of large flexible launch vehicles is also shown to be effective and robust.

Wie, Bong; Du, Wei; Whorton, Mark

2008-01-01

77

Entry Vehicle Control System Design for the Mars Smart Lander  

NASA Technical Reports Server (NTRS)

The NASA Langley Research Center, in cooperation with the Jet Propulsion Laboratory, participated in a preliminary design study of the Entry, Descent and Landing phase for the Mars Smart Lander Project. This concept utilizes advances in Guidance, Navigation and Control technology to significantly reduce uncertainty in the vehicle landed location on the Mars surface. A candidate entry vehicle controller based on the Reaction Control System controller for the Apollo Lunar Excursion Module digital autopilot is proposed for use in the entry vehicle attitude control. A slight modification to the phase plane controller is used to reduce jet-firing chattering while maintaining good control response for the Martian entry probe application. The controller performance is demonstrated in a six-degree-of-freedom simulation with representative aerodynamics.

Calhoun, Philip C.; Queen, Eric M.

2002-01-01

78

Design considerations for Mars transfer vehicles using nuclear thermal propulsion  

NASA Astrophysics Data System (ADS)

The design of a Mars Transfer Vehicle (MTV) utilizing nuclear propulsion will require that careful consideration be given to the nuclear radiation environment in which it will operate. The extremely high neutron and gamma fluxes characteristic of nuclear thermal propulsion systems will cause significant heating of the fluid systems in close proximity to the reactor, especially in the lower propellant tanks. Crew radiation doses are also a concern particularly late in a mission when there is less shielding from the propellant tanks. In this study, various vehicle configuration and shielding strategies were examined and the resulting time dependent radiation fields evaluated. A common cluster of three particle bed reactor (PBR) engines were used in all configurations examined. In general, it appears that long, relatively narrow vehicles perform the best from a radiation standpoint, however, good shield optimization will be critical in maintaining a low radiation environment while minimizing the shield weight penalty.

Emrich, William J.

1995-01-01

79

Aerodynamic design of electric and hybrid vehicles: A guidebook  

NASA Technical Reports Server (NTRS)

A typical present-day subcompact electric hybrid vehicle (EHV), operating on an SAE J227a D driving cycle, consumes up to 35% of its road energy requirement overcoming aerodynamic resistance. The application of an integrated system design approach, where drag reduction is an important design parameter, can increase the cycle range by more than 15%. This guidebook highlights a logic strategy for including aerodynamic drag reduction in the design of electric and hybrid vehicles to the degree appropriate to the mission requirements. Backup information and procedures are included in order to implement the strategy. Elements of the procedure are based on extensive wind tunnel tests involving generic subscale models and full-scale prototype EHVs. The user need not have any previous aerodynamic background. By necessity, the procedure utilizes many generic approximations and assumptions resulting in various levels of uncertainty. Dealing with these uncertainties, however, is a key feature of the strategy.

Kurtz, D. W.

1980-01-01

80

Design studies of continuously variable transmissions for electric vehicles  

NASA Technical Reports Server (NTRS)

Preliminary design studies were performed on four continuously variable transmission (CVT) concepts for use with a flywheel equipped electric vehicle of 1700 kg gross weight. Requirements of the CVT's were a maximum torque of 450 N-m (330 lb-ft), a maximum output power of 75 kW (100 hp), and a flywheel speed range of 28,000 to 14,000 rpm. Efficiency, size, weight, cost, reliability, maintainability, and controls were evaluated for each of the four concepts which included a steel V-belt type, a flat rubber belt type, a toroidal traction type, and a cone roller traction type. All CVT's exhibited relatively high calculated efficiencies (68 percent to 97 percent) over a broad range of vehicle operating conditions. Estimated weight and size of these transmissions were comparable to or less than equivalent automatic transmission. The design of each concept was carried through the design layout stage.

Parker, R. J.; Loewenthal, S. H.; Fischer, G. K.

1981-01-01

81

Design of an autonomous Lunar construction utility vehicle  

NASA Technical Reports Server (NTRS)

In order to prepare a site for a manned lunar base, an autonomously operated construction vehicle is necessary. A Lunar Construction Utility Vehicle (LCUV), which utilizes interchangeable construction implements, was designed conceptually. Some elements of the machine were studied in greater detail. Design of an elastic loop track system has advanced to the testing stage. A standard coupling device was designed to insure a proper connection between the different construction tools and the LCUV. Autonomous control of the track drive motors was simulated successfully through the use of a joystick and computer interface. A study of hydrogen-oxygen fuel cells has produced estimates of reactant and product size requirements and identified multi-layer insulation techniques. Research on a 100 kW heat rejection system has determined that it is necessary to house a radiator panel on a utility trailer. The impact of a 720 hr use cycle has produced a very large logistical support lien which requires further study.

Ash, Robert L.; Chew, Mason; Dixon, Iain (editor)

1990-01-01

82

Manipulator design and development for the Ranger satellite servicing vehicle  

NASA Technical Reports Server (NTRS)

The Ranger program is a planned series of low cost telerobotics flight experiments, based on the use of Pegasus launch vehicles. As the first step towards this goal, the Space Systems Lab was developing a neutral buoyancy version of Ranger for use in design verification and operations testing. The design approach and results of the Ranger manipulator development program is related. Ranger is designed to incorporate four appendages: a pair of dexterous, seven degree of freedom manipulators for general manipulation; a six DOF grappling arm for securing the vehicle to the local work site; and a five DOF positioning manipulator for the stereo camera pair that provide feedback to the remote operator. Each of these manipulators incorporate unique approaches to satisfying design requirements. The numerical and operational requirements are given for Ranger manipulators, and the evolution is discussed of the differing design approaches based on similarities and differences in the requirements. Testing results for individual joints and manipulator assemblies are presented, followed by initial results of operational testing on satellite servicing tasks with the integrated Ranger neutral buoyancy vehicle.

Howard, Russell D.; Akin, David L.

1992-01-01

83

Kistler reusable vehicle facility design and operational approach  

NASA Astrophysics Data System (ADS)

Kistler Aerospace Corporation is designing and developing the K-1, the world's first fully reusable aerospace vehicle to deliver satellites into orbit. The K-1 vehicle test program will be conducted in Woomera, Australia, with commercial operations scheduled to begin shortly afterwards. Both stages of the K-1 will return to the launch site utilizing parachutes and airbags for a soft landing within 24 h after launch. The turnaround flow of the two stages will cycle from landing site to a maintenance/refurbishment facility and through the next launch in only 9 days. Payload processing will occur in a separate facility in parallel with recovery and refurbishment operations. The vehicle design and on-board checkout capability of the avionics system eliminates the need for an abundance of ground checkout equipment. Payload integration, vehicle assembly, and K-1 transport to the launch pad will be performed horizontally, simplifying processing and reducing infrastructure requirements. This simple, innovative, and cost-effective approach will allow Kistler to offer its customers flexible, low-cost, and on-demand launch services.

Fagan, D.; McInerney, F.; Johnston, C.; Tolson, B.

84

The design of two-stage-to-orbit vehicles  

NASA Technical Reports Server (NTRS)

Two separate student design groups developed conceptual designs for a two-stage-to-orbit vehicle, with each design group consisting of a carrier team and an orbiter team. A two-stage-to-orbit system is considered in the event that single-stage-to-orbit is deemed not feasible in the foreseeable future; the two-stage system would also be used as a complement to an already existing heavy lift vehicle. The design specifications given are to lift a 10,000-lb payload 27 ft long by 10 ft diameter, to low Earth orbit (300 n.m.) using an air breathing carrier configuration that will take off horizontally within 15,000 ft. The staging Mach number and altitude were to be determined by the design groups. One group designed a delta wing/body carrier with the orbiter nested within the fuselage of the carrier, and the other group produced a blended cranked-delta wing/body carrier with the orbiter in the more conventional piggyback configuration. Each carrier used liquid hydrogen-fueled turbofanramjet engines, with data provided by General Electric Aircraft Engine Group. While one orbiter used a full-scale Space Shuttle Main Engine (SSME), the other orbiter employed a half-scale SSME coupled with scramjet engines, with data again provided by General Electric. The two groups conceptual designs, along with the technical trade-offs, difficulties, and details that surfaced during the design process are presented.

1991-01-01

85

Conceptual design of a manned orbital transfer vehicle  

NASA Technical Reports Server (NTRS)

With the advent of the manned space station, man now requires a spacecraft based on the space station with the ability to deploy, recover, and repair satellites quickly and economically. Such a craft would prolong and enhance the life and performance of many satellites. A basic design was developed for an orbital tansfer vehicle (OTV). The basic design criteria are discussed. The design of the OTV and systems were researched in the following areas: avionics, crew systems, electrical power systems, environmental control/life support systems, navigation and orbital maneuvers, propulsion systems, reaction control systems (RCS), servicing systems, and structures. The basic concepts in each of the areas are summarized.

Davis, Richard; Duquette, Miles; Fredrick, Rebecca; Schumacher, Daniel; Somers, Schaeffer; Stafira, Stanley; Williams, James; Zelinka, Mark

1988-01-01

86

Design of an autonomous lunar construction utility vehicle  

NASA Technical Reports Server (NTRS)

In order to prepare a site for a lunar base, an autonomously operated construction vehicle is necessary. Discussed here is a Lunar Construction Utility Vehicle (LCUV), which uses interchangeable construction implements. Design of an elastic loop track system has advanced to the testing stage. A standard coupling device has been designed to insure a proper connection between the different construction tools and the LCUV. Autonomous control of the track drive motors was simulated successfully through the use of a joystick and a computer interface. A study of hydrogen-oxygen fuel cells produced estimates of reactant and product requirements and identified multilayer insulation needs. Research on the 100-kW heat rejection system determined that it is necessary to transport the radiator panel on a utility trailer. Extensive logistical support for the 720 hour use cycle requires further study.

1990-01-01

87

Computer-aided conceptual design of Air Cushion Vehicles  

NASA Astrophysics Data System (ADS)

This paper describes the development and use of a computer-aided design tool which has been used to explore preferred options for amphibious Air-Cushion Vehicle (ACV) and Surface-Effect Ship (SES) designs in support of U.S. Navy and U.S. Army programs. The tool, referred to as the ACV Design Synthesis Model (ADSM), is an interactive computer program which provides a description of feasible ACV or SES concepts that could be developed, by a competent design team, to perform the mission described by the input parameters. The paper discusses how the program was used to explore parametrically the design of a range of self-propelled hoverbarges to meet requirements of the U.S. Army Logistics Over the Shore (LOTS) phases of an amphibious landing. Examples of results are presented to illustrate the method used in determining design and performance trade-offs.

Band, E. G. U.; Lavis, D. R.

88

Pointing control design for autonomous space vehicle applications  

SciTech Connect

This paper addresses the design of pointing control systems for autonomous space vehicles. The function of the pointing control system is to keep distant orbiting objects within the field-of-view of an on-board optical sensor. We outline the development of novel nonlinear control algorithms which exploit the availability of on- board sensors. Simulation results comparing the performance of the different pointing control implementations are presented.

Young, K.D.

1993-03-01

89

75 FR 34483 - In the Matter of Certain Automotive Vehicles and Designs Therefore; Notice of Investigation  

Federal Register 2010, 2011, 2012, 2013

...Automotive Vehicles and Designs Therefore; Notice of...automotive vehicles and designs therefore by reason of...Trade Commission, 500 E Street, SW., Room 112, Washington...automotive vehicles and designs therefore that infringe...Inc., 719 Nogales Street, City of...

2010-06-17

90

NASA advanced aeronautics design solar powered remotely piloted vehicle  

NASA Technical Reports Server (NTRS)

Environmental problems such as the depletion of the ozone layer and air pollution demand a change in traditional means of propulsion that is sensitive to the ecology. Solar powered propulsion is a favorable alternative that is both ecologically harmless as well as cost effective. Integration of solar energy into designs ranging from futuristic vehicles to heating is beneficial to society. The design and construction of a Multi-Purpose Remotely Piloted Vehicle (MPRPV) seeks to verify the feasibility of utilizing solar propulsion as a primary fuel source. This task has been a year long effort by a group of ten students, divided into five teams, each dealing with different aspects of the design. The aircraft was designed to take-off, climb to the design altitude, fly in a sustained figure-eight flight path, and cruise for approximately one hour. This mission requires flight at Reynolds numbers between 150,000 and 200,000 and demands special considerations in the aerodynamic design in order to achieve flight in this regime. Optimal performance requires a light weight configuration with both structural integrity and maximum power availability. The structure design and choice of solar cells for the propulsion was governed by the weight, efficiency, and cost considerations. The final design is a MPRPV weighting 35 N which cruises 7 m/s at the design altitude of 50 m. The configuration includes a wing composed of balsa and foam NACA 6409 airfoil sections and carbon fiber spars, a tail of similar construction, and a truss structure fuselage. The propulsion system consists of 98 10 percent efficient solar cells donated by Mobil Solar, a NiCad battery for energy storage, and a folding propeller regulated by a lightweight and efficient control system. The airfoils and propeller chosen for the design were research and tested during the design process.

Elario, David S.; Guillmette, Neal H.; Lind, Gregory S.; Webster, Jonathan D.; Ferreira, Michael J.; Konstantakis, George C.; Marshall, David L.; Windt, Cari L.

1991-01-01

91

Use of the Collaborative Optimization Architecture for Launch Vehicle Design  

NASA Technical Reports Server (NTRS)

Collaborative optimization is a new design architecture specifically created for large-scale distributed-analysis applications. In this approach, problem is decomposed into a user-defined number of subspace optimization problems that are driven towards interdisciplinary compatibility and the appropriate solution by a system-level coordination process. This decentralized design strategy allows domain-specific issues to be accommodated by disciplinary analysts, while requiring interdisciplinary decisions to be reached by consensus. The present investigation focuses on application of the collaborative optimization architecture to the multidisciplinary design of a single-stage-to-orbit launch vehicle. Vehicle design, trajectory, and cost issues are directly modeled. Posed to suit the collaborative architecture, the design problem is characterized by 5 design variables and 16 constraints. Numerous collaborative solutions are obtained. Comparison of these solutions demonstrates the influence which an priori ascent-abort criterion has on development cost. Similarly, objective-function selection is discussed, demonstrating the difference between minimum weight and minimum cost concepts. The operational advantages of the collaborative optimization

Braun, R. D.; Moore, A. A.; Kroo, I. M.

1996-01-01

92

Preliminary design of a lunar construction utility vehicle  

NASA Technical Reports Server (NTRS)

Construction of a lunar base, prior to manned occupancy, is one of the most demanding technological challenges facing space system designers today. A flexible lunar construction machine is needed that can be operated remotely and that can perform a variety of construction tasks over a wide range of lunar conditions. A preliminary lunar construction utility vehicle (LCUV) design has been developed as part of a capstone design course at Old Dominion University and is described in this summary report. The design requirements are taken from a 1988 USRA Summer Design Report entitled The Lunar Split Mission: A Robotic Constructed Lunar Base Scenario, and from the proceedings of a workshop hosted by United Technologies Corporation entitled Report of the In Situ Resources Utilization Workshop. The first report describes a bootstrap base concept in which a minimum of essential surface elements are delivered and configured such that minimum EVA is required to bring the initial base on-line. The base is to be built in three phases, the first of which will be unmanned, while the second and third will be manned. The key to these concepts is the development of a semiautonomous, telerobotic lunar construction utility vehicle (LCUV). The tasks required of this robotic vehicle during the phase 1 build-up are as follows: (1) surface element transportation, handling, and assembly; (2) soil excavation and movement for site preparation; (3) radiation protection and materials processing; and (4) repair and maintenance of surface elements. In order to meet the stated requirements, the LCUV must be: (1) transformable to perform a wide variety of tasks; (2) self supporting; (3) designed to allow for telerobotic control as well as autonomous operation; (4) able to transport one fully configured space station common module (SSCM); (5) upgradable to allow for future growth; and (6) easy to maintain.

Bryant, C. A.; Alcorn, D.; Bentley, R.; Campbell, B.; Coulson, T.; Jacobs, J.; Stiles, P.

1989-01-01

93

Development of Integrated Programs for Aerospace-vehicle design (IPAD): Reference design process  

NASA Technical Reports Server (NTRS)

The airplane design process and its interfaces with manufacturing and customer operations are documented to be used as criteria for the development of integrated programs for the analysis, design, and testing of aerospace vehicles. Topics cover: design process management, general purpose support requirements, design networks, and technical program elements. Design activity sequences are given for both supersonic and subsonic commercial transports, naval hydrofoils, and military aircraft.

Meyer, D. D.

1979-01-01

94

Design of roadway test system for motor vehicle brake performance and its evaluation methods  

Microsoft Academic Search

Service braking test and evaluation are of importance for vehicle braking performance. The vehicle braking performance roadway test system was firstly designed in the paper, whose main instrument was GPS-based VBOX III. Then the systematic vehicle braking performance tests were conducted on the vehicle proving ground. Based on the real straight-line braking test data, two indexes, braking distance and mean

Zhang Xiaolong; Peng Jiankun; Xia Ping

2010-01-01

95

Design Guidelines for Quiet Fans and Pumps for Space Vehicles  

NASA Technical Reports Server (NTRS)

This document presents guidelines for the design of quiet fans and pumps of the class used on space vehicles. A simple procedure is presented for the prediction of fan noise over the meaningful frequency spectrum. A section also presents general design criteria for axial flow fans, squirrel cage fans, centrifugal fans, and centrifugal pumps. The basis for this report is an experimental program conducted by Hamilton Standard under NASA Contract NAS 9-12457. The derivations of the noise predicting methods used in this document are explained in Hamilton Standard Report SVHSER 6183, "Fan and Pump Noise Control," dated May 1973 (6).

Lovell, John S.; Magliozzi, Bernard

2008-01-01

96

Post-Optimality Analysis In Aerospace Vehicle Design  

NASA Technical Reports Server (NTRS)

This analysis pertains to the applicability of optimal sensitivity information to aerospace vehicle design. An optimal sensitivity (or post-optimality) analysis refers to computations performed once the initial optimization problem is solved. These computations may be used to characterize the design space about the present solution and infer changes in this solution as a result of constraint or parameter variations, without reoptimizing the entire system. The present analysis demonstrates that post-optimality information generated through first-order computations can be used to accurately predict the effect of constraint and parameter perturbations on the optimal solution. This assessment is based on the solution of an aircraft design problem in which the post-optimality estimates are shown to be within a few percent of the true solution over the practical range of constraint and parameter variations. Through solution of a reusable, single-stage-to-orbit, launch vehicle design problem, this optimal sensitivity information is also shown to improve the efficiency of the design process, For a hierarchically decomposed problem, this computational efficiency is realized by estimating the main-problem objective gradient through optimal sep&ivity calculations, By reducing the need for finite differentiation of a re-optimized subproblem, a significant decrease in the number of objective function evaluations required to reach the optimal solution is obtained.

Braun, Robert D.; Kroo, Ilan M.; Gage, Peter J.

1993-01-01

97

Mobile large-vehicle inspection system design issues  

NASA Astrophysics Data System (ADS)

X-ray systems capable of scanning semitrailers using conventional fanbeam technology are restricted to transmission-based imaging techniques that suffer from superposition of clutter. MobileSearchTM I is a truck-mounted 450 KeV pencil beam system incorporating x-ray backscatter imaging to produce near photo-like images, which was reported on in a paper by Swift in 1996. Since that time MobileSearchTM II added a transmission detector providing both backscatter and transmission in a single pass. The transmission detector design is the result of extensive x-ray and optical simulations. The radiation safety was studied extensively using the GEANT2 simulation system. The simulations were extended from 450 KeV to 5 MeV, to determine the safety implications of increasing the x-ray energy. Operationally, a 14 foot high, 8 foot 6 inch wide vehicle can be parked on a level area and the MobileSearchTM II system driven alongside to examine the contents. Deployment and setup are facilitated by having a self-contained system, which can be driven over the road and cen be operational in less than an hour. MobileSearchTM II is also capable of continuous mode scanning. In this mode, a line of vehicles can be scanned without having to stop and reposition or queue vehicles. The system is designed to fit in a C17 for easy air transport to a distant location.

Smith, Gerald J.; Adams, William L.; Huang, Suzhou

1998-12-01

98

Use of axiomatic design principles to develop vehicle suspension controls for variable stiffness and ride height  

E-print Network

Axiomatic Design principles are used to design a vehicle suspension system. The use of Axiomatic Design helps to guide the design of a decoupled system. The Design Matrix (DM) illustrates the independence among the Functional ...

Luu, Way

2005-01-01

99

Assured crew return vehicle post landing configuration design and test  

NASA Technical Reports Server (NTRS)

The 1991-1992 senior Mechanical and Aerospace Engineering Design class continued work on the post landing configurations for the Assured Crew Return Vehicle (ACRV) and the Emergency Egress Couch (EEC). The ACRV will be permanently docked to Space Station Freedom fulfilling NASA's commitment of Assured Crew Return Capability in the event of an accident or illness aboard Space Station Freedom. The EEC provides medical support and a transportation surface for an incapacitated crew member. The objective of the projects was to give the ACRV Project Office data to feed into their feasibility studies. Four design teams were given the task of developing models with dynamically and geometrically scaled characteristics. Groups one and two combined efforts to design a one-fifth scale model for the Apollo Command Module derivative, an on-board flotation system, and a lift attachment point system. This model was designed to test the feasibility of a rigid flotation and stabilization system and to determine the dynamics associated with lifting the vehicle during retrieval. However, due to priorities, it was not built. Group three designed a one-fifth scale model of the Johnson Space Center (JSC) benchmark configuration, the Station Crew Return Alternative Module (SCRAM) with a lift attachment point system. This model helped to determine the flotation and lifting characteristics of the SCRAM configuration. Group four designed a full scale EEC with changeable geometric and geometric and dynamic characteristics. This model provided data on the geometric characteristics of the EEC and on the placement of the CG and moment of inertia. It also gave the helicopter rescue personnel direct input to the feasibility study. Section 1 describes in detail the design of a one-fifth scale model of the Apollo Command Module Derivative (ACMD) ACRV. The objective of the ACMD Configuration Model Team was to use geometric and dynamic constraints to design a one-fifth scale working model of the Apollo Command Module Derivative (ACMD) configuration with a Lift Attachment Point (LAP) System. This model was required to incorporate a rigidly mounted flotation system and the egress system designed the previous academic year. The LAP system was to be used to determine the dynamic effects of locating the lifting points at different locations on the vehicle. The team was then to build and test the model; however, due to priorities, this did not occur. To better simulate the ACMD after a water landing, the nose cone section was removed and the deck area exposed. The areas researched during the design process were construction, center of gravity and moment of inertia, and lift attachment points.

1992-01-01

100

AVID - A design system for technology studies of advanced transportation concepts. [Aerospace Vehicle Interactive Design  

NASA Technical Reports Server (NTRS)

The basic AVID (Aerospace Vehicle Interactive Design) is a general system for conceptual and preliminary design currently being applied to a broad range of future space transportation and spacecraft vehicle concepts. AVID hardware includes a minicomputer allowing rapid designer interaction. AVID software includes (1) an executive program and communication data base which provide the automated capability to couple individual programs, either individually in an interactive mode or chained together in an automatic sequence mode; and (2) the individual technology and utility programs which provide analysis capability in areas such as graphics, aerodynamics, propulsion, flight performance, weights, sizing, and costs.

Wilhite, A. W.; Rehder, J. J.

1979-01-01

101

GPS Auto-Navigation Design for Unmanned Air Vehicles  

NASA Technical Reports Server (NTRS)

A GPS auto-navigation system is designed for Unmanned Air Vehicles. The objective is to enable the air vehicle to be used as a test-bed for novel flow control concepts. The navigation system uses pre-programmed GPS waypoints. The actual GPS position, heading, and velocity are collected by the flight computer, a PC104 system running in Real-Time Linux, and compared with the desired waypoint. The navigator then determines the necessity of a heading correction and outputs the correction in the form of a commanded bank angle, for a level coordinated turn, to the controller system. This controller system consists of 5 controller! (pitch rate PID, yaw damper, bank angle PID, velocity hold, and altitude hold) designed for a closed loop non-linear aircraft model with linear aerodynamic coefficients. The ability and accuracy of using GPS data, is validated by a GPS flight. The autopilots are also validated in flight. The autopilot unit flight validations show that the designed autopilots function as designed. The aircraft model, generated on Matlab SIMULINK is also enhanced by the flight data to accurately represent the actual aircraft.

Nilsson, Caroline C. A.; Heinzen, Stearns N.; Hall, Charles E., Jr.; Chokani, Ndaona

2003-01-01

102

Real-time Trajectory Design for Unmanned Aerial Vehicles using Receding Horizon Control  

E-print Network

Real-time Trajectory Design for Unmanned Aerial Vehicles using Receding Horizon Control by Yoshiaki Students #12;2 #12;Real-time Trajectory Design for Unmanned Aerial Vehicles using Receding Horizon Control This thesis investigates the coordination and control of fleets of unmanned aerial vehicles (UAVs). Future

103

DESIGN AND DEVELOPMENT OF A MICRO AIR VEHICLE (AV) CONCEPT: PROJECT BIDULE  

E-print Network

and the prop-wash can be kept to an acceptable level. Keywords: micro Unmanned Aerial Vehicles (UAVs), design, propeller effects, wind tunnel. Introduction The concept of micro-sized Unmanned Aerial Vehicles (UAVsDESIGN AND DEVELOPMENT OF A MICRO AIR VEHICLE (µµµµAV) CONCEPT: PROJECT BIDULE Mr T. Spoerry1 , Dr

Wong, K. C.

104

Design, analysis, and optimization of composite leaf springs for light vehicle applications  

Microsoft Academic Search

Design and manufacture of a functional composite spring for a solar powered light vehicle is described. The objective is to provide an understanding of the manufacture, use, and capabilities of composite leaf springs produced by using unidirectional Eglass' roving impregnated by an epoxy resin for light vehicle applications where the vehicle weight is of primary concern. The current design application

Erol Sancaktar; Mathieu Gratton

1999-01-01

105

A systematic design approach for two planetary gear split hybrid vehicles  

Microsoft Academic Search

Multiple power sources in a hybrid vehicle allow for flexible vehicle power-train operations, but also impose kinematic constraints due to component characteristics. This paper presents a design process that enables systematic search and screening through all three major dimensions of hybrid vehicle designs – system configuration, component sizing and control, to achieve optimal performance while satisfying the imposed constraints. An

Jinming Liu; Huei Peng

2010-01-01

106

Aerodynamic design of electric and hybrid vehicles: a guidebook  

SciTech Connect

A typical present-day subcompact EHV, operating on an SAE J227a D driving cycle, consumes up to 35% of its road energy requirement overcoming aerodynamic resistance. The application of an integrated system design approach, where drag reduction is an important design parameter, can increase the cycle range by more than 15%. This guidebook highlights a logic strategy for including aerodynamic drag reduction in the design of electric and hybrid vehicles to the degree appropriate to the mission requirements. Backup information and procedures are included in order to implement the strategy. Elements of the procedure are based on extensive wind tunnel tests involving generic subscale models and full-scale prototype EHVs. The user need not have any previous aerodynamic background. By necessity, the procedure utilizes many generic approximations and assumptions resulting in various levels of uncertainty. Dealing with these uncertainties, however, is a key feature of the strategy.

Kurtz, D.W.

1980-09-30

107

Vehicle Design Validation via Remote Vehicle Diagnosis: A feasibility study on battery management system  

Microsoft Academic Search

In recent years, passenger vehicle product development faces great challenges to maintain high vehicle quality due to the proliferation of Electronics, Control and Software (ECS) features and the resultant system complexity. Quickly detecting and trouble-shooting faults of integrated vehicle systems during the validation stage in a key to enhancing vehicle quality. In this paper, we present a feasibilty study of

Yilu Zhang; Gary W. Gantt Jr; Mark Rychlinski; Ryan Edwards; John Correia; Calvin Wolf

2008-01-01

108

Design principles for a flywheel energy store for road vehicles  

SciTech Connect

This paper introduces a flywheel energy storage device capable of enhancing the fuel economy of a hybrid-type road vehicle. A number of possible drive types is considered and the permanent magnet machine drive is shown to provide the best solution. Reasons for selecting a device using an axial-field configuration with single rotor and double stator sections are described. Electrical, magnetic and mechanical design data are presented for a full-scale prototype device with 240 kJ of usable energy storage and 25 kW of power transfer, operating at speeds up to 50,000 revs per minute, with a 10% duty cycle.

Acarnley, P.P.; Mecrow, B.C.; Burdess, J.S.; Fawcett, J.N.; Kelly, J.G.; Dickinson, P.G. [Univ. of Newcastle Upon Tyne (United Kingdom)

1995-12-31

109

Design principles for a flywheel energy store for road vehicles  

SciTech Connect

This paper introduces a flywheel energy storage device capable of enhancing the fuel economy of a hybrid-type road vehicle. A number of possible drive types are considered and the permanent magnet machine drive is shown to provide the best solution. Reasons for selecting a device using an axial-field configuration with single-rotor and double-stator sections are described. Electrical, magnetic, and mechanical design data are presented for a full-scale prototype device with 240 KJ of usable energy storage and 25 kW of power transfer, operating at speeds up to 50,000 r/min, with a 10% duty cycle.

Acarnley, P.P.; Mecrow, B.C.; Burdess, J.S.; Fawcett, J.N.; Kelly, J.G.; Dickinson, P.G. [Univ. of Newcastle, Newcastle upon Tyne (United Kingdom)] [Univ. of Newcastle, Newcastle upon Tyne (United Kingdom)

1996-11-01

110

Assured crew return vehicle post landing configuration design and test  

NASA Technical Reports Server (NTRS)

The 1991-1992 senior Mechanical and Aerospace Engineering Design class continued work on the post landing configurations for the Assured Crew Return Vehicle (ACRV) and the Emergency Egress Couch (EEC). The ACRV will be permanently docked to Space Station Freedom, fulfilling NASA's commitment of Assured Crew Return Capability in the event of an accident or illness aboard Space Station Freedom. The EEC provides medical support and a transportation surface for an incapacitated crew member. The objective of the projects was to give the ACRV Project Office data to feed into their feasibility studies. Four design teams were given the task of developing models with dynamically and geometrically scaled characteristics. Groups one and two combined effort to design a one-fifth scale model of the Apollo Command Module derivative, an on-board flotation system, and a lift attachment point system. This model was designed to test the feasibility of a rigid flotation and stabilization system and to determine the dynamics associated with lifting the vehicle during retrieval. However, due to priorities, it was not built. Group three designed a one-fifth scale model of the Johnson Space Center (JSC) benchmark configuration, the Station Crew Return Alternative Module (SCRAM) with a lift attachment point system. This model helped to determine the flotation and lifting characteristics of the SCRAM configuration. Group four designed a full scale EEC with changeable geometric and dynamic characteristics. This model provided data on the geometric characteristics of the EEC and on the placement of the CG and moment of inertia. It also gave the helicopter rescue personnel direct input to the feasibility study.

Anderson, Loren A.; Armitage, Pamela Kay

1992-01-01

111

Modelling and Design Optimization of Low Speed Fuel Cell Hybrid Electric Vehicles  

E-print Network

1.2. Hydrogen Fuel Cells - an Alternative Solution........................................................................................................... 9 1.5. Hydrogen Fuel Cell VehiclesModelling and Design Optimization of Low Speed Fuel Cell Hybrid Electric Vehicles by Matthew Blair

Victoria, University of

112

Design, development, and validation of a remotely reconfigurable vehicle telemetry system for consumer and government applications  

E-print Network

This thesis explores the design and development of a cost-effective, easy-to-use system for remotely monitoring vehicle performance and drivers' habits, with the aim of collecting data for vehicle characterization and ...

Siegel, Joshua Eric

2011-01-01

113

36 CFR 212.57 - Monitoring of effects of motor vehicle use on designated roads and trails and in designated areas.  

...false Monitoring of effects of motor vehicle use on designated roads and trails...Roads, Trails, and Areas for Motor Vehicle Use § 212.57 Monitoring of effects of motor vehicle use on designated roads and...

2014-07-01

114

Postlanding optimum designs for the assured crew return vehicle  

NASA Technical Reports Server (NTRS)

The optimized preliminary engineering design concepts for postlanding operations of a water-landing Assured Crew Return Vehicle (ACRV) during a medical rescue mission are presented. Two ACRVs will be permanently docked to Space Station Freedom, fulfilling NASA's commitment to Assured Crew Return Capability in the event of an accident or illness. The optimized configuration of the ACRV is based on an Apollo command module (ACM) derivative. The scenario assumes landing a sick or injured crewmember on water with the possibility of a delayed rescue. Design emphasis is placed on four major areas. First is the design of a mechanism that provides a safe and time-critical means of removing the sick or injured crewmember from the ACRV. Support to the assisting rescue personnel is also provided. Second is the design of a system that orients and stabilizes the craft after landing so as to cause no further injury or discomfort to the already ill or injured crewmember. Third is the design of a system that provides full medical support to a sick or injured crewmember aboard the ACRV from the time of separation from the space station to rescue by recovery forces. Last is the design of a system that provides for the comfort and safety of the entire crew after splashdown up to the point of rescue. The four systems are conceptually integrated into the ACRV.

Hosterman, Kenneth C.; Anderson, Loren A.

1990-01-01

115

Aeroheating Design Issues for Reusable Launch Vehicles: A Perspective  

NASA Technical Reports Server (NTRS)

An overview of basic aeroheating design issues for Reusable Launch Vehicles (RLV), which addresses the application of hypersonic ground-based testing, and computational fluid dynamic (CFD) and engineering codes, is presented. Challenges inherent to the prediction of aeroheating environments required for the successful design of the RLV Thermal Protection System (TPS) are discussed in conjunction with the importance of employing appropriate experimental/computational tools. The impact of the information garnered by using these tools in the resulting analyses, ultimately enhancing the RLV TPS design is illustrated. A wide range of topics is presented in this overview; e.g. the impact of flow physics issues such as boundary-layer transition, including effects of distributed and discrete roughness, shock-shock interactions, and flow separation/reattachment. Also, the benefit of integrating experimental and computational studies to gain an improved understanding of flow phenomena is illustrated. From computational studies, the effect of low-density conditions and of uncertainties in material surface properties on the computed heating rates a r e highlighted as well as the significant role of CFD in improving the Outer Mold Line (OML) definition to reduce aeroheating while maintaining aerodynamic performance. Appropriate selection of the TPS design trajectories and trajectory shaping to mitigate aeroheating levels and loads are discussed. Lastly, an illustration of an aeroheating design process is presented whereby data from hypersonic wind-tunnel tests are integrated with predictions from CFD codes and engineering methods to provide heating environments along an entry trajectory as required for TPS design.

Zoby, E. Vincent; Thompson, Richard A.; Wurster, Kathryn E.

2004-01-01

116

A comparison of hydrogen, methanol and gasoline as fuels for fuel cell vehicles: implications for vehicle design and infrastructure development  

NASA Astrophysics Data System (ADS)

All fuel cells currently being developed for near term use in electric vehicles require hydrogen as a fuel. Hydrogen can be stored directly or produced onboard the vehicle by reforming methanol, or hydrocarbon fuels derived from crude oil (e.g., gasoline, diesel, or middle distillates). The vehicle design is simpler with direct hydrogen storage, but requires developing a more complex refueling infrastructure. In this paper, we present modeling results comparing three leading options for fuel storage onboard fuel cell vehicles: (a) compressed gas hydrogen storage, (b) onboard steam reforming of methanol, (c) onboard partial oxidation (POX) of hydrocarbon fuels derived from crude oil. We have developed a fuel cell vehicle model, including detailed models of onboard fuel processors. This allows us to compare the vehicle performance, fuel economy, weight, and cost for various vehicle parameters, fuel storage choices and driving cycles. The infrastructure requirements are also compared for gaseous hydrogen, methanol and gasoline, including the added costs of fuel production, storage, distribution and refueling stations. The delivered fuel cost, total lifecycle cost of transportation, and capital cost of infrastructure development are estimated for each alternative. Considering both vehicle and infrastructure issues, possible fuel strategies leading to the commercialization of fuel cell vehicles are discussed.

Ogden, Joan M.; Steinbugler, Margaret M.; Kreutz, Thomas G.

117

Series hybrid vehicles and optimized hydrogen engine design  

NASA Astrophysics Data System (ADS)

Lawrence Livermore, Sandia Livermore and Los Alamos National Laboratories have a joint project to develop an optimized hydrogen fueled engine for series hybrid automobiles. The major divisions of responsibility are: system analysis, engine design and kinetics modeling by LLNL; performance and emission testing, and friction reduction by SNL; computational fluid mechanics and combustion modeling by LANL. This project is a component of the Department of Energy, Office of Utility Technology, National Hydrogen Program. We report here on the progress on system analysis and preliminary engine testing. We have done system studies of series hybrid automobiles that approach the PNGV design goal of 34 km/liter (80 mpg), for 384 km (240 mi) and 608 km (380 mi) ranges. Our results indicate that such a vehicle appears feasible using an optimized hydrogen engine. The impact of various on-board storage options on fuel economy are evaluated. Experiments with an available engine at the Sandia Combustion Research Facility demonstrated NO(x) emissions of 10 to 20 ppm at an equivalence ratio of 0.4, rising to about 500 ppm at 0.5 equivalence ratio using neat hydrogen. Hybrid vehicle simulation studies indicate that exhaust NO(x) concentrations must be less than 180 ppm to meet the 0.2 g/mile California Air Resources Board ULEV or Federal Tier-2 emissions regulations. We have designed and fabricated a first generation optimized hydrogen engine head for use on an existing single cylinder Onan engine. This head currently features 14.8:1 compression ratio, dual ignition, water cooling, two valves and open quiescent combustion chamber to minimize heat transfer losses.

Smith, J. R.; Aceves, S.; Vanblarigan, P.

1995-05-01

118

THE DEFINITION AND INTERPRETATION OF TERRESTRIAL ENVIRONMENT DESIGN INPUTS FOR VEHICLE DESIGN CONSIDERATIONS  

NASA Technical Reports Server (NTRS)

The description and interpretation of the terrestrial environment (0-90 km altitude) is an important driver of aerospace vehicle structural, control, and thermal system design. NASA is currently in the process of reviewing the meteorological information acquired over the past decade and producing an update to the 1993 Terrestrial Environment Guidelines for Aerospace Vehicle Design and Development handbook. This paper addresses the contents of this updated handbook, with special emphasis on new material being included in the areas of atmospheric thermodynamic models, wind dynamics, atmospheric composition, atmospheric electricity, cloud phenomena, atmospheric extremes, sea state, etc. In addition, the respective engineering design elements will be discussed relative to the importance and influence of terrestrial environment inputs that require consideration and interpretation for design applications. Specific lessons learned that have contributed to the advancements made in the acquisition, interpretation, application and awareness of terrestrial environment inputs for aerospace engineering applications are discussed.

Johnson, Dale L.; Keller, Vernon W.; Vaughan, William W.

2005-01-01

119

Design and validation process of in-vehicle embedded electronic systems Franoise Simonot-Lion  

E-print Network

Design and validation process of in-vehicle embedded electronic systems Françoise Simonot.............................................................................................................12 2 Abstraction levels for in-vehicle embedded system description............................................................................................................13 2.2 EAST-ADL for in-vehicle embedded system modelling

Boyer, Edmond

120

Design and Evaluation of a Vehicle Data Distribution and Collection System  

E-print Network

Design and Evaluation of a Vehicle Data Distribution and Collection System Jacob LeBlanc 1 target application areas for vehicle telematics is in local area hot spots. This is the approach computers in police vehicles provides a platform for displaying and interacting with large amounts of data

New Hampshire, University of

121

MULTI-FUNCTIONALAUTOPILOT DESIGN AND EXPERIMENTS FOR ROTORCRAFT-BASED UNMANNED AERIAL VEHICLES  

E-print Network

MULTI-FUNCTIONALAUTOPILOT DESIGN AND EXPERIMENTS FOR ROTORCRAFT-BASED UNMANNED AERIAL VEHICLES is considered risky, unnecessary, and/or impossible. For these situations,Unmanned Aerial Vehicles (UAVs for rotorcraft-basedunmanned aerial vehicles (RUAVs) for cooperative multi-agent scenarios.The issues of multi

Sastry, S. Shankar

122

Cross Layer Design for Mobile Ad-Hoc Unmanned Aerial Vehicle Communication Networks  

E-print Network

Cross Layer Design for Mobile Ad-Hoc Unmanned Aerial Vehicle Communication Networks Abdel Ilah of the Unmanned Aerial Vehicle (UAV) Ad-Hoc net- work, the layered architecture is not flexible enough to achieve for Unmanned Aerial Vehicle (IMAC UAV). As for the routing protocol, We developed the Optimized Link State

Dong, Liang

123

Design and Implementation of a SemiAutonomous Unmanned Ground Vehicle  

Microsoft Academic Search

This paper presents the design, control and implementation of a generic wireless-operated semi autonomous unmanned ground vehicle (SUGV). The compact and lightweight robotic platform provides a safe and effective means to deal with hazardous-duty operations. The configuration of the vehicle system includes robust and easy to transport mobile base unit housing a single board computer for the vehicle control, and

Zainab Saleem; Aneel Kumar; Saba Ahsan; Tooba Rizvi

124

Design and Analysis of an Underwater Vehicle for Controlled Gliding 1  

E-print Network

­ inary analysis of a small underwater vehicle built to demonstrate and test dynamics and control of underDesign and Analysis of an Underwater Vehicle for Controlled Gliding 1 Joshua Graver, Jonathan Liu of gravity and steering is maintained by controlling the location of the center of gravity of the vehicle

Leonard, Naomi

125

High-speed aerodynamic design of space vehicle and required hypersonic wind tunnel facilities  

Microsoft Academic Search

Problems associated with the aerodynamic design of space vehicles with emphasis of the role of hypersonic wind tunnel facilities in the development of the vehicle are considered. At first, to identify wind tunnel and computational fluid dynamics (CFD) requirements, operational environments are postulated for hypervelocity vehicles. Typical flight corridors are shown with the associated flow density: real gas effects, low

Seizou Sakakibara; Kouichi Hozumi; Kunio Soga; Shigeaki Nomura

1992-01-01

126

Technical Report of National Aerospace Laboratory: Design and Development of the Hypersonic Flight Experiment (HYFLEX) Vehicle.  

National Technical Information Service (NTIS)

The Hypersonic Flight Experiment (HYFLEX) was conducted in February 1996 as Japan's first bypersonic flight of a lifting vehicle with the basic characteristics of a reentry vehicle. This paper describes details of the final design of the vehicle sub-syste...

2003-01-01

127

American Institute of Aeronautics and Astronautics Exploring Mass Trade-Offs In Preliminary Vehicle Design  

E-print Network

- Objective Genetic Algorithm to a multidisciplinary design framework to generate a set of Pareto of the fundamental challenges in preliminary vehicle design is developing a design that is both highly desirable

Lewis, Kemper E.

128

A hybrid vehicle evaluation code and its application to vehicle design  

SciTech Connect

This report describes a hybrid vehicle simulation model, which can be applied to many of the vehicles currently being considered for low pollution and high fuel economy. The code operates interactively, with all the vehicle information stored in data files. The code calculates fuel economy for three driving schedules, time for 0-96 km/h at maximum acceleration, hill climbing performance, power train dimensions, and pollution generation rates. This report also documents the application of the code to a hybrid vehicle that operates with a hydrogen internal combustion engine. The simulation model is used for parametric studies of the vehicle. The results show the fuel economy of the vehicle as a function of vehicle mass, aerodynamic drag, engine-generator efficiency, flywheel efficiency, and flywheel energy and power capacities.

Aceves, S.M.; Smith, J.R.

1994-07-15

129

Coupled Vehicle Design and Network Flow Optimization for Air Transportation Systems  

E-print Network

Coupled Vehicle Design and Network Flow Optimization for Air Transportation Systems Christine: 10.2514/1.27320 Traditionally, the design of a transportation system has focused on either vehicle for a transportation system, it is advantageous to expand the system boundary during the design process to include

de Weck, Olivier L.

130

Man-vehicle systems research facility: Design and operating characteristics  

NASA Technical Reports Server (NTRS)

The Man-Vehicle Systems Research Facility (MVSRF) provides the capability of simulating aircraft (two with full crews), en route and terminal air traffic control and aircrew interactions, and advanced cockpit (1995) display representative of future generations of aircraft, all within the full mission context. The characteristics of this facility derive from research, addressing critical human factors issues that pertain to: (1) information requirements for the utilization and integration of advanced electronic display systems, (2) the interaction and distribution of responsibilities between aircrews and ground controllers, and (3) the automation of aircrew functions. This research has emphasized the need for high fidelity in simulations and for the capability to conduct full mission simulations of relevant aircraft operations. This report briefly describes the MVSRF design and operating characteristics.

1983-01-01

131

GPS Receiver Design for Spin-Stabilized Launch Vehicles  

NASA Astrophysics Data System (ADS)

This paper describes the design and development of a dedicated GPS receiver for spin stabilized launch vehicles. The receiver is built around a commercially available low cost GPS chip set and operates an enhanced firmware specifically adapted for high dynamics applications. In order to keep tracking a sufficient number of GPS signals even during the spinning motion, we use multiple GPS patch antennas and space them equally apart each other around the cylindrical launcher body. A new signal combining scheme was developed to avoid deep fading in antenna gain pattern. This technique requires phase control to keep signals received on multiple antennas in phase with each other. A dualantenna GPS receiver was developed to evaluate the proposed signal combining algorithm. The result showed that the proposed algorithm was capable of providing stable and continuous signal tracking under a high-rate spinning motion while simple RF combining through a power combiner was failed.

Ebinuma, Takuji; Kusu, Tomomichi; Abe, Toshio; Saito, Hirobumi

132

PAYCOS: A new multidisciplinary analysis program for hypersonic vehicle design  

NASA Technical Reports Server (NTRS)

The Payload Conceptual Sizing Code (PAYCOS), a new multidisciplinary computer program for use in the conceptual development phase of hypersonic lifting vehicles (HV's), is described. The program allows engineers to rapidly determine the feasibility of an HV concept and then improve upon the concept by means of optimization theory. The code contains analysis modules for aerodynamics, thermodynamics, mass properties, flight stability, controls, loads, structures, and packaging. Motivation for the code lies with the increased complexity of HV's over their body-of-revolution ballistic predecessors. With these new shapes, the need to rapidly screen out poor concepts and actively develop new and better concepts is an even more crucial part of the early design process. Preliminary results are given which demonstrate the optimization capabilities of the code.

Stubbe, J. R.

1990-01-01

133

Zinc-bromine battery design for electric vehicles  

NASA Astrophysics Data System (ADS)

Design projections for zinc-bromine batteries are attractive for electric vehicle applications in terms of low manufacturing costs ($28/kWh) and good performance characteristics. Zinc-bromine battery projections (60-80 Wh/kg, 130-200 W/kg) compare favorably to both current lead acid batteries and proposed advanced battery candidates. The performance of recently developed battery components with 1200 sq/cm electrodes in a 120V, 10 kWh module is described. Similarly constructed smaller scale (600 sq/cm) components have shown lifetimes exceeding 400 cycles and the ability to follow both regenerative braking (J227aD) and random cycling regimes. Initial dynamometer evaluations of full scale 20 kWh batteries is expected in early 1984.

Bellows, R. J.; Grimes, P.; Einstein, H.; Kantner, E.; Malachesky, P.; Newby, K.

1983-02-01

134

Hybrid Wing Body Planform Design with Vehicle Sketch Pad  

NASA Technical Reports Server (NTRS)

The objective of this paper was to provide an update on NASA s current tools for design and analysis of hybrid wing body (HWB) aircraft with an emphasis on Vehicle Sketch Pad (VSP). NASA started HWB analysis using the Flight Optimization System (FLOPS). That capability is enhanced using Phoenix Integration's ModelCenter(Registered TradeMark). Model Center enables multifidelity analysis tools to be linked as an integrated structure. Two major components are linked to FLOPS as an example; a planform discretization tool and VSP. The planform discretization tool ensures the planform is smooth and continuous. VSP is used to display the output geometry. This example shows that a smooth & continuous HWB planform can be displayed as a three-dimensional model and rapidly sized and analyzed.

Wells, Douglas P.; Olson, Erik D.

2011-01-01

135

Aeroassisted-vehicle design studies for a manned Mars mission  

NASA Technical Reports Server (NTRS)

An aerobrake design that has matured over several years of development accounting for all of the important flow phenomenology which are characteristic of aerobraking vehicles is proposed as the mission baseline. Flight regimes and aerothermal environments for both Mars and Earth entry are calculated using advanced methods to account for real-gas, thermochemical, relaxation effects. The results are correlated with thermal-protection and structural requirements and mission performance capability. The importance of nonequilibrium radiative heating for Earth aerocapture is demonstrated. It is suggested that two aerobrakes of different sizes will produce optimal performance for the three phases of the mission (i.e., one aerobrake for Mars aerocapture and descent of the surface lander and another for Earth return).

Menees, Gene P.

1987-01-01

136

Design of a Vehicle Based Intervention System to Prevent Ozone Loss  

NASA Technical Reports Server (NTRS)

This project was designed to be completed over a period of three years. Overall project goals were: (1) To understand the processes that contribute to stratospheric ozone loss; (2) To determine the best prevention scheme for loss; (3) To design a delivery vehicle to accomplish the prevention scheme. The 1994-1995 design objectives included: (1) To review the results of the 1993-1994 design team, including a reevaluation of the major assumptions and criteria selected to choose a vehicle; (2) To evaluate preliminary vehicle concepts and perform quantitative trade studies to select the optimal vehicle concept.

Cole, Robin; Fisher, Daniel; Meade, Matt; Neel, James; Olson, Kristin; Pittman, Andrew; Valdivia, Anne; Wibisono, Aria; Mason, William H.; Kirschbaum, Nathan

1995-01-01

137

OPTIMAL DESIGN AND DYNAMIC SIMULATION OF A HYBRID SOLAR VEHICLE  

Microsoft Academic Search

The paper deals with a detailed study on the optimal sizing of a solar hybrid car, based on a longitudinal vehicle dynamic model and considering energy flows, weight and costs. The model describes the effects of solar panels area and position, vehicle dimensions and propulsion system components on vehicle performance, weight, fuel savings and costs. It is shown that significant

Ivan Arsie; Gianfranco Rizzo; Marco Sorrentino

138

Automatic Guided Vehicles: Robust Controller Design in Image Space  

Microsoft Academic Search

We have been interested in Automatic Guided Vehicles (AGV) for several years. In this paper, we synthesize controllers for AGV applications using monocular vision. In particular, we are interested in road following and direction change tasks, and in analyzing the influence of extrinsic camera parameter perturbations on vehicle behavior. We use the bicycle as the kinematic vehicle model, and we

P. Martinet; C. Thibaud

2000-01-01

139

Design and construction of a solar-electric vehicle  

Microsoft Academic Search

Recent concerns relating to global warming caused by greenhouse gases, coupled with a growing awareness of the limited available resources of fossil fuels, have spurred an interest in alternative energy powered vehicles. This paper describes the analysis, development, and testing of an aerodynamic vehicle powered by photovoltaic cells. The primary components of the vehicle are the composite material body, the

S. H. Bhavnani

1994-01-01

140

Enhanced Control Effector Designs for Airbreathing Transatmospheric Vehicles  

NASA Technical Reports Server (NTRS)

A study was conducted to evaluate the potential effectiveness of a moveable cowl-trailing-edge design for airbreathing hypersonic single-stage-to-orbit (SSTO) configurations, which can be extended or deflected from the nominal position in order to provide additional pitching moment capability. This additional pitching moment capability may reduce the necessary deflection angle from conventional control surfaces and the associated trim drag penalty. Calculations for a generic SSTO configuration with baseline and modified cowl trailing edge geometries were performed at Mach 6 and 10 initially with an engineering analysis code in order to examine several design parametrics. In order to more accurately model geometries and flow physics, 2-D viscous computational fluid dynamics (CFD) predictions were obtained. FInally, a limited set of 3D CFD predictions were obtained at Mach 6 in order to show the effects of modeling 3D flow fields as well as the full 3D vehicle geometry. Comparisons of aftbody surface pressures and force and moment predictions show differences between initial predictions and 2-D CFD solutions due to geometry modeling and calculation method differences. The 3-D CFD predictions confirm the trends observed in the 2-D solutions and provide additional information on 3D effects. These analyses shows that cowl-trailing-edge extensions were effective in providing additional (nose-down) pitching moment increments as well as increased thrust compared to the baseline geometry. These effects reduce the control surface deflection angle required to trim the vehicle and the associated trim drag. Cowl-trailingedge deflections were not as effective, generating more nose-up pitching moment and decreased thrust compared to non-deflected cases.

Cockrell, Charles E.; McMinn, John D.

1997-01-01

141

Design of a vehicle based system to prevent ozone loss  

NASA Technical Reports Server (NTRS)

Reduced quantities of ozone in the atmosphere allow greater levels of ultraviolet light (UV) radiation to reach the earth's surface. This is known to cause skin cancer and mutations. Chlorine liberated from Chlorofluorocarbons (CFC's) and natural sources initiate the destruction of stratospheric ozone through a free radical chain reaction. The project goals are to understand the processes which contribute to stratospheric ozone loss, examine ways to prevent ozone loss, and design a vehicle-based system to carry out the prevention scheme. The 1992/1993 design objectives were to accomplish the first two goals and define the requirements for an implementation vehicle to be designed in detail starting next year. Many different ozone intervention schemes have been proposed though few have been researched and none have been tested. A scheme proposed by R.J. Cicerone, Scott Elliot and R.P.Turco late in 1991 was selected because of its research support and economic feasibility. This scheme uses hydrocarbon injected into the Antarctic ozone hole to form stable compounds with free chlorine, thus reducing ozone depletion. Because most polar ozone depletion takes place during a 3-4 week period each year, the hydrocarbon must be injected during this time window. A study of the hydrocarbon injection requirements determined that 100 aircraft traveling Mach 2.4 at a maximum altitude of 66,000 ft. would provide the most economic approach to preventing ozone loss. Each aircraft would require an 8,000 nm. range and be able to carry 35,000 lbs. of propane. The propane would be stored in a three-tank high pressure system. Missions would be based from airport regions located in South America and Australia. To best provide the requirements of mission analysis, an aircraft with L/D(sub cruise) = 10.5, SFC = 0.65 (the faculty advisor suggested that this number is too low) and a 250,000 lb TOGW was selected as a baseline. Modularity and multi-role functionality were selected to be key design features. Modularity provides ease of turnaround for the down-time critical mission. Multi-role functionality allows the aircraft to be used beyond its design mission, perhaps as an High Speed Civil Transport (HSCT) or for high altitude research.

Lynn, Sean R.; Bunker, Deborah; Hesbach, Thomas D., Jr.; Howerton, Everett B.; Hreinsson, G.; Mistr, E. Kirk; Palmer, Matthew E.; Rogers, Claiborne; Tischler, Dayna S.; Wrona, Daniel J.

1993-01-01

142

Comparative Ergonomic Evaluation of Spacesuit and Space Vehicle Design  

NASA Technical Reports Server (NTRS)

With the advent of the latest human spaceflight objectives, a series of prototype architectures for a new launch and reentry spacesuit that would be suited to the new mission goals. Four prototype suits were evaluated to compare their performance and enable the selection of the preferred suit components and designs. A consolidated approach to testing was taken: concurrently collecting suit mobility data, seat-suit-vehicle interface clearances, and qualitative assessments of suit performance within the volume of a Multi-Purpose Crew Vehicle mockup. It was necessary to maintain high fidelity in a mockup and use advanced motion-capture technologies in order to achieve the objectives of the study. These seemingly mutually exclusive goals were accommodated with the construction of an optically transparent and fully adjustable frame mockup. The construction of the mockup was such that it could be dimensionally validated rapidly with the motioncapture system. This paper describes the method used to create a space vehicle mockup compatible with use of an optical motion-capture system, the consolidated approach for evaluating spacesuits in action, and a way to use the complex data set resulting from a limited number of test subjects to generate hardware requirements for an entire population. Kinematics, hardware clearance, anthropometry (suited and unsuited), and subjective feedback data were recorded on 15 unsuited and 5 suited subjects. Unsuited subjects were selected chiefly based on their anthropometry in an attempt to find subjects who fell within predefined criteria for medium male, large male, and small female subjects. The suited subjects were selected as a subset of the unsuited medium male subjects and were tested in both unpressurized and pressurized conditions. The prototype spacesuits were each fabricated in a single size to accommodate an approximately average-sized male, so select findings from the suit testing were systematically extrapolated to the extremes of the population to anticipate likely problem areas. This extrapolation was achieved by first comparing suited subjects performance with their unsuited performance, and then applying the results to the entire range of the population. The use of a transparent space vehicle mockup enabled the collection of large amounts of data during human-in-the-loop testing. Mobility data revealed that most of the tested spacesuits had sufficient ranges of motion for the selected tasks to be performed successfully. A suited subject's inability to perform a task most often stemmed from a combination of poor field of view in a seated position, poor dexterity of the pressurized gloves, or from suit/vehicle interface issues. Seat ingress and egress testing showed that problems with anthropometric accommodation did not exclusively occur with the largest or smallest subjects, but also with specific combinations of measurements that led to narrower seat ingress/egress clearance.

England, Scott; Cowley, Matthew; Benson, Elizabeth; Harvill, Lauren; Blackledge, Christopher; Perez, Esau; Rajulu, Sudhakar

2012-01-01

143

Launch Vehicle Propulsion Parameter Design Multiple Selection Criteria  

NASA Technical Reports Server (NTRS)

The optimization tool described herein addresses and emphasizes the use of computer tools to model a system and focuses on a concept development approach for a liquid hydrogen/liquid oxygen single-stage-to-orbit system, but more particularly the development of the optimized system using new techniques. This methodology uses new and innovative tools to run Monte Carlo simulations, genetic algorithm solvers, and statistical models in order to optimize a design concept. The concept launch vehicle and propulsion system were modeled and optimized to determine the best design for weight and cost by varying design and technology parameters. Uncertainty levels were applied using Monte Carlo Simulations and the model output was compared to the National Aeronautics and Space Administration Space Shuttle Main Engine. Several key conclusions are summarized here for the model results. First, the Gross Liftoff Weight and Dry Weight were 67% higher for the design case for minimization of Design, Development, Test and Evaluation cost when compared to the weights determined by the minimization of Gross Liftoff Weight case. In turn, the Design, Development, Test and Evaluation cost was 53% higher for optimized Gross Liftoff Weight case when compared to the cost determined by case for minimization of Design, Development, Test and Evaluation cost. Therefore, a 53% increase in Design, Development, Test and Evaluation cost results in a 67% reduction in Gross Liftoff Weight. Secondly, the tool outputs define the sensitivity of propulsion parameters, technology and cost factors and how these parameters differ when cost and weight are optimized separately. A key finding was that for a Space Shuttle Main Engine thrust level the oxidizer/fuel ratio of 6.6 resulted in the lowest Gross Liftoff Weight rather than at 5.2 for the maximum specific impulse, demonstrating the relationships between specific impulse, engine weight, tank volume and tank weight. Lastly, the optimum chamber pressure for Gross Liftoff Weight minimization was 2713 pounds per square inch as compared to 3162 for the Design, Development, Test and Evaluation cost optimization case. This chamber pressure range is close to 3000 pounds per square inch for the Space Shuttle Main Engine.

Shelton, Joey Dewayne

2004-01-01

144

Estimating Basic Preliminary Design Performances of Aerospace Vehicles  

NASA Technical Reports Server (NTRS)

Aerodynamics and Performance Estimation Toolset is a collection of four software programs for rapidly estimating the preliminary design performance of aerospace vehicles represented by doing simplified calculations based on ballistic trajectories, the ideal rocket equation, and supersonic wedges through standard atmosphere. The program consists of a set of Microsoft Excel worksheet subprograms. The input and output data are presented in a user-friendly format, and calculations are performed rapidly enough that the user can iterate among different trajectories and/or shapes to perform "what-if" studies. Estimates that can be computed by these programs include: 1. Ballistic trajectories as a function of departure angles, initial velocities, initial positions, and target altitudes; assuming point masses and no atmosphere. The program plots the trajectory in two-dimensions and outputs the position, pitch, and velocity along the trajectory. 2. The "Rocket Equation" program calculates and plots the trade space for a vehicle s propellant mass fraction over a range of specific impulse and mission velocity values, propellant mass fractions as functions of specific impulses and velocities. 3. "Standard Atmosphere" will estimate the temperature, speed of sound, pressure, and air density as a function of altitude in a standard atmosphere, properties of a standard atmosphere as functions of altitude. 4. "Supersonic Wedges" will calculate the free-stream, normal-shock, oblique-shock, and isentropic flow properties for a wedge-shaped body flying supersonically through a standard atmosphere. It will also calculate the maximum angle for which a shock remains attached, and the minimum Mach number for which a shock becomes attached, all as functions of the wedge angle, altitude, and Mach number.

Luz, Paul L.; Alexander, Reginald

2004-01-01

145

Unmanned, space-based, reusable orbital transfer vehicle, DARVES. Volume 1: Trade analysis and design  

NASA Technical Reports Server (NTRS)

The design of an unmanned, space-based, reusable Orbital Transfer Vehicle (OTV) is presented. This OTV will be utilized for the delivery and retrieval of satellites from geosynchronous Earth orbit (GEO) in conjunction with a space station assumed to be in existence in low Earth orbit (LEO). The trade analysis used to determine the vehicle design is presented, and from this study a vehicle definition is given.

1988-01-01

146

Design and Research on Air Conditioning Control Network of Electric Vehicle Based on CAN-Bus  

Microsoft Academic Search

The design of the electric air-conditioning CANbus communication system makes a target of electric vehicles in order to form digital control network of a number of electronic control unit in electric vehicles, develop electric vehicles CAN (Controller Area Network)bus system, adopting communication protocol SAE J1939;the use of microprocessor STC12C5A60S2 complete design of CAN bus interface circuit; The digital simulation of

Fan Xin; Hu Chun

2010-01-01

147

The Effect of Predicted Vehicle Displacement on Ground Crew Task Performance and Hardware Design  

NASA Technical Reports Server (NTRS)

NASA continues to explore new launch vehicle concepts that will carry astronauts to low- Earth orbit to replace the soon-to-be retired Space Transportation System (STS) shuttle. A tall vertically stacked launch vehicle (> or =300 ft) is exposed to the natural environment while positioned on the launch pad. Varying directional winds and vortex shedding cause the vehicle to sway in an oscillating motion. Ground crews working high on the tower and inside the vehicle during launch preparations will be subjected to this motion while conducting critical closeout tasks such as mating fluid and electrical connectors and carrying heavy objects. NASA has not experienced performing these tasks in such environments since the Saturn V, which was serviced from a movable (but rigid) service structure; commercial launchers are likewise attended by a service structure that moves away from the vehicle for launch. There is concern that vehicle displacement may hinder ground crew operations, impact the ground system designs, and ultimately affect launch availability. The vehicle sway assessment objective is to replicate predicted frequencies and displacements of these tall vehicles, examine typical ground crew tasks, and provide insight into potential vehicle design considerations and ground crew performance guidelines. This paper outlines the methodology, configurations, and motion testing performed while conducting the vehicle displacement assessment that will be used as a Technical Memorandum for future vertically stacked vehicle designs.

Atencio, Laura Ashley; Reynolds, David W.

2011-01-01

148

Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration  

NASA Technical Reports Server (NTRS)

Investigation of problems related to the design and control of a mobile planetary vehicle to implement a systematic plan for the exploration of Mars has been undertaken. Problem areas receiving attention include: vehicle configuration, control, dynamics, systems and propulsion; systems analysis; terrain modeling and path selection; and chemical analysis of specimens. The following specific tasks have been under study: vehicle model design, mathematical modeling of a dynamic vehicle, experimental vehicle dynamics, obstacle negotiation, electromechanical controls, collapsibility and deployment, construction of a wheel tester, wheel analysis, payload design, system design optimization, effect of design assumptions, accessory optimal design, on-board computer sybsystem, laser range measurement, discrete obstacle detection, obstacle detection systems, terrain modeling, path selection system simulation and evaluation, gas chromatograph/mass spectrometer system concepts, chromatograph model evaluation and improvement.

Frederick, D. K.; Lashmet, P. K.; Sandor, G. N.; Shen, C. N.; Smith, E. J.; Yerazunis, S. W.

1972-01-01

149

Development of Response Surface Models for Rapid Analysis and Multidisciplinary Optimization of Launch Vehicle Design Concepts  

NASA Technical Reports Server (NTRS)

Multidisciplinary design optimization (MDO) is an important step in the design and evaluation of launch vehicles, since it has a significant impact on performance and lifecycle cost. The objective in MDO is to search the design space to determine the values of design parameters that optimize the performance characteristics subject to system constraints. Vehicle Analysis Branch (VAB) at NASA Langley Research Center has computerized analysis tools in many of the disciplines required for the design and analysis of launch vehicles. Vehicle performance characteristics can be determined by the use of these computerized analysis tools. The next step is to optimize the system performance characteristics subject to multidisciplinary constraints. However, most of the complex sizing and performance evaluation codes used for launch vehicle design are stand-alone tools, operated by disciplinary experts. They are, in general, difficult to integrate and use directly for MDO.

Unal, Resit

1999-01-01

150

Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration  

NASA Technical Reports Server (NTRS)

The following tasks related to the design, construction, and evaluation of a mobile planetary vehicle for unmanned exploration of Mars are discussed: (1) design and construction of a 0.5 scale dynamic vehicle; (2) mathematical modeling of vehicle dynamics; (3) experimental 0.4 scale vehicle dynamics measurements and interpretation; (4) vehicle electro-mechanical control systems; (5) remote control systems; (6) collapsibility and deployment concepts and hardware; (7) design, construction and evaluation of a wheel with increased lateral stiffness, (8) system design optimization; (9) design of an on-board computer; (10) design and construction of a laser range finder; (11) measurement of reflectivity of terrain surfaces; (12) obstacle perception by edge detection; (13) terrain modeling based on gradients; (14) laser scan systems; (15) path selection system simulation and evaluation; (16) gas chromatograph system concepts; (17) experimental chromatograph separation measurements and chromatograph model improvement and evaluation.

Frederick, D. K.; Lashmet, P. K.; Moyer, W. R.; Sandor, G. N.; Shen, C. N.; Smith, E. J.; Yerazunis, S. W.

1973-01-01

151

Reaction Control System Design Considerations for Mars Entry Vehicles  

NASA Technical Reports Server (NTRS)

The next generation of Mars exploration landers must precisely deliver scientific payloads to sites of interest, unlike previous Mars missions. The past missions, such as Viking and Pathfinder, performed landings to within 100s of kilometers from their targets using an unguided atmospheric entry. Guided entry of a capsule with a relatively high lift-to-drag ratio will allow landing to within 10s of kilometers from the target with a significantly more massive payload. Successful guided entry requires the use of a reaction control system (RCS) for both attitude correction and entry guidance maneuvers. Various aspects of the entry, descent and landing (EDL) system performance may be impacted by the operation of the RCS during entry. This paper illustrates the risks that arise from the gasdynamic interaction of the entry vehicle (EV) and RCS, and which require attention in the areas of aerodynamics and control, and aerothermal environments. This paper will review the methods to address the design challenges associated with integration of RCS into the atmospheric entry system. Among these challenges is the analysis of the potential for the aerodynamic interference due to both the direct jet plume impingement and more complex plume interactions with the wake flow. These interactions can result in enhanced aeroheating, requiring that a different approach to the thermal protection system (TPS) selection and sizing be used. The recent findings for Mars Science Laboratory and Mars Phoenix will be presented to help illustrate some of the phenomena. Current design solutions will be discussed.

Dyakonov, Artem A.; Schoenenberger, Mark; Edquist, Karl T.; Cheatwood, F. M.; Wright, Michael J.

2007-01-01

152

A hybrid vehicle evaluation code and its application to vehicle design. Revision 1  

SciTech Connect

This paper describes a hybrid vehicle simulation model which can be applied to many of the vehicles currently being considered for low pollution and high fuel economy. The code operates in batch mode with all the vehicle information stored in data files. The code calculates fuel economy for three driving schedules, time for 0--96 km/h at maximum acceleration, hill climbing performance, power train dimensions, and pollution generation rates. This paper also documents the application of the code to a hybrid vehicle that utilizes a hydrogen internal combustion engine. The simulation model is used for parametric studies of the vehicle. The results show the fuel economy of the vehicle as a function of vehicle mass, aerodynamic drag, engine efficiency, accessory load, and flywheel efficiency. The code also calculates the minimum flywheel energy and power to obtain a desired performance. The hydrogen hybrid vehicle analyzed in the paper has a predicted range of 480 km (300 miles), with a gasoline equivalent fuel efficiency of 34.2 km/liter (80.9 mpg).

Aceves, S.M.; Smith, J.R.

1994-09-15

153

A hybrid vehicle evaluation code and its application to vehicle design. Revision 2  

SciTech Connect

This paper describes a hybrid vehicle simulation model which can be applied to many of the vehicles currently being considered for low pollution and high fuel economy. The code operates in batch mode with all the vehicle information stored in data files. The code calculates power train dimensions, fuel economy for three driving schedules, time for 0-96 km/h at maximum acceleration, hill climbing performance, and pollution generation rates. This paper also documents the application of the code to a hybrid vehicle that utilizes a hydrogen internal combustion engine. The simulation model is used for parametric studies of the vehicle. The results show the fuel economy of the vehicle as a function of vehicle mass, aerodynamic drag, engine efficiency, accessory load, and flywheel efficiency. The code also calculates the minimum flywheel energy and power to obtain a desired performance. The hydrogen hybrid vehicle analyzed in the paper has a range of 480 km (300 miles), with a predicted gasoline equivalent fuel efficiency of 33.7 km/liter (79.3 mpg).

Aceves, S.M.; Smith, J.R.

1994-12-13

154

Adjoint-Based Aerothermodynamic Shape Design of Hypersonic Vehicles in Non-Equilibrium Flows  

E-print Network

Adjoint-Based Aerothermodynamic Shape Design of Hypersonic Vehicles in Non-Equilibrium Flows Sean R Rigid-rotator harmonic-oscillator I. Introduction The hypersonic aerothermodynamic environment. The hypersonic vehicle design process requires the synthesis of aerothermodynamic, structural, TPS material

Alonso, Juan J.

155

Design and Implementation of a Wireless Multimedia Advertising Vehicle Terminal System  

Microsoft Academic Search

A new extensible multi-function vehicle terminal system for multimedia advertising is designed, and the software and hardware design and realization method are also introduced. The terminal support remote release of text advertisement and audio advertisement and which was combined with the master server, vehicle LED screen, microphone, empty-car indicator light, taximeter to make up a multimedia advertising remote release system.

Fan Ya; Zhu Pingan; Zhou Baozhuo; Chen Shaojie

2010-01-01

156

Design and Implementation of Renewable Hydrogen Fuel Cell Vehicles  

Microsoft Academic Search

In this paper, a systematic approach for investigating a hydrogen fuel cell hybrid vehicle system is considered. This approach involves developing a mathematical model incorporating renewable hydrogen production, storage and refuelling of the fuel cell vehicle system. The University of Glamorgan's (UOG) Sustainable Environment Research Centre (SERC) have developed the UK's first alternative energy refuelling facility at the University's Hydrogen

Kary Thanapalan; Jonathan Williams; Alan Guwy

2011-01-01

157

Enhanced supervisory control system design of an unmanned ground vehicle  

Microsoft Academic Search

The supervisory control of unmanned ground vehicles due to their inherent growing complexity has become a very important component. A framework is presented in this paper for the enhanced supervisory control of such systems based on formal approaches of discrete event systems and supervisory control theory. Within this framework, supervisory control of the vehicle is implemented at both behavioral and

Xiongfeng Feng; Peter C. Y. Chen; A. N. Poo; Javier Ibanez Guzman; C. W. Chan

2004-01-01

158

Controller design for improving lateral vehicle dynamic stability  

Microsoft Academic Search

A vehicle dynamics control system has been developed in this study for improving vehicle dynamic stability under critical lateral motions. The system consists of a feedforward controller, a state feedback controller, and an estimator for the body sideslip angle. The linear quadratic regulator theory has been exploited for the state feedback gain, and for estimation of the body sideslip angle,

Seung-Jin Heo; Inho Baek

2001-01-01

159

Design and Control of a Fully Automated Vehicle door  

E-print Network

a pull of the door handle, utilizes an IR sensor to detect objects in its path. The vehicle door utilizes a linear direct current (DC) actuator with a built in potentiometer to power and control the vehicle door. The built in potentiometer provides...

Hong, Kyung-Min

2010-07-14

160

Aerospace Vehicle Design, Spacecraft Section. Volume 1: Project Groups 3-5  

NASA Technical Reports Server (NTRS)

Three groups of student engineers in an aerospace vehicle design course present their designs for a vehicle that can be used to resupply the Space Station Freedom and provide an emergency crew return to earth capability. The vehicle's requirements include a lifetime that exceeds six years, low cost, the capability for withstanding pressurization, launch, orbit, and reentry hazards, and reliability. The vehicle's subsystems are analyzed. These subsystems are structures, communication and command data systems, attitude and articulation control, life support and crew systems, power and propulsion, reentry and recovery systems, and mission management, planning, and costing.

1989-01-01

161

Hybrid vehicle system studies and optimized hydrogen engine design  

NASA Astrophysics Data System (ADS)

We have done system studies of series hydrogen hybrid automobiles that approach the PNGV design goal of 34 km/liter (80 mpg), for 384 km (240 mi) and 608 km (380 mi) ranges. Our results indicate that such a vehicle appears feasible using an optimized hydrogen engine. We have evaluated the impact of various on-board storage options on fuel economy. Experiments in an available engine at the Sandia CRF demonstrated NO(x) emissions of 10 to 20 ppM at an equivalence ratio of 0.4, rising to about 500 ppm at 0.5 equivalence ratio using neat hydrogen. Hybrid simulation studies indicate that exhaust NO(x) concentrations must be less than 180 ppM to meet the 0.2 g/mile ULEV or Federal Tier II emissions regulations. LLNL has designed and fabricated a first generation optimized hydrogen engine head for use on an existing Onan engine. This head features 15:1 compression ratio, dual ignition, water cooling, two valves and open quiescent combustion chamber to minimize heat transfer losses. Initial testing shows promise of achieving an indicated efficiency of nearly 50% and emissions of less than 100 ppM NO(x). Hydrocarbons and CO are to be measured, but are expected to be very low since their only source is engine lubricating oil. A successful friction reduction program on the Onan engine should result in a brake thermal efficiency of about 42% compared to today's gasoline engines of 32%. Based on system studies requirements, the next generation engine will be about 2 liter displacement and is projected to achieve 46% brake thermal efficiency with outputs of 15 kW for cruise and 40 kW for hill climb.

Smith, J. R.; Aceves, S.

1995-04-01

162

Design of a Network Coverage Analyzer for Roadside-to-Vehicle Telematics Networks  

Microsoft Academic Search

This paper designs a connectivity analysis scheme for the roadside-to-vehicle telematics network based on the real movement history of vehicle objects collected from taxi telematics system currently in operation, aiming at providing a useful guideline and information to build a telematics network.The implemented analyzer can locate the current and previous positions of all vehicles, decide whether it can be connected

Junghoon Lee

2008-01-01

163

Parametric estimation of R&M parameters during the conceptual design of space vehicles  

NASA Technical Reports Server (NTRS)

Reliability and maintainability parameters of proposed space vehicles are estimated based on a comparability analysis of similar aircraft subsystems. Using multiple regression techniques, parametric equations are developed for each subsystem to predict mean flying hours between failure as a function of vehicle design and performance specifications. These estimates are then adjusted to account for reliability growth, environmental differences, and new technologies. Overall vehicle mission reliability may then be computed from subsystem reliability estimates.

Ebeling, Charles E.

1992-01-01

164

Simultaneous D-stabilisation robust controller design for autonomous vehicle steering  

Microsoft Academic Search

This paper presents a new robust controller design method for autonomous vehicle steering, satisfying the non-switching simultaneous D-stability requirement. The non-linearity of the vehicle introduced by variable speed and mass of the vehicle is characterised by the linearised time-invariant models at various operating points which cover the full range of the operating regimes. In this way parameter variations caused by

Yongji Wang; Michael Schinkel; Tilmann Schmitt-Hartmann; Ken J. Hunt

165

76 FR 14070 - In the Matter of Certain Automotive Vehicles and Designs Therefore; Notice of Commission Issuance...  

Federal Register 2010, 2011, 2012, 2013

...of Certain Automotive Vehicles and Designs Therefore; Notice of Commission Issuance...International Trade Commission, 500 E Street, SW., Washington, DC 20436, telephone...of certain automotive vehicles and designs therefor by reason of...

2011-03-15

166

Final design report of a personnel launch system and a family of heavy lift launch vehicles  

NASA Technical Reports Server (NTRS)

The objective was to design both a Personnel Launch System (PLS) and a family of Heavy Lift Launch Vehicles (FHLLVs) that provide low cost and efficient operation in missions not suited for the Shuttle. The PLS vehicle is designed primarily for space station crew rotation and emergency crew return. The final design of the PLS vehicle and its interior is given. The mission of the FHLLVs is to place large, massive payloads into Earth orbit with payload flexibility being considered foremost in the design. The final design of three launch vehicles was found to yield a payload capacity range from 20 to 200 mt. These designs include the use of multistaged, high thrust liquid engines mounted on the core stages of the rocket.

Tupa, James; Merritt, Debbie; Riha, David; Burton, Lee; Kubinski, Russell; Drake, Kerry; Mann, Darrin; Turner, Ken

1991-01-01

167

Design for manufacturing analysis on the Small Unmanned Ground Vehicle  

E-print Network

iRobot is responsible for delivering the Small Unmanned Ground Vehicle (SUGV) as part of the U.S. Army's Future Combat Systems (FCS) initiative. With increasing external competition and pressures, iRobot must deliver an ...

Yu, Ada (Ada Cheuk Ying)

2008-01-01

168

Hybrid vehicle design using global optimisation Wenzhong Gao  

E-print Network

is to achieve maximum fuel economy, subject to the constraints of vehicle performance. The model in the loop professor and Associate Chair of Department of Automation in 1994. He worked for General Electric Canada Inc

Mi, Chunting "Chris"

169

Rotorcraft control system design for uncertain vehicle dynamics using quantitative feedback theory  

NASA Technical Reports Server (NTRS)

Quantitative Feedback Theory describes a frequency-domain technique for the design of multi-input, multi-output control systems which must meet time or frequency domain performance criteria when specified uncertainty exists in the linear description of the vehicle dynamics. This theory is applied to the design of the longitudinal flight control system for a linear model of the BO-105C rotorcraft. Uncertainty in the vehicle model is due to the variation in the vehicle dynamics over a range of airspeeds from 0-100 kts. For purposes of exposition, the vehicle description contains no rotor or actuator dynamics. The design example indicates the manner in which significant uncertainty exists in the vehicle model. The advantage of using a sequential loop closure technique to reduce the cost of feedback is demonstrated by example.

Hess, R. A.

1994-01-01

170

A RAPID PROTOTYPING ENVIRONMENT FOR THE DESIGN OF EXTENSIBLE IN-VEHICLE TELEMATICS SYSTEMS  

Microsoft Academic Search

In view of the sharp uptake of mobile computing and communications technologies, many hardware and software vendors and telecommunication services providers (IBM & Motorola), (Sun Microsystems), (NEWSBYTES) have developed keen interests in the deployment of these technologies in vehicles as so-called In-Vehicle Telematics Systems (IVTS). Design is recognised as a vital discipline to envision innovative applications of new and existing

D. Reilly; A. Taleb Bendiab; M. Merabti

171

Design for hybrid electric drive system of armored vehicle with two energy storage devices  

Microsoft Academic Search

Aimed at characteristic of regenerative brake of hybrid electric drive system of armored vehicle, hybrid electric drive system of armored vehicle with two energy storage devices (battery and flywheel) in series is designed for steal running and electro-thermal chemical gun in future combat field. Battery and flywheel are coordinated to store maximum feedback energy. Heavy current within short time is

Li Hua; Zhang Jian; Xu Da; Ma Xiaojun

2009-01-01

172

Interface Design for Unmanned Vehicle Supervision through Hybrid Cognitive Task Analysis  

E-print Network

Interface Design for Unmanned Vehicle Supervision through Hybrid Cognitive Task Analysis Jamie C While there is currently significant interest in developing Unmanned Aerial Systems (UASs) that can- manned Aerial Vehicle (UAV) along with multiple scouting UAVs. This paper will detail the development

Cummings, Mary "Missy"

173

Design of a supercapacitor-battery storage system for a waste collection vehicle  

Microsoft Academic Search

This paper deals with the design of battery-supercapacitors energy storage for an electric waste collection vehicle. The vehicle was simulated on an urban driving cycle and a simple power flow management based on the power limitation in battery was developed. The main benefit of the hybridization, the reduction of the losses within the battery, is outlined and we show how

S. Butterbach; B. Vulturescu; G. Coquery; C. Forgez; G. Friedrich

2010-01-01

174

Design and implementation of management vehicle information system based on the .NET Framework  

Microsoft Academic Search

This paper analyzes the present domestic situation of vehicle transportation industry. Because compatibility, high load and exists in the vehicle monitoring system, a solution, based on the .NET Framework 2.0, integration of GPS(Global Position System), wireless communication technology, Microsoft SQL Server 2005 database , Google Maps API V3 and Ajax technology solutions is proposed. The design principle and implementation method

Zhao Yunbo; Wang Jian

2011-01-01

175

Original Design of an Unmanned Ground Vehicle for Exploration in Rough Terrain  

Microsoft Academic Search

This paper introduces an originally designed tracked robot. This robot belongs to the variable geometry single-tracked vehicle (VGSTV) category. Two active joints are used to control the shape of the vehicle and the tension of the tracks. Thus, it becomes possible to adapt the shape of the robot and the ground\\/robot contact points to the obstacle by controlling the joints.

Jean-Luc Paillat; Philippe Lucidarme; Laurent Hardouin

2010-01-01

176

Design of Electric or Hybrid vehicle alert sound system for pedestrian  

E-print Network

is to equip vehicle with an external loudspeaker which diffuses a sound representative of the car's drivingDesign of Electric or Hybrid vehicle alert sound system for pedestrian J.-C. Chamard and V to solve this problem is to generate an alert sound. This signal has to improve the interaction

Boyer, Edmond

177

Robust Controller Design for Supercavitating Vehicles Based on BTT Maneuvering Strategy  

Microsoft Academic Search

Supercavitating vehicles can achieve very high speeds under water because of reduced drag. With proper design, a cavitation bubble is generated at the nose so that skin friction drag is drastically reduced. A 6 DOF mathematic model has been established. As discussed in this paper, control and maneuvering of supercavitating vehicle meet special challenges, The need for a BTT (bank-to-turn)

Maoli Wang; Guoliang Zhao; Jian Li

2007-01-01

178

A design of bi-verification vehicle access intelligent control system based on RFID  

Microsoft Academic Search

Radio-frequency identification (RFID) technology is widespread developed and common for vehicle management in intelligent community. However, smart card used as the sole certificate of identification could also be impersonated by criminals when the card is lost or stolen. In this paper, an improvement design to the current widely-used vehicle monitoring systems, which utilize the RFID technology to carry on is

Xiaohu Fan; Yulin Zhang

2009-01-01

179

Design and Implementation of Time Efficient Trajectories for an Underwater Vehicle  

E-print Network

vehicle (ROV) handles the up close exploration. AUV mission profiles of this sort are best suited through of an ROV. This approach has its advantages and disadvantages. Note though, more and more autonomous vehicles are being designed to take over these jobs from the ROV's [24]. However, we should not let

Smith, Ryan N.

180

A four-step method to design an energy management strategy for hybrid vehicles  

Microsoft Academic Search

This paper presents an innovative four-step method to analyze and design an optimal energy management strategy for a power split power train hybrid vehicle. A hybrid dynamical system theory is introduced to formulate the problem of hybrid vehicle control system that incorporates both continuous and discrete dynamics. The sequential quadratic programming (SQP) method is proposed to optimize power distribution. The

Yuan Zhu; Yaobin Chen; Guangyu Tian; Hao Wu; Quanshi Chen

2004-01-01

181

Environmental Controls and Life Support System (ECLSS) Design for a Space Exploration Vehicle (SEV)  

NASA Technical Reports Server (NTRS)

Engineers at Johnson Space Center (JSC) are developing an Environmental Control and Life Support System (ECLSS) design for the Space Exploration Vehicle (SEV). The SEV will aid to expand the human exploration envelope for Geostationary Transfer Orbit (GEO), Near Earth Object (NEO), or planetary missions by using pressurized surface exploration vehicles. The SEV, formerly known as the Lunar Electric Rover (LER), will be an evolutionary design starting as a ground test prototype where technologies for various systems will be tested and evolve into a flight vehicle. This paper will discuss the current SEV ECLSS design, any work contributed toward the development of the ECLSS design, and the plan to advance the ECLSS design based on the SEV vehicle and system needs.

Stambaugh, Imelda; Sankaran, Subra

2010-01-01

182

Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration  

NASA Technical Reports Server (NTRS)

Problems related to an unmanned exploration of the planet Mars by means of an autonomous roving planetary vehicle are investigated. These problems include: design, construction and evaluation of the vehicle itself and its control and operating systems. More specifically, vehicle configuration, dynamics, control, propulsion, hazard detection systems, terrain sensing and modelling, obstacle detection concepts, path selection, decision-making systems, and chemical analyses of samples are studied. Emphasis is placed on development of a vehicle capable of gathering specimens and data for an Augmented Viking Mission or to provide the basis for a Sample Return Mission.

Gisser, D. G.; Frederick, D. K.; Lashmet, P. K.; Sandor, G. N.; Shen, C. N.; Yerazunis, S. Y.

1975-01-01

183

Third Conference on Fibrous Composites in Flight Vehicle Design, part 1  

NASA Technical Reports Server (NTRS)

The use of fibrous composite materials in the design of aircraft and space vehicle structures and their impact on future vehicle systems are discussed. The topics covered include: flight test work on composite components, design concepts and hardware, specialized applications, operational experience, certification and design criteria. Contributions to the design technology base include data concerning material properties, design procedures, environmental exposure effects, manufacturing procedures, and flight service reliability. By including composites as baseline design materials, significant payoffs are expected in terms of reduced structural weight fractions, longer structural life, reduced fuel consumption, reduced structural complexity, and reduced manufacturing cost.

1976-01-01

184

Design study of an integrated aerobraking orbital transfer vehicle  

NASA Technical Reports Server (NTRS)

An aerobraking orbital transfer vehicle (AOTV) concept, which has an aerobrake structure that is integrated with the propulsion stage, is discussed. The concept vehicle is to be assembled in space and is space-based. The advantages of aeroassist over an all propulsive vehicle are discussed and it is shown that the vehicle considered is very competitive with inflatable and deployable concepts from mass and performance aspects. The aerobrake geometry is an ellipsoidally blunted, raked-off, elliptical wide-angle cone with a toroidal skirt. Propellant tanks, engines, and subsystems are integrated into a closed, isogrid aerobrake structure which provides rigidity. The vehicle has two side-firing, gimbaled RL-10 type engines and carries 38,000 kg of useable propellant. The trajectory during aerobraking is determined from an adaptive guidance logic, and the heating is determined from engineering correlations as well as 3-D Navier-Stokes solutions. The AOTV is capable of placing 13,500 kg payload into geosynchronous Earth orbit (GEO) or carrying a LEO-GEO-LEO round-trip payload of 7100 kg. A two-stage version considered for lunar missions results in a lunar surface delivery capability of 18,000 kg or a round-trip capability of 6800 kg with 3860 kg delivery-only capability.

Scott, C. D.; Roberts, B. B.; Nagy, K.; Taylor, P.; Gamble, J. D.; Ceremeli, C. J.; Knoll, K. R.; Li, C. P.; Reid, R. C.

1985-01-01

185

Direct-hydrogen-fueled proton-exchange-membrane fuel cell system for transportation applications: Conceptual vehicle design report pure fuel cell powertrain vehicle  

SciTech Connect

In partial fulfillment of the Department of Energy (DOE) Contract No. DE-AC02-94CE50389, {open_quotes}Direct-Hydrogen-Fueled Proton-Exchange-Membrane (PEM) Fuel Cell for Transportation Applications{close_quotes}, this preliminary report addresses the conceptual design and packaging of a fuel cell-only powered vehicle. Three classes of vehicles are considered in this design and packaging exercise, the Aspire representing the small vehicle class, the Taurus or Aluminum Intensive Vehicle (AIV) Sable representing the mid-size vehicle and the E-150 Econoline representing the van-size class. A fuel cell system spreadsheet model and Ford`s Corporate Vehicle Simulation Program (CVSP) were utilized to determine the size and the weight of the fuel cell required to power a particular size vehicle. The fuel cell power system must meet the required performance criteria for each vehicle. In this vehicle design and packaging exercise, the following assumptions were made: fuel cell power system density of 0.33 kW/kg and 0.33 kg/liter, platinum catalyst loading less than or equal to 0.25 mg/cm{sup 2} total and hydrogen tanks containing gaseous hydrogen under 340 atm (5000 psia) pressure. The fuel cell power system includes gas conditioning, thermal management, humidity control, and blowers or compressors, where appropriate. This conceptual design of a fuel cell-only powered vehicle will help in the determination of the propulsion system requirements for a vehicle powered by a PEMFC engine in lieu of the internal combustion (IC) engine. Only basic performance level requirements are considered for the three classes of vehicles in this report. Each vehicle will contain one or more hydrogen storage tanks and hydrogen fuel for 560 km (350 mi) driving range. Under these circumstances, the packaging of a fuel cell-only powered vehicle is increasingly difficult as the vehicle size diminishes.

Oei, D.; Kinnelly, A.; Sims, R.; Sulek, M.; Wernette, D.

1997-02-01

186

Modified Universal Design Survey: Enhancing Operability of Launch Vehicle Ground Crew Worksites  

NASA Technical Reports Server (NTRS)

Operability is a driving requirement for next generation space launch vehicles. Launch site ground operations include numerous operator tasks to prepare the vehicle for launch or to perform preflight maintenance. Ensuring that components requiring operator interaction at the launch site are designed for optimal human use is a high priority for operability. To promote operability, a Design Quality Evaluation Survey based on Universal Design framework was developed to support Human Factors Engineering (HFE) evaluation for NASA s launch vehicles. Universal Design per se is not a priority for launch vehicle processing however; applying principles of Universal Design will increase the probability of an error free and efficient design which promotes operability. The Design Quality Evaluation Survey incorporates and tailors the seven Universal Design Principles and adds new measures for Safety and Efficiency. Adapting an approach proven to measure Universal Design Performance in Product, each principle is associated with multiple performance measures which are rated with the degree to which the statement is true. The Design Quality Evaluation Survey was employed for several launch vehicle ground processing worksite analyses. The tool was found to be most useful for comparative judgments as opposed to an assessment of a single design option. It provided a useful piece of additional data when assessing possible operator interfaces or worksites for operability.

Blume, Jennifer L.

2010-01-01

187

Designing sustainable heavy lift launch vehicle architectures adaptability, lock-in, and system evolution  

E-print Network

Long term human space exploration depends on the development of a sustainable heavy lift launch vehicle (HLLV). But what exactly is sustainability in the context of launch systems and how can it addressed in the design ...

Silver, Matthew Robin

2005-01-01

188

Control Relevant Modeling and Design of Scramjet-Powered Hypersonic Vehicles  

NASA Astrophysics Data System (ADS)

This report provides an overview of scramjet-powered hypersonic vehicle modeling and control challenges. Such vehicles are characterized by unstable non-minimum phase dynamics with significant coupling and low thrust margins. Recent trends in hypersonic vehicle research are summarized. To illustrate control relevant design issues and tradeoffs, a generic nonlinear 3DOF longitudinal dynamics model capturing aero-elastic-propulsive interactions for wedge-shaped vehicle is used. Limitations of the model are discussed and numerous modifications have been made to address control relevant needs. Two different baseline configurations are examined over a two-stage to orbit ascent trajectory. The report highlights how vehicle level-flight static (trim) and dynamic properties change over the trajectory. Thermal choking constraints are imposed on control system design as a direct consequence of having a finite FER margin. The implication of this state-dependent nonlinear FER margin constraint, the right half plane (RHP) zero, and lightly damped flexible modes, on control system bandwidth (BW) and FPA tracking has been discussed. A control methodology has been proposed that addresses the above dynamics while providing some robustness to modeling uncertainty. Vehicle closure (the ability to fly a trajectory segment subject to constraints) is provided through a proposed vehicle design methodology. The design method attempts to use open loop metrics whenever possible to design the vehicle. The design method is applied to a vehicle/control law closed loop nonlinear simulation for validation. The 3DOF longitudinal modeling results are validated against a newly released NASA 6DOF code.

Dickeson, Jeffrey James

189

Preliminary power train design for a state-of-the-art electric vehicle (executive summary)  

NASA Technical Reports Server (NTRS)

The preliminary design of a state-of-the-art electric power train is part of a national effort to reap the potential benefit of useful urban electric passenger vehicles. Outlined in a detailed presentation are: (1) assessment of the state-of-the-art in electric vehicle technology; (2) state-of-the-art power train design; (3) improved power train; and (4) summary and recommendations.

1978-01-01

190

Design of an Inspection Class Autonomous Underwater Vehicle  

Microsoft Academic Search

Autonomous Underwater Vehicles (AUVs) have become ever more common in ocean science, military, and industrial applications. In particular, AUVs are becoming a significant option for undersea search and survey. Bottom following, tight turning radius, stability, and elimination of tow cables make AUVs appealing in this role. Recent commercial success has proven that AUVs can be competitive survey platforms. While AUVs

R. Damus; J. Manley; S. Desset; J. Morash; C. Chryssostomidis

2002-01-01

191

Vehicle lateral controller design exploiting properties of SITO systems  

E-print Network

is equipped with an electric motor acting on the steering angle (the command in- put) and a vision system wires placed along the road. The problem, in the case of passenger cars, was analyzed in this framework intelligent vehicles, given from the mid 1970's till early 1990's are surveyed by Tsugawa [18]. In paper [5

Regruto, Diego

192

DESIGN OF A FLIGHT CONTROLLER FOR HYPERSONIC FLIGHT EXPERIMENT VEHICLE  

Microsoft Academic Search

National Aerospace Laboratory (NAL) and National Space Development Agency (NASDA) of Japan launched a hypersonic flight experiment vehicle (HYFLEX) for flight experiment of reentry phase to the top of the atmosphere in 1996. Flight condition in the experiment varied from an altitude of 107km and a speed of Mach 15 to an altitude of 30km and a speed of Mach

Yoshimasa Ochi

2004-01-01

193

Power converter design for a fuel cell electric vehicle  

Microsoft Academic Search

This research is developed the electric vehicle by the fuel cell. Between fuel cell source and motor controller, we add new power converter, offer steady output voltage to motor controller and drive the direct current hub motor. Converter not only offers steady output voltage but it also combines with coupling inductance technology to battery charger. Besides offers energy to drive

Van-Tsai Liu; Jia-Wei Hong; Kuo-Ching Tseng

2010-01-01

194

Design of an urban driverless ground vehicle Rodrigo Benenson  

E-print Network

of a driverless car for populated urban environments. We propose a system that explicitly map the static obstacles, detects and track the moving obstacle, consider the unobserved areas, provide a motion plan with safety on real time an electric vehicle into an unvisited area with moving obstacles. The overview

Paris-Sud XI, Université de

195

Control-Relevant Modeling, Analysis, and Design for Scramjet-Powered Hypersonic Vehicles  

NASA Technical Reports Server (NTRS)

Within this paper, control-relevant vehicle design concepts are examined using a widely used 3 DOF (plus flexibility) nonlinear model for the longitudinal dynamics of a generic carrot-shaped scramjet powered hypersonic vehicle. Trade studies associated with vehicle/engine parameters are examined. The impact of parameters on control-relevant static properties (e.g. level-flight trimmable region, trim controls, AOA, thrust margin) and dynamic properties (e.g. instability and right half plane zero associated with flight path angle) are examined. Specific parameters considered include: inlet height, diffuser area ratio, lower forebody compression ramp inclination angle, engine location, center of gravity, and mass. Vehicle optimizations is also examined. Both static and dynamic considerations are addressed. The gap-metric optimized vehicle is obtained to illustrate how this control-centric concept can be used to "reduce" scheduling requirements for the final control system. A classic inner-outer loop control architecture and methodology is used to shed light on how specific vehicle/engine design parameter selections impact control system design. In short, the work represents an important first step toward revealing fundamental tradeoffs and systematically treating control-relevant vehicle design.

Rodriguez, Armando A.; Dickeson, Jeffrey J.; Sridharan, Srikanth; Benavides, Jose; Soloway, Don; Kelkar, Atul; Vogel, Jerald M.

2009-01-01

196

The Household Market for Electric Vehicles: Testing the Hybrid Household Hypothesis--A Reflively Designed Survey of New-car-buying, Multi-vehicle California Households  

E-print Network

survey of 13,692 new car buyers PAGE THE HOUSEHOLD MARKET FOR ELECTRICElectric Vehicles: Testing the Hybrid Household Hypothesis - A Reflively Designed Survey of New-car-Electric Vehicles: Testing the Hybrid Household Hypothesis— A Reflexively Designed Survey of New-car-

Turrentine, Thomas; Kurani, Kenneth

1995-01-01

197

Heavy Vehicle Systems, Int. J. of Vehicle Design, Vol. 11, Nos. 3/4, 2004 349 Modelling and control of a medium-duty hybrid  

E-print Network

Heavy Vehicle Systems, Int. J. of Vehicle Design, Vol. 11, Nos. 3/4, 2004 349 Modelling and control of a medium-duty hybrid electric truck C.-C. Lin, Z. Filipi, L. Louca, H. Peng*, D. Assanis, J. Stein tool, and its application to the design of a power management control algorithm. The hybrid electric

Peng, Huei

198

Modular Approach to Launch Vehicle Design Based on a Common Core Element  

NASA Technical Reports Server (NTRS)

With a heavy lift launch vehicle as the centerpiece of our nation's next exploration architecture's infrastructure, the Advanced Concepts Office at NASA's Marshall Space Flight Center initiated a study to examine the utilization of elements derived from a heavy lift launch vehicle for other potential launch vehicle applications. The premise of this study is to take a vehicle concept, which has been optimized for Lunar Exploration, and utilize the core stage with other existing or near existing stages and boosters to determine lift capabilities for alternative missions. This approach not only yields a vehicle matrix with a wide array of capabilities, but also produces an evolutionary pathway to a vehicle family based on a minimum development and production cost approach to a launch vehicle system architecture, instead of a purely performance driven approach. The upper stages and solid rocket booster selected for this study were chosen to reflect a cross-section of: modified existing assets in the form of a modified Delta IV upper stage and Castor-type boosters; potential near term launch vehicle component designs including an Ares I upper stage and 5-segment boosters; and longer lead vehicle components such as a Shuttle External Tank diameter upper stage. The results of this approach to a modular launch system are given in this paper.

Creech, Dennis M.; Threet, Grady E., Jr.; Philips, Alan D.; Waters, Eric D.; Baysinger, Mike

2010-01-01

199

DESIGN OF SMALL SCALE GAS TURBINE SYSTEMS FOR UNMANNED-AERIAL VEHICLES  

E-print Network

) Inlet, diffuser and nozzle design system (6) Gas Turbine Component Matching (3) Gas Turbine HealthDESIGN OF SMALL SCALE GAS TURBINE SYSTEMS FOR UNMANNED-AERIAL VEHICLES (AERSP 597/497-K) SPRING 814 865 9871 cxc11@psu.edu Summary : The proposed course is a three-credit gas turbine design course

Camci, Cengiz

200

DESIGN AND DEVELOPMENT OF AN AGILE, MAN PORTABLE UNMANNED GROUND VEHICLE  

Microsoft Academic Search

An omnidirectional unmanned ground vehicle (UGV) is able to move in any planar direction regardless of its current pose. To date, nearly all designs and analyses of omnidirectional robots have considered the case of motion on flat, smooth terrain. This paper presents the design, analysis, and prototype development of a man portable omnidirectional UGV designed for operation in rough terrain.

Karl Iagnemma; Martin Udengaard; Genya Ishigami; Matthew Spenko; Sinan Oncu; Imad Khan; James Overholt; Gregory Hudas

201

Design of Dragonfly Micro Air Vehicles at the University of Arizona  

Microsoft Academic Search

A new autonomous micro air vehicle (MAV) system, Dragonfly III, featuring improvements in the airframe aerodynamic design, as well as in the autopilot controls is presented in this design report. An approach for simultaneous aerodynamics and closed-loop control design for MAVs was employed, including wind tunnel experiments, and CFD simulations. The control laws were constructed and validated numerically using a

D. Coopamah; B. Malladi; D. Silin; S. Shkarayev

202

Space Shuttle Solid Rocket Booster decelerator subsystem - Air drop test vehicle/B-52 design  

NASA Technical Reports Server (NTRS)

The air drop development test program for the Space Shuttle Solid Rocket Booster Recovery System required the design of a large drop test vehicle that would meet all the stringent requirements placed on it by structural loads, safety considerations, flight recovery system interfaces, and sequence. The drop test vehicle had to have the capability to test the drogue and the three main parachutes both separately and in the total flight deployment sequence and still be low-cost to fit in a low-budget development program. The design to test large ribbon parachutes to loads of 300,000 pounds required the detailed investigation and integration of several parameters such as carrier aircraft mechanical interface, drop test vehicle ground transportability, impact point ground penetration, salvageability, drop test vehicle intelligence, flight design hardware interfaces, and packaging fidelity.

Runkle, R. E.; Drobnik, R. F.

1979-01-01

203

Design of an unmanned, reusable vehicle to de-orbit debris in Earth orbit  

NASA Technical Reports Server (NTRS)

The space debris problem is becoming more important because as orbital missions increase, the amount of debris increases. It was the design team's objective to present alternative designs and a problem solution for a deorbiting vehicle that will alleviate the problem by reducing the amount of large debris in earth orbit. The design team was asked to design a reusable, unmanned vehicle to de-orbit debris in earth orbit. The design team will also construct a model to demonstrate the system configuration and key operating features. The alternative designs for the unmanned, reusable vehicle were developed in three stages: selection of project requirements and success criteria, formulation of a specification list, and the creation of alternatives that would satisfy the standards set forth by the design team and their sponsor. The design team selected a Chain and Bar Shot method for deorbiting debris in earth orbit. The De-orbiting Vehicle (DOV) uses the NASA Orbital Maneuvering Vehicle (OMV) as the propulsion and command modules with the deorbiting module attached to the front.

Aziz, Shahed; Cunningham, Timothy W.; Moore-Mccassey, Michelle

1990-01-01

204

Development of Response Surface Models for Rapid Analysis & Multidisciplinary Optimization of Launch Vehicle Design Concepts  

NASA Technical Reports Server (NTRS)

Multdisciplinary design optimization (MDO) is an important step in the design and evaluation of launch vehicles, since it has a significant impact on performance and lifecycle cost. The objective in MDO is to search the design space to determine the values of design parameters that optimize the performance characteristics subject to system constraints. Vehicle Analysis Branch (VAB) at NASA Langley Research Center has computerized analysis tools in many of the disciplines required for the design and analysis of launch vehicles. Vehicle performance characteristics can be determined by the use of these computerized analysis tools. The next step is to optimize the system performance characteristics subject to multidisciplinary constraints. However, most of the complex sizing and performance evaluation codes used for launch vehicle design are stand-alone tools, operated by disciplinary experts. They are, in general, difficult to integrate and use directly for MDO. An alternative has been to utilize response surface methodology (RSM) to obtain polynomial models that approximate the functional relationships between performance characteristics and design variables. These approximation models, called response surface models, are then used to integrate the disciplines using mathematical programming methods for efficient system level design analysis, MDO and fast sensitivity simulations. A second-order response surface model of the form given has been commonly used in RSM since in many cases it can provide an adequate approximation especially if the region of interest is sufficiently limited.

Unal, Resit

1999-01-01

205

The battery designer's challenge — satisfying the ever-increasing demands of vehicle electrical systems  

NASA Astrophysics Data System (ADS)

The automotive battery designer of the 1990s and beyond will encounter an unprecedented array of complex challenges imposed by consumer desires, governmental mandates, and vehicle manufacturers' specifications. It is predicted that enhanced feature content in the areas of safety, convenience, performance, and guidance will result in a three- to six-fold increase in electrical power consumption in vehicles by the year 2000. In the absence of major break-throughs in vehicle electrical systems, these new loads will significantly modify the duty cycle to which the battery is subjected. The micro- and macro-environment in which the battery must survive will significantly impact the product's design and material specifications. Severe weight and size limits will be imposed on batteries in an attempt to meet mandated Corporate Average Fuel Economy (CAFE) requirements and additional pre-start electrical loads may be introduced to reduce objectionable emissions. Finally, quality and reliability levels of vehicles and their component parts must undergo continuous improvement. In order to respond to these diverse and sometimes contradictory demands, the battery designer must participate as an integral part of the vehicle electrical system development team. Design considerations for the future must include elevated and multiple voltages, multiple batteries per vehicle designed for specific functions, and further improvements in power and energy density, as well as cycle-life.

Pierson, John R.; Johnson, Richard T.

206

System design concepts and requirements for aeroassisted orbital transfer vehicles  

NASA Technical Reports Server (NTRS)

The Orbital Transfer Vehicle (OTV) is an advanced upper stage concept which will deliver spacecraft from operating systems at Low Earth Orbit (LEO) such as Space Shuttle, Earth-To-Orbit (ETO) vehicles, and Space Operations Center (SOC), to High Earth Orbit (HEO) and planetary excursions. The OTV will be driven by the need to achieve significant reductions in the operational costs for delivering payloads to Geostationary Equatorial Orbit (GEO). Aeroassist is a technological capability that has a potential for OTV's ranging from mission enhancing (reusable OTV for payload delivery) to mission enabling (manned GEO and some DOD). It is shown that the use of aeroassist for OTV's is a high leverage technology which can potentially reduce space transportation costs and enable a number of highly desirable missions.

Austin, R. E.; Cruz, M. I.; French, J. R.

1982-01-01

207

Dual throat engine design for a SSTO launch vehicle  

NASA Technical Reports Server (NTRS)

A propulsion system analysis of a dual fuel, dual throat engine for launch vehicle application was conducted. Basic dual throat engine characterization data are presented to allow vehicle optimization studies to be conducted. A preliminary baseline engine system was defined. Dual throat engine performance, envelope, and weight parametric data were generated over the parametric range of thrust from 890 to 8896 KN (200K to 2M lb-force), chamber pressure from 6.89 million to 34.5 million N/sq m (1000 to 5000 psia) thrust ratio from 1.2 to 5, and a range of mixture ratios for the two tripropellant combinations: LO2/RP-1 + LH2 and LO2/LCH4 + LH2. The results of the study indicate that the dual fuel dual throat engine is a viable single stage to orbit candidate.

Obrien, C. J.; Salmon, J. W.

1980-01-01

208

Flight Test Experiment Design for Characterizing Stability and Control of Hypersonic Vehicles  

NASA Technical Reports Server (NTRS)

A maneuver design method that is particularly well-suited for determining the stability and control characteristics of hypersonic vehicles is described in detail. Analytical properties of the maneuver design are explained. The importance of these analytical properties for maximizing information content in flight data is discussed, along with practical implementation issues. Results from flight tests of the X-43A hypersonic research vehicle (also called Hyper-X) are used to demonstrate the excellent modeling results obtained using this maneuver design approach. A detailed design procedure for generating the maneuvers is given to allow application to other flight test programs.

Morelli, Eugene A.

2008-01-01

209

Function-based design process for an intelligent ground vehicle vision system  

NASA Astrophysics Data System (ADS)

An engineering design framework for an autonomous ground vehicle vision system is discussed. We present both the conceptual and physical design by following the design process, development and testing of an intelligent ground vehicle vision system constructed for the 2008 Intelligent Ground Vehicle Competition. During conceptual design, the requirements for the vision system are explored via functional and process analysis considering the flows into the vehicle and the transformations of those flows. The conceptual design phase concludes with a vision system design that is modular in both hardware and software and is based on a laser range finder and camera for visual perception. During physical design, prototypes are developed and tested independently, following the modular interfaces identified during conceptual design. Prototype models, once functional, are implemented into the final design. The final vision system design uses a ray-casting algorithm to process camera and laser range finder data and identify potential paths. The ray-casting algorithm is a single thread of the robot's multithreaded application. Other threads control motion, provide feedback, and process sensory data. Once integrated, both hardware and software testing are performed on the robot. We discuss the robot's performance and the lessons learned.

Nagel, Robert L.; Perry, Kenneth L.; Stone, Robert B.; McAdams, Daniel A.

2010-10-01

210

Water facilities in retrospect and prospect: An illuminating tool for vehicle design  

NASA Technical Reports Server (NTRS)

Water facilities play a fundamental role in the design of air, ground, and marine vehicles by providing a qualitative, and sometimes quantitative, description of complex flow phenomena. Water tunnels, channels, and tow tanks used as flow-diagnostic tools have experienced a renaissance in recent years in response to the increased complexity of designs suitable for advanced technology vehicles. These vehicles are frequently characterized by large regions of steady and unsteady three-dimensional flow separation and ensuing vortical flows. The visualization and interpretation of the complicated fluid motions about isolated vehicle components and complete configurations in a time and cost effective manner in hydrodynamic test facilities is a key element in the development of flow control concepts, and, hence, improved vehicle designs. A historical perspective of the role of water facilities in the vehicle design process is presented. The application of water facilities to specific aerodynamic and hydrodynamic flow problems is discussed, and the strengths and limitations of these important experimental tools are emphasized.

Erickson, G. E.; Peak, D. J.; Delfrate, J.; Skow, A. M.; Malcolm, G. N.

1986-01-01

211

Structural Design and Analysis of Un-pressurized Cargo Delivery Vehicle  

NASA Technical Reports Server (NTRS)

As part of the Exploration Systems Architecture Study, NASA has defined a family of vehicles to support lunar exploration and International Space Station (ISS) re-supply missions after the Shuttle s retirement. The Un-pressurized Cargo Delivery Vehicle (UCDV) has been envisioned to be an expendable logistics delivery vehicle that would be used to deliver external cargo to the ISS. It would be launched on the Crew Launch Vehicle and would replace the Crew Exploration Vehicle. The estimated cargo would be the weight of external logistics to the ISS. Determining the minimum weight design of the UCDV during conceptual design is the major issue addressed in this paper. This task was accomplished using a procedure for rapid weight estimation that was based on Finite Element Analysis and sizing of the vehicle by the use of commercially available codes. Three design concepts were analyzed and their respective weights were compared. The analytical structural weight was increased by a factor to account for structural elements that were not modeled. Significant reduction in weight of a composite design over metallic was achieved for similar panel concepts.

Martinovic, Zoran N.

2007-01-01

212

Systems Analysis and Structural Design of an Unpressurized Cargo Delivery Vehicle  

NASA Technical Reports Server (NTRS)

The International Space Station will require a continuous supply of replacement parts for ongoing maintenance and repair after the planned retirement of the Space Shuttle in 2010. These parts are existing line-replaceable items collectively called Orbital Replacement Units, and include heavy and oversized items such as Control Moment Gyroscopes and stowed radiator arrays originally intended for delivery aboard the Space Shuttle. Current resupply spacecraft have limited to no capability to deliver these external logistics. In support of NASA's Exploration Systems Architecture Study, a team at Langley Research Center designed an Unpressurized Cargo Delivery Vehicle to deliver bulk cargo to the Space Station. The Unpressurized Cargo Delivery Vehicle was required to deliver at least 13,200 lbs of cargo mounted on at least 18 Flight Releasable Attachment Mechanisms. The Crew Launch Vehicle design recommended in the Exploration Systems Architecture Study would be used to launch one annual resupply flight to the International Space Station. The baseline vehicle design developed here has a cargo capacity of 16,000 lbs mounted on up to 20 Flight Releasable Attachment Mechanisms. Major vehicle components are a 5.5m-diameter cargo module containing two detachable cargo pallets with the payload, a Service Module to provide propulsion and power, and an aerodynamic nose cone. To reduce cost and risk, the Service Module is identical to the one used for the Crew Exploration Vehicle design.

Wu, K. Chauncey; Cruz, Jonathan N.; Antol, Jeffrey; Sasamoto, Washito A.

2007-01-01

213

Hypersonic aerospace sizing analysis for the preliminary design of aerospace vehicles  

NASA Technical Reports Server (NTRS)

A review of the hypersonic literature indicated that a general weight and sizing analysis was not available for hypersonic orbital, transport, and fighter vehicles. The objective here is to develop such a method for the preliminary design of aerospace vehicles. This report describes the developed methodology and provides examples to illustrate the model, entitled the Hypersonic Aerospace Sizing Analysis (HASA). It can be used to predict the size and weight of hypersonic single-stage and two-stage-to-orbit vehicles and transports, and is also relevant for supersonic transports. HASA is a sizing analysis that determines vehicle length and volume, consistent with body, fuel, structural, and payload weights. The vehicle component weights are obtained from statistical equations for the body, wing, tail, thermal protection system, landing gear, thrust structure, engine, fuel tank, hydraulic system, avionics, electrical system, equipment payload, and propellant. Sample size and weight predictions are given for the Space Shuttle orbiter and other proposed vehicles, including four hypersonic transports, a Mach 6 fighter, a supersonic transport (SST), a single-stage-to-orbit (SSTO) vehicle, a two-stage Space Shuttle with a booster and an orbiter, and two methane-fueled vehicles.

Harloff, Gary J.; Berkowitz, Brian M.

1990-01-01

214

Modeling, control design, and performance evaluation of high speed ground vehicle dynamics  

SciTech Connect

The interest in developing high speed ground transportation systems is one reason for directing attention to the modeling and simulation of the dynamic behavior of vehicle systems. Rail-guided vehicles; i.e., conventional railways, advanced railway systems, or magnetically levitated trains, represent the practical implementation of such ground transportation systems. One computer program that is well suited for the analysis of rail-guided vehicles is the multibody program MEDYNA. This paper demonstrates the application of MEDYNA for control law design and to performance evaluation of such advanced vehicles. A brief description is made of the modeling requirements of magnetically levitated systems, along with a summary of some of the related capabilities and computational methods of MEDNYA. As a case study, analysis of a vehicle based on the German Transrapid system is presented. System matrices of a simplified vehicle model are established and control design is performed with the aid of MATLAB. Performance evaluation is studied with a complex model of the Transrapid vehicle and elastic guideways.

Faye, I.; Kortum, W.; Schwartz, W. (DFVLR-Institute for Flight Systems Dynamics, D-8031 Weeslin (DE))

1989-01-01

215

A newly developed snow vehicle (SM100S) for Antarctica. Part 2: Design of the system  

NASA Astrophysics Data System (ADS)

This report describes the design of the systems of a newly developed snow vehicle, which will be used for the deep ice coring project at Dome Fuji, East Antarctica. This vehicle is a cab-over full-track type, in which the accommodations for two persons are prepared. The vehicle is 11,500 kg in gross weight and traverses at 5 to 8 km/h pulling seven wooden type sledges each of which is 2.6 t in loaded weight. The vehicle operates at low temperature down to -60 C on the Antarctic ice sheet from the plain up to the high plateau of 4,000 m in altitude. In addition, the preservation of the vehicle is possible under the severe environment as cold as -0 C. In the process of the development, the requested performance was analyzed first, and then the structure, configuration, and dimensions of the vehicle were estimated. Problems from other snow vehicles operated before in Antarctica were extracted and then were solved by means of experiments and researches to make use of the results for the design.

Nakajima, Masashi; Hosoya, Masayuki

1992-11-01

216

A Large-Scale Design Integration Approach Developed in Conjunction with the Ares Launch Vehicle Program  

NASA Technical Reports Server (NTRS)

This paper presents a method for performing large-scale design integration, taking a classical 2D drawing envelope and interface approach and applying it to modern three dimensional computer aided design (3D CAD) systems. Today, the paradigm often used when performing design integration with 3D models involves a digital mockup of an overall vehicle, in the form of a massive, fully detailed, CAD assembly; therefore, adding unnecessary burden and overhead to design and product data management processes. While fully detailed data may yield a broad depth of design detail, pertinent integration features are often obscured under the excessive amounts of information, making them difficult to discern. In contrast, the envelope and interface method results in a reduction in both the amount and complexity of information necessary for design integration while yielding significant savings in time and effort when applied to today's complex design integration projects. This approach, combining classical and modern methods, proved advantageous during the complex design integration activities of the Ares I vehicle. Downstream processes, benefiting from this approach by reducing development and design cycle time, include: Creation of analysis models for the Aerodynamic discipline; Vehicle to ground interface development; Documentation development for the vehicle assembly.

Redmon, John W.; Shirley, Michael C.; Kinard, Paul S.

2012-01-01

217

A CLIPS-based tool for aircraft pilot-vehicle interface design  

NASA Technical Reports Server (NTRS)

The Pilot-Vehicle Interface of modern aircraft is the cognitive, sensory, and psychomotor link between the pilot, the avionics modules, and all other systems on board the aircraft. To assist pilot-vehicle interface designers, a C Language Integrated Production System (CLIPS) based tool was developed that allows design information to be stored in a table that can be modified by rules representing design knowledge. Developed for the Apple Macintosh, the tool allows users without any CLIPS programming experience to form simple rules using a point and click interface.

Fowler, Thomas D.; Rogers, Steven P.

1991-01-01

218

Incorporating Vehicle Emission Models into the Highway Design Process  

E-print Network

the adverse impact of highway transportation on the environment. However, the research regarding the reduction of the adverse impact through highway design is still in its infancy. Furthermore, highway design manuals/guidebooks do not provide any information...

Ko, Myung-Hoon

2012-02-14

219

Importance of the Natural Terrestrial Environment with Regard to Advanced Launch Vehicle Design and Development  

NASA Technical Reports Server (NTRS)

The terrestrial environment is an important forcing function in the design and development of the launch vehicle. The scope of the terrestrial environment includes the following phenomena: Winds; Atmospheric Thermodynamic Models and Properties; Thermal Radiation; U.S. and World Surface Environment Extremes; Humidity; Precipitation, Fog, and Icing; Cloud Characteristics and Cloud Cover Models; Atmospheric Electricity; Atmospheric Constituents; Vehicle Engine Exhaust and Toxic Chemical Release; Occurrences of Tornadoes and Hurricanes; Geological Hazards, and Sea States. One must remember that the flight profile of any launch vehicle is in the terrestrial environment. Terrestrial environment definitions are usually limited to information below 90 km. Thus, a launch vehicle's operations will always be influenced to some degree by the terrestrial environment with which it interacts. As a result, the definition of the terrestrial environment and its interpretation is one of the key launch vehicle design and development inputs. This definition is a significant role, for example, in the areas of structures, control systems, trajectory shaping (performance), aerodynamic heating and take off/landing capabilities. The launch vehicle's capabilities which result from the design, in turn, determines the constraints and flight opportunities for tests and operations.

Pearson, S. D.; Vaughan, W. W.; Batts, G. W.; Jasper, G. L.

1996-01-01

220

IPAD: Integrated Programs for Aerospace-vehicle Design  

NASA Technical Reports Server (NTRS)

The conference was organized to promote wider awareness of the IPAD program and its coming impact on American industry. The program focuses on technology issues that are critical to computer aided design manufacturing. Included is a description of a representative aerospace design process and its interface with manufacturing, the design of a future IPAD integrated computer aided design system, results to date in developing IPAD products and associated technology, and industry experiences and plans to exploit these products.

1980-01-01

221

Development of integrated programs for Aerospace-vehicle Design (IPAD): Product program management systems  

NASA Technical Reports Server (NTRS)

The Integrated Programs for Aerospace Vehicle Design (IPAD) is a computing system to support company-wide design information processing. This document presents a brief description of the management system used to direct and control a product-oriented program. This document, together with the reference design process (CR 2981) and the manufacture interactions with the design process (CR 2982), comprises the reference information that forms the basis for specifying IPAD system requirements.

Isenberg, J. M.; Southall, J. W.

1979-01-01

222

Curving Analysis of Modified Designs of Passenger Railway Vehicle Trucks  

Microsoft Academic Search

In this paper, modified truck designs were studied with an objective to achieving better compatibility between high speed stability and curving behaviour compared to the conventional truck. The analysis has shown that USD truck can be designed to achieve better over all performance compared to other truck designs. The results of steady state curving program were validated using the commercial

Rao V. Dukkipati; Srinivasan Narayanaswamy; Mohammad O. M. Osman

2002-01-01

223

Small Launch Vehicle Design Approaches: Clustered Cores Compared with Multi-Stage Inline Concepts  

NASA Technical Reports Server (NTRS)

In an effort to better define small launch vehicle design options two approaches were investigated from the small launch vehicle trade space. The primary focus was to evaluate a clustered common core design against a purpose built inline vehicle. Both designs focused on liquid oxygen (LOX) and rocket propellant grade kerosene (RP-1) stages with the terminal stage later evaluated as a LOX/methane (CH4) stage. A series of performance optimization runs were done in order to minimize gross liftoff weight (GLOW) including alternative thrust levels, delivery altitude for payload, vehicle length to diameter ratio, alternative engine feed systems, re-evaluation of mass growth allowances, passive versus active guidance systems, and rail and tower launch methods. Additionally manufacturability, cost, and operations also play a large role in the benefits and detriments for each design. Presented here is the Advanced Concepts Office's Earth to Orbit Launch Team methodology and high level discussion of the performance trades and trends of both small launch vehicle solutions along with design philosophies that shaped both concepts. Without putting forth a decree stating one approach is better than the other; this discussion is meant to educate the community at large and let the reader determine which architecture is truly the most economical; since each path has such a unique set of limitations and potential payoffs.

Waters, Eric D.; Beers, Benjamin; Esther, Elizabeth; Philips, Alan; Threet, Grady E., Jr.

2013-01-01

224

Two designs for an orbital transfer vehicle: A comparison of two OTVs  

NASA Technical Reports Server (NTRS)

The basic components of the design for the orbital transfer vehicle (OTV) are outlined. The Project Orion and the MOVERS OTV design are compared. The nature of the work and the specifics will be reviewed. The propellant systems are summarized along with the dollar savings. The strengths and weaknesses are highlighted for each OTV.

1988-01-01

225

The Design of the Embedded Wireless Vehicles Monitoring Management System Based on GPRS: Evidence from China  

Microsoft Academic Search

Unifying the embedded system, the GPRS networking and the car license recognition technology, this article designs and realizes one kind of a embedded wireless vehicle management system which using the ARM9 microprocessor from the hardware and the software. In terms of the hardware, completed the design and connection of arm embedded system, video frequency gathering compression module and GPRS module;

Huanming Yu; Zhifeng Pang; Dongru Ruan

2008-01-01

226

Household market for electric vehicles. Testing the hybrid household hypothesis: A reflexively designed survey of new-car-buying, multi-vehicle California households. Final report  

Microsoft Academic Search

This survey was sponsored by the Air Resources Board in order to assist the Board in its evaluation of the zero-emission vehicle (ZEV) regulation. The survey was designed to test the consumer marketability of electric vehicles (EVs). A total of 454 households in six California metropolitan areas were surveyed. The survey consisted of four main parts: (1) Assessment of household

T. Turrentine; K. Kurani

1995-01-01

227

Coupled Solid Rocket Motor Ballistics and Trajectory Modeling for Higher Fidelity Launch Vehicle Design  

NASA Technical Reports Server (NTRS)

Multi-stage launch vehicles with solid rocket motors (SRMs) face design optimization challenges, especially when the mission scope changes frequently. Significant performance benefits can be realized if the solid rocket motors are optimized to the changing requirements. While SRMs represent a fixed performance at launch, rapid design iterations enable flexibility at design time, yielding significant performance gains. The streamlining and integration of SRM design and analysis can be achieved with improved analysis tools. While powerful and versatile, the Solid Performance Program (SPP) is not conducive to rapid design iteration. Performing a design iteration with SPP and a trajectory solver is a labor intensive process. To enable a better workflow, SPP, the Program to Optimize Simulated Trajectories (POST), and the interfaces between them have been improved and automated, and a graphical user interface (GUI) has been developed. The GUI enables real-time visual feedback of grain and nozzle design inputs, enforces parameter dependencies, removes redundancies, and simplifies manipulation of SPP and POST's numerous options. Automating the analysis also simplifies batch analyses and trade studies. Finally, the GUI provides post-processing, visualization, and comparison of results. Wrapping legacy high-fidelity analysis codes with modern software provides the improved interface necessary to enable rapid coupled SRM ballistics and vehicle trajectory analysis. Low cost trade studies demonstrate the sensitivities of flight performance metrics to propulsion characteristics. Incorporating high fidelity analysis from SPP into vehicle design reduces performance margins and improves reliability. By flying an SRM designed with the same assumptions as the rest of the vehicle, accurate comparisons can be made between competing architectures. In summary, this flexible workflow is a critical component to designing a versatile launch vehicle model that can accommodate a volatile mission scope.

Ables, Brett

2014-01-01

228

Performance and operational considerations in the design of vehicle antennas for mobile satellite communications  

NASA Technical Reports Server (NTRS)

This paper examines the vehicle antenna requirements for mobile satellite systems. The antenna parameters are discussed in the light of the requirements and the limitations in performance imposed by the physical constraints of antenna and by vehicle geometries. Measurements of diffraction and antenna noise temperature in an operational environment are examined, as well as their effects on system margins. Mechanical versus electronic designs are compared with regards to performance, cost, reliability, and design complexity. Comparisons between open-loop and close-loop tracking systems are made and the effects of bandwidth, sidelobe levels, operational constraints, vehicle angular velocity, and acceleration are discussed. Some consideration is given to the use of hybrid systems employing both open and closed-loop tracking. Changes to antenna/terminal specifications are recommended which will provide greater design flexibility and increase the likelihood of meeting the performance and operational requirements.

Milne, R.

1995-01-01

229

Conceptual Design and Cost Estimate of a Subsonic NASA Testbed Vehicle (NTV) for Aeronautics Research  

NASA Technical Reports Server (NTRS)

A conceptual design and cost estimate for a subsonic flight research vehicle designed to support NASA's Environmentally Responsible Aviation (ERA) project goals is presented. To investigate the technical and economic feasibility of modifying an existing aircraft, a highly modified Boeing 717 was developed for maturation of technologies supporting the three ERA project goals of reduced fuel burn, noise, and emissions. This modified 717 utilizes midfuselage mounted modern high bypass ratio engines in conjunction with engine exhaust shielding structures to provide a low noise testbed. The testbed also integrates a natural laminar flow wing section and active flow control for the vertical tail. An eight year program plan was created to incrementally modify and test the vehicle, enabling the suite of technology benefits to be isolated and quantified. Based on the conceptual design and programmatic plan for this testbed vehicle, a full cost estimate of $526M was developed, representing then-year dollars at a 50% confidence level.

Nickol, Craig L.; Frederic, Peter

2013-01-01

230

Design Refinement and Modeling Methods for Highly-Integrated Hypersonic Vehicles  

NASA Astrophysics Data System (ADS)

A method for early-stage design of high-speed airplanes is presented based on analysis of vehicle performance, including internal flow in the engine and external flows around the body. Several ways of evaluating vehicle performance are shown, including thrust maps, combustor mode stability concerns, combustor optimization and trajectory optimization. The design performance analysis relies on a routine that computes the thrust of a dual-mode scramjet, which is a geometric-compression (ramjet) engine with a combustor that can operate both subsonically and supersonically. This strategy applies to any internal flow which is predominantly one-dimensional in character. A reduced-order model for mixing and combustion has been developed that is based on non-dimensional scaling of turbulent jets in crossflow and tabulated flamelet chemistry, and is used in conjunction with conventional conservation equations for quasi one-dimensional flow to compute flowpath performance. Thrust is computed by stream-tube momentum analysis. Vehicle lift and drag are computed using a supersonic panel method, developed separately. Comparisons to computational fluid dynamics solutions and experimental data were conducted to determine the validity of the combustion modeling approach, and results of these simulations are shown. Computations for both ram-mode and scram-mode operation are compared to experimental results, and predictions are made for flight conditions of a hypersonic vehicle built around the given flowpath. Trajectory performance of the vehicle is estimated using a collocation method to find the required control inputs and fuel consumption. The combustor is optimized for minimum fuel consumption over a short scram trajectory, and the scram-mode trajectory is optimized for minimum fuel consumption over a space-access-type trajectory. A vehicle design and associated optimized trajectory are shown, and general design principles for steady and efficient operation of vehicles of this type are discussed.

Torrez, Sean Michael

231

Towards the conceptual design and construction of an unmanned small-scale air-land-water vehicle  

Microsoft Academic Search

This paper describes towards the conceptual design and construction of an unmanned small-scale air-land-water vehicle. Conceptual design refers to the initial design of parts followed by the assemblies to form components of the vehicle. The vehicle features a unique device system consists of four main components; a coaxial rotor set, propeller, suspension, and pontoon set. It independence for another when

Khalid Hasnan; Abas Ab. Wahab

2010-01-01

232

Biomimetic mechanical design for soft-bodied underwater vehicles  

Microsoft Academic Search

This paper describes a biomimetic underwater fish robot prototype and its design methodology. The key question directing our design is the transfer of functionality from fish to a fish robot with respect to efficient mobility. We want to minimize mechanical complexity and achieve a low-cost fabrication. We argue for the case of morphological computation, i.e. achieving high mobility and efficiency

C. Fiazza; T. Salumae; M. Listak; G. Kulikovskis; R. Templeton; O. Akanyeti; W. Megill; P. Fiorini; M. Kruusmaa

2010-01-01

233

Reliability-Based Design Optimization for Durability of Ground Vehicle Suspension System Components  

NASA Astrophysics Data System (ADS)

The effect of materials processing- and component manufacturing-induced uncertainties in material properties and component shape and size on the reliability of component performance is investigated. Specifically, reliability of a suspension system component from a high-mobility multipurpose wheeled vehicle which typically can fail under low-cycle strain-based fatigue conditions is analyzed. Toward that end, the most advanced reliability-based design optimization methods available in the literature were combined with the present understanding of low-cycle fatigue durability and applied to the component in question. This entailed intricate integration of several computational tools such as multibody vehicle dynamics, finite-element simulations, and fatigue strain-life assessment/prediction techniques. The results obtained clearly revealed the importance of consideration of material property uncertainties in attaining vehicle performance of critical structural components in complex systems (e.g., a vehicle).

Grujicic, M.; Arakere, G.; Bell, W. C.; Marvi, H.; Yalavarthy, H. V.; Pandurangan, B.; Haque, I.; Fadel, G. M.

2010-04-01

234

40 CFR 52.2348 - National Highway Systems Designation Act Motor Vehicle Inspection and Maintenance (I/M) Programs.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false National Highway Systems Designation Act Motor Vehicle...CONTINUED) Utah § 52.2348 National Highway Systems Designation Act Motor Vehicle...authority of section 348 of the National Highway Systems Designation Act of...

2011-07-01

235

40 CFR 52.2348 - National Highway Systems Designation Act Motor Vehicle Inspection and Maintenance (I/M) Programs.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false National Highway Systems Designation Act Motor Vehicle...CONTINUED) Utah § 52.2348 National Highway Systems Designation Act Motor Vehicle...authority of section 348 of the National Highway Systems Designation Act of...

2012-07-01

236

40 CFR 52.2348 - National Highway Systems Designation Act Motor Vehicle Inspection and Maintenance (I/M) Programs.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false National Highway Systems Designation Act Motor Vehicle...CONTINUED) Utah § 52.2348 National Highway Systems Designation Act Motor Vehicle...authority of section 348 of the National Highway Systems Designation Act of...

2013-07-01

237

40 CFR 52.2348 - National Highway Systems Designation Act Motor Vehicle Inspection and Maintenance (I/M) Programs.  

...2014-07-01 2014-07-01 false National Highway Systems Designation Act Motor Vehicle...CONTINUED) Utah § 52.2348 National Highway Systems Designation Act Motor Vehicle...authority of section 348 of the National Highway Systems Designation Act of...

2014-07-01

238

40 CFR 52.2348 - National Highway Systems Designation Act Motor Vehicle Inspection and Maintenance (I/M) Programs.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false National Highway Systems Designation Act Motor Vehicle...CONTINUED) Utah § 52.2348 National Highway Systems Designation Act Motor Vehicle...authority of section 348 of the National Highway Systems Designation Act of...

2010-07-01

239

Preliminary subsystem designs for the Assured Crew Return Vehicle (ACRV), volume 1  

NASA Technical Reports Server (NTRS)

A series of design studies is presented concerning the Assured Crew Return Vehicle (ACRV) for Space Station Freedom. Four alternate designs are presented for the ACRV braking and landing system. Options presented include: ballistic and lifting body reentries; the use of high-lift, high-payload aerodynamic decelerators, as well as conventional parachutes; landing systems designed for water landings, land landings, or both; and an aerial recovery system. All four design options presented combine some or all of the above attributes, and all meet performance requirements established by the ACRV Program Office. Two studies of ACRV growth options are also presented. Use of the ACRV or a similarly designed vehicle in several roles for possible future space missions is discussed, along with the required changes to a basic ACRV to allow it to perform these missions optimally. The outcome of these studies is a set of recommendations to the ACRV Program Office describing the vehicle characteristics of the basic ACRV which lend themselves most readily to be adapted for use in other missions. Finally, the impacts on the design of the ACRV due to its role as a medical emergency vehicle were studied and are presented. The use of the ACRV in this manner will impact its shape, internal configuration, and equipment.

1990-01-01

240

The role of mission requirements, vehicle attributes, technologies and uncertainty in rotorcraft system design  

NASA Astrophysics Data System (ADS)

Decisions made during the early stages of design have significant impact on the ultimate success of a system yet are made at a time when design information is least certain. Recent work addressed this concern by propagating design uncertainty to the system-level attributes through probabilistic design techniques. This work addressed uncertainty associated with system concepts (vehicle attributes) and technologies. However, it fell short of addressing the key element, which drives system design, namely the mission requirements. Addressing mission requirements alone and in conjunction with vehicle attributes and technologies, along with the uncertainty associated with this design element, is a needed step in making more educated decisions during the system design phase. The research presented in this dissertation proposed two appropriate design environments to address this gap in probabilistic design methods. The first environment, called the Mission Space Model (MSM), concentrated on mission requirements exclusively and established the feasibility of capturing this design element with a metamodeling approach to probabilistic system design. The MSM established the ability to model multiple missions and capture their impact on the system. The second environment, called the Unified Tradeoff Environment (UTE), provided a design environment that integrated the mission requirements with vehicle attributes and technologies. It established the ability to capture the three design elements in one design environment that is amenable to probabilistic techniques. It further allowed assessment of their simultaneous impact on the system under deterministic and probabilistic scenarios. Design guidance was given for constructing and implementing these design environments. In this work, a helicopter variant of the Future Transport Rotorcraft (FTR) was used as the application vehicle for constructing all design spaces and conducting all proof-of-concept studies. A baseline FIR was identified and all Mission Space Models and Unified Tradeoff Environments were constructed around this baseline. These environments were used to investigate the impact of mission requirement, vehicle attribute, and technology changes on the FTR for both deterministic and probabilistic studies. These environments provide the framework for making more educated decisions during early design stages by addressing the key design elements and the uncertainty associated with them.

Baker, Andrew Paul

241

Computer modeling in the design and evaluation of electric and hybrid vehicles  

SciTech Connect

This demonstration project uses modern simulation techniques to illustrate the important technologies and design variables that an auto-designer would consider in production a high efficiency, low emissions vehicle. Simulation and modeling techniques use the idea of capturing the relationships between real components of the systems with mathematical equations. These equations are then solved on a computer to simulate the behavior or performance of the system under various conditions. In the current demonstration project, we focus on many variations of a hydrogen-powered vehicle.

Aceves, S.M.; Smith, J.R. [Lawrence Livermore National Lab., CA (United States); Johnson, N.L. [Los Alamos National Lab., NM (United States)

1996-08-16

242

A numerical study for design of depth, pitch and roll control system of a towed vehicle  

SciTech Connect

A towed vehicle system, FLYING FISH, is under development for use in making chemical and physical measurements which enable the authors to obtain spacially continuous and real time data in an ocean mixed layer. The heave, pitch and roll of FLYING FISH are controlled by a main wing and horizontal tail wings which permit its stable attitudes and assure accurate measurements. The numerical simulation of motions was carried out to design the optimal control system of this towed vehicle system and the results gave the data for the design of the mechanical parts of the control system.

Koterayama, W.; Yamaguchi, S.; Nakamura, M.; Moriyama, A. [Kyushu Univ., Kasuga (Japan); Akamatsu, T. [Mitsubishi Heavy Industries, Kobe (Japan)

1994-12-31

243

Optimum Aeroelastic Design of Resonance Type Flapping Wing for Micro Air Vehicles  

NASA Astrophysics Data System (ADS)

The optimum aeroelastic design method for a resonance-type flapping wing for a Micro Air Vehicle (MAV) is presented. It uses Complex Method and 3D Navier-Stokes code to determine the optimum structural and aerodynamic parameters of a 2 DOF flapping wing system. The method is used to design a dragonfly-type MAV, and numerical simulation shows that the designed flapping wings can generate sufficient lift to sustain the weight and sufficient thrust to overcome the body drag.

Isogai, Koji; Kamisawa, Yuichi; Sato, Hiroyuki

244

Concurrent trajectory and conceptual vehicle design optimization of an aerobatic air race aircraft  

NASA Astrophysics Data System (ADS)

This paper deals with the development of a framework for the concurrent optimization of trajectory and conceptual vehicle design. The tool is applied to the design of an aerobatic air race aircraft that is required to fly a prescribed slalom course consisting of inflatable pylons in the fastest possible time. It is shown that when the aircraft design is tailored to the characteristics of the race track, an improvement in the lap time of about 1 percent can be achieved.

Visser, Hendrikus G.; Liem, Christiaan

2014-10-01

245

System design of the Pioneer Venus spacecraft. Volume 4: Probe bus and orbiter spacecraft vehicle studies  

NASA Technical Reports Server (NTRS)

The requirements, trades, and design descriptions for the probe bus and orbiter spacecraft configurations, structure, thermal control, and harness are defined. Designs are developed for Thor/Delta and Atlas/Centaur launch vehicles with the latter selected as the final baseline. The major issues examined in achieving the baseline design are tabulated. The importance of spin axis orientation because of the effect on science experiments and earth communications is stressed.

Bozajian, J. M.

1973-01-01

246

Design and control methodology of plug-in hybrid electric vehicles  

Microsoft Academic Search

This paper systematically discussed the design and control methodology of plug-in hybrid electric vehicle (PHEV). Design methodology focused on battery energy and power capacity design. Two lands of typical batteries-NiMH and Li-ion have been discussed. Control strategies focused on all electric range (AER) and charge depletion range (CDR) operations. Also, a constrained engine on and off control strategy has been

Yimin Gao; Mehrdad Ehsani

2008-01-01

247

Design and Control Methodology of Plug-in Hybrid Electric Vehicles  

Microsoft Academic Search

This paper systematically discusses the design and control methodologies of a plug-in hybrid electric vehicle (PHEV). Design methodology is focused on battery energy and power capacity design. Two kinds of typical batteries, namely, NiMH and Li-ion, are discussed. Control strategies focus on all electric range and charge depletion range operations. In addition, a constrained engine on and off control strategy

Yimin Gao; Mehrdad Ehsani

2010-01-01

248

Integrated structural and thermal design of an entry vehicle aeroshell  

E-print Network

utilized a sandwich panel design with the exterior facing comprised of a high temperature composite, the core comprised of a thermal insulator, and the interior facing comprised of graphite / epoxy. The finite element method (FEM) was used to analyze...

Cochran, David Brian

2012-06-07

249

Design of Modular, Shape-transitioning Inlets for a Conical Hypersonic Vehicle  

NASA Technical Reports Server (NTRS)

For a hypersonic vehicle, propelled by scramjet engines, integration of the engines and airframe is highly desirable. Thus, the forward capture shape of the engine inlet should conform to the vehicle body shape. Furthermore, the use of modular engines places a constraint on the shape of the inlet sidewalls. Finally, one may desire a combustor cross- section shape that is different from that of the inlet. These shape constraints for the inlet can be accommodated by employing a streamline-tracing and lofting technique. This design technique was developed by Smart for inlets with a rectangular-to-elliptical shape transition. In this paper, we generalise that technique to produce inlets that conform to arbitrary shape requirements. As an example, we show the design of a body-integrated hypersonic inlet on a winged-cone vehicle, typical of what might be used in a three-stage orbital launch system. The special challenge of inlet design for this conical vehicle at an angle-of-attack is also discussed. That challenge is that the bow shock sits relatively close to the vehicle body.

Gollan, Rowan J.; Smart, Michael K.

2010-01-01

250

Solar Electric Propulsion Vehicle Design Study for Cargo Transfer to Earth-moon L1  

NASA Technical Reports Server (NTRS)

A design study for a cargo transfer vehicle using solar electric propulsion was performed for NASA's Revolutionary Aerospace Systems Concepts program. Targeted for 2016, the solar electric propulsion (SEP) transfer vehicle is required to deliver a propellant supply module with a mass of approximately 36 metric tons from Low Earth Orbit to the first Earth-Moon libration point (LL1) within 270 days. Following an examination of propulsion and power technology options, a SEP transfer vehicle design was selected that incorporated large-area (approx. 2700 sq m) thin film solar arrays and a clustered engine configuration of eight 50 kW gridded ion thrusters mounted on an articulated boom. Refinement of the SEP vehicle design was performed iteratively to properly estimate the required xenon propellant load for the out-bound orbit transfer. The SEP vehicle performance, including the xenon propellant estimation, was verified via the SNAP trajectory code. Further efforts are underway to extend this system model to other orbit transfer missions.

Sarver-Verhey, Timothy R.; Kerslake, Thomas W.; Rawlin, Vincent K.; Falck, Robert D.; Dudzinski, Leonard J.; Oleson, Steven R.

2002-01-01

251

Aerothermal Protuberance Heating Design and Test Configurations for Ascent Vehicle Design  

NASA Technical Reports Server (NTRS)

A series of tests were conducted to evaluate protuberance heating for the purposes of vehicle design and modification. These tests represent a state of the art approach to both testing and instrumentation for defining aerothermal protuberance effects on the protuberance and surrounding areas. The testing was performed with a number of wind tunnel entries beginning with the proof of concept "pathfinder" test in the Test Section 1 (TS1) tunnel in the Langley Unitary Plan Wind Tunnel (UPWT). The TS1 section (see Figures 1a and 1b) is a lower Mach number tunnel and the Test Section 2 (TS2) has overlapping and higher Mach number capability as showin in Figure 1c. The pathfinder concept was proven and testing proceeded for a series of protuberance tests using an existing splitter aluminum protuberance mounting plate, Macor protuberances, thin film gages, total temperature and pressure gages, Kulite pressure transducers, Infra-Red camera imaging, LASER velocimetry evaluations and the UPWT data collection system. A boundary layer rake was used to identify the boundary layer profile at the protuberance locations for testing and helped protuberance design. This paper discusses the techniques and instrumentation used during the protuberance heating tests performed in the UPWT in TS1 and TS2. Runs of the protuberances were made Mach numbers of 1.5, 2.16, 2.65, and 3.51. The data set generated from this testing is for ascent protuberance effects and is termed Protuberance Heating Ascent Data (PHAD) and this testing may be termed PHAD-1 to distinguish it from future testing of this type.

Martin, Charles E.; Neumann, Richard D.; Freeman, Delma

2010-01-01

252

Multi-objective evolutionary optimization design of vehicle magnetorheological fluid damper  

NASA Astrophysics Data System (ADS)

Structure design and parameters selection are crucial steps in developing magnetorheological fluid (MRF) damper for vehicle semi-active suspension system. Most traditional methods for deciding structure parameters by experiential expressions are unilateral and imprecise. In this paper, a multiobjective evolutionary optimization approach will be used to solve the optimization design problem. Based on Bingham fluid models, a structure design for MRF damper with shearing valve mode is completed for vehicle suspension. To reduce the dynamic response time and to enlarge the range the controllable damping force are taken as the optimization objectives. Three crucial parameters, including gap width, effective axial pole length and coil turns number are taken as optimization variables, a hybrid evolutionary algorithm combining particle swarm optimization (PSO) and crossover is employed to search for the Pareto solutions, According to the optimized results, a new type MRF damper design is accomplished for a pickup truck suspension system. The proposed method and analysis present a beneficial reference for MRF damper design.

Zhao, Qiang; Wang, Yang; Gao, Fang

2007-07-01

253

Integrating Human Factors into Crew Exploration Vehicle (CEV) Design  

NASA Technical Reports Server (NTRS)

The purpose of this design process is to apply Human Engineering (HE) requirements and guidelines to hardware/software and to provide HE design, analysis and evaluation of crew interfaces. The topics include: 1) Background/Purpose; 2) HE Activities; 3) CASE STUDY: Net Habitable Volume (NHV) Study; 4) CASE STUDY: Human Modeling Approach; 5) CASE STUDY: Human Modeling Results; 6) CASE STUDY: Human Modeling Conclusions; 7) CASE STUDY: Human-in-the-Loop Evaluation Approach; 8) CASE STUDY: Unsuited Evaluation Results; 9) CASE STUDY: Suited Evaluation Results; 10) CASE STUDY: Human-in-the-Loop Evaluation Conclusions; 11) Near-Term Plan; and 12) In Conclusion

Whitmore, Mihriban; Holden, Kritina; Baggerman, Susan; Campbell, Paul

2007-01-01

254

A wireless sensor network design and implementation for vehicle detection, classification, and tracking  

NASA Astrophysics Data System (ADS)

Vehicle intrusion is considered a significant threat for critical zones specially the militarized zones and therefore vehicles monitoring has a great importance. In this paper a small wireless sensor network for vehicle intrusion monitoring consists of a five inexpensive sensor nodes distributed over a small area and connected with a gateway using star topology has been designed and implemented. The system is able to detect a passage of an intrusive vehicle, classify it either wheeled or tracked, and track the direction of its movement. The approach is based on Vehicle's ground vibrations for detection, vehicle's acoustic signature for classification and the Energy- based target localization for tracking. Detection and classification are implemented by using different algorithms and techniques including Analog to Digital Conversion, Fast Fourier Transformation (FFT) and Neural Network .All of these algorithms and techniques are implemented locally in the sensor node using Microchip dsPIC digital signal controller. Results are sent from the sensor node to the gateway using ZigBee technology and then from the gateway to a web server using GPRS technology.

Aljaafreh, A.; Al Assaf, A.

2013-05-01

255

Refinements in the Design of the Ares V Cargo Launch Vehicle for NASA's, Exploration Strategy  

NASA Technical Reports Server (NTRS)

NASA is developing a new launch vehicle fleet to fulfill the national goals of replacing the shuttle fleet, completing the International Space Station (ISS), and exploring the Moon on the way to eventual exploration of Mars and beyond. Programmatic and technical decisions during early architecture studies and subsequent design activities were focused on safe, reliable operationally efficient vehicles that could support a sustainable exploration program. A pair of launch vehicles was selected to support those goals the Ares I crew launch vehicle and the Ares V cargo launch vehicle. They will be the first new human-rated launch vehicles developed by NASA in more than 30 years (Figure 1). Ares I will be the first to fly, beginning space station ferry operations no later than 2015. It will be able to carry up to six astronauts to ISS or support up to four astronauts for expeditions to the moon. Ares V is scheduled to be operational in the 2020 timeframe and will provide the propulsion systems and payload to truly extend human exploration beyond low-Earth orbit. (LEO).

Creech, Steve

2008-01-01

256

Suntrakker-a student-designed solar vehicle  

Microsoft Academic Search

The purpose of this paper is to highlight the major challenges faced by the student team while designing, building and racing the Suntrakker Solar Car, and competing in the 1993 World Solar Challenge in Australia. The author hopes that this paper will offer a glimpse of the scale of such a project, and by highlighting some of challenges, help any

B. Rogow

1997-01-01

257

The impact of improved vehicle design on highway safety  

Microsoft Academic Search

This paper describes a framework for evaluating the safety of automobile designs in terms of likelihood of accident occurrence and severity of likely injuries sustained. Fault-tree analysis is utilized to model interacting relationships between causative factors that affect accident occurrence. A multiattribute injury model based on harm measures obtained from the National Accident Sampling System Database is presented to describe

J. S. Eisele; Y. Y. Haimes; N. J. Garber; D. Li; J. H. Lambert; P. Kuzminski; M. Chowdhury

1996-01-01

258

The design philosophy of the Phobos-Grunt space vehicle  

NASA Astrophysics Data System (ADS)

This paper covers the main features of Russia's Phobos-Grunt space mission, whose primary goal is to return soil samples from the Martian satellite Phobos. The mission scenario, major design solutions, and evolution of the project throughout its development are described.

Martynov, M. B.

2012-12-01

259

Design and operational requirements for a reusable launch vehicle  

NASA Astrophysics Data System (ADS)

Equipment design, system layout, and operational requirements of reusable launch vechicles are discussed. It is suggested that environmental qualification and lifetime limitations must be reconsidered for extended use of equipment and checkout and accessibility provisions must be enhanced to reduce turnaround time and cost. Spare hardware, procedures and skilled personnel must be available at the launch site for system and equipment maintenance.

Levod, J.

260

Advanced Usage of Vehicle Sketch Pad for CFD-Based Conceptual Design  

NASA Technical Reports Server (NTRS)

Conceptual design is the most fluid phase of aircraft design. It is important to be able to perform large scale design space exploration of candidate concepts that can achieve the design intent to avoid more costly configuration changes in later stages of design. This also means that conceptual design is highly dependent on the disciplinary analysis tools to capture the underlying physics accurately. The required level of analysis fidelity can vary greatly depending on the application. Vehicle Sketch Pad (VSP) allows the designer to easily construct aircraft concepts and make changes as the design matures. More recent development efforts have enabled VSP to bridge the gap to high-fidelity analysis disciplines such as computational fluid dynamics and structural modeling for finite element analysis. This paper focuses on the current state-of-the-art geometry modeling for the automated process of analysis and design of low-boom supersonic concepts using VSP and several capability-enhancing design tools.

Ordaz, Irian; Li, Wu

2013-01-01

261

Development of a dedicated ethanol ultra-low emission vehicle (ULEV) system design  

SciTech Connect

The objective of this 3.5 year project is to develop a commercially competitive vehicle powered by ethanol (or ethanol blend) that can meet California`s ultra-low emission vehicle (ULEV) standards and equivalent corporate average fuel economy (CAFE) energy efficiency for a light-duty passenger car application. The definition of commercially competitive is independent of fuel cost, but does include technical requirements for competitive power, performance, refueling times, vehicle range, driveability, fuel handling safety, and overall emissions performance. This report summarizes a system design study completed after six months of effort on this project. The design study resulted in recommendations for ethanol-fuel blends that shall be tested for engine low-temperature cold-start performance and other criteria. The study also describes three changes to the engine, and two other changes to the vehicle to improve low-temperature starting, efficiency, and emissions. The three engine changes are to increase the compression ratio, to replace the standard fuel injectors with fine spray injectors, and to replace the powertrain controller. The two other vehicle changes involve the fuel tank and the aftertreatment system. The fuel tank will likely need to be replaced to reduce evaporative emissions. In addition to changes in the main catalyst, supplemental aftertreatment systems will be analyzed to reduce emissions before the main catalyst reaches operating temperature.

Bourn, G.; Callahan, T.; Dodge, L.; Mulik, J.; Naegeli, D.; Shouse, K.; Smith, L.; Whitney, K. [Southwest Research Inst., San Antonio, TX (United States)

1995-02-01

262

Analyzing the influence of median cross-section design on highway safety using vehicle dynamics simulations.  

PubMed

Although vehicle dynamics simulations have long been used in vehicle design and crash reconstruction, their use for highway design is rare. This paper investigates the safety of highway medians through iterative simulations of off-road median encroachments. The commercially available software CarSim was used to simulate over one hundred thousand encroachments, representing the entire passenger vehicle fleet and a wide range of encroachment angles, departure speeds, steering inputs, and braking inputs. Each individual simulation output was then weighted using data from previous studies to reflect the probability of each specific accident scenario occurring in a real-life median encroachment. Results of this analysis illustrate the relative influence of median cross-section geometry on the resulting accident outcomes. The simulations indicate that the overall safety of a highway median depends on the occurrence of both vehicle rollover and median crossover events, and the cross-section shape, slope, and width are all shown to greatly affect each of these incidents. An evaluation of the simulation results was conducted with vehicle trajectories from previous experimental crash tests. Further assessment of the aggregate simulation results to actual crash data was achieved through comparison with several databases of crash statistics. Both efforts showed a strong agreement between the simulations and the real-life crash data. PMID:20728628

Stine, Jason S; Hamblin, Bridget C; Brennan, Sean N; Donnell, Eric T

2010-11-01

263

Development of a dedicated ethanol ultra-low emission vehicle (ULEV) system design  

NASA Astrophysics Data System (ADS)

The objective of this 3.5 year project is to develop a commercially competitive vehicle powered by ethanol (or ethanol blend) that can meet California's ultra-low emission vehicle (ULEV) standards and equivalent corporate average fuel economy (CAFE) energy efficiency for a light-duty passenger car application. The definition of commercially competitive is independent of fuel cost, but does include technical requirements for competitive power, performance, refueling times, vehicle range, driveability, fuel handling safety, and overall emissions performance. This report summarizes a system design study completed after six months of effort on this project. The design study resulted in recommendations for ethanol-fuel blends that shall be tested for engine low-temperature cold-start performance and other criteria. The study also describes three changes to the engine and two other changes to the vehicle to improve low-temperature starting, efficiency, and emissions. The three engine changes are to increase the compression ratio, to replace the standard fuel injectors with fine spray injectors, and to replace the powertrain controller. The two other vehicle changes involve the fuel tank and the aftertreatment system. The fuel tank will likely need to be replaced to reduce evaporative emissions. In addition to changes in the main catalyst, supplemental aftertreatment systems will be analyzed to reduce emissions before the main catalyst reaches operating temperature.

Bourn, G.; Callahan, T.; Dodge, L.; Mulik, J.; Naegeli, D.; Shouse, K.; Smith, L.; Whitney, K.

1995-02-01

264

Project EGRESS: The design of an assured crew return vehicle for the space station  

NASA Technical Reports Server (NTRS)

Keeping preliminary studies by NASA in mind, an Assured Crew Return Vehicle (ACRV) was developed. The system allows the escape of one or more crew members from Space Station Freedom in case of emergency. The design of the vehicle addresses propulsion, orbital operations, reentry, landing and recovery, power and communication, and life support. In light of recent modifications in Space Station design, Project EGRESS (Earthbound Guaranteed ReEntry from Space Station) pays particular attention to its impact on Space Station operations, interfaces and docking facilities, and maintenance needs. A water landing, medium lift vehicle was found to best satisfy project goals of simplicity and cost efficiency without sacrificing the safety and reliability requirements. With a single vehicle, one injured crew member could be returned to Earth with minimal pilot involvement. Since the craft is capable of returning up to five crew members, two such permanently docked vehicles would allow full evacuation of the Space Station. The craft could be constructed entirely with available 1990 technology and launched aboard a shuttle orbiter.

1990-01-01

265

The Role of Uncertainty in Aerospace Vehicle Analysis and Design  

NASA Technical Reports Server (NTRS)

Effective uncertainty quantification (UQ) begins at the earliest phase in the design phase for which there are adequate models and continues tightly integrated to the analysis and design cycles as the refinement of the models and the fidelity of the tools increase. It is essential that uncertainty quantification strategies provide objective information to support the processes of identifying, analyzing and accommodating for the effects of uncertainty. Assessments of uncertainty should never render the results more difficult for engineers and decision makers to comprehend, but instead provide them with critical information to assist with resource utilization decisions and risk mitigation strategies. Success would be measured by the tools to enable engineers and decision makers to effectively balance critical project resources against system requirements while accounting for the impact of uncertainty.

Kenny, Sean P.; Crespo, Luis G.

2011-01-01

266

Orbital Transfer Vehicle (OTV) advanced expander cycle engine point design study  

NASA Technical Reports Server (NTRS)

Progress in the development of a performance optimized engine system design for an advanced LOX/hydrogen expander cycle engine is reported. Analysis of the components and engine and the resulting drawings is discussed. The status of the orbit transfer vehicle liquid engine transient simulation computer model is given.

Mellish, J. A.

1980-01-01

267

Design and Evaluation of a Vehicle Data Distribution and Collection System  

Microsoft Academic Search

A key component of today's law enforcement is quick access to updated and relevant information. The emergent use of embedded computers in police vehicles provides a platform for displaying and interacting with large amounts of data making this access to information possible. Distributing and collecting this data however is a significant challenge. In this paper we describe the design of

Jacob LeBlanc; W. Thomas Miller; Andrew L. Kun

268

Highway Aesthetics: The Design of Motor Vehicles. Teaching Art with Art.  

ERIC Educational Resources Information Center

Addresses the design of highway vehicles as one means for students to learn about forms of three-dimensional art. Focuses on the Corvette, mass-produced cars like the Chrysler Concorde, the modern semi-trailer, and an antique 1931 Dusenberg Model J Murphy Aluminum Top Coupe. (CMK)

Hubbard, Guy

1999-01-01

269

Motor design considerations and test results of an interior permanent magnet synchronous motor for electric vehicles  

Microsoft Academic Search

This paper describes the high performance motor design of an interior permanent magnet synchronous motor (IPM motor) for electric vehicles. The authors examined the differences in motor characteristics based on how the magnets were embedded. For this comparison, they set conditions so that the volume of magnets remained constant, and they used both computer simulation and experiments with a prototype

Yukio Honda; Tomokazu Nakamura; Toshiro Higaki; Yoji Takeda

1997-01-01

270

Trajectory Design for Autonomous Underwater Vehicles based on Ocean Model Predictions for  

E-print Network

of oceanographic data. To make new discoveries and improve our overall understanding of the ocean, scientists mustTrajectory Design for Autonomous Underwater Vehicles based on Ocean Model Predictions for Feature-valued locations for data collection. We con- sider the use of ocean model predictions to determine the locations

Sukhatme, Gaurav S.

271

Modelling and PID controller design for a quadrotor unmanned air vehicle  

Microsoft Academic Search

this paper presents the modelling of a four rotor vertical take-off and landing (VTOL) unmanned air vehicle known as the quadrotor aircraft. The paper presents a new model design method for the flight control of an autonomous quad rotor .The paper describes the controller architecture for the quadrotor as well. The dynamic model of the quad-rotor, which is an under

Atheer L. Salih; M. Moghavvemi; Haider A. F. Mohamed; Khalaf Sallom Gaeid

2010-01-01

272

Design of a quadruped walking vehicle for dynamic walking and stair climbing  

Microsoft Academic Search

This paper discusses the design of a quadruped walking vehicle for walking dynamically at high speed and climbing ordinary stairs (30-40°). To realize these requests, new mechanisms are introduced, which are (1) a prismatic joint leg that does not interfere with the steps of a staircase and which performs a cylindrical coordinate motion with good energy efficiency, (2) an articulated

Shigeo Hirose; Kan Yoneda; Kazuhiko Arai; Tomoyoshi Ibe

1994-01-01

273

Optimal Design and Allocation of Electrified Vehicles and Dedicated Charging Infrastructure for Minimum Greenhouse Gas Emissions  

E-print Network

412-268-3348 ---- Word Count in Text: 4,910 Tables: 3 Figures: 4 Total Word Count Including Tables gasoline to electricity. GHG reduction potential depends on vehicle design, adoption, driving and charging size and acceleration to a Toyota Prius under urban EPA driving conditions. We find that under today

Michalek, Jeremy J.

274

78 FR 68748 - Federal Motor Vehicle Safety Standards; Designated Seating Positions  

Federal Register 2010, 2011, 2012, 2013

...Petitions for Reconsideration A. Definition of DSP B. Analysis of Safety Problem C. Seating...of ``designated seating position'' (DSP), as that term is used in the Federal...Occupant Crash Protection, requires that each DSP in a light vehicle be provided with...

2013-11-15

275

Solar Power System for experimental unmanned aerial vehicle (UAV); design and fabrication  

Microsoft Academic Search

A Solar Power System for experimental unmanned aerial vehicle (UAV) is designed and summarized. For the aircraft represented in this paper, solar cells were used to increase the endurance of the aircraft. Obtaining this goal, an electrical circuit was developed to measure the output power of the batteries of the aircraft during the flight. Flight tests showed that in cruise

H. Bahrami Torabi; M. Sadi; A. Yazdian Varjani

2011-01-01

276

NASA advanced-aeronautics design solar-powered remotely piloted vehicle  

Microsoft Academic Search

Environmental problems such as the depletion of the ozone layer and air pollution demand a change in traditional means of propulsion that is sensitive to the ecology. Solar powered propulsion is a favorable alternative that is both ecologically harmless as well as cost effective. Integration of solar energy into designs ranging from futuristic vehicles to heating is beneficial to society.

D. S. Elario; N. H. Guillmette; G. S. Lind; J. D. Webster; M. J. Ferreira; G. C. Konstantakis; D. L. Marshall; C. L. Windt

1991-01-01

277

Grid Generation for Multidisciplinary Design and Optimization of an Aerospace Vehicle: Issues and Challenges  

NASA Technical Reports Server (NTRS)

The purpose of this paper is to discuss grid generation issues and to challenge the grid generation community to develop tools suitable for automated multidisciplinary analysis and design optimization of aerospace vehicles. Special attention is given to the grid generation issues of computational fluid dynamics and computational structural mechanics disciplines.

Samareh, Jamshid A.

2000-01-01

278

Rotor hover performance and system design of an efficient coaxial rotary wing micro air vehicle  

Microsoft Academic Search

Rotary-wing Micro air vehicles (MAVs) due to their unique hovering and low-speed flight capabilities are specially suited for missions that require operation in constrained spaces. Size restrictions force MAVs to operate in a low Reynolds number aerodynamic regime where viscous effects are dominant. This results in poor aerodynamic performance of conventional airfoils and rotor configurations. This dissertation explores the design

Felipe Bohorquez

2007-01-01

279

Design and Control of a Passively Steered, Dual Axle Vehicle  

Microsoft Academic Search

In this paper we describe the steering, suspension and control systems of the rover Zoë, a solar-powered robot designed to explore the Mars-like landscapes of the Atacama Desert in Chile. We are developing the Zoë chassis as an alternative to the traditional six-wheeled, rocker-bogie system used by Mars rovers flown in the past ten years. Zoë travels over rough terrain

Michael Wagner; Stuart Heys; David Wettergreen; James Teza; Dimitrios Apostolopoulos; George Kantor; William Whittaker

2005-01-01

280

AEVITA : designing biomimetic vehicle-to-pedestrian communication protocols for autonomously operating & parking on-road electric vehicles  

E-print Network

With research institutions from various private, government and academic sectors performing research into autonomous vehicle deployment strategies, the way we think about vehicles must adapt. But what happens when the ...

Pennycooke, Nicholas (Nicholas D.)

2012-01-01

281

Design of Z-Pinch and Dense Plasma Focus Powered Vehicles  

NASA Technical Reports Server (NTRS)

Z-pinch and Dense Plasma Focus (DPF) are two promising techniques for bringing fusion power to the field of in-space propulsion. A design team comprising of engineers and scientists from UAHuntsville, NASA's George C. Marshall Space Flight Center and the University of Wisconsin developed concept vehicles for a crewed round trip mission to Mars and an interstellar precursor mission. Outlined in this paper are vehicle concepts, complete with conceptual analysis of the mission profile, operations, structural and thermal analysis and power/avionics design. Additionally engineering design of the thruster itself is included. The design efforts adds greatly to the fidelity of estimates for power density (alpha) and overall performance for these thruster concepts

Polsgrove, Tara; Fincher, Sharon; Adams, Robert B.; Cassibry, Jason; Cortez, Ross; Turner, Matthew; Maples, C. Daphne; Miermik, Janie N.; Statham, Geoffrey N.; Fabisinski, Leo; Santarius, John; Percy, Tom

2011-01-01

282

The promise of air cargo: System aspects and vehicle design  

NASA Technical Reports Server (NTRS)

The current operation of the air cargo system is reviewed. An assessment of the future of air cargo is provided by: (1) analyzing statistics and trends, (2) by noting system problems and inefficiencies, (3) by analyzing characteristics of 'air eligible' commodities, and (4) by showing the promise of new technology for future cargo aircraft with significant improvements in costs and efficiency. The following topics are discussed: (1) air cargo demand forecasts; (2) economics of air cargo transport; (3) the integrated air cargo system; (4) evolution of airfreighter design; and (5) the span distributed load concept.

Whitehead, A. H., Jr.

1976-01-01

283

Hover and wind-tunnel testing of shrouded rotors for improved micro air vehicle design  

Microsoft Academic Search

The shrouded-rotor configuration has emerged as the most popular choice for rotary-wing Micro Air Vehicles (MAVs), because of the inherent safety of the design and the potential for significant performance improvements. However, traditional design philosophies based on experience with large-scale ducted propellers may not apply to the low-Reynolds-number (˜20,000) regime in which MAVs operate. An experimental investigation of the effects

Jason L. Pereira

2008-01-01

284

Ideas and Technology of Control Systems @RT 2011 CDC-ECC 2011 Control Design of Unmanned Aerial Vehicles  

E-print Network

of UAVs UAVs: Unmanned aerial vehicles of different size which may be used for monitoring and detection for Mission Design and Autopilot Integration: an Application to Micro Aerial Vehicles," Euro-SIW 2008Ideas and Technology of Control Systems @RT 2011 CDC-ECC 2011 CNR-IEIIT Control Design of Unmanned

Tempo, Roberto

285

Full Envelope Reconfigurable Control Design for the X-33 Vehicle  

NASA Technical Reports Server (NTRS)

In the event of a control surface failure, the purpose of a reconfigurable control system is to redistribute the control effort among the remaining working surfaces such that satisfactory stability and performance are retained. An Off-line Nonlinear General Constrained Optimization (ONCO) approach was used for the reconfigurable X-33 control design method. Three example failures are shown using a high fidelity 6 DOF simulation (case I ascent with a left body flap jammed at 25 deg.; case 2 entry with a right inboard elevon jam at 25 deg.; and case 3, landing (TAEM) with a left rudder jam at -30 deg.) Failure comparisons between responses with the nominal controller and reconfigurable controllers show the benefits of reconfiguration. Single jam aerosurface failures were considered, and failure detection and identification is considered accomplished in the actuator controller. The X-33 flight control system will incorporate reconfigurable flight control in the baseline system.

Cotting, M. Christopher; Burken, John J.; Lee, Seung-Hee (Technical Monitor)

2001-01-01

286

Design and implementation of small navigation system on land vehicle  

NASA Astrophysics Data System (ADS)

This paper is focused on the problem of frame loss and truncation on multi-channel universal asynchronous receiver transmitter (UART) embedded in Integrated Navigation Systems, and it contains attitude heading reference system (AHRS) and global positioning system (GPS). An advanced design based on FPGA and ARM processor is discussed in this paper, in which FPGA would be used to coordinate with each logic modules, expand UART for GPS and AHRS, resolve navigation information, and save specify data to SD card, which can reduce the delay in data receiving and resolving, while ARM is applied in the area of parameters estimation and navigation algorithms. The experiment results show that this navigation system can use UART to receive, resolve data frames and save data while ARM execute parameter estimation and navigation algorithms in real time. This integrated navigation can effectively avoid the phenomenon of data frame loss or truncation in UART receiving, and can improve the navigation precision.

Ma, Shuaiqi

2013-03-01

287

A Design for Composing and Extending Vehicle Models  

NASA Technical Reports Server (NTRS)

The Systems Development Branch (SDB) at NASA Langley Research Center (LaRC) creates simulation software products for research. Each product consists of an aircraft model with experiment extensions. SDB treats its aircraft models as reusable components, upon which experiments can be built. SDB has evolved aircraft model design with the following goals: 1. Avoid polluting the aircraft model with experiment code. 2. Discourage the copy and tailor method of reuse. The current evolution of that architecture accomplishes these goals by reducing experiment creation to extend and compose. The architecture mechanizes the operational concerns of the model's subsystems and encapsulates them in an interface inherited by all subsystems. Generic operational code exercises the subsystems through the shared interface. An experiment is thus defined by the collection of subsystems that it creates ("compose"). Teams can modify the aircraft subsystems for the experiment using inheritance and polymorphism to create variants ("extend").

Madden, Michael M.; Neuhaus, Jason R.

2003-01-01

288

Reductions in vehicle fuel consumption due to refinements in aerodynamic design. [for trailer trucks  

NASA Technical Reports Server (NTRS)

Over-the-highway fuel consumption and coastdown drag tests were performed on cab-over-engine, van type trailer trucks and modifications of these vehicles incorporating refinements in aerodynamic design. In addition, 1/25-scale models of these configurations, and derivatives of these configurations were tested in a wind tunnel to determine the effects of wind on the magnitude of the benefits that aerodynamic refinements can provide. The results of these tests are presented for a vehicle incorporating major redesign features and for a relatively simple add-on modification. These results include projected fuel savings on the basis of annual savings per vehicle year as well as probable nationwide fuel savings.

Saltzman, E. J.

1979-01-01

289

Preliminary power train design for a state-of-the-art electric vehicle  

NASA Technical Reports Server (NTRS)

Power train designs which can be implemented within the current state-of-the-art were identified by means of a review of existing electric vehicles and suitable off-the-shelf components. The affect of various motor/transmission combinations on vehicle range over the SAE J227a schedule D cycle was evaluated. The selected, state-of-the-art power train employs a dc series wound motor, SCR controller, variable speed transmission, regenerative braking, drum brakes and radial ply tires. Vehicle range over the SAE cycle can be extended by approximately 20% by the further development of separately excited, shunt wound DC motors and electrical controllers. Approaches which could improve overall power train efficiency, such as AC motor systems, are identified. However, future emphasis should remain on batteries, tires and lightweight structures if substantial range improvements are to be achieved.

Mighdoll, P.; Hahn, W. F.

1978-01-01

290

Preliminary Design of a Manned Nuclear Electric Propulsion Vehicle Using Genetic Algorithms  

SciTech Connect

Nuclear electric propulsion (NEP) vehicles will be needed for future manned missions to Mars and beyond. Candidate designs must be identified for further detailed design from a large array of possibilities. Genetic algorithms have proven their utility in conceptual design studies by effectively searching a large design space to pinpoint unique optimal designs. This research combined analysis codes for NEP subsystems with a genetic algorithm. The use of penalty functions with scaling ratios was investigated to increase computational efficiency. Also, the selection of design variables for optimization was considered to reduce computation time without losing beneficial design search space. Finally, trend analysis of a reference mission to the asteroids yielded a group of candidate designs for further analysis.

Irwin, Ryan W. [School of Aeronautics and Astronautics, Purdue University, West Lafayette, IN 47907 (United States); Tinker, Michael L. [Spacecraft and Vehicle Systems Department, NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States)

2005-02-06

291

Design, testing, and performance of a hybrid micro vehicle---The Hopping Rotochute  

NASA Astrophysics Data System (ADS)

The Hopping Rotochute is a new hybrid micro vehicle that has been developed to robustly explore environments with rough terrain while minimizing energy consumption over long periods of time. The device consists of a small coaxial rotor system housed inside a lightweight cage. The vehicle traverses an area by intermittently powering a small electric motor which drives the rotor system, allowing the vehicle to hop over obstacles of various shapes and sizes. A movable internal mass controls the direction of travel while the egg-like exterior shape and low mass center allows the vehicle to passively reorient itself to an upright attitude when in contact with the ground. This dissertation presents the design, fabrication, and testing of a radio-controlled Hopping Rotochute prototype as well as an analytical study of the flight performance of the device. The conceptual design iterations are first outlined which were driven by the mission and system requirements assigned to the vehicle. The aerodynamic, mechanical, and electrical design of a prototype is then described, based on the final conceptual design, with particular emphasis on the fundamental trades that must be negotiated for this type of hopping vehicle. The fabrication and testing of this prototype is detailed as well as experimental results obtained from a motion capture system. Basic flight performance of the prototype are reported which demonstrates that the Hopping Rotochute satisfies all appointed system requirements. A dynamic model of the Hopping Rotochute is also developed in this thesis and employed to predict the flight performance of the vehicle. The dynamic model includes aerodynamic loads from the body and rotor system as well as a soft contact model to estimate the forces and moments during ground contact. The experimental methods used to estimate the dynamic model parameters are described while comparisons between measured and simulated motion are presented. Good correlation between these motions is shown to validate the dynamic model. Using the validated dynamic model, simulations were performed to better understand the dynamics of the device. In addition, key parameters such as system weight, rotor speed, internal mass weight and location, as well as battery capacity are varied to explore and optimize flight performance characteristics such as single hop height and range, number of hops, and total achievable range. The sensitivity of the Hopping Rotochute to atmospheric winds is also investigated as is the ability of the device to perform trajectory shaping.

Beyer, Eric W.

292

Model Development and Experimental Validation of the Fusible Heat Sink Design for Exploration Vehicles  

NASA Technical Reports Server (NTRS)

The Fusible Heat Sink is a novel vehicle heat rejection technology which combines a flow through radiator with a phase change material. The combined technologies create a multi-function device able to shield crew members against Solar Particle Events (SPE), reduce radiator extent by permitting sizing to the average vehicle heat load rather than to the peak vehicle heat load, and to substantially absorb heat load excursions from the average while constantly maintaining thermal control system setpoints. This multi-function technology provides great flexibility for mission planning, making it possible to operate a vehicle in hot or cold environments and under high or low heat load conditions for extended periods of time. This paper describes the modeling and experimental validation of the Fusible Heat Sink technology. The model developed was intended to meet the radiation and heat rejection requirements of a nominal MMSEV mission. Development parameters and results, including sizing and model performance will be discussed. From this flight-sized model, a scaled test-article design was modeled, designed, and fabricated for experimental validation of the technology at Johnson Space Center thermal vacuum chamber facilities. Testing showed performance comparable to the model at nominal loads and the capability to maintain heat loads substantially greater than nominal for extended periods of time.

Cognata, Thomas J.; Leimkuehler, Thomas; Sheth, Rubik; Le, Hung

2013-01-01

293

Alloy Design and Thermomechanical Processing of a Beta Titanium Alloy for a Heavy Vehicle Application  

SciTech Connect

With the strength of steel, but at half the weight, titanium has the potential to offer significant benefits in the weight reduction of heavy vehicle components while possibly improving performance. However, the cost of conventional titanium fabrication is a major barrier in implementation. New reduction technologies are now available that have the potential to create a paradigm shift in the way the United States uses titanium, and the economics associated with fabrication of titanium components. This CRADA project evaluated the potential to develop a heavy vehicle component from titanium powders. The project included alloy design, development of manufacturing practices, and modeling the economics associated with the new component. New Beta alloys were designed for this project to provide the required mechanical specifications while utilizing the benefits of the new fabrication approach. Manufacturing procedures were developed specific to the heavy vehicle component. Ageing and thermal treatment optimization was performed to provide the desired microstructures. The CRADA partner established fabrication practices and targeted capital investment required for fabricating the component out of titanium. Though initial results were promising, the full project was not executed due to termination of the effort by the CRADA partner and economic trends observed in the heavy vehicle market.

Blue, C.A.; Peter, W.H.

2010-07-02

294

Alloy Design and Thermomechanical Processing of a Beta Titanium Alloy for a Heavy Vehicle Application  

SciTech Connect

With the strength of steel, but at half the weight, titanium has the potential to offer significant benefits in the weight reduction of heavy vehicle components while possibly improving performance. However, the cost of conventional titanium fabrication is a major barrier in implementation. New reduction technologies are now available that have the potential to create a paradigm shift in the way the United States uses titanium, and the economics associated with fabrication of titanium components. This CRADA project evaluated the potential to develop a heavy vehicle component from titanium powders. The project included alloy design, development of manufacturing practices, and modeling the economics associated with the new component. New Beta alloys were designed for this project to provide the required mechanical specifications while utilizing the benefits of the new fabrication approach. Manufacturing procedures were developed specific to the heavy vehicle component. Ageing and thermal treatment optimization was performed to provide the desired microstructures. The CRADA partner established fabrication practices and targeted capital investment required for fabricating the component out of titanium. Though initial results were promising, the full project was not executed due to termination of the effort by the CRADA partner and economic trends observed in the heavy vehicle market.

Peter, William H [ORNL; Blue, Craig A [ORNL

2010-08-01

295

Design of an energy storage unit for fuel-cell and hybrid-electric vehicles  

NASA Astrophysics Data System (ADS)

This dissertation describes an ESU design methodology capable of minimizing the volume, weight and cost of the MES and ESU (i.e., battery pack, ultracapacitor pack and PE interfaces) while allowing for the implementation of power management in a cost-effective manner. The proposed ESU design methodology is based on a holistic approach that includes the vehicle performance requirements and allows for the optimization of the ESU with respect to predetermined goals of minimum volume, weight and cost. Substantial weight and volume reductions are accomplish when combining batteries and ultracapacitors even when considering the efficiencies of the PE interfaces. The optimized BU-ESU achieved a volume reduction of over 37% (from 135 liters to 84 liters) and a weight reduction of over 66% (from 333 kg to 148 kg) when compared to a 'classic' BO-ESU design. The benefits of the optimized BU-ESU are not limited to weight and volume reductions since sweeping the battery cost in $/kW predicts that the BU-ESU provides the lowest cost path to meet the vehicles energy and power requirements. Additional benefits, such as improve ESU efficiency, vehicle acceleration, regenerative braking capabilities, and battery life are also identified in this research work. The proposed ESU design and optimization procedure also includes the associated PE interfaces by selecting and designing the most suitable converter topology. The design is carried out by encompassing the wide output-to-input voltage ratio variation and output power typical on this automotive application. The comparison process identifies the half-bridge converter topology as the most cost-effective converter topology for this application. A novel design approach that incorporated a ratio defined as transitioning power ratio is proposed to overcome shortcoming of the 'classical' approach. This novel design approach allows the minimization of inductor size requirements and current stresses present in active components when designing converters with wide output-to-input voltage ratio.

Schupbach, Roberto Marcelo

296

Design optimization of the electrically peaking hybrid (ELPH) vehicle. Research report  

SciTech Connect

Electrically Peaking Hybrid (ELPH) is a parallel hybrid electric vehicle propulsion concept that was invented at Texas A and M University, by the advanced vehicle systems research group. Over the past six years, design methodologies, component development, and system optimization work has been going on for this invention. This project was a first attempt in integrating the above developments into an optimized design of an ELPH passenger car. Design specifications were chosen for a full size passenger car, performing as well as any conventional car, over the EPA-FTP-75 combined city/highway drive cycles. The results of this design project were two propulsion systems. Both were appropriate for commercial production, from the points of view of cost, availability of the technologies, and components. One utilized regenerative braking and the other did not. Substantial fuel savings and emissions reductions resulted from simulating these designs on the FTP-75 drive cycle. For example, the authors` ELPH full size car, with regenerative braking, was capable of delivering over 50 miles per gallon in city driving, with corresponding reductions in its emissions. This project established the viability of the authors` ELPH concept and their design methodologies, in computer simulations. More work remains to be done on investigating more advanced power plants, such as fuel cells, and more advanced components, such as switched reluctance motor drives, for the authors` designs. Furthermore, the authors` design optimization can be carried out to more detailed levels, for prototyping and production.

Ehsani, M.; Gao, Y.; Butler, K.

1998-10-01

297

Preliminary Design and Analysis of the ARES Atmospheric Flight Vehicle Thermal Control System  

NASA Technical Reports Server (NTRS)

The Aerial Regional-scale Environmental Survey (ARES) is a proposed 2007 Mars Scout Mission that will be the first mission to deploy an atmospheric flight vehicle (AFV) on another planet. This paper will describe the preliminary design and analysis of the AFV thermal control system for its flight through the Martian atmosphere and also present other analyses broadening the scope of that design to include other phases of the ARES mission. Initial analyses are discussed and results of trade studies are presented which detail the design process for AFV thermal control. Finally, results of the most recent AFV thermal analysis are shown and the plans for future work are discussed.

Gasbarre, J. F.; Dillman, R. A.

2003-01-01

298

Needs and Opportunities for Uncertainty-Based Multidisciplinary Design Methods for Aerospace Vehicles  

NASA Technical Reports Server (NTRS)

This report consists of a survey of the state of the art in uncertainty-based design together with recommendations for a Base research activity in this area for the NASA Langley Research Center. This report identifies the needs and opportunities for computational and experimental methods that provide accurate, efficient solutions to nondeterministic multidisciplinary aerospace vehicle design problems. Barriers to the adoption of uncertainty-based design methods are identified. and the benefits of the use of such methods are explained. Particular research needs are listed.

Zang, Thomas A.; Hemsch, Michael J.; Hilburger, Mark W.; Kenny, Sean P; Luckring, James M.; Maghami, Peiman; Padula, Sharon L.; Stroud, W. Jefferson

2002-01-01

299

Building Operations Efficiencies into NASA's Ares I Crew Launch Vehicle Design  

NASA Technical Reports Server (NTRS)

The U.S. Vision for Space Exploration guides the National Aeronautics and Space Administration's (NASA's) challenging missions that expand humanity's boundaries and open new routes to the space frontier. With the Agency's commitment to complete the International Space Station (ISS) and to retire the venerable Space Shuttle by 2010, the NASA Administrator commissioned the Exploration Systems Architecture Study (ESAS) in 2005 to analyze options for safe, simple, cost-efficient launch solutions that could deliver human-rated space transportation capabilities in a timely manner within fixed budget guidelines. The Exploration Launch Projects (ELP) Office, chartered by the Constellation Program in October 2005, has been conducting systems engineering studies and business planning to successively refine the design configurations and better align vehicle concepts with customer and stakeholder requirements, such as significantly reduced life-cycle costs. As the Agency begins the process of replacing the Shuttle with a new generation of spacecraft destined for missions beyond low-Earth orbit to the Moon and Mars, NASA is designing the follow-on crew and cargo launch systems for maximum operational efficiencies. To sustain the long-term exploration of space, it is imperative to reduce the $4 billion NASA typically spends on space transportation each year. This paper gives toplevel information about how the follow-on Ares I Crew Launch Vehicle (CLV) is being designed for improved safety and reliability, coupled with reduced operations costs. These methods include carefully developing operational requirements; conducting operability design and analysis; using the latest information technology tools to design and simulate the vehicle; and developing a learning culture across the workforce to ensure a smooth transition between Space Shuttle operations and Ares vehicle development.

Dumbacher, Daniel L.; Davis, Stephan R.

2007-01-01

300

Phase 1 of the near team hybrid passenger vehicle development program. Appendix C: Preliminary design data package, volume 1  

NASA Technical Reports Server (NTRS)

The methodology used for vehicle layout and component definition is described as well as techniques for system optimization and energy evaluation. The preliminary design is examined with particular attention given to body and structure; propulsion system; crash analysis and handling; internal combustion engine; DC motor separately excited; Ni-Zn battery; transmission; control system; vehicle auxiliarries; weight breakdown, and life cycle costs. Formulas are given for the quantification of energy consumption and results are compared with the reference vehicle.

Piccolo, R.

1979-01-01

301

Design of a Flush Airdata System (FADS) for the Hypersonic Air Launched Option (HALO) Vehicle  

NASA Technical Reports Server (NTRS)

This paper presents a design study for a pressure based Flush airdata system (FADS) on the Hypersonic Air Launched Option (HALO) Vehicle. The analysis will demonstrate the feasibility of using a pressure based airdata system for the HALO and provide measurement uncertainty estimates along a candidate trajectory. The HALO is a conceived as a man-rated vehicle to be air launched from an SR-71 platform and is proposed as a testbed for an airbreathing hydrogen scramjet. A feasibility study has been performed and indicates that the proposed trajectory is possible with minimal modifications to the existing SR71 vehicle. The mission consists of launching the HALO off the top of an SR-71 at Mach 3 and 80,000 ft. A rocket motor is then used to accelerate the vehicle to the test condition. After the scramjet test is completed the vehicle will glide to a lakebed runway landing. This option provides reusability of the vehicle and scramjet engine. The HALO design will also allow for various scramjet engine and flowpath designs to be flight tested. For the HALO flights, measurements of freestream airdata are considered to be a mission critical to perform gain scheduling and trajectory optimization. One approach taken to obtaining airdata involves measurement of certain parameters such as external atmospheric winds, temperature, etc to estimate the airdata quantities. This study takes an alternate approach. Here the feasibility of obtaining airdata using a pressure-based flush airdata system (FADS) methods is assessed. The analysis, although it is performed using the HALO configuration and trajectory, is generally applicable to other hypersonic vehicles. The method to be presented offers the distinct advantage of inferring total pressure, Mach number, and flow incidence angles, without stagnating the freestream flow. This approach allows for airdata measurements to be made using blunt surfaces and significantly diminishes the heating load at the sensor. In the FADS concept a matrix of flush ports is placed in the vicinity of the aircraft nose, and the airdata are inferred indirectly from the measured pressures.

Whitmore, Stephen A.; Moes, Timothy R.; Deets, Dwain A. (Technical Monitor)

1994-01-01

302

Quantum dots as a platform for nanoparticle drug delivery vehicle design.  

PubMed

Nanoparticle-based drug delivery (NDD) has emerged as a promising approach to improving upon the efficacy of existing drugs and enabling the development of new therapies. Proof-of-concept studies have demonstrated the potential for NDD systems to simultaneously achieve reduced drug toxicity, improved bio-availability, increased circulation times, controlled drug release, and targeting. However, clinical translation of NDD vehicles with the goal of treating particularly challenging diseases, such as cancer, will require a thorough understanding of how nanoparticle properties influence their fate in biological systems, especially in vivo. Consequently, a model system for systematic evaluation of all stages of NDD with high sensitivity, high resolution, and low cost is highly desirable. In theory, this system should maintain the properties and behavior of the original NDD vehicle, while providing mechanisms for monitoring intracellular and systemic nanocarrier distribution, degradation, drug release, and clearance. For such a model system, quantum dots (QDots) offer great potential. QDots feature small size and versatile surface chemistry, allowing their incorporation within virtually any NDD vehicle with minimal effect on overall characteristics, and offer superb optical properties for real-time monitoring of NDD vehicle transport and drug release at both cellular and systemic levels. Though the direct use of QDots for drug delivery remains questionable due to their potential long-term toxicity, the QDot core can be easily replaced with other organic drug carriers or more biocompatible inorganic contrast agents (such as gold and magnetic nanoparticles) by their similar size and surface properties, facilitating translation of well characterized NDD vehicles to the clinic, maintaining NDD imaging capabilities, and potentially providing additional therapeutic functionalities such as photothermal therapy and magneto-transfection. In this review we outline unique features that make QDots an ideal platform for nanocarrier design and discuss how this model has been applied to study NDD vehicle behavior for diverse drug delivery applications. PMID:23000745

Probst, Christine E; Zrazhevskiy, Pavel; Bagalkot, Vaishali; Gao, Xiaohu

2013-05-01

303

Design analysis of an aluminum-air battery for vehicle operations. Transportation systems research  

Microsoft Academic Search

The objective of the study reported was to perform a detailed configuration analysis of an aluminum-air battery, evaluate various automobile propulsion systems utilizing the Al-air battery, and estimate the performance and cost of vehicles incorporating these propulsion systems. A preliminary engineering design is performed. A physical model and a cell-performance model of a conceptual mass-produced Al-air battery were constructed and

E. Behrin; R. L. Wood; J. D. Salisbury; D. J. Whisler; C. L. Hudson

1983-01-01

304

Universal Space Vehicle Design Concept to Defend the Earth against Asteroidal-Cometary Danger  

Microsoft Academic Search

Theoretical and experimental estimations are given on the structure of a universal space interceptor designed on the modular principle. The interceptor comprising one command-impact module and a variable number of separable impact modules, each with propulsion and guidance systems, can be injected into a trajectory towards an Earth approaching space object by launch vehicles MOLNIYA, PROTON, TITAN-4, ARIANE-5, N-2, and

V. A. Volkov; V. A. Danilkin; V. G. Degtyar; G. G. Sytyi

305

Sustainable design for automotive products: dismantling and recycling of end-of-life vehicles.  

PubMed

The growth in automotive production has increased the number of end-of-life vehicles (ELVs) annually. The traditional approach ELV processing involves dismantling, shredding, and landfill disposal. The "3R" (i.e., reduce, reuse, and recycle) principle has been increasingly employed in processing ELVs, particularly ELV parts, to promote sustainable development. The first step in processing ELVs is dismantling. However, certain parts of the vehicle are difficult to disassemble and use in practice. The extended producer responsibility policy requires carmakers to contribute in the processing of scrap cars either for their own developmental needs or for social responsibility. The design for dismantling approach can be an effective solution to the existing difficulties in dismantling ELVs. This approach can also provide guidelines in the design of automotive products. This paper illustrates the difficulty of handling polymers in dashboards. The physical properties of polymers prevent easy separation and recycling by using mechanical methods. Thus, dealers have to rely on chemical methods such as pyrolysis. Therefore, car designers should use a single material to benefit dealers. The use of materials for effective end-of-life processing without sacrificing the original performance requirements of the vehicle should be explored. PMID:24326159

Tian, Jin; Chen, Ming

2014-02-01

306

Design of blast deflectors for a mine resistant vehicle by CFD/CSD simulations  

SciTech Connect

Results of a successful effort to significantly improve resistance of the tactical wheeled vehicle to mine detonation are reported. The design methodology is based on a comprehensive use of numerical simulation for blast/structure interaction and structure deformation as a result of blast load. Both Computational Fluid and Structural Dynamic (CFD and CSD) simulations are performed in three dimensions for the most comprehensive representation of the tactical wheeled vehicle geometry. Detailed three dimensional simulations of interaction of the blast waves generated by mine detonations against full configurations of tactical wheeled vehicles were validated by dedicated experiments. Three main scenarios for mine detonation were considered: command detonation of a mine under the truck crew cab, detonation of the mine under the front wheel, and detonation under the middle or aft wheel. Blast deflectors, designed using this comprehensive CFD/CSD methodology, were built and tested for blast loads generated by high explosive detonations. Results of these tests demonstrate a remarkable level of blast protection achieved by low cost deflectors of very simple geometry placed in key locations. The study demonstrates the advantages of including high level CFD/CSD simulations in blast deflectors design.

Lottati, I.; Eidelman, S. [Science Applications International Corp., McLean, VA (United States); Dillon, J.; Sergi, S.; Sousk, S. [Army Communications-Electronics Command, Ft. Belvoir, VA (United States). Research Development and Engineering Center

1996-12-31

307

Conceptual Design of a Flight Validation Mission for a Hypervelocity Asteroid Intercept Vehicle  

NASA Technical Reports Server (NTRS)

Near-Earth Objects (NEOs) are asteroids and comets whose orbits approach or cross Earth s orbit. NEOs have collided with our planet in the past, sometimes to devastating effect, and continue to do so today. Collisions with NEOs large enough to do significant damage to the ground are fortunately infrequent, but such events can occur at any time and we therefore need to develop and validate the techniques and technologies necessary to prevent the Earth impact of an incoming NEO. In this paper we provide background on the hazard posed to Earth by NEOs and present the results of a recent study performed by the NASA/Goddard Space Flight Center s Mission Design Lab (MDL) in collaboration with Iowa State University s Asteroid Deflection Research Center (ADRC) to design a flight validation mission for a Hypervelocity Asteroid Intercept Vehicle (HAIV) as part of a Phase 2 NASA Innovative Advanced Concepts (NIAC) research project. The HAIV is a two-body vehicle consisting of a leading kinetic impactor and trailing follower carrying a Nuclear Explosive Device (NED) payload. The HAIV detonates the NED inside the crater in the NEO s surface created by the lead kinetic impactor portion of the vehicle, effecting a powerful subsurface detonation to disrupt the NEO. For the flight validation mission, only a simple mass proxy for the NED is carried in the HAIV. Ongoing and future research topics are discussed following the presentation of the detailed flight validation mission design results produced in the MDL.

Barbee, Brent W.; Wie, Bong; Steiner, Mark; Getzandanner, Kenneth

2013-01-01

308

A design approach for Intelligent Vehicle Black Box System with intra-vehicular communication using LIN\\/Flex-ray protocols  

Microsoft Academic Search

The current paper discusses a design approach for Intelligent vehicle black box system with vehicle networking. It is also proposed that the system will consists of intelligent router (based on LIN or Flex-ray) which on activation will execute for authentication & validation. After confirmation it will form packets of emergency data depending upon rise & kind of emergency situation. The

Milind Khanapurkar; Preeti Bajaj; Dakshata Gharode

2008-01-01

309

The eyeball ROV: Design and control of a spherical underwater vehicle steered by an internal eccentric mass  

Microsoft Academic Search

A Remotely Operated Vehicle (ROV) is developed for use in the inspection of underwater structures in hazardous environments. The vehicle presented can change orientation like an eyeball using a novel gimbal mechanism for moving an internal eccentric mass. Combined with a pair of thrusters, the Eyeball ROV can move in any direction with non-holonomic constraints. In this paper the design

Ian C. Rust; H. Harry Asada

2011-01-01

310

Applying Monte Carlo Simulation to Launch Vehicle Design and Requirements Analysis  

NASA Technical Reports Server (NTRS)

This Technical Publication (TP) is meant to address a number of topics related to the application of Monte Carlo simulation to launch vehicle design and requirements analysis. Although the focus is on a launch vehicle application, the methods may be applied to other complex systems as well. The TP is organized so that all the important topics are covered in the main text, and detailed derivations are in the appendices. The TP first introduces Monte Carlo simulation and the major topics to be discussed, including discussion of the input distributions for Monte Carlo runs, testing the simulation, how many runs are necessary for verification of requirements, what to do if results are desired for events that happen only rarely, and postprocessing, including analyzing any failed runs, examples of useful output products, and statistical information for generating desired results from the output data. Topics in the appendices include some tables for requirements verification, derivation of the number of runs required and generation of output probabilistic data with consumer risk included, derivation of launch vehicle models to include possible variations of assembled vehicles, minimization of a consumable to achieve a two-dimensional statistical result, recontact probability during staging, ensuring duplicated Monte Carlo random variations, and importance sampling.

Hanson, J. M.; Beard, B. B.

2010-01-01

311

Feasibility study of an Integrated Program for Aerospace vehicle Design (IPAD). Volume 2: The design process  

NASA Technical Reports Server (NTRS)

The extent to which IPAD is to support the design process is identified. Case studies of representative aerospace products were developed as models to characterize the design process and to provide design requirements for the IPAD computing system.

Gillette, W. B.; Turner, M. J.; Southall, J. W.; Whitener, P. C.; Kowalik, J. S.

1973-01-01

312

Engaging Inner City Students in Learning Through Designing Remote Operated Vehicles  

NASA Astrophysics Data System (ADS)

For the past year we have been developing and implementing a program in which students design and construct remote operated vehicles. In this paper, we report on a pilot study that occurred over the course of an academic year in an inner city high school. Specifically, we have been investigating whether students learn meaningful science content through design activities. Through our teaching experiment methodological stance and analysis we found that (1) student attendance and engagement increased, (2) students learned physics content and recognized connections to their other coursework (3) teachers adopted an "organized chaos" posture and shifted their role from one of discipline keeper and content gatekeeper to one of coach and facilitator, (4) design projects need to be modularized if they are to be effective urban classrooms, and (5) teachers need to balance the tradeoffs between allowing students to develop aesthetically pleasing designs versus learning content and creating designs that are functional and useable.

Barnett, Michael

2005-03-01

313

Next Generation Civil Transport Aircraft Design Considerations for Improving Vehicle and System-Level Efficiency  

NASA Technical Reports Server (NTRS)

The future of aviation will benefit from research in aircraft design and air transportation management aimed at improving efficiency and reducing environmental impacts. This paper presents civil transport aircraft design trends and opportunities for improving vehicle and system-level efficiency. Aircraft design concepts and the emerging technologies critical to reducing thrust specific fuel consumption, reducing weight, and increasing lift to drag ratio currently being developed by NASA are discussed. Advancements in the air transportation system aimed towards system-level efficiency are discussed as well. Finally, the paper describes the relationship between the air transportation system, aircraft, and efficiency. This relationship is characterized by operational constraints imposed by the air transportation system that influence aircraft design, and operational capabilities inherent to an aircraft design that impact the air transportation system.

Acosta, Diana M.; Guynn, Mark D.; Wahls, Richard A.; DelRosario, Ruben,

2013-01-01

314

A Design Comparison of Atmospheric Flight Vehicles for the Exploration of Titan  

NASA Technical Reports Server (NTRS)

Titan, the largest moon of Saturn, is one of the most scientifically interesting locations in the Solar System. With a very cold atmosphere that is five times as dense as Earth s, and one and a half times the surface pressure, it also provides one of the most aeronautically fascinating environments known to humankind. While this may seem the ideal place to attempt atmospheric flight, many challenges await any vehicle attempting to navigate through it. In addition to these physical challenges, any scientific exploration mission to Titan will most likely have several operational constraints. One difficult constraint is the desire for a global survey of the planet and thus, a long duration flight within the atmosphere. Since many of the scientific measurements that would be unique to a vehicle flying through the atmosphere (as opposed to an orbiting spacecraft) desire near-surface positioning of their associated instruments, the vehicle must also be able to fly within the first scale height of the atmosphere. Another difficult constraint is that interaction with the surface, whether by landing or dropped probe, is also highly desirable from a scientific perspective. Two common atmospheric flight platforms that might be used for this mission are the airplane and airship. Under the assumption of a mission architecture that would involve an orbiting relay spacecraft delivered via aerocapture and an atmospheric flight vehicle delivered via direct entry, designs were developed for both platforms that are unique to Titan. Consequently, after a viable design was achieved for each platform, their advantages and disadvantages were compared. This comparison included such factors as deployment risk, surface interaction capability, mass, and design heritage. When considering all factors, the preferred candidate platform for a global survey of Titan is an airship.

Gasbarre, Joseph F.; Wright, Henry S.; Lewis, Mark J.

2005-01-01

315

Integration of Launch Vehicle Simulation/Analysis Tools and Lunar Cargo Lander Design. Part 1/2  

NASA Technical Reports Server (NTRS)

Simulation and analysis of vehicle performance is essential for design of a new launch vehicle system. It is more and more demand to have an integrated, highly efficient, robust simulation tool with graphical user interface (GUI) for vehicle performance and simulations. The objectives of this project are to integrate and develop launch vehicle simulation and analysis tools in MATLAB/Simulink under PC Platform, to develop a vehicle capable of being launched on a Delta-IV Heavy Launch Vehicle which can land on the moon with the goal of pre-implanting cargo for a new lunar mission, also with the capability of selecting other launch vehicles that are capable of inserting a payload into Trans-Lunar Injection (TLI). The vehicle flight simulation software, MAVERIC-II (Marshall Aerospace VEhicle Representation In 'C'), developed by Marshall Space Flight Center was selected as a starting point for integration of simulation/analysis tools. The goals are to convert MAVERIC-II from UNIX to PC platform and build input/output GUI s in the MATLAB environment, and then integrate them under MATLAB/Simulink with other modules. Currently, MAVERIC-II has been successfully converted from UNIX to PC using Microsoft Services for UNIX subsystem on PC. Input/Output GUI's have been done for some key input/output files. Calling MAVERIC-II from Simulink has been tested. Details regarding Lunar Cargo Lander Design are described in Part 2/2 of the paper on page X-1.

Shiue, Yeu-Sheng Paul

2005-01-01

316

Development and application of ride-quality criteria. [considering vehicle vibration damping design  

NASA Technical Reports Server (NTRS)

Ride quality vibration criteria applicable to the design and evaluation of air and surface transportation systems are described. Consideration is given to the magnitude of vehicle vibration experienced by the passenger, the frequency of vibration, the direction of vibration measurements are presented for a variety of air and surface transportation systems. In addition, simulator data on seat dynamics and passenger response are presented. Results suggest the relative merits of various physical descriptors and measurement locations for characterizing the vibration in terms suitable for the design and/or evaluation of transportation systems.

Stephens, D. G.

1974-01-01

317

Cryogenic gear technology for an orbital transfer vehicle engine and tester design  

NASA Technical Reports Server (NTRS)

Technology available for gears used in advanced Orbital Transfer Vehicle rocket engines and the design of a cryogenic adapted tester used for evaluating advanced gears are presented. The only high-speed, unlubricated gears currently in cryogenic service are used in the RL10 rocket engine turbomachinery. Advanced rocket engine gear systems experience operational load conditions and rotational speed that are beyond current experience levels. The work under this task consisted of a technology assessment and requirements definition followed by design of a self-contained portable cryogenic adapted gear test rig system.

Calandra, M.; Duncan, G.

1986-01-01

318

The design and results of an algorithm for intelligent ground vehicles  

NASA Astrophysics Data System (ADS)

This paper addresses the design, design method, test platform, and test results of an algorithm used in autonomous navigation for intelligent vehicles. The Bluefield State College (BSC) team created this algorithm for its 2009 Intelligent Ground Vehicle Competition (IGVC) robot called Anassa V. The BSC robotics team is comprised of undergraduate computer science, engineering technology, marketing students, and one robotics faculty advisor. The team has participated in IGVC since the year 2000. A major part of the design process that the BSC team uses each year for IGVC is a fully documented "Post-IGVC Analysis." Over the nine years since 2000, the lessons the students learned from these analyses have resulted in an ever-improving, highly successful autonomous algorithm. The algorithm employed in Anassa V is a culmination of past successes and new ideas, resulting in Anassa V earning several excellent IGVC 2009 performance awards, including third place overall. The paper will discuss all aspects of the design of this autonomous robotic system, beginning with the design process and ending with test results for both simulation and real environments.

Duncan, Matthew; Milam, Justin; Tote, Caleb; Riggins, Robert N.

2010-01-01

319

Aerospace Meteorology Lessons Learned Relative to Aerospace Vehicle Design and Operations  

NASA Technical Reports Server (NTRS)

Aerospace Meteorology came into being in the 1950s as the development of rockets for military and civilian usage grew in the United States. The term was coined to identify those involved in the development of natural environment models, design/operational requirements, and environment measurement systems to support the needs of aerospace vehicles, both launch vehicles and spacecraft. It encompassed the atmospheric environment of the Earth, including Earth orbit environments. Several groups within the United States were active in this area, including the Department of Defense, National Aeronautics and Space Administration, and a few of the aerospace industry groups. Some aerospace meteorology efforts were similar to those being undertaken relative to aviation interests. As part of the aerospace meteorology activities a number of lessons learned resulted that produced follow on efforts which benefited from these experiences, thus leading to the rather efficient and technologically current descriptions of terrestrial environment design requirements, prelaunch monitoring systems, and forecast capabilities available to support the development and operations of aerospace vehicles.

Vaughan, William W.; Anderson, B. Jeffrey

2004-01-01

320

Design and analysis of aluminum/air battery system for electric vehicles  

NASA Astrophysics Data System (ADS)

Aluminum (Al)/air batteries have the potential to be used to produce power to operate cars and other vehicles. These batteries might be important on a long-term interim basis as the world passes through the transition from gasoline cars to hydrogen fuel cell cars. The Al/air battery system can generate enough energy and power for driving ranges and acceleration similar to gasoline powered cars. From our design analysis, it can be seen that the cost of aluminum as an anode can be as low as US 1.1/kg as long as the reaction product is recycled. The total fuel efficiency during the cycle process in Al/air electric vehicles (EVs) can be 15% (present stage) or 20% (projected) comparable to that of internal combustion engine vehicles (ICEs) (13%). The design battery energy density is 1300 Wh/kg (present) or 2000 Wh/kg (projected). The cost of battery system chosen to evaluate is US 30/kW (present) or US$ 29/kW (projected). Al/air EVs life-cycle analysis was conducted and compared to lead/acid and nickel metal hydride (NiMH) EVs. Only the Al/air EVs can be projected to have a travel range comparable to ICEs. From this analysis, Al/air EVs are the most promising candidates compared to ICEs in terms of travel range, purchase price, fuel cost, and life-cycle cost.

Yang, Shaohua; Knickle, Harold

321

Preliminary power train design for a state-of-the-art electric vehicle  

NASA Technical Reports Server (NTRS)

The state-of-the-art (SOTA) of electric vehicles built since 1965 was reviewed to establish a base for the preliminary design of a power train for a SOTA electric vehicle. The performance of existing electric vehicles were evaluated to establish preliminary specifications for a power train design using state-of-the-art technology and commercially available components. Power train components were evaluated and selected using a computer simulation of the SAE J227a Schedule D driving cycle. Predicted range was determined for a number of motor and controller combinations in conjunction with the mechanical elements of power trains and a battery pack of sixteen lead-acid batteries - 471.7 kg at 0.093 MJ/Kg (1040 lbs. at 11.7 Whr/lb). On the basis of maximum range and overall system efficiency using the Schedule D cycle, an induction motor and 3 phase inverter/controller was selected as the optimum combination when used with a two-speed transaxle and steel belted radial tires. The predicted Schedule D range is 90.4 km (56.2 mi). Four near term improvements to the SOTA were identified, evaluated, and predicted to increase range approximately 7%.

Ross, J. A.; Wooldridge, G. A.

1978-01-01

322

Feasibility study of an Integrated Program for Aerospace vehicle Design (IPAD). Volume 4: IPAD system design  

NASA Technical Reports Server (NTRS)

The computing system design of IPAD is described and the requirements which form the basis for the system design are discussed. The system is presented in terms of a functional design description and technical design specifications. The functional design specifications give the detailed description of the system design using top-down structured programming methodology. Human behavioral characteristics, which specify the system design at the user interface, security considerations, and standards for system design, implementation, and maintenance are also part of the technical design specifications. Detailed specifications of the two most common computing system types in use by the major aerospace companies which could support the IPAD system design are presented. The report of a study to investigate migration of IPAD software between the two candidate 3rd generation host computing systems and from these systems to a 4th generation system is included.

Goldfarb, W.; Carpenter, L. C.; Redhed, D. D.; Hansen, S. D.; Anderson, L. O.; Kawaguchi, A. S.

1973-01-01

323

Design for implementation : fully integrated charging & docking infrastructure used in Mobility-on-Demand electric vehicle fleets  

E-print Network

As the technology used in electric vehicles continues to advance, there is an increased demand for urban-appropriate electric charging stations emphasizing a modern user interface, robust design, and reliable functionality. ...

Martin, Jean Mario Nations

2012-01-01

324

Development of an Expert Judgement Elicitation and Calibration Methodology for Risk Analysis in Conceptual Vehicle Design  

NASA Technical Reports Server (NTRS)

A comprehensive expert-judgment elicitation methodology to quantify input parameter uncertainty and analysis tool uncertainty in a conceptual launch vehicle design analysis has been developed. The ten-phase methodology seeks to obtain expert judgment opinion for quantifying uncertainties as a probability distribution so that multidisciplinary risk analysis studies can be performed. The calibration and aggregation techniques presented as part of the methodology are aimed at improving individual expert estimates, and provide an approach to aggregate multiple expert judgments into a single probability distribution. The purpose of this report is to document the methodology development and its validation through application to a reference aerospace vehicle. A detailed summary of the application exercise, including calibration and aggregation results is presented. A discussion of possible future steps in this research area is given.

Unal, Resit; Keating, Charles; Conway, Bruce; Chytka, Trina

2004-01-01

325

Preliminary Assessment of Artificial Gravity Impacts to Deep-Space Vehicle Design  

NASA Technical Reports Server (NTRS)

Even after more than thirty years of scientific investigation, serious concerns regarding human physiological effects of long-duration microgravity exposure remain. These include loss of bone mineral density, skeletal muscle atrophy, and orthostatic hypertension, among others. In particular, "Safe Passage: Astronaut Care for Exploration Missions," states "loss of bone density, which apparently occurs at a rate of 1% per month in microgravity, is relatively manageable on the short-duration missions of the space shuttle, but it becomes problematic on the ISS [International Space Station]. ...If this loss is not mitigated, interplanetary missions will be impossible." While extensive investigations into potential countermeasures are planned on the ISS, the delay in attaining full crew complement and onboard facilities, and the potential for extending crews tours of duty threaten the timely (< 20 years!) accumulation of sufficient data for countermeasures formulation. Indeed, there is no guarantee that even with the data, a practical or sufficiently robust set of countermeasures will be forthcoming. Providing an artificial gravity (AG) environment by crew centrifugation aboard deep-space human exploration vehicles, long a staple technique of science fiction, has received surprisingly limited engineering assessment. This is most likely due to a number of factors: the lack of definitive design requirements, especially acceptable artificial gravity levels and rotation rates, the perception of high vehicle mass and performance penalties, the incompatibility of resulting vehicle configurations with space propulsion options (i.e., aerocapture), the perception of complications associated with de-spun components such as antennae and photovoltaic arrays, and the expectation of effective crew micro-gravity countermeasures. These perception and concerns may have been overstated, or may be acceptable alternatives to countermeasures of limited efficacy. This study was undertaken as an initial step to try to understand the implications of and potential solutions to incorporating artificial gravity in the design of human deep-space exploration vehicles. Of prime interest will be the mass penalties incurred by incorporating AG, along with any mission performance degradation.

Joosten, B. Kent

2007-01-01

326

Design and implementation of a high-efficiency on- board battery charger for electric vehicles with frequency control strategy  

Microsoft Academic Search

This paper presents a design and implementation of 3.3 kW on-board battery charger for electric vehicles or plug-in hybrid electric vehicles. A series-loaded resonant dc-dc converter and frequency control are adopted in consideration of efficiency, reliability, volume, cost, and so on. In order to obtain high efficiency and less volume within 6 liters, a prototype of the charger is designed

Jong-Soo Kim; Gyu-Yeong Choe; Hye-Man Jung; Byoung-Kuk Lee; Young-Jin Cho; Kyu-Bum Han

2010-01-01

327

Cost-effectiveness of integrated analysis/design systems /IPAD/ An executive summary. II. [for aerospace vehicles  

NASA Technical Reports Server (NTRS)

Evaluation of the cost-effectiveness of integrated analysis/design systems with particular attention to Integrated Program for Aerospace-Vehicle Design (IPAD) project. An analysis of all the ingredients of IPAD indicates the feasibility of a significant cost and flowtime reduction in the product design process involved. It is also concluded that an IPAD-supported design process will provide a framework for configuration control, whereby the engineering costs for design, analysis and testing can be controlled during the air vehicle development cycle.

Miller, R. E., Jr.; Hansen, S. D.; Redhed, D. D.; Southall, J. W.; Kawaguchi, A. S.

1974-01-01

328

Mission analysis and guidance, navigation, and control design for rendezvous and docking phase of advanced reentry vehicle mission  

NASA Astrophysics Data System (ADS)

Advanced Reentry Vehicle (ARV) belongs to the family of vehicles designed to perform rendezvous and docking (RvD) with the International space station (ISS) [1]. Differently from its predecessor ATV (Automated Transfer Vehicle), the ARV will transport a reentry capsule, equipped with a heatshield and able to bring back cargo, experiments, or, as a possible future development, even crew, being this latter scenario very attracting in view of the Space Shuttle retirement. GMV, as subcontractor of EADS-Astrium Germany, is in charge of the RvD and departure mission analysis and GNC (Guidance, Navigation, and Control) design of ARV mission. This paper will present the main outcomes of the study.

Strippoli, L.; Colmenarejo, P.; Strauch, H.

2013-12-01

329

Rex 2 : design, construction, and operation of an unmanned underwater vehicle  

E-print Network

The practical usage of unmanned underwater vehicles (UUVs) is limited by vehicle and operation cost, difficulty in accurate navigation, and communication between the vehicle and operator. The "Rex 2" UUV employs a system ...

Owens, Dylan

2009-01-01

330

Human Exploration Using Real-Time Robotic Operations (HERRO)- Crew Telerobotic Control Vehicle (CTCV) Design  

NASA Technical Reports Server (NTRS)

The HERRO concept allows real time investigation of planets and small bodies by sending astronauts to orbit these targets and telerobotically explore them using robotic systems. Several targets have been put forward by past studies including Mars, Venus, and near Earth asteroids. A conceptual design study was funded by the NASA Innovation Fund to explore what the HERRO concept and it's vehicles would look like and what technological challenges need to be met. This design study chose Mars as the target destination. In this way the HERRO studies can define the endpoint design concepts for an all-up telerobotic exploration of the number one target of interest Mars. This endpoint design will serve to help planners define combined precursor telerobotics science missions and technology development flights. A suggested set of these technologies and demonstrator missions is shown in Appendix B. The HERRO concept includes a crewed telerobotics orbit vehicle as well three Truck rovers, each supporting two teleoperated geologist robots Rockhounds (each truck/Rockhounds set is landed using a commercially launched aeroshell landing system.) Options include a sample ascent system teamed with an orbital telerobotic sample rendezvous and return spacecraft (S/C) (yet to be designed). Each truck rover would be landed in a science location with the ability to traverse a 100 km diameter area, carrying the Rockhounds to 100 m diameter science areas for several week science activities. The truck is not only responsible for transporting the Rockhounds to science areas, but also for relaying telecontrol and high-res communications to/from the Rockhound and powering/heating the Rockhound during the non-science times (including night-time). The Rockhounds take the place of human geologists by providing an agile robotic platform with real-time telerobotics control to the Rockhound from the crew telerobotics orbiter. The designs of the Truck rovers and Rockhounds will be described in other publications. This document focuses on the CTCV design.

Oleson, Steven R.; McGuire, Melissa L.; Burke, Laura; Chato, David; Fincannon, James; Landis, Geoff; Sandifer, Carl; Warner, Joe; Williams, Glenn; Colozza, Tony; Fittje, Jim; Martini, Mike; Packard, Tom; McCurdy, Dave; Gyekenyesi, John

2010-01-01

331

NASA/USRA advanced space design program: The laser powered interorbital vehicle  

NASA Technical Reports Server (NTRS)

A preliminary design is presented for a low-thrust Laser Powered Interorbital Vehicle (LPIV) intended for cargo transportation between an earth space station and a lunar base. The LPIV receives its power from two iodide laser stations, one orbiting the earth and the other located on the surface of the moon. The selected mission utilizes a spiral trajectory, characteristic of a low-thrust spacecraft, requiring 8 days for a lunar rendezvous and an additional 9 days for return. The ship's configuration consists primarily of an optical train, two hydrogen plasma engines, a 37.1 m box beam truss, a payload module, and fuel tanks. The total mass of the vehicle fully loaded is 63300 kg. A single plasma, regeneratively cooled engine design is incorporated into the two 500 N engines. These are connected to the spacecraft by turntables which allow the vehicle to thrust tangentially to the flight path. Proper collection and transmission of the laser beam to the thrust chambers is provided through the optical train. This system consists of the 23 m diameter primary mirror, a convex parabolic secondary mirror, a beam splitter and two concave parabolic tertiary mirrors. The payload bay is capable of carrying 18000 kg of cargo. The module is located opposite the primary mirror on the main truss. Fuel tanks carrying a maximum of 35000 kg of liquid hydrogen are fastened to tracks which allow the tanks to be moved perpendicular to the main truss. This capability is required to prevent the center of mass from moving out of the thrust vector line. The laser beam is located and tracked by means of an acquisition, pointing and tracking system which can be locked onto the space-based laser station. Correct orientation of the spacecraft with the laser beam is maintained by control moment gyros and reaction control rockets. Additionally an aerobrake configuration was designed to provide the option of using the atmospheric drag in place of propulsion for a return trajectory.

1989-01-01

332

Continuous high order sliding mode controller design for a flexible air-breathing hypersonic vehicle.  

PubMed

This paper investigates the problem of tracking control with uncertainties for a flexible air-breathing hypersonic vehicle (FAHV). In order to overcome the analytical intractability of this model, an Input-Output linearization model is constructed for the purpose of feedback control design. Then, the continuous finite time convergence high order sliding mode controller is designed for the Input-Output linearization model without uncertainties. In addition, a nonlinear disturbance observer is applied to estimate the uncertainties in order to compensate the controller and disturbance suppression, where disturbance observer and controller synthesis design is obtained. Finally, the synthesis of controller and disturbance observer is used to achieve the tracking for the velocity and altitude of the FAHV and simulations are presented to illustrate the effectiveness of the control strategies. PMID:24534328

Wang, Jie; Zong, Qun; Su, Rui; Tian, Bailing

2014-05-01

333

High-Alpha Research Vehicle (HARV) longitudinal controller: Design, analyses, and simulation resultss  

NASA Technical Reports Server (NTRS)

This paper describes the design, analysis, and nonlinear simulation results (batch and piloted) for a longitudinal controller which is scheduled to be flight-tested on the High-Alpha Research Vehicle (HARV). The HARV is an F-18 airplane modified for and equipped with multi-axis thrust vectoring. The paper includes a description of the facilities, a detailed review of the feedback controller design, linear analysis results of the feedback controller, a description of the feed-forward controller design, nonlinear batch simulation results, and piloted simulation results. Batch simulation results include maximum pitch stick agility responses, angle of attack alpha captures, and alpha regulation for full lateral stick rolls at several alpha's. Piloted simulation results include task descriptions for several types of maneuvers, task guidelines, the corresponding Cooper-Harper ratings from three test pilots, and some pilot comments. The ratings show that desirable criteria are achieved for almost all of the piloted simulation tasks.

Ostroff, Aaron J.; Hoffler, Keith D.; Proffitt, Melissa S.; Brown, Philip W.; Phillips, Michael R.; Rivers, Robert A.; Messina, Michael D.; Carzoo, Susan W.; Bacon, Barton J.; Foster, John F.

1994-01-01

334

Building Operations Efficiencies into NASA's Ares I Crew Launch Vehicle Design  

NASA Technical Reports Server (NTRS)

The U.S. Vision for Space Exploration guides the National Aeronautics and Space Administration s (NASA's) challenging missions that expand humanity s boundaries and open new routes to the space frontier. With the Agency's commitment to complete the International Space Station (ISS) and to retire the venerable Space Shuttle by 2010, the NASA Administrator commissioned the Exploration Systems Architecture Study (ESAS) in mid 2005 to analyze options for safe, simple, cost-efficient launch solutions that could deliver human-rated space transportation capabilities in a timely manner within fixed budget guidelines. The Exploration Launch Projects Office, chartered in October 2005, has been conducting systems engineering studies and business planning over the past few months to successively refine the design configurations and better align vehicle concepts with customer and stakeholder requirements, such as significantly reduced life-cycle costs. As the Agency begins the process of replacing the Shuttle with a new generation of spacecraft destined for missions beyond low-Earth orbit to the Moon and Mars, NASA is designing the follow-on crew and cargo launch systems for maximum operational efficiencies. To sustain the long-term exploration of space, it is imperative to reduce the $4.5 billion NASA typically spends on space transportation each year. This paper gives top-level information about how the follow-on Ares I Crew Launch Vehicle (CLV) is being designed for improved safety and reliability, coupled with reduced operations costs.

Dumbacher, Daniel

2006-01-01

335

Weight and volume estimates for aluminum-air batteries designed for electric vehicle applications  

NASA Astrophysics Data System (ADS)

The weights and volumes of reactants, electrolyte, and hardware components are estimated for an aluminum-air battery designed for a 40-kW (peak), 70-kWh aluminum-air battery. Generalized equations are derived which express battery power and energy content as functions of total anode area, aluminum-anode weight, and discharge current density. Equations are also presented which express total battery weight and volume as linear combinations of the variables, anode area and anode weight. The sizing and placement of battery components within the engine compartment of typical five-passenger vehicles is briefly discussed.

Cooper, J. F.

1980-01-01

336

Multidisciplinary Design Technology Development: A Comparative Investigation of Integrated Aerospace Vehicle Design Tools  

NASA Technical Reports Server (NTRS)

This research effort is a joint program between the Departments of Aerospace and Mechanical Engineering and the Computer Science and Engineering Department at the University of Notre Dame. The purpose of the project was to develop a framework and systematic methodology to facilitate the application of Multidisciplinary Design Optimization (MDO) to a diverse class of system design problems. For all practical aerospace systems, the design of a systems is a complex sequence of events which integrates the activities of a variety of discipline "experts" and their associated "tools". The development, archiving and exchange of information between these individual experts is central to the design task and it is this information which provides the basis for these experts to make coordinated design decisions (i.e., compromises and trade-offs) - resulting in the final product design. Grant efforts focused on developing and evaluating frameworks for effective design coordination within a MDO environment. Central to these research efforts was the concept that the individual discipline "expert", using the most appropriate "tools" available and the most complete description of the system should be empowered to have the greatest impact on the design decisions and final design. This means that the overall process must be highly interactive and efficiently conducted if the resulting design is to be developed in a manner consistent with cost and time requirements. The methods developed as part of this research effort include; extensions to a sensitivity based Concurrent Subspace Optimization (CSSO) NMO algorithm; the development of a neural network response surface based CSSO-MDO algorithm; and the integration of distributed computing and process scheduling into the MDO environment. This report overviews research efforts in each of these focus. A complete bibliography of research produced with support of this grant is attached.

Renaud, John E.; Batill, Stephen M.; Brockman, Jay B.

1999-01-01

337

Hybrid Vehicle Turbine Engine Technology Support (HVTE-TS) ceramic design manual  

SciTech Connect

This ceramic component design manual was an element of the Advanced Turbine Technology Applications Project (ATTAP). The ATTAP was intended to advance the technological readiness of the ceramic automotive gas turbine engine as a primary power plant. Of the several technologies requiring development before such an engine could become a commercial reality, structural ceramic components represented the greatest technical challenge, and was the prime focus of the program. HVTE-TS, which was created to support the Hybrid Electric Vehicle (HEV) program, continued the efforts begun in ATTAP to develop ceramic components for an automotive gas turbine engine. In HVTE-TS, the program focus was extended to make this technology applicable to the automotive gas turbine engines that form the basis of hybrid automotive propulsion systems consisting of combined batteries, electric drives, and on-board power generators as well as a primary power source. The purpose of the ceramic design manual is to document the process by which ceramic components are designed, analyzed, fabricated, assembled, and tested in a gas turbine engine. Interaction with ceramic component vendors is also emphasized. The main elements of the ceramic design manual are: an overview of design methodology; design process for the AGT-5 ceramic gasifier turbine rotor; and references. Some reference also is made to the design of turbine static structure components to show methods of attaching static hot section ceramic components to supporting metallic structures.

NONE

1997-10-01

338

Concurrent Computational and Dimensional Analyses of Design of Vehicle Floor-Plates for Landmine-Blast Survivability  

NASA Astrophysics Data System (ADS)

Development of military vehicles capable of surviving landmine blast is seldom done using full-scale prototype testing because of the associated prohibitively-high cost, the destructive nature of testing, and the requirements for major large-scale experimental-test facilities and a large crew of engineers committed to the task. Instead, tests of small-scale models are generally employed and the model-based results are scaled up to the full-size vehicle. In these scale-up efforts, various dimensional analyses are used whose establishment and validation requires major experimental testing efforts and different-scale models. In the present work, an approach is proposed within which concurrent and interactive applications of the computational analyses (of landmine detonation and the interaction of detonation products and soil ejecta with the vehicle hull-floor) and the corresponding dimensional analysis are utilized. It is argued that this approach can guide the design of military-vehicle hull-floors which provide the required level of protection to the vehicle occupants under landmine blast attack without introducing unnecessarily high weight to the vehicle. To validate this approach, a combined Eulerian/Lagrangian formulation for landmine detonation and the interaction of detonation products and soil ejecta with the vehicle hull-floor (developed in our previous work) has been utilized along with the experimental results pertaining to small-scale model and full-scale vehicle testing.

Grujicic, M.; Cheeseman, B. A.

2014-01-01

339

Preliminary Subsystem Designs for the Assured Crew Return Vehicle (ACRV), volumes 1-3  

NASA Technical Reports Server (NTRS)

A long term manned facility in space must include provisions for the safety of the crew. The resolution of this need was the design of an Assured Crew Return Vehicle (ACRV). The main focus is on the braking and landing system of the ACRV. This subsystem of the ACRV was divided into three phases. The Phase 1 analysis showed that the use of a tether to aid in the reentry of the ACRV was infeasible due to cost and efficiency. Therefore, a standard rocket would be used for reentry. It was also found that the continental United States was an achievable landing site for the ACRV. The Phase 2 analysis determined the L/D of the vehicle to be 1.8, thus requiring the use of a lifting body for reentry. It was also determined that shuttle tiles would be used for the thermal protection system. In addition, a parachute sequence for further deceleration was included, namely a ringslot drogue chute, a pilot chute, and finally a ringsail main parachute. This sequence was found to be capable of slowing the vehicle to a descent velocity of 9 to 10 m/s, which is the required velocity for aerial recovery. The Phase 3 analysis proved that a Sikorsky CH-53E helicopter is capable of retrieving the ACRV at 5.5 km altitude with minimal g-forces induced on the ACRV and minimal induced moments on the helicopter upon hookup. The helicopter would be modified such that it could stabilize the ACRV close to the bottom of helicopter and carry it to the nearest designated trauma center.

1990-01-01

340

Design of an integral thermal protection system for future space vehicles  

NASA Astrophysics Data System (ADS)

Thermal protection systems (TPS) are the features incorporated into a spacecraft's design to protect it from severe aerodynamic heating during high-speed travel through planetary atmospheres. The ablative TPS on the space capsule Apollo and ceramic tiles and blankets on the Space Shuttle Orbiter were designed as add-ons to the main load-bearing structure of the vehicles. They are usually incompatible with the structure due to mismatch in coefficient of thermal expansion and as a result the robustness of the external surface of the spacecraft is compromised. This could potentially lead to catastrophic consequences because the TPS forms the external surface of the vehicle and is subjected to numerous other loads like aerodynamic pressure loads, small object high-speed impacts and handling damages during maintenance. In order to make the spacecraft external surface robust, an Integral Thermal Protection System (ITPS) concept has been proposed in this research in which the load-bearing structure and the TPS are combined into one single structure. The design of an ITPS is a formidable task because the requirement of a load-bearing structure and a TPS are often contradictory to one another. The design process has been formulated as an optimization problem with mass per unit area of the ITPS as the objective function and the various functions of the ITPS were formulated as constraints. This is a multidisciplinary design optimization problem involving heat transfer and structural analysis fields. The constraints were expressed as response surface approximations obtained from a large number of finite element analyses, which were carried out with combinations of design variables obtained from an optimized Latin-Hypercube sampling scheme. A MATLABRTM code has been developed to carry out these FE analyses automatically in conjunction with ABAQUSRTM . Corrugated-core structures were designed for ITPS applications with loads and boundary conditions similar to that of a Space Shuttle-like vehicle. Temperature, buckling, deflection and stress constraints were considered for the design process. An optimized mass ranging between 3.5--5 lb/ft2 was achieved by the design. This is considerably heavier when compared to conventional TPS designs. However, the ITPS can withstand substantially large mechanical loads when compared to the conventional TPS. Truss-core geometries used for ITPS design in this research were found to be unsuitable as they could not withstand large thermal gradients frequently encountered in ITPS applications. The corrugated-core design was used for further studying the influence of the various input parameters on the final design weight of the ITPS. It was observed that boundary conditions not only significantly influence the ITPS design but also have a major impact on the effect of various input parameters. It was found that even a small amount of heat loss from bottom face sheet leads to significant reduction in ITPS weight. Aluminum and Beryllium are the most suitable materials for bottom face sheet with Beryllium having considerable advantages in terms of heat capacity, stiffness and density. Although ceramic matrix composites have many superior properties when compared to metal alloys (Titanium alloys and Inconel), their low tensile strength presents difficulties in ITPS applications.

Bapanapalli, Satish Kumar

341

Design of a toy submarine using underwater vehicle design optimization framework  

Microsoft Academic Search

This paper presents a framework for optimum design of a small, low-cost, light-weight toy submarine for recre- ational purposes. Two state of the art optimization algorithms namely Non-dominated sorting genetic algorithm (NSGA-II) and Infeasibility driven evolutionary algorithm (IDEA) have been used in this study to carry out optimization of the toy submarine design. Single objective formulation of the toy submarine

Khairul Alam; Tapabrata Ray; Sreenatha G. Anavatti

2011-01-01

342

Euler Calculations at Off-Design Conditions for an Inlet of Inward Turning RBCC-SSTO Vehicle  

NASA Technical Reports Server (NTRS)

The inviscid performance of an inward turning inlet design is calculated computationally for the first time. Hypersonic vehicle designs based on the inward turning inlets have been shown analytically to have increased effective specific impulse and lower heat load than comparably designed vehicles with two-dimensional inlets. The inward turning inlets are designed inversely from inviscid stream surfaces of known flow fields. The computational study is performed on a Mach 12 inlet design to validate the performance predicted by the design code (HAVDAC) and calculate its off-design Mach number performance. The three-dimensional Euler equations are solved for Mach 4, 8, and 12 using a software package called SAM, which consists of an unstructured mesh generator (SAMmesh), a three-dimensional unstructured mesh flow solver (SAMcfd), and a CAD-based software (SAMcad). The computed momentum averaged inlet throat pressure is within 6% of the design inlet throat pressure. The mass-flux at the inlet throat is also within 7 % of the value predicted by the design code thereby validating the accuracy of the design code. The off-design Mach number results show that flow spillage is minimal, and the variation in the mass capture ratio with Mach number is comparable to an ideal 2-D inlet. The results from the inviscid flow calculations of a Mach 12 inward turning inlet indicate that the inlet design has very good on and off-design performance which makes it a promising design candidate for future air-breathing hypersonic vehicles.

Takashima, N.; Kothari, A. P.

1998-01-01

343

Multidisciplinary Design Technology Development: A Comparative Investigation of Integrated Aerospace Vehicle Design Tools  

NASA Technical Reports Server (NTRS)

This research effort is a joint program between the Departments of Aerospace and Mechanical Engineering and the Computer Science and Engineering Department at the University of Notre Dame. Three Principal Investigators; Drs. Renaud, Brockman and Batill directed this effort. During the four and a half year grant period, six Aerospace and Mechanical Engineering Ph.D. students and one Masters student received full or partial support, while four Computer Science and Engineering Ph.D. students and one Masters student were supported. During each of the summers up to four undergraduate students were involved in related research activities. The purpose of the project was to develop a framework and systematic methodology to facilitate the application of Multidisciplinary Design Optimization (N4DO) to a diverse class of system design problems. For all practical aerospace systems, the design of a systems is a complex sequence of events which integrates the activities of a variety of discipline "experts" and their associated "tools". The development, archiving and exchange of information between these individual experts is central to the design task and it is this information which provides the basis for these experts to make coordinated design decisions (i.e., compromises and trade-offs) - resulting in the final product design. Grant efforts focused on developing and evaluating frameworks for effective design coordination within a MDO environment. Central to these research efforts was the concept that the individual discipline "expert", using the most appropriate "tools" available and the most complete description of the system should be empowered to have the greatest impact on the design decisions and final design. This means that the overall process must be highly interactive and efficiently conducted if the resulting design is to be developed in a manner consistent with cost and time requirements. The methods developed as part of this research effort include; extensions to a sensitivity based Concurrent Subspace Optimization (CSSO) MDO algorithm; the development of a neural network response surface based CSSO-MDO algorithm; and the integration of distributed computing and process scheduling into the MDO environment. This report overviews research efforts in each of these focus. A complete bibliography of research produced with support of this grant is attached.

Renaud, John E.; Batill, Stephen M.; Brockman, Jay B.

1998-01-01

344

Design analysis of an aluminum-air battery for vehicle operations. Transportation systems research  

SciTech Connect

The objective of the study reported was to perform a detailed configuration analysis of an aluminum-air battery, evaluate various automobile propulsion systems utilizing the Al-air battery, and estimate the performance and cost of vehicles incorporating these propulsion systems. A preliminary engineering design is performed. A physical model and a cell-performance model of a conceptual mass-produced Al-air battery were constructed and work together to characterize the battery system. The physical battery model is based on a specific battery design concept and defines the mass and volume of a complete Al-air battery system. The cell-performance model simulates the electrical and electrochemical characteristics of the battery. The physical model and two versions of the cell-performance model - near-term and optimistic - were used in a vehicle-conversion analysis to evaluate three automotive propulsion systems - Al-air battery only, Al-air battery/secondary battery, and Al-air battery/flywheel. (LEW)

Behrin, E.; Wood, R.L.; Salisbury, J.D.; Whisler, D.J.; Hudson, C.L.

1983-03-18

345

Design and development considerations for biologically inspired flapping-wing micro air vehicles  

NASA Astrophysics Data System (ADS)

In this paper, the decade of numerical and experimental investigations leading to the development of the authors' unique flapping-wing micro air vehicle is summarized. Early investigations included the study of boundary layer energization by means of a small flapping foil embedded in a flat-plate boundary layer, the reduction of the recirculatory flow region behind a backward-facing step by means of a small flapping foil, and the reduction or suppression of flow separation behind blunt or cusped airfoil trailing edges by flapping a small foil located in the wake flow region. These studies were followed by systematic investigations of the aerodynamic characteristics of single flapping airfoils and airfoil combinations. These unsteady flows were described using flow visualization, laser-Doppler velocimetry in addition to panel and Navier-Stokes computations. It is then shown how this flapping-wing database was used to conceive, design and develop a micro air vehicle which has a fixed wing for lift and two flapping wings for thrust generation. While animal flight is characterized by a coupled force generation, the present design appears to separate lift and thrust. However, in fact, the performance of one surface is closely coupled to the other surfaces.

Jones, Kevin D.; Platzer, Max F.

346

Hardware-Based Non-Optimum Factors for Launch Vehicle Structural Design  

NASA Technical Reports Server (NTRS)

During aerospace vehicle conceptual and preliminary design, empirical non-optimum factors are typically applied to predicted structural component weights to account for undefined manufacturing and design details. Non-optimum factors are developed here for 32 aluminum-lithium 2195 orthogrid panels comprising the liquid hydrogen tank barrel of the Space Shuttle External Tank using measured panel weights and manufacturing drawings. Minimum values for skin thickness, axial and circumferential blade stiffener thickness and spacing, and overall panel thickness are used to estimate individual panel weights. Panel non-optimum factors computed using a coarse weights model range from 1.21 to 1.77, and a refined weights model (including weld lands and skin and stiffener transition details) yields non-optimum factors of between 1.02 and 1.54. Acreage panels have an average 1.24 non-optimum factor using the coarse model, and 1.03 with the refined version. The observed consistency of these acreage non-optimum factors suggests that relatively simple models can be used to accurately predict large structural component weights for future launch vehicles.

Wu, K. Chauncey; Cerro, Jeffrey A.

2010-01-01

347

Design of elevator control surface actuated by LIPCA for small unmanned air vehicle  

NASA Astrophysics Data System (ADS)

There have been persistent interests in high performance actuators suitable for the actuation of control surfaces of small aircraft and helicopter blades and for active vibration control of aerospace and submarine structures that need high specific force and displacement. What is really needed for active actuation is a large-displacement actuator with a compact source, i.e., much higher strain. A lot of effort has been made to develop compact actuators with large displacement at a high force. One of the representative actuator is LIPCA actuator that was introduced by Yoon et al. The LIPCA design offers the advantages to be applied as actuator for the small aerial vehicle comparing with any other actuators. The weight is one of the main concerns for aerospace field, and since LIPCA has lighter weight than any other piezo-actuator thus it is suitable as actuator for small aircraft control surface. In this paper, a conceptual design of LIPCA-actuated control surface is introduced. A finite element model was constructed and analyzed to predict the deflection angle of the control surface. The hinge moment that produced by the aerodynamic forces was calculated to determine the optimum position of the hinge point, which could produce the deflection as high as possible with reasonable hinge moment. To verify the prediction, a prototype of SUAV (small unmanned air vehicle) control surface was manufactured and tested both in static condition and in the wind tunnel. The prediction and test results showed a good agreement on the control surface deflection angle.

Yoon, K. J.; Setiawan, Hery; Goo, N. S.

2006-03-01

348

Design of overload vehicle monitoring and response system based on DSP  

NASA Astrophysics Data System (ADS)

The overload vehicles are making much more damage to the road surface than the regular ones. Many roads and bridges are equipped with structural health monitoring system (SHM) to provide early-warning to these damage and evaluate the safety of road and bridge. However, because of the complex nature of SHM system, it's expensive to manufacture, difficult to install and not well-suited for the regular bridges and roads. Based on this application background, this paper designs a compact structural health monitoring system based on DSP, which is highly integrated, low-power, easy to install and inexpensive to manufacture. The designed system is made up of sensor arrays, the charge amplifier module, the DSP processing unit, the alarm system for overload, and the estimate for damage of the road and bridge structure. The signals coming from sensor arrays go through the charge amplifier. DSP processing unit will receive the amplified signals, estimate whether it is an overload signal or not, and convert analog variables into digital ones so that they are compatible with the back-end digital circuit for further processing. The system will also restrict certain vehicles that are overweight, by taking image of the car brand, sending the alarm, and transferring the collected pressure data to remote data center for further monitoring analysis by rain-flow counting method.

Yu, Yan; Liu, Yiheng; Zhao, Xuefeng

2014-03-01

349

Robust, nonlinear, high angle-of-attack control design for a supermaneuverable vehicle  

NASA Technical Reports Server (NTRS)

High angle-of-attack flight control laws are developed for a supermaneuverable fighter aircraft. The methods of dynamic inversion and structured singular value synthesis are combined into an approach which addresses both the nonlinearity and robustness problems of flight at extreme operating conditions. The primary purpose of the dynamic inversion control elements is to linearize the vehicle response across the flight envelope. Structured singular value synthesis is used to design a dynamic controller which provides robust tracking to pilot commands. The resulting control system achieves desired flying qualities and guarantees a large margin of robustness to uncertainties for high angle-of-attack flight conditions. The results of linear simulation and structured singular value stability analysis are presented to demonstrate satisfaction of the design criteria. High fidelity nonlinear simulation results show that the combined dynamics inversion/structured singular value synthesis control law achieves a high level of performance in a realistic environment.

Adams, Richard J.

1993-01-01

350

Design and performance analysis of an aero-maneuvering orbital-transfer vehicle concept  

NASA Technical Reports Server (NTRS)

Systems requirements for design-optimized, lateral-turn performance were determined for reusable, space-based applications and low-Earth orbits involving large multiple plane-inclination changes. The aerothermodynamic analysis is the most advanced available for rarefield-hypersonic flow over lifting surfaces at incidence. The effects of leading-edge bluntness, low-density viscous phenomena, and finite-rate flow-field chemistry and surface catalysis are accounted for. The predicted aerothermal heating characteristics are correlated with thermal-control and flight-performance capabilities. The mission payload capacity for delivery, retrieval, and combined operations was determined for round-trip sorties extending to polar orbits. Recommendations are given for future design refinements. The results help to identify technology issues required to develop prototype operational vehicles.

Menees, G. P.

1985-01-01

351

Design and Performance Analysis of a Conical Aerobrake Orbital Transfer Vehicle Concept  

NASA Technical Reports Server (NTRS)

A Shuttle-compatible systems design based on the core concept of attachable modules for the major vehicle components is proposed. The principal features include a disposable cargo/extra-propellant tank module; a porous, radiative, back-scattering drag-brake surface material of thin silica cloth; and a lightweight carbon-composite support structure. The mission payload capability for delivery, retrieval, and combined operations is determined for a broad range of missions including NASA/DOD requirements and extending through cislunar space. The effects of finite-rate surface catalysis, negative lift, and multiple atmospheric passes in reducing the aerothermodynamic heating rates are also investigated. In addition, the structural and thermal protection problems of the drag-brake support apparatus are analyzed, and recommendations are proposed for future design refinements.

Menees, Gene P.; Park, Chul; Wilson, John F.

1985-01-01

352

Design and performance analysis of an aeromaneuvering orbital-transfer vehicle concept  

NASA Astrophysics Data System (ADS)

Systems requirements for design-optimized, lateral-turn performance were determined for reusable, space-based applications and low-earth orbits involving large multiple plane-inclination changes. The aerothermodynamic analysis is the most advanced available for rarefied-hypersonic flow over lifting surfaces at incidence. The effects of leading-edge bluntness, low-density viscous phenomena, and finite-rate flow-field chemistry and surface catalysis are accounted for. The predicted aerothermal heating characteristics are correlated with thermal-control and flight-performance capabilities. The mission payload capacity for delivery, retrieval, and combined operations was determined for round-trip sorties extending to polar orbits. Recommendations are given for future design refinements. The results help to identify technology issues required to develop prototype operational vehicles.

Menees, G. P.

1985-10-01

353

Statistical methods for launch vehicle guidance, navigation, and control (GN&C) system design and analysis  

NASA Astrophysics Data System (ADS)

A novel trajectory and attitude control and navigation analysis tool for powered ascent is developed. The tool is capable of rapid trade-space analysis and is designed to ultimately reduce turnaround time for launch vehicle design, mission planning, and redesign work. It is streamlined to quickly determine trajectory and attitude control dispersions, propellant dispersions, orbit insertion dispersions, and navigation errors and their sensitivities to sensor errors, actuator execution uncertainties, and random disturbances. The tool is developed by applying both Monte Carlo and linear covariance analysis techniques to a closed-loop, launch vehicle guidance, navigation, and control (GN&C) system. The nonlinear dynamics and flight GN&C software models of a closed-loop, six-degree-of-freedom (6-DOF), Monte Carlo simulation are formulated and developed. The nominal reference trajectory (NRT) for the proposed lunar ascent trajectory is defined and generated. The Monte Carlo truth models and GN&C algorithms are linearized about the NRT, the linear covariance equations are formulated, and the linear covariance simulation is developed. The performance of the launch vehicle GN&C system is evaluated using both Monte Carlo and linear covariance techniques and their trajectory and attitude control dispersion, propellant dispersion, orbit insertion dispersion, and navigation error results are validated and compared. Statistical results from linear covariance analysis are generally within 10% of Monte Carlo results, and in most cases the differences are less than 5%. This is an excellent result given the many complex nonlinearities that are embedded in the ascent GN&C problem. Moreover, the real value of this tool lies in its speed, where the linear covariance simulation is 1036.62 times faster than the Monte Carlo simulation. Although the application and results presented are for a lunar, single-stage-to-orbit (SSTO), ascent vehicle, the tools, techniques, and mathematical formulations that are discussed are applicable to ascent on Earth or other planets as well as other rocket-powered systems such as sounding rockets and ballistic missiles.

Rose, Michael Benjamin

354

Nozzle design study for a quasi-axisymmetric scramjet-powered vehicle at Mach 7.9 flight conditions  

NASA Astrophysics Data System (ADS)

A nozzle shape optimization study for a quasi-axisymmetric scramjet has been performed for a Mach 7.9 operating condition with hydrogen fuel, aiming at the application of a hypersonic airbreathing vehicle. In this study, the nozzle geometry which is parameterized by a set of design variables, is optimized for the single objective of maximum net thrust using an in-house CFD solver for inviscid flowfields with a simple force prediction methodology. The combustion is modelled using a simple chemical reaction code. The effects of the nozzle design on the overall vehicle performance are discussed. For the present geometry, net thrust is achieved for the optimized vehicle design. The results of the nozzle-optimization study show that performance is limited by the nozzle area ratio that can be incorporated into the vehicle without leading to too large a base diameter of the vehicle and increasing the external drag of the vehicle. This study indicates that it is very difficult to achieve positive thrust at Mach 7.9 using the basic geometry investigated.

Tanimizu, Katsuyoshi; Mee, David J.; Stalker, Raymond J.; Jacobs, Peter A.

2013-09-01

355

Design optimization of an axial gap permanent magnet brushless dc motor for electric vehicle applications  

SciTech Connect

This paper describes a method of design and multiobjective optimization of an axial field permanent magnet brushless dc machine (BDCM), primarily aimed for electric vehicle propulsion applications. The disc type permanent magnet brushless dc motor has two stator windings connected in parallel with its rotor sandwiched between them. The simplified design equations for an axial gap trapezoidal back emf motor are obtained and programmed using the software package QPRO. Then using classical design approach, design parameters for a 100 Hp, 3,200 Rpm, 216 Volts BDCM are obtained. This design configuration is then used as the starting design point for the multiobjective optimization process, where the objective is to maximize the efficiency and the specific power.The feasibility frontier is obtained as a set of optimal solutions, from which a most suitable design parameters can be selected depending on the user preferences. A specific power as high as 4.54 Hp/Lb. (at 94% efficiency) and an efficiency as high as 98.06% (at specific power of 0.69 Hp/Lb.) have been achieved during the optimization process. The cost factors in the respective cases being 223$ and 649$. A very high and relatively flat efficiency curve over the torque speed plane is also achieved during the process, especially when the weighting coefficient related to efficiency function is made bigger. Advantage of this method is that much time is saved in developing the optimization program. Also, the motor design engineer does not have to be an expert in optimization theory in order to obtain a superior design with a very short time.

Wijenayake, A.H.; Bailey, J.M. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Electrical and Computer Engineering; McCleer, P.J. [McCleer Power Inc., Jackson, MI (United States)

1995-12-31

356

An omni-directional design tool for series hybrid electric vehicle design  

E-print Network

??????????????????????????????.. 101 viii LIST OF TABLES P age Table 1: Average power with full and no regenerative braking for different drive cycles???????????????????????.???? 39 Table 2: Freedoms of the new design tool and possible... versus time................................. 25 11 Instantaneous power and average power with full and zero regenerative braking in some typical driving cycles ......................................................... 27 12 Variation...

Shidore, Neeraj Shripad

2005-02-17

357

Kandler Smith, NREL EDV Battery Robust Design -1 Design of Electric Drive Vehicle  

E-print Network

and energy performance requirements at the end-of-life · HEVs: only 10% to 25% of energy is used · Toyota EDV Battery Robust Design - 5 Performance Life Cost Safety Requirements Multi-Scale Physics in Li for Long Life and Low Cost Robustness to Geographic and Consumer-Usage Variation Kandler Smith* Tony Markel

358

Modeling and inverse controller design for an unmanned aerial vehicle based on the self-organizing map  

Microsoft Academic Search

The next generation of aircraft will have dynamics that vary considerably over the operating regime. A single controller will have difficulty to meet the design specifications. In this paper, a self-organizing map (SOM)-based local linear modeling scheme of an unmanned aerial vehicle (UAV) is developed to design a set of inverse controllers. The SOM selects the operating regime depending only

Jeongho Cho; José Carlos Príncipe; Deniz Erdogmus; Mark A. Motter

2006-01-01

359

Near-term hybrid vehicle program, phase 1. Appendix B: Design trade-off studies report. Volume 2: Supplement to design trade-off studies  

NASA Technical Reports Server (NTRS)

Results of studies leading to the preliminary design of a hybrid passenger vehicle which is projected to have the maximum potential for reducing petroleum consumption in the near term are presented. Heat engine/electric hybrid vehicle tradeoffs, assessment of battery power source, and weight and cost analysis of key components are among the topics covered. Performance of auxiliary equipment, such as power steering, power brakes, air conditioning, lighting and electrical accessories, heating and ventilation is discussed along with the selection of preferred passenger compartment heating procedure for the hybrid vehicle. Waste heat from the engine, thermal energy storage, and an auxiliary burner are among the approaches considered.

1979-01-01

360

Design and Implementation of a Biomimetic Turtle Hydrofoil for an Autonomous Underwater Vehicle  

PubMed Central

This paper presents the design and implementation of a turtle hydrofoil for an Autonomous Underwater Vehicle (AUV). The final design of the AUV must have navigation performance like a turtle, which has also been the biomimetic inspiration for the design of the hydrofoil and propulsion system. The hydrofoil design is based on a National Advisory Committee for Aeronautics (NACA) 0014 hydrodynamic profile. During the design stage, four different propulsion systems were compared in terms of propulsion path, compactness, sealing and required power. The final implementation is based on a ball-and-socket mechanism because it is very compact and provides three degrees of freedom (DoF) to the hydrofoil with very few restrictions on the propulsion path. The propulsion obtained with the final implementation of the hydrofoil has been empirically evaluated in a water channel comparing different motion strategies. The results obtained have confirmed that the proposed turtle hydrofoil controlled with a mechanism with three DoF generates can be used in the future implementation of the planned AUV. PMID:22247660

Font, Davinia; Tresanchez, Marcel; Siegentahler, Cedric; Palleja, Tomas; Teixido, Merce; Pradalier, Cedric; Palacin, Jordi

2011-01-01

361

Design Evolution and Performance Characterization of the GTX Air-Breathing Launch Vehicle Inlet  

NASA Technical Reports Server (NTRS)

The design and analysis of a second version of the inlet for the GTX rocket-based combine-cycle launch vehicle is discussed. The previous design did not achieve its predicted performance levels due to excessive turning of low-momentum comer flows and local over-contraction due to asymmetric end-walls. This design attempts to remove these problems by reducing the spike half-angle to 10- from 12-degrees and by implementing true plane of symmetry end-walls. Axisymmetric Reynolds-Averaged Navier-Stokes simulations using both perfect gas and real gas, finite rate chemistry, assumptions were performed to aid in the design process and to create a comprehensive database of inlet performance. The inlet design, which operates over the entire air-breathing Mach number range from 0 to 12, and the performance database are presented. The performance database, for use in cycle analysis, includes predictions of mass capture, pressure recovery, throat Mach number, drag force, and heat load, for the entire Mach range. Results of the computations are compared with experimental data to validate the performance database.

DeBonis, J. R.; Steffen, C. J., Jr.; Rice, T.; Trefny, C. J.

2002-01-01

362

Design and implementation of a biomimetic turtle hydrofoil for an autonomous underwater vehicle.  

PubMed

This paper presents the design and implementation of a turtle hydrofoil for an Autonomous Underwater Vehicle (AUV). The final design of the AUV must have navigation performance like a turtle, which has also been the biomimetic inspiration for the design of the hydrofoil and propulsion system. The hydrofoil design is based on a National Advisory Committee for Aeronautics (NACA) 0014 hydrodynamic profile. During the design stage, four different propulsion systems were compared in terms of propulsion path, compactness, sealing and required power. The final implementation is based on a ball-and-socket mechanism because it is very compact and provides three degrees of freedom (DoF) to the hydrofoil with very few restrictions on the propulsion path. The propulsion obtained with the final implementation of the hydrofoil has been empirically evaluated in a water channel comparing different motion strategies. The results obtained have confirmed that the proposed turtle hydrofoil controlled with a mechanism with three DoF generates can be used in the future implementation of the planned AUV. PMID:22247660

Font, Davinia; Tresanchez, Marcel; Siegentahler, Cedric; Pallejà, Tomàs; Teixidó, Mercè; Pradalier, Cedric; Palacin, Jordi

2011-01-01

363

Aerodynamic Design Criteria for Class 8 Heavy Vehicles Trailer Base Devices to Attain Optimum Performance  

SciTech Connect

Lawrence Livermore National Laboratory (LLNL) as part of its Department of Energy (DOE), Energy Efficiency and Renewable Energy (EERE), and Vehicle Technologies Program (VTP) effort has investigated class 8 tractor-trailer aerodynamics for many years. This effort has identified many drag producing flow structures around the heavy vehicles and also has designed and tested many new active and passive drag reduction techniques and concepts for significant on the road fuel economy improvements. As part of this effort a database of experimental, computational, and conceptual design for aerodynamic drag reduction devices has been established. The objective of this report is to provide design guidance for trailer base devices to improve their aerodynamic performance. These devices are commonly referred to as boattails, base flaps, tail devices, and etc. The information provided here is based on past research and our most recent full-scale experimental investigations in collaboration with Navistar Inc. Additional supporting data from LLNL/Navistar wind tunnel, track test, and on the road test will be published soon. The trailer base devices can be identified by 4 flat panels that are attached to the rear edges of the trailer base to form a closed cavity. These devices have been engineered in many different forms such as, inflatable and non-inflatable, 3 and 4-sided, closed and open cavity, and etc. The following is an in-depth discussion with some recommendations, based on existing data and current research activities, of changes that could be made to these devices to improve their aerodynamic performance. There are 6 primary factors that could influence the aerodynamic performance of trailer base devices: (1) Deflection angle; (2) Boattail length; (3) Sealing of edges and corners; (4) 3 versus 4-sided, Position of the 4th plate; (5) Boattail vertical extension, Skirt - boattail transition; and (6) Closed versus open cavity.

Salari, K; Ortega, J

2010-12-13

364

Design considerations for a lithium-aluminum/iron sulfide electric vehicle battery  

NASA Astrophysics Data System (ADS)

A study has been made of battery-vehicle design interactions using a Toyota Carina converted to electric drive with a Li-Al/FeS battery used as a power and energy source. Energy and power requirements were calculated based on a range of 120 or 200 km with acceleration requirements typical of today's internal-combustion automobiles. Cell modeling analysis was employed to relate the specific energy of the battery to its power capability in terms of the P/E ratio, and this relationship was then used to estimate the battery weight and volume. Based on the results of the study, the specifications and performance of a compact electric automobile have been derived. It is concluded that, when fully developed, the Li-Al/FeS battery can provide a power source of high energy and power density for a personal electric vehicle. The battery is safe, rugged, requires no maintenance, and may offer the possibility of range extension through quick recharge.

Chilenskas, A. A.; Gay, E. C.; Shimotake, H.; Barney, D. L.; Kawahara, K.; Goto, K.

365

Solar Electric Propulsion Technologies Being Designed for Orbit Transfer Vehicle Applications  

NASA Technical Reports Server (NTRS)

There is increasing interest in employing Solar Electric Propulsion (SEP) for new missions requiring transfer from low Earth orbit to the Earth-Moon Lagrange point, L1. Mission architecture plans place the Gateway Habitat at L1 in the 2011 to 2016 timeframe. The Gateway Habitat is envisioned to be used for Lunar exploration, space telescopes, and planetary mission staging. In these scenarios, an SEP stage, or "tug," is used to transport payloads to L1--such as the habitat module, lunar excursion and return vehicles, and chemical propellant for return crew trips. SEP tugs are attractive because they are able to efficiently transport large (less than 10,000 kg) payloads while minimizing propellant requirements. To meet the needs of these missions, a preliminary conceptual design for a general-purpose SEP tug was developed that incorporates several of the advanced space power and in-space propulsion technologies (such as high-power gridded ion and Hall thrusters, high-performance thin-film photovoltaics, lithium-ion batteries, and advanced high-voltage power processing) being developed at the NASA Glenn Research Center. A spreadsheet-based vehicle system model was developed for component sizing and is currently being used for mission planning. This model incorporates a low-thrust orbit transfer algorithm to make preliminary determinations of transfer times and propellant requirements. Results from this combined tug mass estimation and orbit transfer model will be used in a higher fidelity trajectory model to refine the analysis.

Sarver-Verhey, Timothy R.; Hoffman, David J.; Kerslake, Thomas W.; Oleson, Steven R.; Falck, Robert D.

2002-01-01

366

Design, building, and testing of the postlanding systems for the assured crew return vehicle  

NASA Technical Reports Server (NTRS)

The design, building, and testing of the postlanding support systems for a water-landing Assured Crew Return Vehicle (ACRV) are presented. One ACRV will be permanently docked to Space Station Freedom, fulfilling NASA's commitment to Assured Crew Return Capability in the event of an accident or illness. The configuration of the ACRV is based on an Apollo Command Module (ACM) derivative. The 1990-1991 effort concentrated on the design, building, and testing of a one-fifth scale model of the egress and stabilization systems. The objective was to determine the feasibility of (1) stabilizing the ACM out of the range of motions that cause seasickness and (2) the safe and rapid removal of a sick or injured crew member from the ACRV. The development of the ACRV postlanding systems model was performed at the University of Central Florida with guidance from the Kennedy Space Center ACRV program managers. Emphasis was placed on four major areas. First was design and construction of a one-fifth scale model of the ACM derivative to accommodate the egress and stabilization systems for testing. Second was the identification of a water test facility suitable for testing the model in all possible configurations. Third was the construction of the rapid egress mechanism designed in the previous academic year for incorporation into the ACRV model. The fourth area was construction and motion response testing of the attitude ring and underwater parachute systems.

Hosterman, Kenneth C.; Anderson, Loren A.

1991-01-01

367

Integrated Optimization of Airframe Design and Flight Trajectory for Advanced Space Transportation Vehicle  

NASA Astrophysics Data System (ADS)

Authors have been attempting to develop a multidisciplinary design optimization tool for a large-scale system using Genetic Algorithm (GA), and to apply this tool to the integrated optimization problem of the airframe design and its flight trajectory for an advanced space transportation vehicle that is a spaceplane. The results of the latest calculation for the problem above obtained by the developed tool showed that airframes (solutions) converged on four areas in the solution space and sensitivity of design variables of the airframe shape was remarkably different in each convergence area. Although high-ranking solutions having good value of the performance index have various airframe configurations, those flight trajectories hardly changed. The best solution showed that it is necessary to reduce the weights of airframe components and to improve the performance of air-breathing engine for realizing a feasible airframe size. It is suggested that this tool is absolutely useful for searching a solution at the conceptual designing phase of a spaceplane.

Motohashi, Kazuhiro; Yoshida, Hiroaki; Yamaguchi, Katsuhito; Ishikawa, Yoshio

368

Design considerations to improve cognitive ergonomic issues of unmanned vehicle interfaces utilizing video game controllers.  

PubMed

Unmanned (UAVs, UCAVs, and UGVs) systems still have major human factors and ergonomic challenges related to the effective design of their control interface systems, crucial to their efficient operation, maintenance, and safety. Unmanned system interfaces with a human centered approach promote intuitive interfaces that are easier to learn, and reduce human errors and other cognitive ergonomic issues with interface design. Automation has shifted workload from physical to cognitive, thus control interfaces for unmanned systems need to reduce mental workload on the operators and facilitate the interaction between vehicle and operator. Two-handed video game controllers provide wide usability within the overall population, prior exposure for new operators, and a variety of interface complexity levels to match the complexity level of the task and reduce cognitive load. This paper categorizes and provides taxonomy for 121 haptic interfaces from the entertainment industry that can be utilized as control interfaces for unmanned systems. Five categories of controllers were based on the complexity of the buttons, control pads, joysticks, and switches on the controller. This allows the selection of the level of complexity needed for a specific task without creating an entirely new design or utilizing an overly complex design. PMID:22317628

Oppold, P; Rupp, M; Mouloua, M; Hancock, P A; Martin, J

2012-01-01

369

The Role of Design-of-Experiments in Managing Flow in Compact Air Vehicle Inlets  

NASA Technical Reports Server (NTRS)

It is the purpose of this study to demonstrate the viability and economy of Design-of-Experiments methodologies to arrive at microscale secondary flow control array designs that maintain optimal inlet performance over a wide range of the mission variables and to explore how these statistical methods provide a better understanding of the management of flow in compact air vehicle inlets. These statistical design concepts were used to investigate the robustness properties of low unit strength micro-effector arrays. Low unit strength micro-effectors are micro-vanes set at very low angles-of-incidence with very long chord lengths. They were designed to influence the near wall inlet flow over an extended streamwise distance, and their advantage lies in low total pressure loss and high effectiveness in managing engine face distortion. The term robustness is used in this paper in the same sense as it is used in the industrial problem solving community. It refers to minimizing the effects of the hard-to-control factors that influence the development of a product or process. In Robustness Engineering, the effects of the hard-to-control factors are often called noise , and the hard-to-control factors themselves are referred to as the environmental variables or sometimes as the Taguchi noise variables. Hence Robust Optimization refers to minimizing the effects of the environmental or noise variables on the development (design) of a product or process. In the management of flow in compact inlets, the environmental or noise variables can be identified with the mission variables. Therefore this paper formulates a statistical design methodology that minimizes the impact of variations in the mission variables on inlet performance and demonstrates that these statistical design concepts can lead to simpler inlet flow management systems.

Anderson, Bernhard H.; Miller, Daniel N.; Gridley, Marvin C.; Agrell, Johan

2003-01-01

370

Design and characterization of Hover Nano Aerial Vehicle (HNAV) propulsion system  

E-print Network

On October 4th 2005, DARPA released a request for proposals for a Nano-Air Vehicle (NAV) program. The program sought to develop an advanced urban reconnaissance vehicle. According the requirement imposed by DARPA, the NAV ...

Sato, Sho, Ph. D. Massachusetts Institute of Technology

2008-01-01

371

A methodology for the validated design space exploration of fuel cell powered unmanned aerial vehicles  

NASA Astrophysics Data System (ADS)

Unmanned Aerial Vehicles (UAVs) are the most dynamic growth sector of the aerospace industry today. The need to provide persistent intelligence, surveillance, and reconnaissance for military operations is driving the planned acquisition of over 5,000 UAVs over the next five years. The most pressing need is for quiet, small UAVs with endurance beyond what is capable with advanced batteries or small internal combustion propulsion systems. Fuel cell systems demonstrate high efficiency, high specific energy, low noise, low temperature operation, modularity, and rapid refuelability making them a promising enabler of the small, quiet, and persistent UAVs that military planners are seeking. Despite the perceived benefits, the actual near-term performance of fuel cell powered UAVs is unknown. Until the auto industry began spending billions of dollars in research, fuel cell systems were too heavy for useful flight applications. However, the last decade has seen rapid development with fuel cell gravimetric and volumetric power density nearly doubling every 2--3 years. As a result, a few design studies and demonstrator aircraft have appeared, but overall the design methodology and vehicles are still in their infancy. The design of fuel cell aircraft poses many challenges. Fuel cells differ fundamentally from combustion based propulsion in how they generate power and interact with other aircraft subsystems. As a result, traditional multidisciplinary analysis (MDA) codes are inappropriate. Building new MDAs is difficult since fuel cells are rapidly changing in design, and various competitive architectures exist for balance of plant, hydrogen storage, and all electric aircraft subsystems. In addition, fuel cell design and performance data is closely protected which makes validation difficult and uncertainty significant. Finally, low specific power and high volumes compared to traditional combustion based propulsion result in more highly constrained design spaces that are problematic for design space exploration. To begin addressing the current gaps in fuel cell aircraft development, a methodology has been developed to explore and characterize the near-term performance of fuel cell powered UAVs. The first step of the methodology is the development of a valid MDA. This is accomplished by using propagated uncertainty estimates to guide the decomposition of a MDA into key contributing analyses (CAs) that can be individually refined and validated to increase the overall accuracy of the MDA. To assist in MDA development, a flexible framework for simultaneously solving the CAs is specified. This enables the MDA to be easily adapted to changes in technology and the changes in data that occur throughout a design process. Various CAs that model a polymer electrolyte membrane fuel cell (PEMFC) UAV are developed, validated, and shown to be in agreement with hardware-in-the-loop simulations of a fully developed fuel cell propulsion system. After creating a valid MDA, the final step of the methodology is the synthesis of the MDA with an uncertainty propagation analysis, an optimization routine, and a chance constrained problem formulation. This synthesis allows an efficient calculation of the probabilistic constraint boundaries and Pareto frontiers that will govern the design space and influence design decisions relating to optimization and uncertainty mitigation. A key element of the methodology is uncertainty propagation. The methodology uses Systems Sensitivity Analysis (SSA) to estimate the uncertainty of key performance metrics due to uncertainties in design variables and uncertainties in the accuracy of the CAs. A summary of SSA is provided and key rules for properly decomposing a MDA for use with SSA are provided. Verification of SSA uncertainty estimates via Monte Carlo simulations is provided for both an example problem as well as a detailed MDA of a fuel cell UAV. Implementation of the methodology was performed on a small fuel cell UAV designed to carry a 2.2 kg payload with 24 hours of endurance. Uncertainty distributions for both design

Moffitt, Blake Almy

372

Use of Probabilistic Engineering Methods in the Detailed Design and Development Phases of the NASA Ares Launch Vehicle  

NASA Technical Reports Server (NTRS)

The United States National Aeronautics and Space Administration (NASA) is in the midst of a space exploration program called Constellation to send crew and cargo to the international Space Station, to the moon, and beyond. As part of the Constellation program, a new launch vehicle, Ares I, is being developed by NASA Marshall Space Flight Center. Designing a launch vehicle with high reliability and increased safety requires a significant effort in understanding design variability and design uncertainty at the various levels of the design (system, element, subsystem, component, etc.) and throughout the various design phases (conceptual, preliminary design, etc.). In a previous paper [1] we discussed a probabilistic functional failure analysis approach intended mainly to support system requirements definition, system design, and element design during the early design phases. This paper provides an overview of the application of probabilistic engineering methods to support the detailed subsystem/component design and development as part of the "Design for Reliability and Safety" approach for the new Ares I Launch Vehicle. Specifically, the paper discusses probabilistic engineering design analysis cases that had major impact on the design and manufacturing of the Space Shuttle hardware. The cases represent important lessons learned from the Space Shuttle Program and clearly demonstrate the significance of probabilistic engineering analysis in better understanding design deficiencies and identifying potential design improvement for Ares I. The paper also discusses the probabilistic functional failure analysis approach applied during the early design phases of Ares I and the forward plans for probabilistic design analysis in the detailed design and development phases.

Fayssal, Safie; Weldon, Danny

2008-01-01

373

Design of an Autonomous Underwater Vehicle to Calibrate the Europa Clipper Ice-Penetrating Radar  

NASA Astrophysics Data System (ADS)

Jupiter's moon Europa has been prioritized as the target for the Europa Clipper flyby mission. A key science objective for the mission is to remotely characterize the ice shell and any subsurface water, including their heterogeneity, and the nature of surface-ice-ocean exchange. This objective is a critical component of the mission's overarching goal of assessing the habitability of Europa. The instrument targeted for addressing key aspects of this goal is an ice-penetrating radar (IPR). As a primary goal of our work, we will tightly couple airborne IPR studies of the Ross Ice Shelf by the Europa Clipper radar team with ground-truth data to be obtained from sub-glacial sonar and bio-geochemical mapping of the corresponding ice-water and water-rock interfaces using an advanced autonomous underwater vehicle (AUV). The ARTEMIS vehicle - a heavily morphed long-range, low drag variant of the highly successful 4-degree-of-freedom hovering sub-ice ENDURANCE bot -- will be deployed from a sea-ice drill hole adjacent the McMurdo Ice Shelf (MIS) and will perform three classes of missions. The first includes original exploration and high definition mapping of both the ice-water interface and the benthic interface on a length scale (approximately 10 kilometers under-ice penetration radius) that will definitively tie it to the synchronous airborne IPR over-flights. These exploration and mapping missions will be conducted at up to 10 different locations along the MIS in order to capture varying ice thickness and seawater intrusion into the ice shelf. Following initial mapping characterization, the vehicle will conduct astrobiology-relevant proximity operations using bio-assay sensors (custom-designed UV fluorescence and machine-vision-processed optical imagery) followed by point-targeted studies at regions of interest. Sample returns from the ice-water interface will be triggered autonomously using real-time-processed instrument data and onboard decision-to-collect algorithms. ARTEMIS will be capable of conducting precision hovering proximity science in an unexplored environment, followed by high speed (1.5 m/s) return to the melt hole. The navigation system will significantly advance upon the successes of the prior DEPTHX and ENDURANCE systems and several novel pose-drift correction technologies will be developed and tested under ice during the project. The method of down-hole deployment and auto-docking return will be extended to a vertically-deployed, horizontally-recovered concept that is depth independent and highly relevant to an ice-water deployment on an icy moon. The presentation will discuss the mission down-select architecture for the ARTEMIS vehicle and its implications for the design of a Europa 'fast mover' carrier AUV, the onboard instrument suite, and the Antarctic mission CONOPS. The vehicle and crew will deploy to Antarctica in the 2015/2016 season.

Stone, W.; Siegel, V.; Kimball, P.; Richmond, K.; Flesher, C.; Hogan, B.; Lelievre, S.

2013-12-01

374

Conceptual design of a hypervelocity asteroid intercept vehicle (HAIV) and its flight validation mission  

NASA Astrophysics Data System (ADS)

An intercept mission with nuclear explosives is the most effective of the practical mitigation options against the impact threat of near-Earth objects (NEOs) with a short warning time (e.g., much less than 10 years). The existing penetrated subsurface nuclear explosion technology limits the intercept velocity to less than approximately 300 m/s. Consequently, an innovative concept of blending a hypervelocity kinetic impactor with a subsurface nuclear explosion has been developed for optimal penetration, fragmentation, and dispersion of the target NEO. A proposed hypervelocity asteroid intercept vehicle (HAIV) consists of a kinetic-impact leader spacecraft and a follower spacecraft carrying nuclear explosives. This paper describes the conceptual development and design of a baseline HAIV system and its flight validation mission architecture for three mission cost classifications (e.g., 500 M, 1 B, and $1.5 B).

Pitz, A.; Kaplinger, B.; Vardaxis, G.; Winkler, T.; Wie, B.

2014-01-01

375

Autonomous Underwater Vehicle Survey Design for Monitoring Carbon Capture and Storage Sites  

NASA Astrophysics Data System (ADS)

Long-term monitoring of sub-seabed Carbon Capture and Storage (CCS) sites will require systems that are flexible, independent, and have long-endurance. In this presentation we will discuss the utility of autonomous underwater vehicles equipped with different sensor packages in monitoring storage sites. We will present data collected using Autosub AUV, as part of the ECO2 project, from the Sleipner area of the North Sea. The Autosub AUV was equipped with sidescan sonar, an EM2000 multibeam systems, a Chirp sub-bottom profiler, and a variety of chemical sensors. Our presentation will focus on survey design, and the simultaneous use of multiple sensor packages in environmental monitoring on the continental shelf.

Bull, J. M.; Cevatoglu, M.; Connelly, D.; Wright, I. C.; McPhail, S.; Shitashima, K.

2013-12-01

376

Novel transport-vehicle design for moving optic modules in the National Ignition Facility  

SciTech Connect

The National Ignition Facility, currently under design and construction at Lawrence Livermore National Laboratory, will be the world`s largest laser when complete. The NIF will use about 8,000 large optics of 26 different types to focus up to 192 laser beams on a dime-size target. Given the constraints of the NIF operating environment, the tasks associated with optics transport and handling require a novel, versatile transport system. The system will consist of a computer system containing guidance, traffic management and order entry functions, and four or more automated laser-guided vehicles. This transport system will transport optics enclosures that are essentially portable clean rooms and will lift, align, and position them as needed to contact and engage mating points on the laser support structure.

Grasz, E.; Tiszauer, D.

1998-05-07

377

Analysis, Design and Optimization of Non-Cylindrical Fuselage for Blended-Wing-Body (BWB) Vehicle  

NASA Technical Reports Server (NTRS)

Initial results of an investigation towards finding an efficient non-cylindrical fuselage configuration for a conceptual blended-wing-body flight vehicle were presented. A simplified 2-D beam column analysis and optimization was performed first. Then a set of detailed finite element models of deep sandwich panel and ribbed shell construction concepts were analyzed and optimized. Generally these concepts with flat surfaces were found to be structurally inefficient to withstand internal pressure and resultant compressive loads simultaneously. Alternatively, a set of multi-bubble fuselage configuration concepts were developed for balancing internal cabin pressure load efficiently, through membrane stress in inner-stiffened shell and inter-cabin walls. An outer-ribbed shell was designed to prevent buckling due to external resultant compressive loads. Initial results from finite element analysis appear to be promising. These concepts should be developed further to exploit their inherent structurally efficiency.

Mukhopadhyay, V.; Sobieszczanski-Sobieski, J.; Kosaka, I.; Quinn, G.; Charpentier, C.

2002-01-01

378

The role of fracture mechanics in the design of fuel tanks in space vehicles  

NASA Technical Reports Server (NTRS)

With special reference to design of fuel tanks in space vehicles, the principles of fracture mechanics are reviewed. An approximate but extremely simple relationship is derived among the operating stress level, the length of crack, and the number of cycles of failure. Any one of the variables can be computed approximately from the knowledge of the other two, if the loading schedule (mission of the tank) is not greatly altered. Two sample examples illustrating the procedures of determining the allowable safe operating stress corresponding to a set of assumed loading schedule are included. The selection of sample examples is limited by the relatively meager available data on the candidate material for various stress ratios in the cycling.

Denton, S. J.; Liu, C. K.

1976-01-01

379

Reconfigurable Flight Control Designs With Application to the X-33 Vehicle  

NASA Technical Reports Server (NTRS)

Two methods for control system reconfiguration have been investigated. The first method is a robust servomechanism control approach (optimal tracking problem) that is a generalization of the classical proportional-plus-integral control to multiple input-multiple output systems. The second method is a control-allocation approach based on a quadratic programming formulation. A globally convergent fixed-point iteration algorithm has been developed to make onboard implementation of this method feasible. These methods have been applied to reconfigurable entry flight control design for the X-33 vehicle. Examples presented demonstrate simultaneous tracking of angle-of-attack and roll angle commands during failures of the right body flap actuator. Although simulations demonstrate success of the first method in most cases, the control-allocation method appears to provide uniformly better performance in all cases.

Burken, John J.; Lu, Ping; Wu, Zhenglu

1999-01-01

380

Robust design strategy applied to a vehicle suspension system with high camber angle Estelle Koensgen  

E-print Network

Koensgen Renault SAS / Vehicle Dynamics Research Group, 1 av Golf 78280 Guyancourt, France, estelle.koensgen@renault.com Estelle Koensgen is working in the Vehicle Dynamics Research group of Renault. Sébastien Berger MIPS / Vehicle Dynamics Research Group, 1 av Golf 78280 Guyancourt, France, christophe

Paris-Sud XI, Université de

381

Electric and hybrid vehicle performance and design goal determination study. Final report  

Microsoft Academic Search

Recommendations are set forth for performance standards for near-term and advanced electric and hybrid vehicles. Limited market surveys and interviews with present owners of electric vehicles indicated that the most important criterion for private vehicles is low operating cost. This criterion, combined with the low specific energy density and relatively short life of present storage batteries, was the key factor

J. Brennand; R. Curtis; H. Fox

1977-01-01

382

H? observer-based robust multiple controller design for vehicle lateral dynamics  

Microsoft Academic Search

This paper deals with the H? robust output control for vehicle dynamics where the sideslip angle is unavailable for measurement. This study uses the multiple model approach to represent the vehicle model. The road adhesion conditions change and modeling errors are taking into account by introducing uncertainties. Thus, giving a nonlinear vehicle model, its representation by a multiple model is

M. Chadli; A. El Hajjaji; A. Rabhi

2010-01-01

383

Design and Testing of a Prototype Lunar or Planetary Surface Landing Research Vehicle (LPSLRV)  

NASA Technical Reports Server (NTRS)

This handbook describes a two-semester senior design course sponsored by the NASA Office of Education, the Exploration Systems Mission Directorate (ESMD), and the NASA Space Grant Consortium. The course was developed and implemented by the Mechanical and Aerospace Engineering Department (MAE) at Utah State University. The course final outcome is a packaged senior design course that can be readily incorporated into the instructional curriculum at universities across the country. The course materials adhere to the standards of the Accreditation Board for Engineering and Technology (ABET), and is constructed to be relevant to key research areas identified by ESMD. The design project challenged students to apply systems engineering concepts to define research and training requirements for a terrestrial-based lunar landing simulator. This project developed a flying prototype for a Lunar or Planetary Surface Landing Research Vehicle (LPSRV). Per NASA specifications the concept accounts for reduced lunar gravity, and allows the terminal stage of lunar descent to be flown either by remote pilot or autonomously. This free-flying platform was designed to be sufficiently-flexible to allow both sensor evaluation and pilot training. This handbook outlines the course materials, describes the systems engineering processes developed to facilitate design fabrication, integration, and testing. This handbook presents sufficient details of the final design configuration to allow an independent group to reproduce the design. The design evolution and details regarding the verification testing used to characterize the system are presented in a separate project final design report. Details of the experimental apparatus used for system characterization may be found in Appendix F, G, and I of that report. A brief summary of the ground testing and systems verification is also included in Appendix A of this report. Details of the flight tests will be documented in a separate flight test report. This flight test report serves as a complement to the course handbook presented here. This project was extremely ambitious, and achieving all of the design and test objectives was a daunting task. The schedule ran slightly longer than a single academic year with the complete design closure not occurring until early April. Integration and verification testing spilled over into late May and the first flight did not occur until mid to late June. The academic year at Utah State University ended on May 8, 2010. Following the end of the academic year, testing and integration was performed by the faculty advisor, paid research assistants, and volunteer student help

Murphy, Gloria A.

2010-01-01

384

Design of a reconfigurable liquid hydrogen fuel tank for use in the Genii unmanned aerial vehicle  

NASA Astrophysics Data System (ADS)

Long endurance flight, on the order of days, is a leading flight performance characteristic for Unmanned Aerial Vehicles (UAVs). Liquid hydrogen (LH2) is well suited to providing multi-day flight times with a specific energy 2.8 times that of conventional kerosene based fuels. However, no such system of LH2 storage, delivery, and use is currently available for commercial UAVs. In this paper, we develop a light weight LH2 dewar for integration and testing in the proton exchange membrane (PEM) fuel cell powered, student designed and constructed, Genii UAV. The fuel tank design is general for scaling to suit various UAV platforms. A cylindrical vacuum-jacketed design with removable end caps was chosen to incorporate various fuel level gauging, pressurizing, and slosh mitigation systems. Heat and mechanical loadings were modeled to compare with experimental results. Mass performance of the fuel tank is characterized by the fraction of liquid hydrogen to full tank mass, and the insulation performance was characterized by effective thermal conductivity and boil-off rate.

Adam, Patrick; Leachman, Jacob

2014-01-01

385

Leading Edge Aerothermal Inverse Design of Hyersonic Vehicle Based on Homotopy Optimization Method  

NASA Astrophysics Data System (ADS)

Blunt leading edge with profiles of circular or power law shape is often used to decrease the aerodynamic heating of a vehicle when it flights into hypersonic regime. In order to further reduce the peak of heat flux of the leading edge, an inverse shape design method is presented in this paper. The leading edge is parameterized by using B-spline curve method. The hypersonic flow field and the heat flux distribution around the leading edge is evaluated by computational fluid dynamics. A homotopy method is developed as the optimizer. The computational heat flux distribution is driven by the optimizer to meet the objective . In order to verify the validity of the method, the inverse aerothermal design of a 2D leading edge with the thickness of 5 mm was carried out in the design condition Mach number is 6.5. The initial profile of the leading edge approximates to a circular arc. An H-type structured grid was used to discrete the computational domain. A 2D thin-layer Reynolds-averaged Navier-Stokes equations in strong conservation law form was employed as the solver. The results have shown that the peak value of the heat flux decreases about 4.6%.

Cui, K.; Hu, S. C.; Gao, T. Y.; Wang, X. P.; Yang, G. W.

2011-09-01

386

A Water Vapor Differential Absorption LIDAR Design for Unpiloted Aerial Vehicles  

NASA Technical Reports Server (NTRS)

This system study proposes the deployment of a water vapor Differential Absorption LIDAR (DIAL) system on an Altair unmanned aerial vehicle (UAV) platform. The Altair offers improved payload weight and volume performance, and longer total flight time as compared to other commercial UAV's. This study has generated a preliminary design for an Altair based water vapor DIAL system. The design includes a proposed DIAL schematic, a review of mechanical challenges such as temperature and humidity stresses on UAV deployed DIAL systems, an assessment of the available capacity for additional instrumentation (based on the proposed design), and an overview of possible weight and volume improvements associated with the use of customized electronic and computer hardware, and through the integration of advanced fiber-optic and laser products. The results of the study show that less than 17% of the available weight, less than 19% of the volume capacity, and approximately 11% of the electrical capacity is utilized by the proposed water vapor DIAL system on the Altair UAV.

DeYoung, Russell J.; Mead, Patricia F.

2004-01-01

387

Vehicle Sketch Pad: a Parametric Geometry Modeler for Conceptual Aircraft Design  

NASA Technical Reports Server (NTRS)

The conceptual aircraft designer is faced with a dilemma, how to strike the best balance between productivity and fidelity? Historically, handbook methods have required only the coarsest of geometric parameterizations in order to perform analysis. Increasingly, there has been a drive to upgrade analysis methods, but these require considerably more precise and detailed geometry. Attempts have been made to use computer-aided design packages to fill this void, but their cost and steep learning curve have made them unwieldy at best. Vehicle Sketch Pad (VSP) has been developed over several years to better fill this void. While no substitute for the full feature set of computer-aided design packages, VSP allows even novices to quickly become proficient in defining three-dimensional, watertight aircraft geometries that are adequate for producing multi-disciplinary meta-models for higher order analysis methods, wind tunnel and display models, as well as a starting point for animation models. This paper will give an overview of the development and future course of VSP.

Hahn, Andrew S.

2010-01-01

388

Assessment, design and control strategy development of a fuel cell hybrid electric vehicle for CSU's EcoCAR  

NASA Astrophysics Data System (ADS)

Advanced automotive technology assessment and powertrain design are increasingly performed through modeling, simulation, and optimization. But technology assessments usually target many competing criteria making any individual optimization challenging and arbitrary. Further, independent design simulations and optimizations take considerable time to execute, and design constraints and objectives change throughout the design process. Changes in design considerations usually require re-processing of simulations and more time. In this thesis, these challenges are confronted through CSU's participation in the EcoCAR2 hybrid vehicle design competition. The complexity of the competition's design objectives leveraged development of a decision support system tool to aid in multi-criteria decision making across technologies and to perform powertrain optimization. To make the decision support system interactive, and bypass the problem of long simulation times, a new approach was taken. The result of this research is CSU's architecture selection and component sizing, which optimizes a composite objective function representing the competition score. The selected architecture is an electric vehicle with an onboard range extending hydrogen fuel cell system. The vehicle has a 145kW traction motor, 18.9kWh of lithium ion battery, a 15kW fuel cell system, and 5kg of hydrogen storage capacity. Finally, a control strategy was developed that improves the vehicles performance throughout the driving range under variable driving conditions. In conclusion, the design process used in this research is reviewed and evaluated against other common design methodologies. I conclude, through the highlighted case studies, that the approach is more comprehensive than other popular design methodologies and is likely to lead to a higher quality product. The upfront modeling work and decision support system formulation will pay off in superior and timely knowledge transfer and more informed design decisions. The hypothesis is supported by the three case studies examined in this thesis.

Fox, Matthew D.

389

Project EGRESS: Earthbound Guaranteed Reentry from Space Station. the Design of an Assured Crew Recovery Vehicle for the Space Station  

NASA Technical Reports Server (NTRS)

Unlike previously designed space-based working environments, the shuttle orbiter servicing the space station will not remain docked the entire time the station is occupied. While an Apollo capsule was permanently available on Skylab, plans for Space Station Freedom call for a shuttle orbiter to be docked at the space station for no more than two weeks four times each year. Consideration of crew safety inspired the design of an Assured Crew Recovery Vehicle (ACRV). A conceptual design of an ACRV was developed. The system allows the escape of one or more crew members from Space Station Freedom in case of emergency. The design of the vehicle addresses propulsion, orbital operations, reentry, landing and recovery, power and communication, and life support. In light of recent modifications in space station design, Project EGRESS (Earthbound Guaranteed ReEntry from Space Station) pays particular attention to its impact on space station operations, interfaces and docking facilities, and maintenance needs. A water-landing medium-lift vehicle was found to best satisfy project goals of simplicity and cost efficiency without sacrificing safety and reliability requirements. One or more seriously injured crew members could be returned to an earth-based health facility with minimal pilot involvement. Since the craft is capable of returning up to five crew members, two such permanently docked vehicles would allow a full evacuation of the space station. The craft could be constructed entirely with available 1990 technology, and launched aboard a shuttle orbiter.

1990-01-01

390

Aerodynamics of road vehicles  

SciTech Connect

This introduction to aerodynamic aspects of motor vehicle design will be of use both to vehicle designers and students of automobile engineering. Content covers vehicle systems, ventilation and aerodynamic design to reduce drag and increase stability of cars, commercial vehicles and PSVs. Topics considered include automobile aerodynamics; some fundamentals of fluid mechanics; performance of cars and light vans; aerodynamic drag of passenger cars; driving stability in sidewinds; operation, safety and comfort; high-performance vehicle aerodynamics; commercial vehicles; engine cooling systems; heating, ventilation and air conditioning of motor vehicles; wind tunnels for automobile aerodynamics; measuring and testing techniques; and numerical methods for computation of flow around road vehicles.

Hucho, W.H.

1987-01-01

391

Design and development of an unconventional VTOL micro air vehicle: The Cyclocopter  

NASA Astrophysics Data System (ADS)

This paper discusses the systematic experimental and vehicle design/development studies conducted at the University of Maryland which culminated in the development of the first flying Cyclocopter in the history. Cyclocopter is a novel Vertical Take-Off and Landing (VTOL) aircraft, which utilizes cycloidalrotors (cyclorotors), a revolutionary horizontal axis propulsion concept, that has many advantages such as higher aerodynamic efficiency, maneuverability and high-speed forward flight capability when compared to a conventional helicopter rotor. The experimental studies included a detailed parametric study to understand the effect of rotor geometry and blade kinematics on cyclorotor hover performance. Based on the experimental results, higher blade pitch angles were found to improve thrust and increase the power loading (thrust per unit power) of the cyclorotor. Asymmetric pitching with higher pitch angle at the top than at the bottom produced better power loading. The chordwise optimum pitching axis location was observed to be around 25-35% of the blade chord. Because of the flow curvature effects, the cycloidal rotor performance was a strong function of the chord/radius ratio. The optimum chord/radius ratios were extremely high, around 0.5-0.8, depending on the blade pitching amplitude. A flow field investigation was also conducted using Particle Image Velocimetry (PIV) to unravel the physics behind thrust production of a cyclorotor. PIV studies indicated evidence of a stall delay as well as possible increases in lift on the blades from the presence of a leading edge vortex. The goal of all these studies was to understand and optimize the performance of a micro-scale cyclorotor so that it could be used in a flying vehicle. An optimized cyclorotor was used to develop a 200 gram cyclocopter capable of autonomous stable hover using an onboard feedback controller.

Benedict, Moble; Chopra, Inderjit

2012-06-01

392

Mars Lander/Rover vehicle development: An advanced space design project for USRA and NASA/OAST  

NASA Technical Reports Server (NTRS)

The accomplishments of the Utah State University (USU) Mars Lander/Rover (MLR) design class during the Winter Quarter are delineated and explained. Environment and trajectory, ground systems, balloon system, and payload system are described. Results from this effort will provide a valid and useful basis for further studies of Mars exploratory vehicles.

1987-01-01

393

Engineering and design of vehicles for long distance road transport of livestock: the example of cattle transport in northern Australia.  

PubMed

The author outlines the design of road vehicles for the long distance transport of livestock, mainly cattle, which are used in the tropical and sub-Mediterranean climatic regions of Australia and which have been engineered to meet animal welfare principles. Over 50% of journeys exceed 500 km. Journeys of 2 000 to 3 000 km do occur and involve the resting of animals once or twice during the journey. Specialised vehicles, known as 'road trains', are employed and these consist of multiple trailers with multi-deck containers or stock crates for animals, which are hauled by a prime mover or tractor. The starting point for design is safety for both people and animals and the need to preserve transport infrastructure such as roads and bridges. The move to volume livestock loading, where livestock are loaded according to the volume they occupy rather than their weight, was a major early breakthrough. Details are given of the design of vehicles and loading facilities. Vehicle design includes suspensions and the floors, interior walls, doors, partitions and penning, deck supports and arrangements for through loading of stock crates. Loading and unloading ramps can be a major source of stress and standardised heights have been adopted in Australia. PMID:20405427

Lapworth, John W

2008-01-01

394

A bi-criterion optimization approach for the design and planning of hydrogen supply chains for vehicle  

E-print Network

;Introduction The use of hydrogen as an alternative fuel and energy carrier is receiving increasing interest homes and offices. In particular, its use as a transportation fuel in fuel cell vehicles offersA bi-criterion optimization approach for the design and planning of hydrogen supply chains

Grossmann, Ignacio E.

395

Highly efficient brushless motor design for an air-conditioner of the next generation 42 V vehicle  

Microsoft Academic Search

In the past few years, worldwide awareness of environmental problems has grown dramatically. The idling stop and 42 V battery system has attracted large attention for next generation vehicle. In order to adapt to idling stop, air-conditioning compressors are required to be changed to electric-motor driven from gasoline engine driven. This paper discusses the optimum design of a high speed

Hiroshi Murakami; Hisakazu Kataoka; Yukio Honda; Shigeo Morimoto; Yoji Takeda

2001-01-01

396

PROCEEDINGS of the Third International Driving Symposium on Human Factors in Driver Assessment, Training and Vehicle Design STEERING ENTROPY REVISITED  

E-print Network

. Steering entropy was introduced to quantify drivers' efforts to maintain their lateral safety margins frequencies and an increased number of safety margin violations. Steering entropy (SE) was developed, Training and Vehicle Design 25 STEERING ENTROPY REVISITED Erwin R. Boer LUEBEC San Diego, California, USA E

Goodrich, Michael A.

397

Engineering and design of vehicles for long distance road transport of livestock: the example of cattle transport in northern Australia  

Microsoft Academic Search

Summary The author outlines the design of road vehicles for the long distance transport of livestock, mainly cattle, which are used in the tropical and sub-Mediterranean climatic regions of Australia and which have been engineered to meet animal welfare principles. Over 50% of journeys exceed 500 km. Journeys of 2 000 to 3 000 km do occur and involve the

John W. Lapworth

398

Int. J. of Heavy Vehicle Systems, Vol. 11, Nos 3/4, 2004 372 Combined optimisation of design and power  

E-print Network

Int. J. of Heavy Vehicle Systems, Vol. 11, Nos 3/4, 2004 372 Combined optimisation of design and power management of the hydraulic hybrid propulsion system for the 6 Ã? 6 medium truck Z. Filipi*, L are one of the critical technologies on the roadmap to future ultra-efficient trucks. While

Papalambros, Panos

399

Multidisciplinary design and optimization of an air launched satellite launch vehicle using a hybrid heuristic search algorithm  

Microsoft Academic Search

A multidisciplinary design and optimization strategy for a multistage air launched satellite launch vehicle comprising of a solid propulsion system to low earth orbit with the implementation of a hybrid heuristic search algorithm is proposed in this article. The proposed approach integrated the search properties of a genetic algorithm and simulated annealing, thus achieving an optimal solution while satisfying the

A. F. Rafique; L. S. He; Q. Zeeshan; A. Kamran; K. Nisar

2011-01-01

400

Methods for Determining the Level of Autonomy to Design into a Human Spaceflight Vehicle: A Function Specific Approach  

Microsoft Academic Search

The next -generation human spaceflight vehicle is in a unique position to realize the benefits of more than thirty years of technological advancements since the Space Shuttle was designed. Computer enhancements, the emergence of highly reliable decision-making algorithms, and an emphasis on efficiency make an increased use of autonomous systems highly likely. NASA is in a position to take advantage

Ryan W. Proud; Jeremy J. Hart; Richard B. Mrozinski

401

Tools for Designing Thermal Management of Batteries in Electric Drive Vehicles (Presentation)  

SciTech Connect

Temperature has a significant impact on life, performance, and safety of lithium-ion battery technology, which is expected to be the energy storage of choice for electric drive vehicles (xEVs). High temperatures degrade Li-ion cells faster while low temperatures reduce power and energy capabilities that could have cost, reliability, range, or drivability implications. Thermal management of battery packs in xEVs is essential to keep the cells in the desired temperature range and also reduce cell-to-cell temperature variations, both of which impact life and performance. The value that the battery thermal management system provides in reducing battery life and improving performance outweighs its additional cost and complexity. Tools that are essential for thermal management of batteries are infrared thermal imaging, isothermal calorimetry, thermal conductivity meter and computer-aided thermal analysis design software. This presentation provides details of these tools that NREL has used and we believe are needed to design right-sized battery thermal management systems.

Pesaran, A.; Keyser, M.; Kim, G. H.; Santhanagopalan, S.; Smith, K.

2013-02-01

402

Design study of steel V-Belt CVT for electric vehicles  

NASA Technical Reports Server (NTRS)

A continuously variable transmission (CVT) design layout was completed. The intended application was for coupling the flywheel to the driveline of a flywheel battery hybrid electric vehicle. The requirements were that the CVT accommodate flywheel speeds from 14,000 to 28,000 rpm and driveline speeds of 850 to 5000 rpm without slipping. Below 850 rpm a slipping clutch was used between the CVT and the driveline. The CVT was required to accommodate 330 ft-lb maximum torque and 100 hp maximum transient. The weighted average power was 22 hp, the maximum allowable full range shift time was 2 seconds and the required lift was 2600 hours. The resulting design utilized two steel V-belts in series to accommodate the required wide speed ratio. The size of the CVT, including the slipping clutch, was 20.6 inches long, 9.8 inches high and 13.8 inches wide. The estimated weight was 155 lb. An overall potential efficiency of 95 percent was projected for the average power condition.

Swain, J. C.; Klausing, T. A.; Wilcox, J. P.

1980-01-01

403

Design, building, and testing of the post landing systems for the assured crew return vehicle  

NASA Technical Reports Server (NTRS)

The design, building, and testing of the post landing support systems for a water landing Assured Crew Return Vehicle (ACRV) are presented. One ACRV will be permanently docked to Space Station Freedom, fulfilling NASA's commitment to Assured Crew Return Capability in the event of an accident or illness. The configuration of the ACRV is based on an Apollo Command Module (ACM) derivative. The 1990 to 91 effort concentrated on the design, building, and testing of a 1/5 scale model of the egress and stabilization systems. The objective was to determine the feasibility of: (1) stabilizing the ACM out of the range of motions which cause sea sickness; and (2) the safe and rapid removal of a sick or injured crewmember from the ACRV. The ACRV model construction is presented along with a discussion of the water test facility. The rapid egress system is also presented along with a discussion of the ACRV stabilization control systems. Results are given and discussed in detail.

Anderson, Loren A.

1991-01-01

404

On the mechanics, computational modeling, and design implementation of piezoelectric actuators on micro air vehicles  

NASA Astrophysics Data System (ADS)

This document details the research performed on applying piezoelectric macro fiber composite actuators on micro air vehicles. The research objective was to apply the minimum number of macro fiber composites to the aircraft in an optimized manner in order to obtain complete control authority. To do this, a local-global approach was taken. Numerical predictions, experiments, and finite element models were used to model the macro fiber composites in a local manner, approximating the curvature of the actuator when bonded to a substrate. The substrate was selected to maximize the curvature when submitted to expected loads. In a global manner, the design of the aircraft was optimized, using a computational model, to provide the largest control authority under expected flight conditions. A variety of experimental tests were conducted to create an accurate aeroelastic computer model, including tests to determine material properties, static loading tests, and wind tunnel testing. Two of the optimized designs were tested in the wind tunnel to verify the predicted improvement, which confirmed the accuracy of the computer model. Other experimental results are also included, including experiments examining the unimorph fabrication technique, rigid assumptions used for the aerodynamic model, and high frequency dynamics of the macro fiber composite unimorph.

Lacroix, Bradley W.

405

Design and performance evaluation of a rotary magnetorheological damper for unmanned vehicle suspension systems.  

PubMed

We designed and validated a rotary magnetorheological (MR) damper with a specified damping torque capacity, an unsaturated magnetic flux density (MFD), and a high magnetic field intensity (MFI) for unmanned vehicle suspension systems. In this study, for the rotary type MR damper to have these satisfactory performances, the roles of the sealing location and the cover case curvature of the MR damper were investigated by using the detailed 3D finite element model to reflect asymmetrical shapes and sealing components. The current study also optimized the damper cover case curvature based on the MFD, the MFI, and the weight of the MR damper components. The damping torques, which were computed using the characteristic equation of the MR fluid and the MFI of the MR damper, were 239.2, 436.95, and 576.78 N·m at currents of 0.5, 1, and 1.5 A, respectively, at a disk rotating speed of 10 RPM. These predicted damping torques satisfied the specified damping torque of 475 N·m at 1.5 A and showed errors of less than 5% when compared to experimental measurements from the MR damper manufactured by the proposed design. The current study could play an important role in improving the performance of rotary type MR dampers. PMID:23533366

Lee, Jae-Hoon; Han, Changwan; Ahn, Dongsu; Lee, Jin Kyoo; Park, Sang-Hu; Park, Seonghun

2013-01-01

406

Modeling, Simulation Design and Control of Hybrid-Electric Vehicle Drives  

SciTech Connect

Ohio State University (OSU) is uniquely poised to establish such a center, with interdisciplinary emphasis on modeling, simulation, design and control of hybrid-electric drives for a number of reasons, some of which are: (1) The OSU Center for Automotive Research (CAR) already provides an infrastructure for interdisciplinary automotive research and graduate education; the facilities available at OSU-CAR in the area of vehicle and powertrain research are among the best in the country. CAR facilities include 31,000 sq. feet of space, multiple chassis and engine dynamometers, an anechoic chamber, and a high bay area. (2) OSU has in excess of 10 graduate level courses related to automotive systems. A graduate level sequence has already been initiated with GM. In addition, an Automotive Systems Engineering (ASE) program cosponsored by the mechanical and electrical engineering programs, had been formulated earlier at OSU, independent of the GATE program proposal. The main objective of the ASE is to provide multidisciplinary graduate education and training in the field of automotive systems to Masters level students. This graduate program can be easily adapted to fulfill the spirit of the GATE Center of Excellence. (3) A program in Mechatronic Systems Engineering has been in place at OSU since 1994; this program has a strong emphasis on automotive system integration issues, and has emphasized hybrid-electric vehicles as one of its application areas. (4) OSU researchers affiliated with CAR have been directly involved in the development and study of: HEV modeling and simulation; electric drives; transmission design and control; combustion engines; and energy storage systems. These activities have been conducted in collaboration with government and automotive industry sponsors; further, the same researchers have been actively involved in continuing education programs in these areas with the automotive industry. The proposed effort will include: (1) The development of a laboratory facility that will include: electric drive and IC engine test benches; a test vehicle designed for rapid installation of prototype drives; benches for the measurement and study of HEV energy storage components (batteries, ultra-capacitors, flywheels); hardware-in-the-loop control system development tools. (2) The creation of new courses and upgrades of existing courses on subjects related to: HEV modeling and simulation; supervisory control of HEV drivetrains; engine, transmission, and electric drive modeling and control. Specifically, two new courses (one entitled HEV Component Analysis: and the other entitled HEV System Integration and Control) will be developed. Two new labs, that will be taught with the courses (one entitled HEV Components Lab and one entitled HEV Systems and Control lab) will also be developed. (3) The consolidation of already existing ties among faculty in electrical and mechanical engineering departments. (4) The participation of industrial partners through: joint laboratory development; internship programs; continuing education programs; research project funding. The proposed effort will succeed because of the already exceptional level of involvement in HEV research and in graduate education in automotive engineering at OSU, and because the PIs have a proven record of interdisciplinary collaboration as evidenced by joint proposals, joint papers, and co-advising of graduate students. OSU has been expanding its emphasis in Automotive Systems for quite some time. This has led to numerous successes such as the establishment of the Center of Automotive Research, a graduate level course sequence with GM, and numerous grants and contracts on automotive research. The GATE Center of Excellence is a natural extension of what educators at OSU already do well.

Giorgio Rizzoni

2005-09-30

407

Controller Hardware-In-the-Loop simulation for design of power management strategies for fuel cell vehicle with energy storage  

Microsoft Academic Search

Designing digital control system for fuel cell vehicle (FCV) with energy storage (ES) power management strategy can be costly and time consuming. In this paper, Controller Hardware-In-the-Loop (CHIL) simulations are used to design power management strategies using Real Time Digital Simulator (RTDS) for a FCV system with ES. CHIL simulation is a rapid, low-cost prototyping and testing method for digital

Yuhang Deng; Hui Li; Simon Foo

2009-01-01

408

Phase 1 of the near team hybrid passenger vehicle development program. Appendix C: Preliminary design data package. Volume 2: Appendices  

NASA Technical Reports Server (NTRS)

The design, development, efficiency, manufacturability, production costs, life cycle cost, and safety of sodium-sulfur, nickel-zinc, and lead-acid batteries for electric hybrid vehicles are discussed. Models are given for simulating the vehicle handling quality, and for finding the value of: (1) the various magnetic quantities in the different sections in which the magnetic circuit of the DC electric machine is divided; (2) flux distribution in the air gap and the magnetization curve under load conditions; and (3) the mechanical power curves versus motor speed at different values of armature current.

Piccolo, R.

1979-01-01

409

Micromechanical analysis and design of an integrated thermal protection system for future space vehicles  

NASA Astrophysics Data System (ADS)

Thermal protection systems (TPS) are the key features incorporated into a spacecraft's design to protect it from severe aerodynamic heating during high-speed travel through planetary atmospheres. The thermal protection system is the key technology that enables a spacecraft to be lightweight, fully reusable, and easily maintainable. Add-on TPS concepts have been used since the beginning of the space race. The Apollo space capsule used ablative TPS and the Space Shuttle Orbiter TPS technology consisted of ceramic tiles and blankets. Many problems arose from the add-on concept such as incompatibility, high maintenance costs, non-load bearing, and not being robust and operable. To make the spacecraft's TPS more reliable, robust, and efficient, we investigated Integral Thermal Protection System (ITPS) concept in which the load-bearing structure and the TPS are combined into one single component. The design of an ITPS was a challenging task, because the requirement of a load-bearing structure and a TPS are often conflicting. Finite element (FE) analysis is often the preferred method of choice for a structural analysis problem. However, as the structure becomes complex, the computational time and effort for an FE analysis increases. New structural analytical tools were developed, or available ones were modified, to perform a full structural analysis of the ITPS. With analytical tools, the designer is capable of obtaining quick and accurate results and has a good idea of the response of the structure without having to go to an FE analysis. A MATLABRTM code was developed to analytically determine performance metrics of the ITPS such as stresses, buckling, deflection, and other failure modes. The analytical models provide fast and accurate results that were within 5% difference from the FEM results. The optimization procedure usually performs 100 function evaluations for every design variable. Using the analytical models in the optimization procedure was a time saver, because the optimization time to reach an optimum design was reached in less than an hour, where as an FE optimization study would take hours to reach an optimum design. Corrugated-core structures were designed for ITPS applications with loads and boundary conditions similar to that of a Space Shuttle-like vehicle. Temperature, buckling, deflection and stress constraints were considered for the design and optimization process. An optimized design was achieved with consideration of all the constraints. The ITPS design obtained from the analytical solutions was lighter (4.38 lb/ft2) when compared to the ITPS design obtained from a finite element analysis (4.85 lb/ft 2). The ITPS boundary effects added local stresses and compressive loads to the top facesheet that was not able to be captured by the 2D plate solutions. The inability to fully capture the boundary effects lead to a lighter ITPS when compared to the FE solution. However, the ITPS can withstand substantially large mechanical loads when compared to the previous designs. Truss-core structures were found to be unsuitable as they could not withstand the large thermal gradients frequently encountered in ITPS applications.

Martinez, Oscar

410

The Household Market for Electric Vehicles: Testing the Hybrid Household Hypothesis--A Reflively Designed Survey of New-car-buying, Multi-vehicle California Households  

Microsoft Academic Search

We report the results of a survey of the potential demand for electric vehicles (EVs) among a subset of California households. We limit our analysis to one group of potential hybrid households. These households own two or more light duty vehicles and buy new vehicles of the body styles we expect will be offered as electric vehicles. These characteristics identify

Thomas Turrentine; Kenneth Kurani

1995-01-01

411

Directivity Design of RFID Tag Antenna Using Side-view Mirror for Vehicle  

Microsoft Academic Search

Radio Frequency Identification (RFID) is well-known technique for wireless data transmission. RFID technology is useful, efficient and universal in the near field communication application. An automatable vehicle RFID system is useful by various management manpower is not necessary. If vehicles are by RFID system identified, transit fares, parking-lot fees, tollgate fees and so on are collected automatically. Most of the

Min-Seong Kim; Kyeong-Sik Min; Dae-Hwan Park

2008-01-01

412

Pios fuel cell Motorcycle; design, development and test of hydrogen fuel cell powered vehicle  

Microsoft Academic Search

Motorcycles are the most popular vehicles for motorised individual transport in Asia. Millions of motorcycles cause the majority of traffic-based air pollution. A prototype of a clean, silent and fuel efficient hydrogen fuel cell powered. Motorcycle demonstrates an alternative. The fuel cell motorcycle prototype named ldquoPiosrdquo is the latest model of a series of fuel cell experiment vehicle. For the

J. Weigl; I. Inayati; E. Zind; H. Said

2008-01-01

413

Conceptual design and selection of a biodiesel fuel processor for a vehicle fuel cell APU  

Microsoft Academic Search

Within the European project BIOFEAT (Biodiesel Fuel Processor for a Fuel cell Auxiliary Power Unit for a Vehicle), a complete modular 10 kWe biodiesel fuel processor capable of feeding a PEMFC will be developed, built and tested to generate electricity for a vehicle auxiliary power unit (APU). Tail pipe emissions reduction, increased use of renewable fuels, increase of hydrogen-fuel economy

S. Specchia; F. W. A. Tillemans; P. F. van den Oosterkamp; G. Saracco

414

Design and control of the propulsion for a series Hybrid Electric Vehicle  

Microsoft Academic Search

As one of the future most popular vehicles, Hybrid Electric Vehicle has to satisfy the challenging and often conflicting requirements. Environment concerns have motivated the legislated action by government around the world to reduce nocuous emissions. The requirements for reduction of CO2 need a high fuel economy. The people's demands for low cost and efficient require a high reliability control

Junjie Li; Xiumin Yu; Huajie Ding; Ping Sun

2010-01-01

415

Design and development of the redundant launcher stabilization system for the Atlas 2 launch vehicle  

NASA Technical Reports Server (NTRS)

The Launcher Stabilization System (LSS) is a pneumatic/hydraulic ground system used to support an Atlas launch vehicle prior to launch. The redesign and development activity undertaken to achieve an LSS with increased load capacity and a redundant hydraulic system for the Atlas 2 launch vehicle are described.

Nakamura, M.

1991-01-01

416

Architectural design of a situated multiagent system for controlling automatic guided vehicles  

Microsoft Academic Search

Automatic Guided Vehicles (AGVs) are fully automated vehicles that are able to transport goods in an industrial environment. To cope with new and future system requirements such as flexibility and openness, we have applied a situated multiagent system to developed a decentralized control architecture for AGV transportation systems. In this paper, we give an overview of the software ar- chitecture

Danny Weyns; Tom Holvoet

2008-01-01

417

A novel design and feasibility analysis of a fuel cell plug-in hybrid electric vehicle  

Microsoft Academic Search

Hydrogen powered fuel cell vehicles (FCVs) are receiving global attention, stimulated by the urgent need for more fuel-efficient vehicles. However, current challenges for fuel cells such as high cost, sizing problem, and limited driving range, greatly affect the pace of FCV development. At the same time, domestic and renewable energy resource usage is frequently being encouraged for future electric propulsion

Di Wu; Sheldon S. Williamson

2008-01-01

418

Designing future underwater vehicles: principles and mechanisms of the weakly electric fish  

Microsoft Academic Search

Future underwater vehicles will be increasingly called upon to work in cluttered environments and to interact with their surroundings. These vehicles will need sensors that work efficiently at short range and be highly maneuverable at low speed. To obtain insights into principles and mechanisms of low-speed operation in cluttered environments, we examine a fish that excels in this regime, the

Malcolm A. MacIver; Ebraheem Fontaine; Joel W. Burdick

2004-01-01

419

Software design techniques for the man machine interface to a complex underwater vehicle  

Microsoft Academic Search

As underwater vehicle complexity grows, so does the manpower needed to operate and maintain them. This paper describes the architecture of the software used to operate FOSS (Fiber-Optic Survey System), a complex full ocean depth towed vehicle. This system operates using the UNIX operating system and the X Windows graphical user interface. It is in constant serial communication with 25

R. P. Stokey

1994-01-01

420

Design of a battery-charger controller for electric vehicle based on RST controller  

Microsoft Academic Search

In order to find better solution for the development of Electric Vehicles (EVs), many research are performed by companies, universities and research laboratories. The main goal of these works is to provide some solutions to reduce the cost, increase the compactness, improve the autonomy and the reliability as well as the vehicle energetic efficiency and last but not least, reduce

S. Lacroix; M. Hilairet; E. Laboure

2011-01-01

421

Analysis and design of a speed and position system for maglev vehicles.  

PubMed

This paper mainly researches one method of speed and location detection for maglev vehicles. As the maglev train doesn't have any physical contact with the rails, it has to use non-contact measuring methods. The technology based on the inductive loop-cable could fulfill the requirement by using an on-board antenna which could detect the alternating magnetic field produced by the loop-cable on rails. This paper introduces the structure of a speed and position system, and analyses the electromagnetic field produced by the loop-cable. The equivalent model of the loop-cable is given and the most suitable component of the magnetic flux density is selected. Then the paper also compares the alternating current (AC) resistance and the quality factor between two kinds of coils which the antenna is composed of. The effect of the rails to the signal receiving is also researched and then the structure of the coils is improved. Finally, considering the common-mode interference, 8-word coils are designed and analyzed. PMID:23012504

Dai, Chunhui; Dou, Fengshan; Song, Xianglei; Long, Zhiqiang

2012-01-01

422

Analysis and Design of a Speed and Position System for Maglev Vehicles  

PubMed Central

This paper mainly researches one method of speed and location detection for maglev vehicles. As the maglev train doesn't have any physical contact with the rails, it has to use non-contact measuring methods. The technology based on the inductive loop-cable could fulfill the requirement by using an on-board antenna which could detect the alternating magnetic field produced by the loop-cable on rails. This paper introduces the structure of a speed and position system, and analyses the electromagnetic field produced by the loop-cable. The equivalent model of the loop-cable is given and the most suitable component of the magnetic flux density is selected. Then the paper also compares the alternating current (AC) resistance and the quality factor between two kinds of coils which the antenna is composed of. The effect of the rails to the signal receiving is also researched and then the structure of the coils is improved. Finally, considering the common-mode interference, 8-word coils are designed and analyzed. PMID:23012504

Dai, Chunhui; Dou, Fengshan; Song, Xianglei; Long, Zhiqiang

2012-01-01

423

Cooperative GN&C development in a rapid prototyping environment. [flight software design for space vehicles  

NASA Technical Reports Server (NTRS)

The Navigation, Control and Aeronautics Division (NCAD) at NASA-JSC is exploring ways of producing Guidance, Navigation and Control (GN&C) flight software faster, better, and cheaper. To achieve these goals NCAD established two hardware/software facilities that take an avionics design project from initial inception through high fidelity real-time hardware-in-the-loop testing. Commercially available software products are used to develop the GN&C algorithms in block diagram form and then automatically generate source code from these diagrams. A high fidelity real-time hardware-in-the-loop laboratory provides users with the capability to analyze mass memory usage within the targeted flight computer, verify hardware interfaces, conduct system level verification, performance, acceptance testing, as well as mission verification using reconfigurable and mission unique data. To evaluate these concepts and tools, NCAD embarked on a project to build a real-time 6 DOF simulation of the Soyuz Assured Crew Return Vehicle flight software. To date, a productivity increase of 185 percent has been seen over traditional NASA methods for developing flight software.

Bordano, Aldo; Uhde-Lacovara, JO; Devall, Ray; Partin, Charles; Sugano, Jeff; Doane, Kent; Compton, Jim

1993-01-01

424

Design and fabrication of microflap actuators for steering of micro air vehicles  

NASA Astrophysics Data System (ADS)

This paper presents the design, analysis, and fabrication of an array of microflap actuators that can produce a substantial aerodynamic force for course corrections of Micro Air Vehicles (MAVs) and low speed projectiles. In the past, several actuation principles, including microjet, magnetic and bubble actuators, and flapping wings have been proposed, and had varying degrees of success. In this paper, we discuss the benefits and drawbacks of past attempts, and the technology that can be used to address the microflap steering problem. We propose a hybrid microflap actuation scheme that combines two types of actuators including: 1) a MEMS fabricated "active" microactuator connected to a microflap, and 2) a "passive" fluidic channel system that harvests the potential energy in the high pressure field on the leading edge of the MAV or high speed projectile to achieve a desired deflection. An array of microflap actuators was prototyped using silicon MEMS fabrication and microassembly. A Silicon On Insulator (SOI) wafer with 100 micron thick device layer was used to as a substrate material to fabricate microflap structures with springs. Front and back side DRIE process was used to etch and release the microstructures including microflaps. Then, the microactuator was assembled on top of the microflap. The static and dynamic behaviors of a microflap were measured using a laser displacement sensor and were compared to the analytic model. In the near future, a prototyped microflap will be tested inside of a wind tunnel to measure the lift and drag at various air speeds.

Zimbru, George C.; Lee, Woo Ho; Popa, Dan O.

2009-05-01

425

Flow analysis and design optimization methods for nozzle afterbody of a hypersonic vehicle  

NASA Technical Reports Server (NTRS)

This report summarizes the methods developed for the aerodynamic analysis and the shape optimization of the nozzle-afterbody section of a hypersonic vehicle. Initially, exhaust gases were assumed to be air. Internal-external flows around a single scramjet module were analyzed by solving the three dimensional Navier-Stokes equations. Then, exhaust gases were simulated by a cold mixture of Freon and Argon. Two different models were used to compute these multispecies flows as they mixed with the hypersonic airflow. Surface and off-surface properties were successfully compared with the experimental data. In the second phase of this project, the Aerodynamic Design Optimization with Sensitivity analysis (ADOS) was developed. Pre and post optimization sensitivity coefficients were derived and used in this quasi-analytical method. These coefficients were also used to predict inexpensively the flow field around a changed shape when the flow field of an unchanged shape was given. Starting with totally arbitrary initial afterbody shapes, independent computations were converged to the same optimum shape, which rendered the maximum axial thrust.

Baysal, Oktay