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1

Laser Lightcraft Vehicle Design  

NASA Technical Reports Server (NTRS)

Current space deployment vehicle research is investigating ways to lower the cost to place payloads into orbit. Beamed energy propulsion is one of the areas that are being studied. The Laser lightcraft concept, which uses a ground based laser as part of its propulsion system, falls into this category. This concept has been developed by previous Strategic Defense Initiative Office (SDIO) research. In this concept, the laser energy is reflected off of a mirror on the craft and is focused inside the cowl to created optical breakdown of the propellant. There are several concerns about the design that must be further studied. These include: 1) Thermodynamic analysis of the cryogenic fuel storage and feed systems, 2) Analysis of the regenerative cooling system for the primary optic, and 3) Analysis of focal blurring of the laser due to off-axis flight.

Buch, Kevin

1999-01-01

2

Hybrid Vehicle Design Challenge  

NSDL National Science Digital Library

Through four lessons and four hands-on associated activities, this unit provides a way to teach the overarching concept of energy as it relates to both kinetic and potential energy. Within these topics, students are exposed to gravitational potential, spring potential, the Carnot engine, temperature scales and simple magnets. During the module, students apply these scientific concepts to solve the following engineering challenge: "The rising price of gasoline has many effects on the US economy and the environment. You have been contracted by an engineering firm to help design a physical energy storage system for a new hybrid vehicle for Nissan. How would you go about solving this problem? What information would you consider to be important to know? You will create a small prototype of your design idea and make a sales pitch to Nissan at the end of the unit." This module is built around the Legacy Cycle, a format that incorporates findings from educational research on how people best learn. This module is written for a first-year algebra-based physics class, though it could easily be modified for conceptual physics.

2014-09-18

3

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

4

Launch vehicle systems design analysis  

NASA Technical Reports Server (NTRS)

Current launch vehicle design emphasis is on low life-cycle cost. This paper applies total quality management (TQM) principles to a conventional systems design analysis process to provide low-cost, high-reliability designs. Suggested TQM techniques include Steward's systems information flow matrix method, quality leverage principle, quality through robustness and function deployment, Pareto's principle, Pugh's selection and enhancement criteria, and other design process procedures. TQM quality performance at least-cost can be realized through competent concurrent engineering teams and brilliance of their technical leadership.

Ryan, Robert; Verderaime, V.

1993-01-01

5

Building Spacecraft & Launch Vehicles! Space Vehicle Design!  

E-print Network

Astronautics, 1958" ·! Energy budgets" ·! MALLAR, MORAD, ARP, MALLIR" ·! Safety and reliability of LOR Braun's acquiescence for LOR" Joe Shea" ·! Evolution of Saturn launch vehicles" ·! Development of rocket

Stengel, Robert F.

6

Modeling Languages Refine Vehicle Design  

NASA Technical Reports Server (NTRS)

Cincinnati, Ohio s TechnoSoft Inc. is a leading provider of object-oriented modeling and simulation technology used for commercial and defense applications. With funding from Small Business Innovation Research (SBIR) contracts issued by Langley Research Center, the company continued development on its adaptive modeling language, or AML, originally created for the U.S. Air Force. TechnoSoft then created what is now known as its Integrated Design and Engineering Analysis Environment, or IDEA, which can be used to design a variety of vehicles and machinery. IDEA's customers include clients in green industries, such as designers for power plant exhaust filtration systems and wind turbines.

2009-01-01

7

Heat source reentry vehicle design study  

NASA Technical Reports Server (NTRS)

The design details are presented of a flight-type heat source reentry vehicle and heat exchanger compatible with the isotope Brayton power conversion system. The reference reentry vehicle and heat exchanger were modified, orbital and superorbital capability was assessed, and a complete set of detail design layout drawings were provided.

Ryan, R. L.

1971-01-01

8

Sensor design for unmanned aerial vehicles  

Microsoft Academic Search

This paper describes the prevailing overall considerations in designing sensors for unmanned aerial vehicles (UAVs). It describes in detail how these considerations and constraints have influenced the design of the sensor suite for the Global Hawk UAV

D. M. Stuart

1997-01-01

9

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

10

Lunar NTR vehicle design and operations study  

NASA Technical Reports Server (NTRS)

The results of a lunar nuclear thermal rocket (NTR) vehicle design and operations study are presented in text and graphic form. The objectives of the study were to evaluate the potential applications of a specific NTR design to past and current (First Lunar Outpost) mission profiles for piloted and cargo lunar missions, and to assess the applicability of utilizing lunar vehicle design concepts for Mars missions.

Hodge, John

1993-01-01

11

Macquarie University Design Standards EMERGENCY VEHICLE ACCESS  

E-print Network

OF ACCESS TO BUILDINGS 14.1 Fire Brigade vehicles shall have direct access to at least one face of everyMacquarie University Design Standards EMERGENCY VEHICLE ACCESS FIRE SAFETY CODE PART 14 MAINTENANCE building by means of a street, bridge, yard or private roadway, in accordance with 14.2 Access Requirements

Wang, Yan

12

Robust observer design for underwater vehicles  

Microsoft Academic Search

In this paper we propose a new observer system for underwater vehicles. The main design objective behind this strategy is to reduce the effect of the destabilizing Coriolis and centripetal forces and moments. For low cost vehicles with limited measurement equipment, these forces and moments represent a significant challenge for automatic control when the forward speed is high. However, by

Jon E. Refsnes; A. J. Sorensen; Kristin Y. Pettersen

2006-01-01

13

Automated mixed traffic vehicle design AMTV 2  

NASA Technical Reports Server (NTRS)

The design of an improved and enclosed Automated Mixed Traffic Transit (AMTT) vehicle is described. AMTT is an innovative concept for low-speed tram-type transit in which suitable vehicles are equipped with sensors and controls to permit them to operate in an automated mode on existing road or walkway surfaces. The vehicle chassis and body design are presented in terms of sketches and photographs. The functional design of the sensing and control system is presented, and modifications which could be made to the baseline design for improved performance, in particular to incorporate a 20-mph capability, are also discussed. The vehicle system is described at the block-diagram-level of detail. Specifications and parameter values are given where available.

Johnston, A. R.; Marks, R. A.; Cassell, P. L.

1982-01-01

14

Design of a current technology electric vehicle  

Microsoft Academic Search

The trade-offs involved in the design of a general-purpose four-passenger electric vehicle are reviewed. The advantages and disadvantages of three design approaches (series motor with chopper controller, separately excited motor with field control, and flywheel\\/electric hybrid) are discussed, along with the impact of battery characteristics on the performance of these three systems. The approaches taken in various aspects of vehicle

R. H. Guess

1978-01-01

15

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

16

Optimal Power Train Design of a Hybrid Refuse Collector Vehicle  

E-print Network

components compared to a heuristically designed vehicle. Keywords: Hybrid Electric Vehicle (HEV), optimization, refuse collector vehicle I. INTRODUCTION Today, hybrid electric vehicles are accepted as a step is possible with most of hybrid electric vehicles, promises significant fuel saving. In addition

Paderborn, Universität

17

TPMS receive antenna design for large vehicles  

Microsoft Academic Search

TPMS (Tire Pressure Monitoring System) is becoming an industry standard for driving safety and fuel efficiency. The receiving antenna for TPMS resides in the near field of the sensor antenna and this makes it very difficult to establish a reliable RF link for large vehicles. In the design of receiving antenna, it is paramount to consider the electric field distribution

Anil Ozdemirli; M. Murat Bilgic; Korkut Yegin

2011-01-01

18

Advanced control design for hybrid turboelectric vehicle  

NASA Astrophysics Data System (ADS)

The new environment standards are a challenge and opportunity for industry and government who manufacture and operate urban mass transient vehicles. A research investigation to provide control scheme for efficient power management of the vehicle is in progress. Different design requirements using functional analysis and trade studies of alternate power sources and controls have been performed. The design issues include portability, weight and emission/fuel efficiency of induction motor, permanent magnet and battery. A strategic design scheme to manage power requirements using advanced control systems is presented. It exploits fuzzy logic, technology and rule based decision support scheme. The benefits of our study will enhance the economic and technical feasibility of technological needs to provide low emission/fuel efficient urban mass transit bus. The design team includes undergraduate researchers in our department. Sample results using NASA HTEV simulation tool are presented.

Abban, Joseph; Norvell, Johnesta; Momoh, James A.

1995-08-01

19

Improving Conceptual Design for Launch Vehicles  

NASA Technical Reports Server (NTRS)

This report summarizes activities performed during the second year of a three year cooperative agreement between NASA - Langley Research Center and Georgia Tech. Year 1 of the project resulted in the creation of a new Cost and Business Assessment Model (CABAM) for estimating the economic performance of advanced reusable launch vehicles including non-recurring costs, recurring costs, and revenue. The current year (second year) activities were focused on the evaluation of automated, collaborative design frameworks (computation architectures or computational frameworks) for automating the design process in advanced space vehicle design. Consistent with NASA's new thrust area in developing and understanding Intelligent Synthesis Environments (ISE), the goals of this year's research efforts were to develop and apply computer integration techniques and near-term computational frameworks for conducting advanced space vehicle design. NASA - Langley (VAB) has taken a lead role in developing a web-based computing architectures within which the designer can interact with disciplinary analysis tools through a flexible web interface. The advantages of this approach are, 1) flexible access to the designer interface through a simple web browser (e.g. Netscape Navigator), 2) ability to include existing 'legacy' codes, and 3) ability to include distributed analysis tools running on remote computers. To date, VAB's internal emphasis has been on developing this test system for the planetary entry mission under the joint Integrated Design System (IDS) program with NASA - Ames and JPL. Georgia Tech's complementary goals this year were to: 1) Examine an alternate 'custom' computational architecture for the three-discipline IDS planetary entry problem to assess the advantages and disadvantages relative to the web-based approach.and 2) Develop and examine a web-based interface and framework for a typical launch vehicle design problem.

Olds, John R.

1998-01-01

20

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

21

The Taurus Launch Vehicle design and capability  

NASA Astrophysics Data System (ADS)

The Taurus launch systems are described with references to typical launch operations and possible interface, volume, and delivery capabilities. The launch system is a four-stage solid-fuel rocket motor with a Pegasus motor stack and avionics. Attention is given to the motorcase, the HTPB propellant, igniter and nozzle designs, and other components of the different stages, and each Taurus stage provides full thrust vector control. Also reviewed are vehicle integration, launch operations, and payload capability, integration, and environment. The vehicles can support payloads of 600-1500 kg for LEO delivery, 500 kg to geotransfer orbits, and 300 kg for interplanetary transfer orbits. The launch vehicle is concluded to reduce mission costs because the system offers several launch-site options and short concept-to-launch times.

Stoecker, Ted; Frazier, Scott; Padavano, Joe

1992-07-01

22

Space Vehicle Terrestrial Environment Design Requirements Guidelines  

NASA Technical Reports Server (NTRS)

The terrestrial environment is an important driver of space vehicle structural, control, and thermal system design. NASA is currently in the process of producing an update to an earlier 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, and sea state. In addition, the respective engineering design elements are discussed relative to terrestrial environment inputs that require consideration. Specific lessons learned that have contributed to the advancements made in the application and awareness of terrestrial environment inputs for aerospace engineering applications are presented.

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

2006-01-01

23

PAYCOS - A multidisciplinary design optimization tool for hypersonic vehicle design  

NASA Astrophysics Data System (ADS)

The Payload Conceptual Sizing Code (PAYCOS), developed at Lockheed Missiles and Space Company (LMSC), is a multidisciplinary design optimization (MDO) code for hypersonic maneuvering reentry and kinetic kill vehicle concept design. The purpose of PAYCOS is to rapidly perform concept sizing, concept evaluation, and associated trade studies for supersonic and hypersonic maneuvering vehicles. PAYCOS is a multidisciplinary analysis code that allows the engineer to determine the best geometric configuration for each design through parametric trade studies and mathematical optimization. This paper presents a brief overview of PAYCOS, with an emphasis on the Optimization Module. The paper concludes with a list of 'lessons learned' for those seeking to implement MDO.

Stubbe, J. R.

1992-09-01

24

Vehicle system controller design for a hybrid electric vehicle  

Microsoft Academic Search

As a way to meet the challenge of developing more fuel efficient and lower emission producing vehicles, auto manufacturers are increasingly looking toward revolutionary changes to conventional powertrain technologies as a solution. One alternative under consideration is that of hybrid electric vehicles (HEV). An HEV combines some of the benefits of electric vehicles (efficient and clean motive power supplied by

Anthony M. Phillips; Miroslava Jankovic; Kathleen E. Bailey

2000-01-01

25

Online Mechanism Design for Electric Vehicle Charging Enrico H. Gerding  

E-print Network

- multiagent systems General Terms Algorithms, Design, Economics Keywords electric vehicle, mechanism designOnline Mechanism Design for Electric Vehicle Charging Enrico H. Gerding eg@ecs.soton.ac.uk Valentin electric vehicles are expected to place a consid- erable strain on local electricity distribution networks

Chen, Yiling

26

A lunar construction shack vehicle: Final design  

NASA Technical Reports Server (NTRS)

A lunar construction shack vehicle is a critical component in most of the plans proposed for the construction of a permanent base on the moon. The Selene Engineering Company (SEC) has developed a concept for this vehicle which is both innovative and practical. The design makes use of the most advanced technology available to meet the goals for a safe, versatile and durable habitat that will serve as a starting point for the initial phase of the construction of a permanent lunar base. This document outlines SEC's proposed design for a lander vehicle which will be fully self-sufficient and will provide for all necessary life support, including consumables and radiation protection, needed by the construction crew until they can complete the assembly of a more permanent habitat. Since it is highly likely that it will take more than one crew to complete the construction of a permanent lunar base, the design emphasis is on systems which can be easily maintained and resupplied and which will take a minimum of start up preparation by succeeding crews.

1988-01-01

27

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

28

Hypersonic drone vehicle design: A multidisciplinary experience  

NASA Technical Reports Server (NTRS)

UCLA's Advanced Aeronautic Design group focussed their efforts on design problems of an unmanned hypersonic vehicle. It is felt that a scaled hypersonic drone is necesary to bridge the gap between present theory on hypersonics and the future reality of the National Aerospace Plane (NASP) for two reasons: (1) to fulfill a need for experimental data in the hypersonic regime, and (2) to provide a testbed for the scramjet engine which is to be the primary mode of propulsion for the NASP. The group concentrated on three areas of great concern to NASP design: propulsion, thermal management, and flight systems. Problem solving in these areas was directed toward design of the drone with the idea that the same design techniques could be applied to the NASP. A 70 deg swept double-delta wing configuration, developed in the 70's at the NASA Langley, was chosen as the aerodynamic and geometric model for the drone. This vehicle would be air launched from a B-1 at Mach 0.8 and 48,000 feet, rocket boosted by two internal engines to Mach 10 and 100,000 feet, and allowed to cruise under power of the scramjet engine until burnout. It would then return to base for an unpowered landing. Preliminary energy calculations based on flight requirements give the drone a gross launch weight of 134,000 pounds and an overall length of 85 feet.

1988-01-01

29

Space transportation vehicle design evaluation using saturated designs  

NASA Technical Reports Server (NTRS)

An important objective in the preliminary design and evaluation of space transportation vehicles is to find the best values of design variables that optimize the performance characteristic (e.g. dry weight). For a given configuration, the vehicle performance can be determined by the use of complex sizing and performance evaluation computer programs. These complex computer programs utilize iterative algorithms and they are generally too expensive and/or difficult to use directly in multidisciplinary design optimization. An alternative is to use response surface methodology (RSM) and obtain quadratic polynomial approximations to the functional relationships between performance characteristics and design variables. In RSM, these approximation models are then used to determine optimum design parameter values and for rapid sensitivity studies. Constructing a second-order model requires that 'n' design parameters be studied at least at 3 levels (values) so that the coefficients in the model can be estimated. There, 3(n) factorial experiments (point designs or observations) may be necessary. For small values of 'n' such as two or three, this design works well. However, when a large number of design parameters are under study, the number of design points required for a full-factorial design may become excessive. Fortunately, these quadratic polynomial approximations can be obtained by selecting an efficient design matrix using central composite designs (CCD) from design of experiments theory. Each unique point design from the CCD matrix is then conducted using computerized analysis tools (e.g. POST, CONSIZ, etc.). In the next step, least squares regression analysis is used to calculate the quadratic polynomial coefficients from the data. However, in some multidisciplinary applications involving a large number of design variables and several disciplines, the computerized performance synthesis programs may get too time consuming and expensive to run even with the use of efficient central composite designs. In such cases, it may be preferable to keep the number of design points to an absolute minimum and trade some model accuracy with cost. For this purpose, another class of experimental designs, called saturated D-optimal designs may be utilized for generating a matrix of vehicle designs. A design is called saturated when the number of design points is exactly equal to the number of terms in the model to be fitted. As a result, saturated designs require the absolute minimum number of design points ((n+1)(n+2)/s) to estimate the quadratic polynomial model coefficients. Saturated designs can be generated using the D-optimality criterion. A good saturated design should give rise to least squares estimates with minimum generalized variance.

Unal, Resit

1993-01-01

30

Vehicle following controller design for autonomous intelligent vehicles  

NASA Technical Reports Server (NTRS)

A new vehicle following controller is proposed for autonomous intelligent vehicles. The proposed vehicle following controller not only provides smooth transient maneuvers for unavoidable nonzero initial conditions but also guarantees the asymptotic platoon stability without the availability of feedforward information. Furthermore, the achieved asymptotic platoon stability is shown to be robust to sensor delays and an upper bound for the allowable sensor delays is also provided in this paper.

Chien, C. C.; Lai, M. C.; Mayr, R.

1994-01-01

31

Hybrid vehicle design using global optimisation Wenzhong Gao  

E-print Network

Hybrid vehicle design using global optimisation algorithms Wenzhong Gao Department of Electrical are applied in the design optimisation of a hybrid electric vehicle (HEV). These four algorithms are: DIRECT; hybrid electric vehicle; PSAT. Reference to this paper should be made as follows: Gao, W. and Mi, C

Mi, Chunting "Chris"

32

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

33

Aeroshell Design Techniques for Aerocapture Entry Vehicles  

NASA Technical Reports Server (NTRS)

A major goal of NASA s In-Space Propulsion Program is to shorten trip times for scientific planetary missions. To meet this challenge arrival speeds will increase, requiring significant braking for orbit insertion, and thus increased deceleration propellant mass that may exceed launch lift capabilities. A technology called aerocapture has been developed to expand the mission potential of exploratory probes destined for planets with suitable atmospheres. Aerocapture inserts a probe into planetary orbit via a single pass through the atmosphere using the probe s aeroshell drag to reduce velocity. The benefit of an aerocapture maneuver is a large reduction in propellant mass that may result in smaller, less costly missions and reduced mission cruise times. The methodology used to design rigid aerocapture aeroshells will be presented with an emphasis on a new systems tool under development. Current methods for fast, efficient evaluations of structural systems for exploratory vehicles to planets and moons within our solar system have been under development within NASA having limited success. Many systems tools that have been attempted applied structural mass estimation techniques based on historical data and curve fitting techniques that are difficult and cumbersome to apply to new vehicle concepts and missions. The resulting vehicle aeroshell mass may be incorrectly estimated or have high margins included to account for uncertainty. This new tool will reduce the guesswork previously found in conceptual aeroshell mass estimations.

Dyke, R. Eric; Hrinda, Glenn A.

2004-01-01

34

Aeroshell design techniques for aerocapture entry vehicles  

NASA Astrophysics Data System (ADS)

A major goal of NASA's In-Space Propulsion Program is to shorten trip times for scientific planetary missions. To meet this challenge arrival speeds will increase, requiring significant braking for orbit insertion, and thus increased deceleration propellant mass that may exceed launch lift capabilities. A technology called aerocapture has been developed to expand the mission potential of exploratory probes destined for planets with suitable atmospheres. Aerocapture inserts a probe into planetary orbit via a single pass through the atmosphere using the probe's aeroshell drag to reduce velocity. The benefit of an aerocapture maneuver is a large reduction in propellant mass that may result in smaller, less costly missions and reduced mission cruise times. The methodology used to design rigid aerocapture aeroshells will be presented with an emphasis on a new systems tool under development. Current methods for fast, efficient evaluations of structural systems for exploratory vehicles to planets and moons within our solar system have been under development within NASA having limited success. Many systems tools that have been attempted applied structural mass estimation techniques based on historical data and curve fitting techniques that are difficult and cumbersome to apply to new vehicle concepts and missions. The resulting vehicle aeroshell mass may be incorrectly estimated or have high margins included to account for uncertainty. This new tool will reduce the guesswork previously found in conceptual aeroshell mass estimations.

Dyke, R. Eric; Hrinda, Glenn A.

2007-12-01

35

Aerospace vehicle design, spacecraft section. Volume 1  

NASA Technical Reports Server (NTRS)

The objective was to create a manned Martian aircraft which can perform: scientific surveys of particular sites distant from the base; a deployment of scientific instrument packages by air drop that land rovers cannot accomplish; and rescue operations. Designing the airfoil requires a wing which can operate within the low Reynolds numbers apparent on Mars. The airfoil, NASA NLF(1)-1015 was chosen. The design of the aircraft is comparable to a P-38 military aircraft. The aircraft uses fuel cells to power the two propellers. A rocket-assisted takeoff is necessary to enable Romulus to liftoff. Although the design and creation of Romulus would be an expensive adventure, such a vehicle could be most useful in evaluating the Mars surface and in creating a habitat for mankind.

1988-01-01

36

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

37

Advances in fuel cell vehicle design  

Microsoft Academic Search

Factors such as global warming, dwindling fossil fuel reserves, and energy security concerns combine to indicate that a replacement for the internal combustion engine (ICE) vehicle is needed. Fuel cell vehicles have the potential to address the problems surrounding the ICE vehicle without imposing any significant restrictions on vehicle performance, driving range, or refuelling time. Though there are currently some

Jennifer Bauman

2008-01-01

38

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

39

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

40

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

41

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

42

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

43

Robust flight design for an advanced launch system vehicle  

NASA Technical Reports Server (NTRS)

Current launch vehicle trajectory design philosophies are generally based on maximizing payload capability. This approach results in an expensive trajectory design process for each mission. Two concepts of robust flight design have been developed to significantly reduce this cost: Standardized Trajectories and Command Multiplier Steering (CMS). These concepts were analyzed for an Advanced Launch System (ALS) vehicle, although their applicability is not restricted to any particular vehicle. Preliminary analysis has demonstrated the feasibility of these concepts at minimal loss in payload capability.

Dhand, Sanjeev K.; Wong, Kelvin K.

1991-01-01

44

CONCEPTUAL DESIGNS FOR A NEW HIGHWAY VEHICLE EMISSIONS ESTIMATION METHODOLOGY  

EPA Science Inventory

The report discusses six conceptual designs for a new highway vehicle emissions estimation methodology and summarizes the recommendations of each design for improving the emissions and activity factors in the emissions estimation process. he complete design reports are included a...

45

Optimal air-breathing launch vehicle design  

NASA Technical Reports Server (NTRS)

A generalized two-point boundary problem methodology, similar to techniques used in deterministic optimal control studies, is applied to the design and flight analysis of a two-stage air-breathing launch vehicle. Simultaneous consideration is given to configuration and trajectory by treating geometry, dynamic discontinuities, and time-dependent flight variables all as controls to be optimized with respect to a single mathematical performance measure. While minimizing fuel consumption, inequality constraints are applied to dynamic pressure and specific force. The optimal system fuel consumption and staging Mach number are found to vary little with changes in the inequality constraints due to substantial geometry and trajectory adjustments. Staging, from an air-breathing first stage to a rocket-powered second stage, consistently occurs near Mach 3.5. The dynamic pressure bound has its most pronounced effects on vehicle geometry, particularly the air-breathing propulsion inlet area, and on the first-stage altitude profile. The specific force has its greatest influence on the second-stage thrust history.

Hattis, P. D.

1981-01-01

46

Propulsion system design of electric and hybrid vehicles  

Microsoft Academic Search

There is a growing interest in electric and hybrid-electric vehicles due to environmental concerns. Efforts are directed toward developing an improved propulsion system for electric and hybrid-electric vehicles applications. This paper is aimed at developing the system design philosophies of electric and hybrid vehicle propulsion systems. The vehicles' dynamics are studied in an attempt to find an optimal torque-speed profile

Mehrdad Ehsani; Khwaja M. Rahman; Hamid A. Toliyat

1997-01-01

47

Communications and Tracking of Visiting Vehicles near ISS: The Design of the Reusable Launch Vehicle Communications  

NASA Technical Reports Server (NTRS)

The International Space Station (ISS) will provide for the visitation of various vehicles such as the Shuttle, Automated Transfer Vehicle (ATV), H-II Transfer Vehicle (HTV), Crew Return Vehicle (CRV), Reusable Launch Vehicle (RLV) and Soyuz. These vehicles will provide for crew replacement, consumables resupply, and equipment delivery. In order for these vehicles to approach and eventually dock with the ISS, there must be near continuous communications coverage between the visiting vehicle and the ISS, as well as communications between the vehicle and a Mission Control Center (MCC). Since the ISS communications systems are already designed and scheduled for ISS activation, the vehicles must either utilize these communications systems or provide their own. There are two means of two-way communications with the ISS. These are (1) S-Band communications using TDRSS, and (2) UHF communications using some form of the Space to Space Station Radio (SSSR) link. The RLV utilizes ISS compatible communications systems to communicate with both the ISS and a Mission Control Center. Since all vehicles must adhere to the Visiting Vehicle Interface requirements given in reference 1, the RLV communications system design must meet these requirements during entry into the ISS Approach Ellipsoid (AE) and during Proximity Operations. Included in this paper are descriptions of these communications approaches as well as their potential utilization in the ISS communications system.

Stillwagen, Frederic H.

1999-01-01

48

Manned Mars aerobrake vehicle design issues  

NASA Technical Reports Server (NTRS)

The paper examines the preliminary definition of the stagnation region aerothermodynamic environment, the effect of convective/radiative effect of trim angle-of-attack mispredictions, packaging issues, and the implications of wake flow for vehicles not having an aft aeroshell. The implications of each of these factors for a Mars aerobrake configuration with a L/D in the range of 0.3-0.5 is evaluated. It is shown that packaging and wake flow requirements have a significant impact on the final design of a low L/D aerobrake. Due to the large proportion of carbonaceous species in the Martian atmosphere, radiative heating is seen to play a more dominant role in the stagnation region aerothermodynamics than for an equivalent earth entry. It is concluded that this radiation amplification is an additional reason to consider a multiple aerobrake system.

Freeman, Delma C., Jr.; Powell, Richard W.; Braun, Robert D.

1990-01-01

49

Optimization of entry-vehicle shapes during conceptual design  

NASA Astrophysics Data System (ADS)

During the conceptual design of a re-entry vehicle, the vehicle shape and geometry can be varied and its impact on performance can be evaluated. In this study, the shape optimization of two classes of vehicles has been studied: a capsule and a winged vehicle. Their aerodynamic characteristics were analyzed using local-inclination methods, automatically selected per vehicle segment. Entry trajectories down to Mach 3 were calculated assuming trimmed conditions. For the winged vehicle, which has both a body flap and elevons, a guidance algorithm to track a reference heat-rate was used. Multi-objective particle swarm optimization was used to optimize the shape using objectives related to mass, volume and range. The optimizations show a large variation in vehicle performance over the explored parameter space. Areas of very strong non-linearity are observed in the direct neighborhood of the two-dimensional Pareto fronts. This indicates the need for robust exploration of the influence of vehicle shapes on system performance during engineering trade-offs, which are performed during conceptual design. A number of important aspects of the influence of vehicle behavior on the Pareto fronts are observed and discussed. There is a nearly complete convergence to narrow-wing solutions for the winged vehicle. Also, it is found that imposing pitch-stability for the winged vehicle at all angles of attack results in vehicle shapes which require upward control surface deflections during the majority of the entry.

Dirkx, D.; Mooij, E.

2014-01-01

50

Design of Launch Vehicle Flight Control Systems Using Ascent Vehicle Stability Analysis Tool  

NASA Technical Reports Server (NTRS)

A launch vehicle represents a complicated flex-body structural environment for flight control system design. The Ascent-vehicle Stability Analysis Tool (ASAT) is developed to address the complicity in design and analysis of a launch vehicle. The design objective for the flight control system of a launch vehicle is to best follow guidance commands while robustly maintaining system stability. A constrained optimization approach takes the advantage of modern computational control techniques to simultaneously design multiple control systems in compliance with required design specs. "Tower Clearance" and "Load Relief" designs have been achieved for liftoff and max dynamic pressure flight regions, respectively, in the presence of large wind disturbances. The robustness of the flight control system designs has been verified in the frequency domain Monte Carlo analysis using ASAT.

Jang, Jiann-Woei; Alaniz, Abran; Hall, Robert; Bedossian, Nazareth; Hall, Charles; Jackson, Mark

2011-01-01

51

Monitoring System Design for Lateral Vehicle Motion  

Microsoft Academic Search

Monitoring of lateral vehicle motion is very useful in many active safety applications such as yaw stability control and rollover prevention. Lateral velocity and sideslip angle are regarded as the most important motion variables. However, it is not feasible during vehicle operation to directly measure them due to the high cost of sensors, limitations to sensor technology, etc. Therefore, the

Sangoh Han; Kunsoo Huh

2011-01-01

52

Novel design for antidazzle vehicle headlight  

NASA Astrophysics Data System (ADS)

Compared to the important role in night driving of vehicle headlights, the dazzling and discomfort problems caused by the headlights are also not ignored. Sometimes the dazzling light is the main factor of causing traffic accidents in the night. In the paper, a novel design using irregular coating mirror to solve the dazzle problem is brought forward. As for the traditional headlamp comprised of a high beam and a low beam filament, the high beam filament causes plenty of the dazzling light. If the high beam filament's lighting density can be reduced without influencing the lighting effect, the problem is to be solved. Because plane-reflect mirror can change the light's transmitting direction, we employ the plan which uses 88 slat glasses whose upper surfaces coated with reflection films and bottom surfaces with light absorbing films, and put the whole mirror in front of the headlamp. When turn on headlight, the dazzling light is reflected by glass' upper plane, then absorbed by bottom plane. So the mirror prevents people from the dazzling light. In addition, the paper presents the experiment results to prove the anti-dazzle effect.

Yu, Liandong; Fei, Yetai

2006-11-01

53

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

54

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

55

DESIGN OF A REMOTELY CONTROLLED HOVERCRAFT VEHICLE FOR SPILL RECONNAISSANCE  

EPA Science Inventory

This program was undertaken to prepare a conceptual design for a practical prototype of a remotely-controlled reconnaissance vehicle for use in hazardous material spill environment. Data from past hazardous material spills were analyzed to determine the type of vehicle best suite...

56

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

57

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

58

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

59

Adaptive Modeling, Engineering Analysis and Design of Advanced Aerospace Vehicles  

NASA Technical Reports Server (NTRS)

This paper describes initial progress towards the development and enhancement of a set of software tools for rapid adaptive modeling, and conceptual design of advanced aerospace vehicle concepts. With demanding structural and aerodynamic performance requirements, these high fidelity geometry based modeling tools are essential for rapid and accurate engineering analysis at the early concept development stage. This adaptive modeling tool was used for generating vehicle parametric geometry, outer mold line and detailed internal structural layout of wing, fuselage, skin, spars, ribs, control surfaces, frames, bulkheads, floors, etc., that facilitated rapid finite element analysis, sizing study and weight optimization. The high quality outer mold line enabled rapid aerodynamic analysis in order to provide reliable design data at critical flight conditions. Example application for structural design of a conventional aircraft and a high altitude long endurance vehicle configuration are presented. This work was performed under the Conceptual Design Shop sub-project within the Efficient Aerodynamic Shape and Integration project, under the former Vehicle Systems Program. The project objective was to design and assess unconventional atmospheric vehicle concepts efficiently and confidently. The implementation may also dramatically facilitate physics-based systems analysis for the NASA Fundamental Aeronautics Mission. In addition to providing technology for design and development of unconventional aircraft, the techniques for generation of accurate geometry and internal sub-structure and the automated interface with the high fidelity analysis codes could also be applied towards the design of vehicles for the NASA Exploration and Space Science Mission projects.

Mukhopadhyay, Vivek; Hsu, Su-Yuen; Mason, Brian H.; Hicks, Mike D.; Jones, William T.; Sleight, David W.; Chun, Julio; Spangler, Jan L.; Kamhawi, Hilmi; Dahl, Jorgen L.

2006-01-01

60

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

61

A control system design of a tethered underwater vehicle  

SciTech Connect

In this paper, a high speed cruising tethered vehicle, which cruises at 6 kt, is designed with eight wing control surfaces and two surge thrusters in order to improve operational efficiency and also to obtain security. The vehicle control system is based on an optimal robust controller. The maneuvering characteristics under current and wave disturbances are tested by 3-dimensional maneuvering simulation. The hydrodynamic forces necessary for design are obtained by tank test. As a result, good robustness against variable disturbances was obtained.

Yamamoto, Ikuo; Nagamatu, Tetuo [Mitsubishi Heavy Industries, Ltd., Nagasaki (Japan)

1994-12-31

62

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

63

Optimal Design of Hybrid Fuel Cell Vehicles  

Microsoft Academic Search

Fuel cells are being considered increasingly as a viable al- ternative energy source for automobiles because of their clean and efficient power generation. Numerous technological con- cepts have been developed and compared in terms of safety, ro- bust operation, fuel economy, and vehicle performance. How- ever, several issues still exist and must be addressed to improve the viability of this

Jeongwoo Han; Michael Kokkolaras; Panos Y. Papalambros

2008-01-01

64

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

65

19 CFR 115.65 - Technical requirements for road vehicles by design type.  

Code of Federal Regulations, 2010 CFR

...Technical requirements for road vehicles by design type...PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY CARGO CONTAINER AND ROAD VEHICLE CERTIFICATION PURSUANT...Procedures for Approval of Road Vehicles by Design Type...

2010-04-01

66

Preventing passenger vehicle occupant injuries by vehicle design--a historical perspective from IIHS.  

PubMed

Motor vehicle crashes result in some 1.2 million deaths and many more injuries worldwide each year and is one of the biggest public health problems facing societies today. This article reviews the history of, and future potential for, one important countermeasure-designing vehicles that reduce occupant deaths and injuries. For many years, people had urged automakers to add design features to reduce crash injuries, but it was not until the mid-1960s that the idea of pursuing vehicle countermeasures gained any significant momentum. In 1966, the U.S. Congress passed the National Traffic and Motor Vehicle Safety Act, requiring the government to issue a comprehensive set of vehicle safety standards. This was the first broad set of requirements issued anywhere in the world, and within a few years similar standards were adopted in Europe and Australia. Early vehicle safety standards specified a variety of safety designs resulting in cars being equipped with lap/shoulder belts, energy-absorbing steering columns, crash-resistant door locks, high-penetration-resistant windshields, etc. Later, the standards moved away from specifying particular design approaches and instead used crash tests and instrumented dummies to set limits on the potential for serious occupant injuries by crash mode. These newer standards paved the way for an approach that used the marketplace, in addition to government regulation, to improve vehicle safety designs-using crash tests and instrumented dummies to provide consumers with comparative safety ratings for new vehicles. The approach began in the late 1970s, when NHTSA started publishing injury measures from belted dummies in new passenger vehicles subjected to frontal barrier crash tests at speeds somewhat higher than specified in the corresponding regulation. This program became the world's first New Car Assessment Program (NCAP) and rated frontal crashworthiness by awarding stars (five stars being the best and one the worst) derived from head and chest injury measures recorded on driver and front-seat test dummies. NHTSA later added side crash tests and rollover ratings to the U.S. NCAP. Consumer crash testing spread worldwide in the 1990s. In 1995, the Insurance Institute for Highway Safety (IIHS) began using frontal offset crash tests to rate and compare frontal crashworthiness and later added side and rear crash assessments. Shortly after, Europe launched EuroNCAP to assesses new car performance including front, side, and front-end pedestrian tests. The influence of these consumer-oriented crash test programs on vehicle designs has been major. From the beginning, U.S. NCAP results prompted manufacturers to improve seat belt performance. Frontal offset tests from IIHS and EuroNCAP resulted in greatly improved front-end crumple zones and occupant compartments. Side impact tests have similarly resulted in improved side structures and accelerated the introduction of side impact airbags, especially those designed to protect occupant's heads. Vehicle safety designs, initially driven by regulations and later by consumer demand because of crash testing, have proven to be very successful public health measures. Since they were first introduced in the late 1960s, vehicle safety designs have saved hundreds of thousands of lives and prevented countless injuries worldwide. The designs that improved vehicle crashworthiness have been particularly effective. Some newer crash avoidance designs also have the potential to be effective-e.g., electronic stability control is already saving many lives in single-vehicle crashes. However, determining the actual effectiveness of these new technologies is a slow process and needs real-world crash experience because there are no assessment equivalent of crash tests for crash avoidance designs. PMID:19333823

O'Neill, Brian

2009-04-01

67

Information Flow in the Launch Vehicle Design/Analysis Process  

NASA Technical Reports Server (NTRS)

This paper describes the results of a team effort aimed at defining the information flow between disciplines at the Marshall Space Flight Center (MSFC) engaged in the design of space launch vehicles. The information flow is modeled at a first level and is described using three types of templates: an N x N diagram, discipline flow diagrams, and discipline task descriptions. It is intended to provide engineers with an understanding of the connections between what they do and where it fits in the overall design process of the project. It is also intended to provide design managers with a better understanding of information flow in the launch vehicle design cycle.

Humphries, W. R., Sr.; Holland, W.; Bishop, R.

1999-01-01

68

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

69

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

70

Design study of toroidal traction CVT for electric vehicles  

NASA Technical Reports Server (NTRS)

The development, evaluation, and optimization of a preliminary design concept for a continuously variable transmission (CVT) to couple the high-speed output shaft of an energy storage flywheel to the drive train of an electric vehicle is discussed. An existing computer simulation program was modified and used to compare the performance of five CVT design configurations. Based on this analysis, a dual-cavity full-toroidal drive with regenerative gearing is selected for the CVT design configuration. Three areas are identified that will require some technological development: the ratio control system, the traction fluid properities, and evaluation of the traction contact performance. Finally, the suitability of the selected CVT design concept for alternate electric and hybrid vehicle applications and alternate vehicle sizes and maximum output torques is determined. In all cases the toroidal traction drive design concept is applicable to the vehicle system. The regenerative gearing could be eliminated in the electric powered vehicle because of the reduced ratio range requirements. In other cases the CVT with regenerative gearing would meet the design requirements after appropriate adjustments in size and reduction gearing ratio.

Raynard, A. E.; Kraus, J.; Bell, D. D.

1980-01-01

71

Design Criteria for Low Risk Re-Entry Vehicles  

NASA Astrophysics Data System (ADS)

The paper shows how a sharp vehicle with low wing loading, is able to follow re-entry trajectories with low thermal risks by using Ultra High Temperature Ceramics (UHTC) to thermally protect the vehicle front edges. These reusable materials can withstand the global radiative equilibrium temperatures that are experienced during reentry characterized by a longer and a more gradual conversion of the kinetic and potential energy of the vehicle into thermal energy. A number of aerothermodynamic problems are addressed to assess the feasibility of the vehicle design and of the thermal protection of the payload. In particular, the boundary layer thermal protection concept is illustrated to show how a UHTC massive tip edges (fuselage and wings) are able to protect also the remaining vehicle structure made of conventional material, promoting a revolutionary approach to the Thermal Protection System (TPS) configuration for hypersonic vehicle flying at small angle of attack. CFD results and engineering formulations are adopted for the computation of the aerodynamic coefficients and heat fluxes. The analysis identifies the design criteria for a conventional looking vehicle for a crew return from LEO (e.g. from the International Space Station).

Monti, R.; Pezzella, G.

2005-02-01

72

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

73

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

74

Advanced vehicle concepts systems and design analysis studies  

NASA Technical Reports Server (NTRS)

The work conducted by the ELORET Institute under this Cooperative Agreement includes the modeling of hypersonic propulsion systems and the evaluation of hypersonic vehicles in general and most recently hypersonic waverider vehicles. This work in hypersonics was applied to the design of a two-stage to orbit launch vehicle which was included in the NASA Access to Space Project. Additional research regarded the Oblique All-Wing (OAW) Project at NASA ARC and included detailed configuration studies of OAW transport aircraft. Finally, work on the modeling of subsonic and supersonic turbofan engines was conducted under this research program.

Waters, Mark H.; Huynh, Loc C.

1994-01-01

75

Conceptual Launch Vehicle and Spacecraft Design for Risk Assessment  

NASA Technical Reports Server (NTRS)

One of the most challenging aspects of developing human space launch and exploration systems is minimizing and mitigating the many potential risk factors to ensure the safest possible design while also meeting the required cost, weight, and performance criteria. In order to accomplish this, effective risk analyses and trade studies are needed to identify key risk drivers, dependencies, and sensitivities as the design evolves. The Engineering Risk Assessment (ERA) team at NASA Ames Research Center (ARC) develops advanced risk analysis approaches, models, and tools to provide such meaningful risk and reliability data throughout vehicle development. The goal of the project presented in this memorandum is to design a generic launch 7 vehicle and spacecraft architecture that can be used to develop and demonstrate these new risk analysis techniques without relying on other proprietary or sensitive vehicle designs. To accomplish this, initial spacecraft and launch vehicle (LV) designs were established using historical sizing relationships for a mission delivering four crewmembers and equipment to the International Space Station (ISS). Mass-estimating relationships (MERs) were used to size the crew capsule and launch vehicle, and a combination of optimization techniques and iterative design processes were employed to determine a possible two-stage-to-orbit (TSTO) launch trajectory into a 350-kilometer orbit. Primary subsystems were also designed for the crewed capsule architecture, based on a 24-hour on-orbit mission with a 7-day contingency. Safety analysis was also performed to identify major risks to crew survivability and assess the system's overall reliability. These procedures and analyses validate that the architecture's basic design and performance are reasonable to be used for risk trade studies. While the vehicle designs presented are not intended to represent a viable architecture, they will provide a valuable initial platform for developing and demonstrating innovative risk assessment capabilities.

Motiwala, Samira A.; Mathias, Donovan L.; Mattenberger, Christopher J.

2014-01-01

76

Systematic design of fuel cell powered hybrid vehicle drive train  

Microsoft Academic Search

A general design methodology of the fuel cell-powered hybrid vehicle drive train has been developed. With the methodology and a computer simulation program, all of the systematic parameters can be designed, such as, the rated power of the electric motor drive, fuel cell system, peaking power source as well as the energy capacity. An overall control strategy has also been

Yimin Gao; Mahrdad Ehsani

2001-01-01

77

Design Considerations for a Launch Vehicle Development Flight Instrumentation System  

NASA Technical Reports Server (NTRS)

When embarking into the design of a new launch vehicle, engineering models of expected vehicle performance are always generated. While many models are well established and understood, some models contain design features that are only marginally known. Unfortunately, these analytical models produce uncertainties in design margins. The best way to answer these analytical issues is with vehicle level testing. The National Aeronautics and Space Administration respond to these uncertainties by using a vehicle level system called the Development Flight Instrumentation, or DFI. This DFI system can be simple to implement, with only a few measurements, or it may be a sophisticated system with hundreds of measurement and video, without a recording capability. From experience with DFI systems, DFI never goes away. The system is renamed and allowed to continue, in most cases. Proper system design can aid the transition to future data requirements. This paper will discuss design features that need to be considered when developing a DFI system for a launch vehicle. It will briefly review the data acquisition units, sensors, multiplexers and recorders, telemetry components and harnessing. It will present a reasonable set of requirements which should be implemented in the beginning of the program in order to start the design. It will discuss a simplistic DFI architecture that could be the basis for the next NASA launch vehicle. This will be followed by a discussion of the "experiences gained" from a past DFI system implementation, such as the very successful Ares I-X test flight. Application of these design considerations may not work for every situation, but they may direct a path toward success or at least make one pause and ask the right questions.

Johnson, Martin L.; Crawford, Kevin

2011-01-01

78

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

79

Design of a recovery system for a reentry vehicle  

NASA Technical Reports Server (NTRS)

Engineers are often required to design decelerator systems which are deployed in cross-wind orientations. If the system is not designed to minimize 'line sail', damage to the parachutes could result. A Reentry Vehicle Analysis Code (RVAC) and an accompanying graphics animation software program (DISPLAY) are presented in this paper. These computer codes allow the user to quickly apply the Purvis line sail modeling technique to any vehicle and then observe the relative motion of the vehicle, nose cap, suspension lines, pilot and drogue bags and canopies on a computer screen. Data files are created which allow plots of velocities, spacial positions, and dynamic pressures versus time to be generated. The code is an important tool for the design engineer because it integrates two degrees of freedom (DOF) line sail equations with a three DOF model of the reentry body and jettisoned nose cap to provide an animated output.

Von Eckroth, Wulf; Garrard, William L.; Miller, Norman

1993-01-01

80

Vehicle drive module having improved terminal design  

DOEpatents

A terminal structure for vehicle drive power electronics circuits reduces the need for a DC bus and thereby the incidence of parasitic inductance. The structure is secured to a support that may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. The support may form a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as by direct contact between the terminal assembly and AC and DC circuit components. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

Beihoff, Bruce C.; Radosevich, Lawrence D.; Phillips, Mark G.; Kehl, Dennis L.; Kaishian, Steven C.; Kannenberg, Daniel G.

2006-04-25

81

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

82

Reliability-based design optimization for crashworthiness of vehicle side impact  

Microsoft Academic Search

With the advent of powerful computers, vehicle safety issues have recently been addressed using computational methods of vehicle crashworthiness, resulting in reductions in cost and time for new vehicle development. Vehicle design demands multidisciplinary optimization coupled with a computational crashworthiness analysis. However, simulation-based optimization generates deterministic optimum designs, which are frequently pushed to the limits of design constraint boundaries, leaving

B. D. Youn; K. K. Choi; R.-J. Yang; L. Gu

2004-01-01

83

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

84

Constrained Aerothermodynamic Design of Hypersonic Vehicles  

NASA Technical Reports Server (NTRS)

An investigation was conducted into possible methods of incorporating a hypersonic design capability with aerothermodynamic constraints into the CDISC aerodynamic design tool. The work was divided into two distinct phases: develop relations between surface curvature and hypersonic pressure coefficient which are compatible with CDISC's direct-iterative design method; and explore and implement possible methods of constraining the heat transfer rate over all or portions of the design surface. The main problem in implementing this method has been the weak relationship between surface shape and pressure coefficient at the stagnation point and the need to design around the surface blunt leading edge where there is a slope singularity. The final results show that some success has been achieved, but further improvements are needed.

Gally, Tom; Campbell, Dick

2002-01-01

85

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

86

Towards Comprehensive Variation Models for Designing Vehicle Monitoring Systems  

NASA Technical Reports Server (NTRS)

When designing vehicle vibration monitoring systems for aerospace devices, it is common to use well-established models of vibration features to determine whether failures or defects exist. Most of the algorithms used for failure detection rely on these models to detect significant changes in a flight environment. In actual practice, however, most vehicle vibration monitoring systems are corrupted by high rates of false alarms and missed detections. This crucial roadblock makes their implementation in real vehicles (e.g., helicopter transmissions and aircraft engines) difficult, making their operation costly and unreliable. Research conducted at the NASA Ames Research Center has determined that a major reason for the high rates of false alarms and missed detections is the numerous sources of statistical variations that are not taken into account in the modeling assumptions. In this paper, we address one such source of variations, namely, those caused during the design and manufacturing of rotating machinery components that make up aerospace systems. We present a novel way of modeling the vibration response by including design variations via probabilistic methods. Using such models, we develop a methodology to account for design and manufacturing variations, and explore the changes in the vibration response to determine its stochastic nature. We explore the potential of the methodology using a nonlinear cam-follower model, where the spring stiffness values are assumed to follow a normal distribution. The results demonstrate initial feasibility of the method, showing great promise in developing a general methodology for designing more accurate aerospace vehicle monitoring systems.

McAdams, Daniel A.; Tumer, Irem Y.; Clancy, Daniel (Technical Monitor)

2002-01-01

87

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

Microsoft Academic Search

All fuel cells cuuenuy 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

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

1999-01-01

88

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

89

Overview of integrated programs for aerospace-vehicle design (IPAD)  

NASA Technical Reports Server (NTRS)

An overview of a joint industry/government project, denoted Integrated Programs for Aerospace-Vehicle Design (IPAD), which focuses on development of technology and associated software for integrated company-wide management of engineering information is presented. Results to date are summarized and include an in-depth documentation of a representative design process for a large engineering project, the definition and design of computer-aided design software needed to support that process, and the release of prototype software to integrated selected design functions.

Fulton, R. E.

1980-01-01

90

The Taurus Launch Vehicle design and capability  

Microsoft Academic Search

The Taurus launch systems are described with references to typical launch operations and possible interface, volume, and delivery capabilities. The launch system is a four-stage solid-fuel rocket motor with a Pegasus motor stack and avionics. Attention is given to the motorcase, the HTPB propellant, igniter and nozzle designs, and other components of the different stages, and each Taurus stage provides

Ted Stoecker; Scott Frazier; Joe Padavano

1992-01-01

91

Design of an urban driverless ground vehicle  

Microsoft Academic Search

AbstractThis paper presents the design and implementation 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 guarantees and executes it. All of it was implemented and integrated into a single computer maneuvering on real time an

Rodrigo Benenson; Michel Parent

2008-01-01

92

Design and testing of a dissociated methanol vehicle  

Microsoft Academic Search

The concept of dissociating methanol with exhaust gas heat to improve the efficiency of methanol-burning engines has often been described in the literature. The concept has been controversial with conflicting results from analysis and experimentation. In this report, we describe the design and testing of a dissociated methanol vehicle based on a Ford Escort. This work draws heavily on the

Karpuk

1989-01-01

93

Design considerations for Mars transfer vehicles using nuclear thermal propulsion  

Microsoft Academic Search

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

William J. Emrich

1995-01-01

94

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

95

ME 409: Flight Vehicle Design I: Information Sheet  

E-print Network

ME 409: Flight Vehicle Design I: Information Sheet 1 INSTRUCTOR: Prof. Don Wroblewski OFFICE HRS: M to answer any of the pre-flight "review questions" · For each class (i.e., set of posted slides) there will be a Piazza forum with several of the harder pre-flight review questions, though you can start a thread

96

Simulation of Wind Profile Perturbations for Launch Vehicle Design  

NASA Technical Reports Server (NTRS)

Ideally, a statistically representative sample of measured high-resolution wind profiles with wavelengths as small as tens of meters is required in design studies to establish aerodynamic load indicator dispersions and vehicle control system capability. At most potential launch sites, high- resolution wind profiles may not exist. Representative samples of Rawinsonde wind profiles to altitudes of 30 km are more likely to be available from the extensive network of measurement sites established for routine sampling in support of weather observing and forecasting activity. Such a sample, large enough to be statistically representative of relatively large wavelength perturbations, would be inadequate for launch vehicle design assessments because the Rawinsonde system accurately measures wind perturbations with wavelengths no smaller than 2000 m (1000 m altitude increment). The Kennedy Space Center (KSC) Jimsphere wind profiles (150/month and seasonal 2 and 3.5-hr pairs) are the only adequate samples of high resolution profiles approx. 150 to 300 m effective resolution, but over-sampled at 25 m intervals) that have been used extensively for launch vehicle design assessments. Therefore, a simulation process has been developed for enhancement of measured low-resolution Rawinsonde profiles that would be applicable in preliminary launch vehicle design studies at launch sites other than KSC.

Adelfang, S. I.

2004-01-01

97

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

98

Designing and building an electric vehicle for commercial fleet operators  

Microsoft Academic Search

Grumman Allied Industries was charged to design an electrically propelled truck that used Grumman's lightweight aluminum truck bodies. A prototype was tested in-house, and failed. It was then redesigned to increase battery mass friction, and to decrease vehicle curb weight. A VW Dasher rear suspension and a VW Rabbit undercarriage configuration were installed. Motor, vent and fill system, propulsion batteries,

S. Ferdman; J. C. Kessler

1982-01-01

99

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 of driverless cars is expected to enhance the traffic circulation in the cities, reduce the number of accidentsDesign of an urban driverless ground vehicle Rodrigo Benenson INRIA Rocquencourt / Mines Paris

Paris-Sud XI, Universit de

100

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

101

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

102

Launch Vehicle Design Process Description and Training Formulation  

NASA Technical Reports Server (NTRS)

A primary NASA priority is to reduce the cost and improve the effectiveness of launching payloads into space. As a consequence, significant improvements are being sought in the effectiveness, cost, and schedule of the launch vehicle design process. In order to provide a basis for understanding and improving the current design process, a model has been developed for this complex, interactive process, as reported in the references. This model requires further expansion in some specific design functions. Also, a training course for less-experienced engineers is needed to provide understanding of the process, to provide guidance for its effective implementation, and to provide a basis for major improvements in launch vehicle design process technology. The objective of this activity is to expand the description of the design process to include all pertinent design functions, and to develop a detailed outline of a training course on the design process for launch vehicles for use in educating engineers whose experience with the process has been minimal. Building on a previously-developed partial design process description, parallel sections have been written for the Avionics Design Function, the Materials Design Function, and the Manufacturing Design Function. Upon inclusion of these results, the total process description will be released as a NASA TP. The design function sections herein include descriptions of the design function responsibilities, interfaces, interactive processes, decisions (gates), and tasks. Associated figures include design function planes, gates, and tasks, along with other pertinent graphics. Also included is an expanded discussion of how the design process is divided, or compartmentalized, into manageable parts to achieve efficient and effective design. A detailed outline for an intensive two-day course on the launch vehicle design process has been developed herein, and is available for further expansion. The course is in an interactive lecture/workshop format to engage the participants in active learning. The course addresses the breadth and depth of the process, requirements, phases, participants, multidisciplinary aspects, tasks, critical elements,as well as providing guidance from previous lessons learned. The participants are led to develop their own understanding of the current process and how it can be improved. Included are course objectives and a session-by-session outline of course content. Also included is an initial identification of visual aid requirements.

Atherton, James; Morris, Charles; Settle, Gray; Teal, Marion; Schuerer, Paul; Blair, James; Ryan, Robert; Schutzenhofer, Luke

1999-01-01

103

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

104

Application of subharmonics for active sound design of electric vehicles.  

PubMed

The powertrain of electric vehicles generates an unfamiliar acoustical environment for customers. This paper seeks optimal interior sound for electric vehicles based on psychoacoustic knowledge and musical harmonic theory. The concept of inserting a virtual sound, which consists of the subharmonics of an existing high-frequency component, is suggested to improve sound quality. Subjective evaluation results indicate that the impression of interior sound can be enhanced in this manner. Increased appeal is achieved through two designed stimuli, which proves the effectiveness of the method proposed. PMID:25480088

Gwak, Doo Young; Yoon, Kiseop; Seong, Yeolwan; Lee, Soogab

2014-12-01

105

Application of Adaptive Autopilot Designs for an Unmanned Aerial Vehicle  

NASA Technical Reports Server (NTRS)

This paper summarizes the application of two adaptive approaches to autopilot design, and presents an evaluation and comparison of the two approaches in simulation for an unmanned aerial vehicle. One approach employs two-stage dynamic inversion and the other employs feedback dynamic inversions based on a command augmentation system. Both are augmented with neural network based adaptive elements. The approaches permit adaptation to both parametric uncertainty and unmodeled dynamics, and incorporate a method that permits adaptation during periods of control saturation. Simulation results for an FQM-117B radio controlled miniature aerial vehicle are presented to illustrate the performance of the neural network based adaptation.

Shin, Yoonghyun; Calise, Anthony J.; Motter, Mark A.

2005-01-01

106

Design optimization by response surface methodology: application to crashworthiness design of vehicle structures  

Microsoft Academic Search

Standards imposed by certification regulations are very strict and the requirements of the customer in terms of vehicle safety are always increasing. It is often necessary to redesign several vehicle components in order to achieve a global better performance. Design optimization by response surface methodology has been effectively used to improve the mechanical behaviour of several automotive components in impact

M. Avalle; G. Chiandussi; G. Belingardi

2002-01-01

107

1 Copyright 2004 by ASME DESIGN FOR CRASHWORTHINESS OF VEHICLE STRUCTURES VIA EQUIVALENT  

E-print Network

1 Copyright 2004 by ASME DESIGN FOR CRASHWORTHINESS OF VEHICLE STRUCTURES VIA EQUIVALENT This paper presents a 3D extension to our previous work on vehicle crashworthiness design that utilizes model. 1. INTRODUCTION Vehicle crashworthiness is an important design attribute which designers strive

Saitou, Kazuhiro "Kazu"

108

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

109

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

110

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

111

Design of cryogenic tanks for launch vehicles  

NASA Technical Reports Server (NTRS)

During the period since January 1990, work was concentrated on the problem of the buckling of the structure of an ALS (advanced launch systems) tank during the boost phase. The primary problem was to analyze a proposed hat stringer made by superplastic forming, and to compare it with an integrally stiffened stringer design. A secondary objective was to determine whether structural rings having the identical section to the stringers will provide adequate support against overall buckling. All of the analytical work was carried out with the TESTBED program on the CONVEX computer, using PATRAN programs to create models. Analyses of skin/stringer combinations have shown that the proposed stringer design is an adequate substitute for the integrally stiffened stringer. Using a highly refined mesh to represent the corrugations in the vertical webs of the hat stringers, effective values were obtained for cross-sectional area, moment of inertia, centroid height, and torsional constant. Not only can these values be used for comparison with experimental values, but they can also be used for beams to replace the stringers and frames in analytical models of complete sections of tank. The same highly refined model was used to represent a section of skin reinforced by a stringer and a ring segment in the configuration of a cross. It was intended that this would provide a baseline buckling analysis representing a basic mode, however, the analysis proved to be beyond the scope of the CONVEX computer. One quarter of this model was analyzed, however, to provide information on buckling between the spot welds. Models of large sections of the tank structure were made, using beam elements to model the stringers and frames. In order to represent the stiffening effects of pressure, stresses and deflections under pressure should first be obtained, and then the buckling analysis should be made on the structure so deflected. So far, uncharacteristic deflections under pressure were obtained from the TESTBED program using two types of structural elements. Similar results were obtained using the ANSYS program on a mainframe computer, although two finite element programs on microcomputers have yielded realistic results.

Copper, Charles; Pilkey, Walter D.; Haviland, John K.

1990-01-01

112

Issues in the design of fault tolerant vehicle management systems for next generation unstable air vehicles  

Microsoft Academic Search

The author describes design issues in fault-tolerant vehicle management systems (VMS) for next-generation high-performance aircraft. Unstable aircraft require a highly reliable fault-tolerant computer to perform dynamic compensation of effector surface controls. Next-generation system requirements for system availability and performance will extend the role of flight criticality beyond the flight data sensors and actuation control functions. Additional control systems requiring a

T. D. Gaska

1988-01-01

113

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

114

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

Microsoft Academic Search

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

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

1991-01-01

115

Design and demonstration of an extended range hydrogen fuel cell utility vehicle  

Microsoft Academic Search

This paper discusses the design, build, and demonstration of two hybrid electric fuel cell utility vehicles for a program sponsored by DLA (Defense Logistics Agency). The design emphasis for the utility vehicles was range extension over state of the art battery systems using a fuel cell power plant. The design work involved vehicle modeling in PSAT to evaluate different battery

C. S. Hearn; M. C. Lewis; R. T. Thompson; D. Chen; J. Hanlm; D. Zuckerman; T. Lindsay

2011-01-01

116

Design and construction of the GUANAY-II autonomous underwater vehicle  

Microsoft Academic Search

This paper presents the design and construction of Guanay II vehicle. It is an autonomous underwater vehicle that navigates over the sea surface and, at certain fixed points, dives vertically to obtain a profile of a water column. The designed vehicle has a double hull structure. The external fiberglass hull, which is not watertight, has been designed in accordance with

S. Gomariz; J. Gonzalez; A. Arbos; I. Masmitja; G. Masmitja; J. Prat

2011-01-01

117

Vibration Challenges in the Design of NASA's Ares Launch Vehicles  

NASA Technical Reports Server (NTRS)

This paper focuses on the vibration challenges inherent in the design of NASA s Ares launch vehicles. A brief overview of the launch system architecture is provided to establish the context for the discussion. Following this is a general discussion of the design considerations and analytical disciplines that are affected by vibration. The first challenge discussed is that of coupling between the vehicle flight control system and fundamental vibrational modes of the vehicle. The potential destabilizing influence of the vibrational dynamics is described along with discussion of the typical methods employed to overcome this issue. Next is a general discussion of the process for developing the design loads for the primary structure. This includes quasi-steady loads and dynamic loads induced by the structural dynamic response. The two principal parts of this response are the gust induced responses of the lower frequency modes and the buffet induced responses of the higher frequency modes. Structural dynamic model validation will also be addressed. Following this, discussions of three somewhat unique topics of Pogo Instability, Solid Booster Thrust Oscillation, and Liquid Rocket Engine Turbopump Rotordynamic Stability and Response are presented.

Ryan, Stephen G.

2009-01-01

118

Design and construction of a solar-electric vehicle  

SciTech Connect

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 aluminum space frame, the wheel hubs and front suspension assembly, the drive train, and the electrical system. The frame was designed using finite element analysis with the components of the frame modeled as beam elements. The body, designed to have a very high strength-to-weight ratio, was of graphite/Kevlar/Nomex sandwich construction. Testing was carried out using the three-point bend test to determine the optimal sandwich cross-sectional configuration. The design of the front suspension, the wheel hubs, and the power transmission are also discussed. The electrical system, based on a monocrystalline photovoltaic cell assembly, and silver-zinc storage cells, is also described. Finally, results of the optimization routine developed are also described.

Bhavnani, S.H. (Auburn Univ., AL (United States). Dept. of Mechanical Engineering)

1994-02-01

119

Privacy on the Roads: How the Design of New Vehicle Safety Communication Technologies Impact Drivers' \\  

Microsoft Academic Search

Recent advances in wireless technologies have led to the development of intelligent, in-vehicle safety applications designed to share information about the actions of nearby vehicles, potential road hazards, and ultimately predict dangerous scenarios or imminent collisions. These vehicle safety communication (VSC) technologies rely on the creation of autonomous, self-organizing, wireless communication networks connecting vehicles with roadside infrastructure and with each

Michael Zimmer

120

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

121

Common Lunar Lander vehicle propulsion system conceptual design  

NASA Astrophysics Data System (ADS)

The Common Lunar Lander (CLL) is a concept for a small, unpiloted vehicle which would provide a low-cost capability to land any of a variety of payloads in the 200 kg class at any point on the surface of the moon. Initiated as a precursor mission for the First Lunar Outpost, it also has considerable potential for use by the scientific community at large. A series of studies has been conducted at the NASA Johnson Space Center to define initial requirements and to initiate the design process. This paper describes the propulsion subsystem design as it existed at the CLL System Design Review. The propulsion subsystem design is described in detail along with the planned operations concept, including the unique concept of using pulsing of main engines for thrust modulation. Design options and trades considered and the verification process philosophy which was being planned for the program are discussed.

Hyatt, C. D.; Riccio, Joseph R.; Moore, Landon

1993-06-01

122

Common Lunar Lander vehicle propulsion system conceptual design  

NASA Technical Reports Server (NTRS)

The Common Lunar Lander (CLL) is a concept for a small, unpiloted vehicle which would provide a low-cost capability to land any of a variety of payloads in the 200 kg class at any point on the surface of the moon. Initiated as a precursor mission for the First Lunar Outpost, it also has considerable potential for use by the scientific community at large. A series of studies has been conducted at the NASA Johnson Space Center to define initial requirements and to initiate the design process. This paper describes the propulsion subsystem design as it existed at the CLL System Design Review. The propulsion subsystem design is described in detail along with the planned operations concept, including the unique concept of using pulsing of main engines for thrust modulation. Design options and trades considered and the verification process philosophy which was being planned for the program are discussed.

Hyatt, C. D.; Riccio, Joseph R.; Moore, Landon

1993-01-01

123

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

124

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

125

Launch Vehicle Propulsion Design with Multiple Selection Criteria  

NASA Technical Reports Server (NTRS)

The approach and techniques described herein define an optimization and evaluation approach for a liquid hydrogen/liquid oxygen single-stage-to-orbit system. The method uses Monte Carlo simulations, genetic algorithm solvers, a propulsion thermo-chemical code, power series regression curves for historical data, and statistical models in order to optimize a vehicle system. The system, including parameters for engine chamber pressure, area ratio, and oxidizer/fuel ratio, was modeled and optimized to determine the best design for seven separate design weight and cost cases by varying design and technology parameters. Significant model results show that a 53% increase in Design, Development, Test and Evaluation cost results in a 67% reduction in Gross Liftoff Weight. Other key findings show the sensitivity of propulsion parameters, technology factors, and cost factors and how these parameters differ when cost and weight are optimized separately. Each of the three key propulsion parameters; chamber pressure, area ratio, and oxidizer/fuel ratio, are optimized in the seven design cases and results are plotted to show impacts to engine mass and overall vehicle mass.

Shelton, Joey D.; Frederick, Robert A.; Wilhite, Alan W.

2005-01-01

126

Expert system approach to design an automated guided vehicle  

NASA Astrophysics Data System (ADS)

The purpose of this paper is to describe an expert system to design the base of an automated guided vehicle. The components of the expert system include: (1) A user-friendly graphic user interface, where the user can enter specifications--like the environment used, application of the robot, etc.; (2) An engine that converts the managerial requirements into technical parameters and designs the robot--initially assuming some parameters and confirming its assumptions during the course of the design; when unable to do so, it iterates with different assumptions until they are met; the code also selects various materials to be used from a corresponding database; (3) A database of various materials from their manufacturers/suppliers; (4) The output data is interfaced with a CAD engine, which generates a 3D solid model of the vehicle; and (5) A `Bill of Materials' file is generated as the output and suggestions for how to assemble them are given. The method has been tested by designing a small mobile robot. The software provides an excellent tool to develop a mobile robot based on performance specifications. Modeling helps the user understand the constraints on the design of the robot and the bill of materials--along with the vendor address, helps the user buy the components needed to assemble the robot.

Kumaraguru, Karthikeyan; Hall, Ernest L.

1998-10-01

127

Design Considerations for Space Transfer Vehicles Using Solar Thermal Propulsion  

NASA Technical Reports Server (NTRS)

The economical deployment of satellites to high energy earth orbits is crucial to the ultimate success of this nations commerical space ventures and is highly desirable for deep space planetary missions requiring earth escape trajectories. Upper stage space transfer vehicles needed to accomplish this task should ideally be simple, robust, and highly efficient. In this regard, solar thermal propulsion is particularly well suited to those missions where high thrust is not a requirement. The Marshall Space Flight Center is , therefore, currently engaged in defining a transfer vehicle employing solar thermal propulsion capable of transferring a 1000 lb. payload from low Earth orbit (LEO) to a geostationary Earth orbit (GEO) using a Lockheed launch vehicle (LLV3) with three Castors and a large shroud. The current design uses liquid hydrogen as the propellant and employs two inflatable 16 x 24 feet eliptical off-axis parabolic solar collectors to focus sunlight onto a tungsten/rhenium windowless black body type absorber. The concentration factor on this design is projected to be approximately 1800:1 for the primary collector and 2.42:1 for the secondary collector for an overall concentration factor of nearly 4400:1. The engine, which is about twice as efficient as the best currently available chemical engines, produces two pounds of thrust with a specific impulse (Isp) of 860 sec. Transfer times to GEO are projected to be on the order of one month. The launch and deployed configurations of the solar thermal upper stage (STUS) are depicted.

Emrich, William J.

1995-01-01

128

Reentry Vehicle Flight Controls Design Guidelines: Dynamic Inversion  

NASA Technical Reports Server (NTRS)

This report addresses issues in developing a flight control design for vehicles operating across a broad flight regime and with highly nonlinear physical descriptions of motion. Specifically it addresses the need for reentry vehicles that could operate through reentry from space to controlled touchdown on Earth. The latter part of controlled descent is achieved by parachute or paraglider - or by all automatic or a human-controlled landing similar to that of the Orbiter. Since this report addresses the specific needs of human-carrying (not necessarily piloted) reentry vehicles, it deals with highly nonlinear equations of motion, and then-generated control systems must be robust across a very wide range of physics. Thus, this report deals almost exclusively with some form of dynamic inversion (DI). Two vital aspects of control theory - noninteracting control laws and the transformation of nonlinear systems into equivalent linear systems - are embodied in DI. Though there is no doubt that the mathematical tools and underlying theory are widely available, there are open issues as to the practicality of using DI as the only or primary design approach for reentry articles. This report provides a set of guidelines that can be used to determine the practical usefulness of the technique.

Ito, Daigoro; Georgie, Jennifer; Valasek, John; Ward, Donald T.

2002-01-01

129

Ducted Fan Designs Lead to Potential New Vehicles  

NASA Technical Reports Server (NTRS)

In 1994, aerospace engineers Rob Bulaga and Mike Moshier formed Trek Aerospace Inc., based in Folsom, California, to develop personal air vehicles using a novel ducted fan design. The company relied on Ames Research Center for a great deal of testing, the results of which have provided greater lift, lowered weight, more power, and improved maneuverability. The technology has been applied to three models: the Dragonfly UMR-1, the Springtail EFV, and the OVIWUN, a small-scale version that is for sale through the company's Web site. It is safer than a manned vehicle, and its size makes it relatively difficult for it to damage itself during test flights the way a larger mass, faster craft could.

2010-01-01

130

Simulation Assisted Risk Assessment Applied to Launch Vehicle Conceptual Design  

NASA Technical Reports Server (NTRS)

A simulation-based risk assessment approach is presented and is applied to the analysis of abort during the ascent phase of a space exploration mission. The approach utilizes groupings of launch vehicle failures, referred to as failure bins, which are mapped to corresponding failure environments. Physical models are used to characterize the failure environments in terms of the risk due to blast overpressure, resulting debris field, and the thermal radiation due to a fireball. The resulting risk to the crew is dynamically modeled by combining the likelihood of each failure, the severity of the failure environments as a function of initiator and time of the failure, the robustness of the crew module, and the warning time available due to early detection. The approach is shown to support the launch vehicle design process by characterizing the risk drivers and identifying regions where failure detection would significantly reduce the risk to the crew.

Mathias, Donovan L.; Go, Susie; Gee, Ken; Lawrence, Scott

2008-01-01

131

Design, Development and Testing of Underwater Vehicles: ITB Experience  

E-print Network

The last decade has witnessed increasing worldwide interest in the research of underwater robotics with particular focus on the area of autonomous underwater vehicles (AUVs). The underwater robotics technology has enabled human to access the depth of the ocean to conduct environmental surveys, resources mapping as well as scientific and military missions. This capability is especially valuable for countries with major water or oceanic resources. As an archipelagic nation with more than 13,000 islands, Indonesia has one of the most abundant living and non-organic oceanic resources. The needs for the mapping, exploration, and environmental preservation of the vast marine resources are therefore imperative. The challenge of the deep water exploration has been the complex issues associated with hazardous and unstructured undersea and sea-bed environments. The paper reports the design, development and testing efforts of underwater vehicle that have been conducted at Institut Teknologi Bandung. Key technology areas...

Muljowidodo, Said D; Budiyono, Agus; Nugroho, Sapto A

2008-01-01

132

Mechatronics Design of Small Electric Vehicles; Research and Education  

E-print Network

Abstract-- This paper proposes mechatronics design of small electric vehicles (SMEV), including Mechatronics design, modeling, simulation and integration of accurate sub-systems and overall system models. the proposed design and models can be used to select, integrate, analyze and validate Mechatronics deign process of SMEV and its sub-systems; including mechanical system, control system, components and electrical energy, resulting in simplification, acceleration and increasing accuracy of design. The proposed overall system model can be modified to include any control strategy and/or any electric machine (motor), where the motor and its associated driving power circuit and /or controller can be replaced with different motors and/or control strategy. The proposed model intended to be used for research purposes as well as, for the application in educational process. The proposed models were created and verified using MATLAB simulink software.

Farhan A. Salem

133

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

134

Multidisciplinary Design Techniques Applied to Conceptual Aerospace Vehicle Design. Ph.D. Thesis Final Technical Report  

NASA Technical Reports Server (NTRS)

Multidisciplinary design optimization (MDO) is an emerging discipline within aerospace engineering. Its goal is to bring structure and efficiency to the complex design process associated with advanced aerospace launch vehicles. Aerospace vehicles generally require input from a variety of traditional aerospace disciplines - aerodynamics, structures, performance, etc. As such, traditional optimization methods cannot always be applied. Several multidisciplinary techniques and methods were proposed as potentially applicable to this class of design problem. Among the candidate options are calculus-based (or gradient-based) optimization schemes and parametric schemes based on design of experiments theory. A brief overview of several applicable multidisciplinary design optimization methods is included. Methods from the calculus-based class and the parametric class are reviewed, but the research application reported focuses on methods from the parametric class. A vehicle of current interest was chosen as a test application for this research. The rocket-based combined-cycle (RBCC) single-stage-to-orbit (SSTO) launch vehicle combines elements of rocket and airbreathing propulsion in an attempt to produce an attractive option for launching medium sized payloads into low earth orbit. The RBCC SSTO presents a particularly difficult problem for traditional one-variable-at-a-time optimization methods because of the lack of an adequate experience base and the highly coupled nature of the design variables. MDO, however, with it's structured approach to design, is well suited to this problem. The result of the application of Taguchi methods, central composite designs, and response surface methods to the design optimization of the RBCC SSTO are presented. Attention is given to the aspect of Taguchi methods that attempts to locate a 'robust' design - that is, a design that is least sensitive to uncontrollable influences on the design. Near-optimum minimum dry weight solutions are determined for the vehicle. A summary and evaluation of the various parametric MDO methods employed in the research are included. Recommendations for additional research are provided.

Olds, John Robert; Walberg, Gerald D.

1993-01-01

135

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

136

Near-term hybrid vehicle program, phase 1. Appendix C: Preliminary design data package  

NASA Technical Reports Server (NTRS)

The design methodology, the design decision rationale, the vehicle preliminary design summary, and the advanced technology developments are presented. The detailed vehicle design, the vehicle ride and handling and front structural crashworthiness analysis, the microcomputer control of the propulsion system, the design study of the battery switching circuit, the field chopper, and the battery charger, and the recent program refinements and computer results are presented.

1979-01-01

137

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

138

Reliability-based design optimization for crashworthiness of vehicle side impact  

Microsoft Academic Search

With the advent of powerful computers, vehi- cle safety issues have recently been addressed using com- putational methods of vehicle crashworthiness, resulting in reductions in cost and time for new vehicle devel- opment. Vehicle design demands multidisciplinary opti- mization coupled with a computational crashworthiness analysis. However, simulation-based optimization gener- ates deterministic optimum designs, which are frequently pushed to the limits

B. D. Youn; K. K. Choi; R.-J. Yang; L. Gu

2003-01-01

139

ODIN: Optimal design integration system. [reusable launch vehicle design  

NASA Technical Reports Server (NTRS)

The report provides a summary of the Optimal Design Integration (ODIN) System as it exists at Langley Research Center. A discussion of the ODIN System, the executive program and the data base concepts are presented. Two examples illustrate the capabilities of the system which have been exploited. Appended to the report are a summary of abstracts for the ODIN library programs and a description of the use of the executive program in linking the library programs.

Glatt, C. R.; Hague, D. S.

1975-01-01

140

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

141

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

142

Vision-based vehicle detection and tracking algorithm design  

NASA Astrophysics Data System (ADS)

The vision-based vehicle detection in front of an ego-vehicle is regarded as promising for driver assistance as well as for autonomous vehicle guidance. The feasibility of vehicle detection in a passenger car requires accurate and robust sensing performance. A multivehicle detection system based on stereo vision has been developed for better accuracy and robustness. This system utilizes morphological filter, feature detector, template matching, and epipolar constraint techniques in order to detect the corresponding pairs of vehicles. After the initial detection, the system executes the tracking algorithm for the vehicles. The proposed system can detect front vehicles such as the leading vehicle and side-lane vehicles. The position parameters of the vehicles located in front are obtained based on the detection information. The proposed vehicle detection system is implemented on a passenger car, and its performance is verified experimentally.

Hwang, Junyeon; Huh, Kunsoo; Lee, Donghwi

2009-12-01

143

Multi-disciplinary design optimization of subsonic fixed-wing unmanned aerial vehicles projected through 2025  

Microsoft Academic Search

Through this research, a robust aircraft design methodology is developed for analysis and optimization of the Air Vehicle (AV) segment of Unmanned Aerial Vehicle (UAV) systems. The analysis functionality of the AV design is integrated with a Genetic Algorithm (GA) to form an integrated Multi-disciplinary Design Optimization (MDO) methodology for optimal AV design synthesis. This research fills the gap in

John Frederick Gundlach IV

2004-01-01

144

Design, Manufacturing, Analysis, and Control for Small-sized Electric Vehicles with Renewable Energy  

Microsoft Academic Search

This report describes the design?manufacturing, analysis, and control activities students conducted for small sized electric vehicles. In 1997, the Kochi University of Technology opened. Since then, the students tried to design and manufacture the electric vehicles in the extra-curricula class and in the laboratory. Engineering education for mechanical engineering needs the practical design and manufacturing, since design and manufacturing is

Haruo Sakamoto; Kohji Amimoto

2005-01-01

145

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

146

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

147

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, shockshock 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 are 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

148

Building Operations Efficiencies into NASA's Crew Launch Vehicle Design  

NASA Technical Reports Server (NTRS)

The U.S. Vision for Space Exploration guides NASA's challenging missions of technological innovation and scientific investigation. With the Agency's commitment to complete the International Space Station (ISS) and to retire the Space Shuttle by 2010, the NASA Administrator commissioned the Exploration Systems Architecture Study (ESAS) in mid 2005 to analyze options for a safer, simpler, more cost efficient launch system that could deliver timely human-rated space transportation capabilities. NASA's finite resources yield discoveries with infinite possibilities. As the Agency begins the process of replacing the Shuttle with new launch vehicles destined for missions beyond low-Earth orbit to the Moon and Mars, NASA is designing the follow-on crew and cargo systems for maximum operational efficiencies. This mandate is imperative to reduce the $4.5 billion NASA spends on space transportation each year. This paper gives top-level details of how the follow-on Crew Launch Vehicle (CLV) is being designed for reduced lifecycle costs as a primary catalyst for the expansion of future frontiers.

Dumbacher, Daniel L.

2006-01-01

149

Structural design and fabrication techniques of composite unmanned aerial vehicles  

NASA Astrophysics Data System (ADS)

Popularity of unmanned aerial vehicles has grown substantially in recent years both in the private sector, as well as for government functions. This growth can be attributed largely to the increased performance of the technology that controls these vehicles, as well as decreasing cost and size of this technology. What is sometimes forgotten though, is that the research and advancement of the airframes themselves are equally as important as what is done with them. With current computer-aided design programs, the limits of design optimization can be pushed further than ever before, resulting in lighter and faster airframes that can achieve longer endurances, higher altitudes, and more complex missions. However, realization of a paper design is still limited by the physical restrictions of the real world and the structural constraints associated with it. The purpose of this paper is to not only step through current design and manufacturing processes of composite UAVs at Oklahoma State University, but to also focus on composite spars, utilizing and relating both calculated and empirical data. Most of the experience gained for this thesis was from the Cessna Longitude project. The Longitude is a 1/8 scale, flying demonstrator Oklahoma State University constructed for Cessna. For the project, Cessna required dynamic flight data for their design process in order to make their 2017 release date. Oklahoma State University was privileged enough to assist Cessna with the mission of supporting the validation of design of their largest business jet to date. This paper will detail the steps of the fabrication process used in construction of the Longitude, as well as several other projects, beginning with structural design, machining, molding, skin layup, and ending with final assembly. Also, attention will be paid specifically towards spar design and testing in effort to ease the design phase. This document is intended to act not only as a further development of current practices, but also as a step-by-step manual for those who aspire to make composite airframes, predominantly the Oklahoma State University MAE students who either are, or will be using these techniques on a daily basis.

Hunt, Daniel Stephen

150

Noise control, sound, and the vehicle design process  

NASA Astrophysics Data System (ADS)

For many products, noise and sound are viewed as necessary evils that need to be dealt with in order to bring the product successfully to market. They are generally not product ``exciters'' although some vehicle manufacturers do tune and advertise specific sounds to enhance the perception of their products. In this paper, influencing the design process for the ``evils,'' such as wind noise and road noise, are considered in more detail. There are three ingredients to successfully dealing with the evils in the design process. The first of these is knowing how excesses in noise effects the end customer in a tangible manner and how that effects customer satisfaction and ultimately sells. The second is having and delivering the knowledge of what is required of the design to achieve a satisfactory or even better level of noise performance. The third ingredient is having the commitment of the designers to incorporate the knowledge into their part, subsystem or system. In this paper, the elements of each of these ingredients are discussed in some detail and the attributes of a successful design process are enumerated.

Donavan, Paul

2005-09-01

151

Should adaptive cruise-control systems be designed to maintain a constant time gap between vehicles?  

Microsoft Academic Search

This paper addresses the stability of traffic flow on a highway when the vehicles operate under an adaptive cruise-control (ACC) system. These systems are commonly designed to maintain a constant time gap between vehicles during vehicle following. Previous researchers in the literature have produced contradictory results on whether the traffic flow is stable when the constant time-gap spacing policy is

Junmin Wang; Rajesh Rajamani

2004-01-01

152

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

153

Modeling of hybrid electric vehicles using gyrator theory: application to design  

Microsoft Academic Search

Modeling and design of advanced vehicles such as hybrid electric vehicles (HEV) and more electric cars (MEC) are challenging because of the presence of two power plants in the vehicle, i.e., an internal combustion engine (ICE) or a fuel cell and an electric power plant. For the modeling of such complex hybrid systems, the gyrator theory has many advantages. The

J. Y. Routex; S. Gay-Desharnais; M. Ehsani

2000-01-01

154

Topology, design, analysis and thermal management of power electronics for hybrid electric vehicle  

E-print Network

Topology, design, analysis and thermal management of power electronics for hybrid electric vehicle an important role in the success of electric, hybrid and fuel cell vehicles. Typical power electronics circuits in hybrid vehicles include electric motor drive circuits and DC/DC converter circuits. Conventional circuit

Mi, Chunting "Chris"

155

Global Optimization of Plug-In Hybrid Vehicle Design and Allocation to  

E-print Network

- tion of conventional (CV), hybrid electric (HEV), and plug-in hybrid electric (PHEV) vehicles to obtain assessment 1 Introduction Plug-in hybrid electric vehicles (PHEVs) offer a potentially promising technologyGlobal Optimization of Plug-In Hybrid Vehicle Design and Allocation to Minimize Life Cycle

Michalek, Jeremy J.

156

EXPLORING THE DESIGN TRADEOFFS AND COMPUTATIONAL SAVINGS OF EXECUTING VEHICLE SIMULATIONS IN A PARALLEL COMPUTING ENVIRONMENT  

Microsoft Academic Search

In this paper, we present an approach for the optimization of a racecar using vehicle dynamics simulation in a parallel- computing environment. The use of vehicle dynamics simulations in the automotive and auto racing industries is widespread. Complex vehicle simulations can include hundreds of parameters and be very computationally expensive to perform. This limits the number of design configurations that

Kurt Hacker; Edward M. Kasprzak; Kemper Lewis

157

Mechanical design engineering. NASA\\/university advanced design program: Lunar Bulk Material Transport Vehicle  

Microsoft Academic Search

The design of a Lunar Bulk Material Transport Vehicle (LBMTV) is discussed. Goals set in the project include a payload of 50 cubic feet of lunar soil with a lunar of approximately 800 moon-pounds, a speed of 15 mph, and the ability to handle a grade of 20 percent. Thermal control, an articulated steering mechanism, a dump mechanism, a self-righting

Paul Daugherty; Stewart Griner; Alan Hendrix; Chris Makarov; Stephen Martiny; Douglas Ralph Meyhoefer; Cody Claxton Platt; John Sivak; Elizabeth Fitch Wheeler

1988-01-01

158

Energy management and design in solar powered vehicles using computer aided engineering  

SciTech Connect

Concerns with the environment have posed demands on high efficient and low contaminating vehicles. Solar powered vehicles are among the most promising alternatives. In order to develop the vehicle`s efficiency to its maximum, an energy management plant should be made. The objective of this work is the development of an interactive program which simulates the performance of solar powered vehicles under different mechanical, electrical and aerodynamic conditions. Global position, time, road and meteorological conditions such as temperature and ideal solar insolation have been taken in consideration for the simulation. From this data, the vehicle`s speed at which the net energy will be maximized subject to minimum total race time is determined. Different programs were developed in Quick Basic and Visual Basic to analyze hypothetical and real models. The user may vary parameters to graphically visualize their effects on the vehicle`s performance and improve design or efficiency.

Diaz Davila, T.R.; Torres, M.; Serrano, D. [Univ. of Puerto Rico, Mayagueez (Puerto Rico). Engineering Research Center

1995-10-01

159

Series hybrid vehicles and optimized hydrogen engine design  

SciTech Connect

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{sub 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{sub x} concentrations must be less than 180 ppm to meet the 0.2 g/mile California Air Resources Board ULEV or Federal Tier II 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. [Lawrence Livermore National Lab., CA (United States); Van Blarigan, P. [Sandia National Labs., Livermore, CA (United States)

1995-05-10

160

Design Study of Wafer Seals for Future Hypersonic Vehicles  

NASA Technical Reports Server (NTRS)

Future hypersonic vehicles require high temperature, dynamic seals in advanced hypersonic engines and on the vehicle airframe to seal the perimeters of movable panels, flaps, and doors. Current seals do not meet the demanding requirements of these applications, so NASA Glenn Research Center is developing improved designs to overcome these shortfalls. An advanced ceramic wafer seal design has shown promise in meeting these needs. Results from a design of experiments study performed on this seal revealed that several installation variables played a role in determining the amount of leakage past the seals. Lower leakage rates were achieved by using a tighter groove width around the seals, a higher seal preload, a tighter wafer height tolerance, and a looser groove length. During flow testing, a seal activating pressure acting behind the wafers combined with simulated vibrations to seat the seals more effectively against the sealing surface and produce lower leakage rates. A seal geometry study revealed comparable leakage for full-scale wafers with 0.125 and 0.25 in. thicknesses. For applications in which lower part counts are desired, fewer 0.25-in.-thick wafers may be able to be used in place of 0.125-in.-thick wafers while achieving similar performance. Tests performed on wafers with a rounded edge (0.5 in. radius) in contact with the sealing surface resulted in flow rates twice as high as those for wafers with a flat edge. Half-size wafers had leakage rates approximately three times higher than those for full-size wafers.

Dunlap, Patrick H.; Finkbeiner, Joshua R.; Steinetz, Bruce M.; DeMange, Jeffrey J.

2005-01-01

161

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

162

Design of Passive Suspension System of Railway Vehicles via Control Theory  

Microsoft Academic Search

This study deals with the design of passive suspension system of railway vehicles. The proposed model has six-degree-of-freedom and can be designed via control theory. Since the classical fixed point theory is no longer applicable to the design of passive suspension system of railway vehicle, many methods have been developed to replace it. In this paper, By utilizing feedback control

Hung Chi Nguyen; Akira Sone; Daisuke Iba; Arata Masuda

2008-01-01

163

Crew Exploration Vehicle Environmental Control and Life Support Design Reference Missions  

NASA Technical Reports Server (NTRS)

In preparation for the contract award of the Crew Exploration Vehicle (CEV), the National Aeronautics and Space Administration (NASA) produced two design reference missions for the vehicle. The design references used teams of engineers across the agency to come up with two configurations. This process helped NASA understand the conflicts and limitations in the CEV design, and investigate options to solve them.

Lewis, John F.; Anderson, Molly K.; Ewert, Mike S.; Stephan, Ryan A.; Carrasquillo, Robyn L.

2007-01-01

164

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.

165

The computational design of a water jet propulsion spherical underwater vehicle  

Microsoft Academic Search

Underwater vehicles have become an important tool to develop oceans. The design of the shape, hardware circuit and software of a water jet propulsion spherical underwater vehicle was introduced, and the characteristics of water jet pump were presented. The design of the thruster and computation of the thrust was proposed, too. A desired movement result was achieved by the designed

Shuxiang Guo; Juan Du; Xiufen Ye; Rui Yan; Hongtao Gao

2011-01-01

166

A New Aerodynamic Data Dispersion Method for Launch Vehicle Design  

NASA Technical Reports Server (NTRS)

A novel method for implementing aerodynamic data dispersion analysis is herein introduced. A general mathematical approach combined with physical modeling tailored to the aerodynamic quantity of interest enables the generation of more realistically relevant dispersed data and, in turn, more reasonable flight simulation results. The method simultaneously allows for the aerodynamic quantities and their derivatives to be dispersed given a set of non-arbitrary constraints, which stresses the controls model in more ways than with the traditional bias up or down of the nominal data within the uncertainty bounds. The adoption and implementation of this new method within the NASA Ares I Crew Launch Vehicle Project has resulted in significant increases in predicted roll control authority, and lowered the induced risks for flight test operations. One direct impact on launch vehicles is a reduced size for auxiliary control systems, and the possibility of an increased payload. This technique has the potential of being applied to problems in multiple areas where nominal data together with uncertainties are used to produce simulations using Monte Carlo type random sampling methods. It is recommended that a tailored physics-based dispersion model be delivered with any aerodynamic product that includes nominal data and uncertainties, in order to make flight simulations more realistic and allow for leaner spacecraft designs.

Pinier, Jeremy T.

2011-01-01

167

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

168

DESIGN AND IMPLEMENTATION OF AN ULTRASONIC POSITION SYSTEM FOR MULTIPLE VEHICLE CONTROL  

E-print Network

DESIGN AND IMPLEMENTATION OF AN ULTRASONIC POSITION SYSTEM FOR MULTIPLE VEHICLE CONTROL By DONALD K........................................................................................................ 1 Position System Dependence.......................................................................................................... 3 2 POSITION SYSTEMS BACKGROUND

Florida, University of

169

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

170

Aerothermodynamic design feasibility of a Mars aerocapture/aeromaneuver vehicle  

NASA Technical Reports Server (NTRS)

Lifting aerodynamic configurations have been screened and selected for the Mars aerocapture mission that (1) meet the geometric packaging requirements of the various payloads and the Space Shuttle cargo bay and (2) provide the aerodynamic performance characteristics required to obtain the atmospheric exit steering accuracy and the parachute deployment conditions desired. Hypersonic heat transfer and aerodynamic loads to the vehicle in the CO2 atmosphere are evaluated. Contemporary low density ablative thermal protection materials were selected that meet all the atmospheric entry requirements and provide a minimum mass solution. Results are presented of the aerodynamic configuration and thermal protection materials screening and selection. It is concluded that the aerothermodynamic design of this concept is feasible using state-of-the-art technology.

Florence, D. E.

1981-01-01

171

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

172

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

173

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

174

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

175

Optimization of Turbine Blade Design for Reusable Launch Vehicles  

NASA Technical Reports Server (NTRS)

To facilitate design optimization of turbine blade shape for reusable launching vehicles, appropriate techniques need to be developed to process and estimate the characteristics of the design variables and the response of the output with respect to the variations of the design variables. The purpose of this report is to offer insight into developing appropriate techniques for supporting such design and optimization needs. Neural network and polynomial-based techniques are applied to process aerodynamic data obtained from computational simulations for flows around a two-dimensional airfoil and a generic three- dimensional wing/blade. For the two-dimensional airfoil, a two-layered radial-basis network is designed and trained. The performances of two different design functions for radial-basis networks, one based on the accuracy requirement, whereas the other one based on the limit on the network size. While the number of neurons needed to satisfactorily reproduce the information depends on the size of the data, the neural network technique is shown to be more accurate for large data set (up to 765 simulations have been used) than the polynomial-based response surface method. For the three-dimensional wing/blade case, smaller aerodynamic data sets (between 9 to 25 simulations) are considered, and both the neural network and the polynomial-based response surface techniques improve their performance as the data size increases. It is found while the relative performance of two different network types, a radial-basis network and a back-propagation network, depends on the number of input data, the number of iterations required for radial-basis network is less than that for the back-propagation network.

Shyy, Wei

1998-01-01

176

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

177

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

178

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

ELECTRIC VEHICLES How many hybrid households are in the California new carElectric 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

179

Nuclear Electric Vehicle Optimization Toolset (NEVOT): Integrated System Design Using Genetic Algorithms  

NASA Technical Reports Server (NTRS)

The Nuclear Electric Vehicle Optimization Toolset (NEVOT) optimizes the design of all major Nuclear Electric Propulsion (NEP) vehicle subsystems for a defined mission within constraints and optimization parameters chosen by a user. The tool uses a Genetic Algorithm (GA) search technique to combine subsystem designs and evaluate the fitness of the integrated design to fulfill a mission. The fitness of an individual is used within the GA to determine its probability of survival through successive generations in which the designs with low fitness are eliminated and replaced with combinations or mutations of designs with higher fitness. The program can find optimal solutions for different sets of fitness metrics without modification and can create and evaluate vehicle designs that might never be conceived of through traditional design techniques. It is anticipated that the flexible optimization methodology will expand present knowledge of the design trade-offs inherent in designing nuclear powered space vehicles and lead to improved NEP designs.

Tinker, Michael L.; Steincamp, James W.; Stewart, Eric T.; Patton, Bruce W.; Pannell, William P.; Newby, Ronald L.; Coffman, Mark E.; Qualls, A. L.; Bancroft, S.; Molvik, Greg

2003-01-01

180

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

181

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

182

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

183

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

NASA Technical Reports Server (NTRS)

The problems related to the design and control of a mobile planetary vehicle to implement a systematic plan for the exploration of Mars were investigated. Problem areas receiving attention include: vehicle configuration, control, dynamics, systems and propulsion; systems analysis; navigation, terrain modeling and path selection; and chemical analysis of specimens. The following specific tasks were studied: vehicle model design, mathematical modeling of 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 subsystem, 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 and transport parameter evaluation.

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

1972-01-01

184

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

NASA Technical Reports Server (NTRS)

Problems related to the design and control of a mobile planetary vehicle to implement a systematic plan for the exploration of Mars are reported. Problem areas include: vehicle configuration, control, dynamics, systems and propulsion; systems analysis, terrain modeling and path selection; and chemical analysis of specimens. These tasks are summarized: vehicle model design, mathematical model of vehicle dynamics, experimental vehicle dynamics, obstacle negotiation, electrochemical controls, remote control, 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 subsystem, laser range measurement, discrete obstacle detection, obstacle detection systems, terrain modeling, path selection system simulation and evaluation, gas chromatograph/mass spectrometer system concepts, and chromatograph model evaluation and improvement.

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

1973-01-01

185

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

186

Life Cycle Energy and Environmental Assessment of Aluminum-Intensive Vehicle Design  

SciTech Connect

Advanced lightweight materials are increasingly being incorporated into new vehicle designs by automakers to enhance performance and assist in complying with increasing requirements of corporate average fuel economy standards. To assess the primary energy and carbon dioxide equivalent (CO2e) implications of vehicle designs utilizing these materials, this study examines the potential life cycle impacts of two lightweight material alternative vehicle designs, i.e., steel and aluminum of a typical passenger vehicle operated today in North America. LCA for three common alternative lightweight vehicle designs are evaluated: current production ( Baseline ), an advanced high strength steel and aluminum design ( LWSV ), and an aluminum-intensive design (AIV). This study focuses on body-in-white and closures since these are the largest automotive systems by weight accounting for approximately 40% of total curb weight of a typical passenger vehicle. Secondary mass savings resulting from body lightweighting are considered for the vehicles engine, driveline and suspension. A cradle-to-cradle life cycle assessment (LCA) was conducted for these three vehicle material alternatives. LCA methodology for this study included material production, mill semi-fabrication, vehicle use phase operation, and end-of-life recycling. This study followed international standards ISO 14040:2006 [1] and ISO 14044:2006 [2], consistent with the automotive LCA guidance document currently being developed [3]. Vehicle use phase mass reduction was found to account for over 90% of total vehicle life cycle energy and CO2e emissions. The AIV design achieved mass reduction of 25% (versus baseline) resulting in reductions in total life cycle primary energy consumption by 20% and CO2e emissions by 17%. Overall, the AIV design showed the best breakeven vehicle mileage from both primary energy consumption and climate change perspectives.

Das, Sujit [ORNL

2014-01-01

187

Load distribution control system design for a semi-track air-cushion vehicle  

Microsoft Academic Search

This paper describes the design principle for a semi-track air-cushion vehicle working on soft terrain. A novel structure, i.e., a flexible joint mechanism is designed for the semi-track air-cushion vehicle suspension system. Focusing on optimizing the total power consumption of the vehicle, three main issues were studied in this paper. First, a theoretical model for minimizing the total power demand

Zhe Luo; Fan Yu

2007-01-01

188

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

189

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

190

Deterministic 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. Four reconfigurable control design methods were investigated for the X-33 vehicle: Redistributed Pseudo-Inverse, General Constrained Optimization, Automated Failure Dependent Gain Schedule, and an Off-line Nonlinear General Constrained Optimization. The Off-line Nonlinear General Constrained Optimization approach was chosen for implementation on the X-33. Two example failures are shown, a right outboard elevon jam at 25 deg. at a Mach 3 entry condition, and a left rudder jam at 30 degrees. Note however, that reconfigurable control laws have been designed for the entire flight envelope. 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.

Wagner, Elaine A.; Burken, John J.; Hanson, Curtis E.; Wohletz, Jerry M.

1998-01-01

191

Combined maximisation of interior comfort and frontal crashworthiness in preliminary vehicle design  

Microsoft Academic Search

Designing for improved interior comfort and crashworthiness is an important but competing objective in vehicle development. These objectives are linked by common design decisions on allocating a fixed total amount of space, and so they should be addressed together. Such combined optimisation is hindered by the large computational effort required for crash analysis using full-scale vehicle models and by the

K. Hamza; I. Hossoy; J. F. Reyes-Luna; P. Y. Papalambros

2004-01-01

192

Design and implementation of an electric drive system for in-wheel motor electric vehicle applications  

Microsoft Academic Search

This paper presents the design and application of a hub drive system for Hybrid (HEV) and All Electric Vehicles (EV). Initially Matlab SIMULINK model of a hub driven hybrid electric vehicle is developed and the performance values are calculated. Two 15 kW brushless dc machines (BLDC) are designed and manufactured to be located inside the rim of the wheels. The

R. Nejat Tuncay; Ozgur Ustun; Murat Yilmaz; Can Gokce; Utku Karakaya

2011-01-01

193

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

194

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

195

Development of the brake system design program for a vehicle  

Microsoft Academic Search

It is quite challenging to estimate the braking performance of a vehicle because the brake system is comprised of many parts,\\u000a including a booster, master cylinder, and caliper. Calculation of characteristics such as braking force through vehicle tests\\u000a requires much time and money. Therefore, the development of a method to estimate the braking performance of a vehicle using\\u000a qualitative methods

S. P. Jung; K. J. Jun; T. W. Park; J. H. Yoon

2008-01-01

196

Design Optimisation and Optimal Control for Hybrid Vehicles  

Microsoft Academic Search

1. Abstract Growing environmental and global crude oil supplies concerns are stimulating research on new vehicle technologies. Hybrid-electric vehicles appear to be one of the most promising technologies for reducing fuel consumption and pollutant emissions. Dieren t types of hybrid-electric powertrains exist: from the mild-hybrid vehicle, equipped with a small electric motor, to the combined hybrid like the Toyota prius.

Gregory Rousseau; Delphine Sinoquet; Antonio Sciarretta; Yohan Milhau

2008-01-01

197

Aerospace Vehicle Design, Spacecraft Section. Final Project Reports. Volume 2; Project Groups 6-8  

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 Freedam and provide 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 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. Special attention is given to spacecraft communications.

1989-01-01

198

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

199

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

200

Design factors analysis for instances of rich vehicle routing problem  

Microsoft Academic Search

Over the last years various extensions of the Vehicle Routing Problem (VRP), considering complicated constraints encountered in the real-life, has been studied. These extensions are often coined as rich VRP. In this work, we tackle a rich VRP namely the Multi Compartment Multi Commodity Heterogeneous Fixed Fleet Vehicle Routing Problem with hard Time Windows (MCMCHFFVRPTW). The objective of the problem

Rahma Lahyani; Mahdi Khemakhem; Habib Chabchoub; Frederic Semet

2011-01-01

201

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

202

System design and development of hybrid electric vehicles  

Microsoft Academic Search

Hybrid electric vehicles (HEVs) powered by electric machines and an internal combustion engine (ICE) are a promising means of reducing emissions and fuel consumption without compromising vehicle functionality and driving performance. Reducing emissions is important because pollution in cities is almost entirely due to transport and is linked to the illness and death of many people. This paper describes the

B. A. Kalan; H. C. Lovatt; M. Brothers; V. Buriak

2002-01-01

203

Design Criteria for Low Risk Re-Entry Vehicles  

Microsoft Academic Search

The paper shows how a sharp vehicle with low wing loading, is able to follow re-entry trajectories with low thermal risks by using Ultra High Temperature Ceramics (UHTC) to thermally protect the vehicle front edges. These reusable materials can withstand the global radiative equilibrium temperatures that are experienced during reentry characterized by a longer and a more gradual conversion of

R. Monti; G. Pezzella

2005-01-01

204

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

205

Hybrid vehicle system studies and optimized hydrogen engine design  

SciTech Connect

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{sub 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{sub 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{sub 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.

1995-04-26

206

Design of an autonomous underwater vehicle to evaluate the blazed array sonar and simultaneous localization and mapping algorithms  

E-print Network

This thesis has investigated aspects of the design of a new highly maneuverable Autonomous Underwater Vehicle - the XAUV. The overall goal for the design of this vehicle is to create a small, highly maneuverable AUV that ...

Uhle, Matthew William

2007-01-01

207

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

208

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

NASA Astrophysics Data System (ADS)

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

1991-05-01

209

Comprehensive Design Tool for Sizing and Simulation of Autonomous Underwater Vehicles  

Microsoft Academic Search

An important issue in the preliminary design of autonomous underwater vehicles (AUVs) is the selection of the optimal dimensions for the vehicle (sizing). These dimensions are dependent on the characteristics of the mission, the operating environment and the chosen technology. This paper presents a computer-based design-tool, which integrates all major design parameters to allow an efficient and rapid trade-off analysis

J. Verdaasdonk; H. Grimmelius; C. Bil; S. Anavatti

2007-01-01

210

Integrating Human Factors into Crew Exploration Vehicle Design  

NASA Technical Reports Server (NTRS)

With NASA's new Vision for Exploration to send humans beyond Earth orbit, it is critical to consider the human as a system that demands early and continuous user involvement, and an iterative prototype/test/redesign process. Addressing human-system interface issues early on can be very cost effective even cost reducing when performed early in the design and development cycle. To achieve this goal within Crew Exploration Vehicle (CEV) Project Office, human engineering (HE) team is formed. Key tasks are to apply HE requirements and guidelines to hardware/software, and provide HE design, analysis and evaluation of crew interfaces. Initial activities included many practice-orientated evaluations using low-fidelity CEV mock-ups. What follows is a description of such evaluations that focused on a HE requirement regarding Net Habitable Volume (NHV). NHV is defined as the total remaining pressurized volume available to on-orbit crew after accounting for the loss of volume due to deployed hardware and structural inefficiencies which decrease functional volume. The goal of the NHV evaluations was to develop requirements providing sufficient CEV NHV for crewmembers to live and perform tasks in support of mission goals. Efforts included development of a standard NHV calculation method using computer models and physical mockups, and crew/ stakeholder evaluations. Nine stakeholders and ten crewmembers participated in the unsuited evaluations. Six crewmembers also participated in a suited evaluation. The mock-up was outfitted with volumetric representation of sub-systems such as seats, and stowage bags. Thirteen scenarios were developed to represent mission/crew tasks and considered to be primary volume drivers (e.g., suit donning) for the CEV. Unsuited evaluations included a structured walkthrough of these tasks. Suited evaluations included timed donning of the existing launch and entry suit to simulate a contingency scenario followed by doffing/ stowing of the suits. All mockup evaluations were videotaped. Structured questionnaires were used to document user interface issues and volume impacts of layout configuration. Computer model and physical measures of the NHV agreed within 1 percent. This included measurement of the gross habitable volume, subtraction of intrusive volumes, and other non-habitable spaces. Calculation method developed was validated as a standard means of measuring NHV, and was recommended as a verification method for the NHV requirements. Evaluations confirmed that there was adequate volume for unsuited scenarios and suit donning/ doffing activity. Seats, suit design stowage and waste hygiene system noted to be critical volume drivers. The low-fidelity mock-up evaluations along with human modeling analysis generated discussions that will lead to high-level systems requirements and human-centered design decisions. This approach allowed HE requirements and operational concepts to evolve in parallel with engineering system concepts and design requirements. As the CEV design matures, these evaluations will continue and help with design decisions, and assessment, verification and validation of HE requirements.

Whitmore, Mihriban; Baggerman, Susan; Campbell, paul

2007-01-01

211

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

212

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

213

Design and Implementation of a Hybrid Energy Supply System for Railway Vehicles  

E-print Network

- 1 - Design and Implementation of a Hybrid Energy Supply System for Railway Vehicles R. Li, A of batteries and ultracapacitors for a railway vehicle is studied. In order to optimize the energy supply ultracapacitors, batteries and the DC-link are investigated together with control strategies comprising

Elsässer, Robert

214

Design electronic control unit of blend brake system for heavy vehicle  

Microsoft Academic Search

Electronic control unit(ECU) of blend brake system based on electro-hydra ulic servo control for heavy vehicle is designed and analyzed in this paper. The study makes full consideration of the requirements of high speed, heavy weight and fast braking for heavy vehicle. Through collected speed signals and pressure signals output by the main brake cylinder, the ECU analyses and judges

Wang Tianxu; Gong Mingde

2011-01-01

215

Design and Control of the Induction Motor Propulsion of an Electric Vehicle  

E-print Network

Design and Control of the Induction Motor Propulsion of an Electric Vehicle B. Tabbache1,2 , A for presizing the induction motor propulsion of an Electric Vehicle (EV). Based on the EV desired performances for the EV propulsion systems is a very important step that requires special attention. In fact

Brest, Universit de

216

Parametric Analysis of Vehicle Design Influence on the Four Phases of Whiplash Motion  

Microsoft Academic Search

Objective. The objective is to establish a basis for motor vehicle test requirements that measure component contributions to Whiplash Associated Disorders (WAD).Methods. Selected vehicle design features are evaluated with regard to their relative contributions to WAD measures. The motion of the occupant cervical spine associated with WAD is divided into four phases: retraction, extension, rebound, and protraction. Injury measures from

Polat Sendur; Robert Thibodeau; John Burge; Allan Tencer

2005-01-01

217

DESIGN OPTIMIZATION OF MULTI-LINK SUSPENSION SYSTEM FOR TOTAL VEHICLE HANDLING AND STABILITY  

Microsoft Academic Search

This paper discusses the design problem of vehicles using multi-link suspension system with the aim of totally optimizing vehicle handling and stability. Since this problem includes many evaluation items, and multi-link suspension system has interconnected behavior, the optimization is so complicated. An efficient and computable model is indispensable for compromising the total optimization. This paper investigates a hierarchical structure of

Kikuo Fujita; Noriyasu Hirokawa; Shinsuke Akagi; Takanori Hirata

1998-01-01

218

Design of longitudinal vehicle velocity observer using fuzzy logic and Kalman filter  

Microsoft Academic Search

An adaptive vehicle longitudinal velocity observer is designed in this paper for Electronic stability control system based on the standard sensors for ESC. At first, wheel speed of each wheel is converted to the center of gravity of the vehicle after they have been converted to free rolling speed; then fuzzy logic is used to get a first estimation of

Liang Chu; LiBo Chao; YongSheng Zhang; YanRu Shi

2011-01-01

219

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

220

Design and Optimization of the University of Wisconsin's Parallel Hybrid-Electric Sport Utility Vehicle  

Microsoft Academic Search

The University of Wisconsin - Madison FutureTruck Team has designed and built a four-wheel drive, charge sustaining, parallel hybrid-electric sport utility vehicle for entry into the FutureTruck 2001 competition. The base vehicle is a 2000 Chevrolet Suburban. Our FutureTruck is nicknamed the \\

Ryan F. Rowe; Jennifer A. Topinka; Ethan K. Brodsky; Julie G. Marshaus; Glenn R. Bower

221

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

222

Visualization of ground target designation from an unmanned aerial vehicle  

NASA Astrophysics Data System (ADS)

The common ground station (CGS) receives data from the joint surveillance and target attack radar system aircraft and from other airborne platforms. High-resolution imagery such as that provided by an unmanned airborne vehicle (UAV) carrying an IR and/or synthetic aperture radar (SAR) sensor will be incorporated into an advanced imagery CGS operation. While this level of integration provides a wealth of valuable information, it also increase the complexity of planning, assessment and exploitation which in turn dictates flexible simulation tools for mission rehearsal and operator training. MITRE has developed a ModSAF-driven model for a UAV equipped with a moving target indicator (MTI) radar for wide-area surveillance, and a battlefield combat identification system for positive identification of friendly forces. The imaging functions are performed by integrating the UAV model with visualization software in order to render the sensor's view in real-time. This model forms the basis for a multisensor CGS simulation controls imaging task assignments which taken place when an MTI track is selected for imaging by means of a mouse click entry on an active MTI display. At that time, the UAV is commanded to fly an automatically determined trajectory in order to align MTI display. At that time, the UAV is commanded to fly an automatically determined trajectory in order to align itself for the imaging task. A beam footprint whose position, size and shape is determined by the sensor position, attitude, and field-of-view appears on the display as an indication of the relationship of the image display to the terrain in the operational scenario. A 3D visualization of the designated target area then takes place on a separate display.

Violette Pierce, Deborah J.; Santapietro, John J.

1998-08-01

223

Visualization of ground target designation from an unmanned aerial vehicle  

E-print Network

The Common Ground Station (CGS) receives data from the Joint Surveillance and Target Attack Radar System (Joint STARS) aircraft and from other airborne platforms. High-resolution imagery such as that provided by an unmanned airborne vehicle (UAV) carrying an infrared (IR) and/or synthetic aperture radar (SAR) sensor will be incorporated into an Advanced Imagery CGS (AI CGS) operation. While this level of integration provides a wealth of valuable information, it also increases the complexity of planning, assessment and exploitation which in turn dictates flexible simulation tools for mission rehearsal and operator training. MITRE has developed a ModSAF-driven model for a UAV equipped with a moving target indicator (MTI) radar for wide-area surveillance, and a Battlefield Combat Identification System (BCIS) for positive identification of friendly forces. The imaging functions are performed by integrating the UAV model with visualization software in order to render the sensors view in real-time. This model forms the basis for a multisensor CGS simulation (MSCGS) which consists of the multisensor UAV combined with a UAV Control Station (UAV CS). The UAV CS controls imaging task assignments which take place when an MTI track is selected for imaging by means of a mouse click entry on an active MTI display. At that time, the UAV is commanded to fly an automatically determined trajectory in order to align itself for the imaging task. A beam footprint whose position, size and shape is determined by the sensor position, attitude, and field-of-view appears on the display as an indication of the relationship of the image display to the terrain in the operational scenario. A three-dimensional visualization of the designated target area then takes place on a separate display.

Deborah J. Violette Pierce; John J. Santapietro

1998-01-01

224

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

225

Environmental Controls and Life Support System Design for a Space Exploration Vehicle  

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 C.; Rodriguez, Branelle; Vonau, Walt, Jr.; Borrego, Melissa

2012-01-01

226

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

227

An REU project on the design of a brushless DC machine for plug-in hybrid electric vehicles  

Microsoft Academic Search

This paper proposes a design methodology for the propulsion motor of a plug-in hybrid electric vehicle. This research was conducted through the Research Experiences for Undergraduates (REU) program supported by National Science Foundation (NSF). The simulation of a representative plug-in hybrid electric vehicle has been performed using ADVISOR vehicle modeling software. The vehicle has been simulated over a set of

Alex J. Borsuk; Berker Bilgin; Alireza Khaligh; Mahesh Krishnamurthy

2011-01-01

228

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

229

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

230

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

231

Mechanical design engineering. NASA/university advanced design program: Lunar Bulk Material Transport Vehicle  

NASA Technical Reports Server (NTRS)

The design of a Lunar Bulk Material Transport Vehicle (LBMTV) is discussed. Goals set in the project include a payload of 50 cubic feet of lunar soil with a lunar of approximately 800 moon-pounds, a speed of 15 mph, and the ability to handle a grade of 20 percent. Thermal control, an articulated steering mechanism, a dump mechanism, a self-righting mechanism, viable power sources, and a probable control panel are analyzed. The thermal control system involves the use of small strip heaters to heat the housing of electronic equipment in the absence of sufficient solar radiation and multi-layer insulation during periods of intense solar radiation. The entire system uses only 10 W and weighs about 60 pounds, or 10 moon-pounds. The steering mechanism is an articulated steering joint at the center of the vehicle. It utilizes two actuators and yields a turning radius of 10.3 feet. The dump mechanism rotates the bulk material container through an angle of 100 degree using one actuator. The self-righting mechanism consists of two four bar linkages, each of which is powered by the same size actuator as the other linkages. The LBMTV is powered by rechargeable batteries. A running time of at least two hours is attained under a worst case analysis. The weight of the batteries is 100 pounds. A control panel consisting of feedback and control instruments is described. The panel includes all critical information necessary to control the vehicle remotely. The LBMTV is capable of handling many types of cargo. It is able to interface with many types of removable bulk material containers. These containers are made to interface with the three-legged walker, SKITTER. The overall vehicle is about 15 feet in length and has a weight of about 1000 pounds, or 170 lunar pounds.

Daugherty, Paul; Griner, Stewart; Hendrix, Alan; Makarov, Chris; Martiny, Stephen; Meyhoefer, Douglas Ralph; Platt, Cody Claxton; Sivak, John; Wheeler, Elizabeth Fitch

1988-01-01

232

A prototype computerized synthesis methodology for generic space access vehicle (SAV) conceptual design  

NASA Astrophysics Data System (ADS)

Today's and especially tomorrow's competitive launch vehicle design environment requires the development of a dedicated generic Space Access Vehicle (SAV) design methodology. A total of 115 industrial, research, and academic aircraft, helicopter, missile, and launch vehicle design synthesis methodologies have been evaluated. As the survey indicates, each synthesis methodology tends to focus on a specific flight vehicle configuration, thus precluding the key capability to systematically compare flight vehicle design alternatives. The aim of the research investigation is to provide decision-making bodies and the practicing engineer a design process and tool box for robust modeling and simulation of flight vehicles where the ultimate performance characteristics may hinge on numerical subtleties. This will enable the designer of a SAV for the first time to consistently compare different classes of SAV configurations on an impartial basis. This dissertation presents the development steps required towards a generic (configuration independent) hands-on flight vehicle conceptual design synthesis methodology. This process is developed such that it can be applied to any flight vehicle class if desired. In the present context, the methodology has been put into operation for the conceptual design of a tourist Space Access Vehicle. The case study illustrates elements of the design methodology & algorithm for the class of Horizontal Takeoff and Horizontal Landing (HTHL) SAVs. The HTHL SAV design application clearly outlines how the conceptual design process can be centrally organized, executed and documented with focus on design transparency, physical understanding and the capability to reproduce results. This approach offers the project lead and creative design team a management process and tool which iteratively refines the individual design logic chosen, leading to mature design methods and algorithms. As illustrated, the HTHL SAV hands-on design methodology offers growth potential in that the same methodology can be continually updated and extended to other SAV configuration concepts, such as the Vertical Takeoff and Vertical Landing (VTVL) SAV class. Having developed, validated and calibrated the methodology for HTHL designs in the 'hands-on' mode, the report provides an outlook how the methodology will be integrated into a prototype computerized design synthesis software AVDS-PrADOSAV in a follow-on step.

Huang, Xiao

2006-04-01

233

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

234

A versatile simulation tool for the design and verification of military vehicle power systems  

E-print Network

modes of operation and system scenarios) and system performance in a dynamic, realistic environment. This thesis proposes a new tool to analyze and design military vehicle platforms: the Advanced Mobile Integrated Power System (AMPS). This tool is useful...

Lipscomb, Melissa Anne

2005-11-01

235

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

236

Trade-off results and preliminary designs of Near-Term Hybrid Vehicles  

NASA Technical Reports Server (NTRS)

Phase I of the Near-Term Hybrid Vehicle Program involved the development of preliminary designs of electric/heat engine hybrid passenger vehicles. The preliminary designs were developed on the basis of mission analysis, performance specification, and design trade-off studies conducted independently by four contractors. THe resulting designs involve parallel hybrid (heat engine/electric) propulsion systems with significant variation in component selection, power train layout, and control strategy. Each of the four designs is projected by its developer as having the potential to substitute electrical energy for 40% to 70% of the petroleum fuel consumed annually by its conventional counterpart.

Sandberg, J. J.

1980-01-01

237

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

238

Design of intelligent Mobile Vehicle Checking system based on ARM7  

Microsoft Academic Search

With ARM7 as the core, the new intelligent mobile vehicle checking system integrated a lot of hardware modules such as video capture, GPS positioning and wireless transmission, the design of the system software used the embedded software developing platform based on ADS integrated development environment. By the hardware\\/software co-design, the new intelligent mobile vehicle checking system implemented the functions of

Lihe; Lv Fang

2010-01-01

239

Computer Aided Design Tool for Electric, Hybrid Electric and Plug-in Hybrid Electric Vehicles  

E-print Network

COMPUTER AIDED DESIGN TOOL FOR ELECTRIC, HYBRID ELECTRIC AND PLUG-IN HYBRID ELECTRIC VEHICLES A Dissertation by ALI ESKANDARI HALVAII Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of DOCTOR OF PHILOSOPHY May 2011 Major Subject: Electrical Engineering COMPUTER AIDED DESIGN TOOL FOR ELECTRIC, HYBRID ELECTRIC AND PLUG-IN HYBRID ELECTRIC VEHICLES A Dissertation by ALI ESKANDARI HALVAII Submitted...

Eskandari Halvaii, Ali

2012-07-16

240

Design and fabrication of metallic thermal protection systems for aerospace vehicles  

NASA Technical Reports Server (NTRS)

A program was conducted to develop a lightweight, efficient metallic thermal protection system (TPS) for application to future shuttle-type reentry vehicles, advanced space transports, and hypersonic cruise vehicles. Technical requirements were generally derived from the space shuttle. A corrugation-stiffened beaded-skin TPS design was used as a baseline. The system was updated and modified to incorporate the latest technology developments and design criteria. The primary objective was to minimize mass for the total system.

Varisco, A.; Bell, P.; Wolter, W.

1978-01-01

241

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

242

Visualization of ground target designation from an unmanned aerial vehicle  

Microsoft Academic Search

The common ground station (CGS) receives data from the joint surveillance and target attack radar system aircraft and from other airborne platforms. High-resolution imagery such as that provided by an unmanned airborne vehicle (UAV) carrying an IR and\\/or synthetic aperture radar (SAR) sensor will be incorporated into an advanced imagery CGS operation. While this level of integration provides a wealth

Deborah J. Violette Pierce; John J. Santapietro

1998-01-01

243

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

244

The design of an electro-hydraulically controlled, manual transmission for a hybrid electric vehicle  

SciTech Connect

An electro-hydraulically controlled, manual transmission has been developed for the Department of Energy's FutureCar Challenge. This project which is jointly sponsored by the DOE and the Partnership for a New Generation of Vehicles (PNGV) seeks to modify a production mid-size car to reach 80 mpg, yet still maintain the safety and consumer acceptability of the original vehicle. To meet this challenge, a 1996 Ford Taurus has been modified into a parallel drive, hybrid electric vehicle. The propulsion system of this vehicle is based on a DC electric motor, which is coupled via a belt drive, in parallel, with a 1.9 liter turbo-charged, direct injection diesel engine. Both propulsion units are then coupled to the transmission. The OEM automatic transmission has been replaced with a five-speed, manual transmission, which was adapted from an earlier model year production Taurus SHO vehicle. This transmission is both lighter and more mechanically efficient than the automatic transmission. In order to provide the automatic transmission shifting capabilities expected by the consumer for a vehicle of this size, an electro-hydraulic control unit was designed and built. This unit automatically engages the clutch and shifts gears as required during vehicle operation. Gear selection is controlled by a programmable logic controller (PLC), which utilizes throttle and vehicle speed input signals. Additionally, the driver may select gears using a modified steering-column PRNDL selector. This paper discusses the final design of this system and provides an evaluation of its performance.

Davis, G.W.; Hoff, C.J.

1998-07-01

245

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

246

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

E-print Network

(emphasize reduced size and use of composite materials) (6) A single stage axial flow turbine design (6DESIGN 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

247

Design and Implementation of Vehicle Wireless Data Transmission Based on MIPS-Linux  

Microsoft Academic Search

This paper introduces the design of an embedded vehicle wireless data transmission system utilizing embedded microprocessor unit AU1200, presenting its implementation based on the embedded linux operating system.We design keys to control GUI which is designed with QT\\/E, and test the validity of the scheme for this wireless data transmission system in the scope of Wi-Fi Mesh.

Zhilong Ke; Lianfen Huang; Yajuan Zheng

2010-01-01

248

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-and-click graphical user interface. The task environment for insertion-extraction missions is assumed to be dynamic interface design con- cepts, but no interface has ever been designed for the domain. In cases where

Cummings, Mary "Missy"

249

Inflatable Re-Entry Vehicle Experiment (IRVE) Design Overview  

NASA Technical Reports Server (NTRS)

Inflatable aeroshells offer several advantages over traditional rigid aeroshells for atmospheric entry. Inflatables offer increased payload volume fraction of the launch vehicle shroud and the possibility to deliver more payload mass to the surface for equivalent trajectory constraints. An inflatable s diameter is not constrained by the launch vehicle shroud. The resultant larger drag area can provide deceleration equivalent to a rigid system at higher atmospheric altitudes, thus offering access to higher landing sites. When stowed for launch and cruise, inflatable aeroshells allow access to the payload after the vehicle is integrated for launch and offer direct access to vehicle structure for structural attachment with the launch vehicle. They also offer an opportunity to eliminate system duplication between the cruise stage and entry vehicle. There are however several potential technical challenges for inflatable aeroshells. First and foremost is the fact that they are flexible structures. That flexibility could lead to unpredictable drag performance or an aerostructural dynamic instability. In addition, durability of large inflatable structures may limit their application. They are susceptible to puncture, a potentially catastrophic insult, from many possible sources. Finally, aerothermal heating during planetary entry poses a significant challenge to a thin membrane. NASA Langley Research Center and NASA's Wallops Flight Facility are jointly developing inflatable aeroshell technology for use on future NASA missions. The technology will be demonstrated in the Inflatable Re-entry Vehicle Experiment (IRVE). This paper will detail the development of the initial IRVE inflatable system to be launched on a Terrier/Orion sounding rocket in the fourth quarter of CY2005. The experiment will demonstrate achievable packaging efficiency of the inflatable aeroshell for launch, inflation, leak performance of the inflatable system throughout the flight regime, structural integrity when exposed to a relevant dynamic pressure and aerodynamic stability of the inflatable system. Structural integrity and structural response of the inflatable will be verified with photogrammetric measurements of the back side of the aeroshell in flight. Aerodynamic stability as well as drag performance will be verified with on board inertial measurements and radar tracking from multiple ground radar stations. The experiment will yield valuable information about zero-g vacuum deployment dynamics of the flexible inflatable structure with both inertial and photographic measurements. In addition to demonstrating inflatable technology, IRVE will validate structural, aerothermal, and trajectory modeling techniques for the inflatable. Structural response determined from photogrammetrics will validate structural models, skin temperature measurements and additional in-depth temperature measurements will validate material thermal performance models, and on board inertial measurements along with radar tracking from multiple ground radar stations will validate trajectory simulation models.

Hughes, Stephen J.; Dillman, Robert A.; Starr, Brett R.; Stephan, Ryan A.; Lindell, Michael C.; Player, Charles J.; Cheatwood, F. McNeil

2005-01-01

250

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

251

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

252

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

253

that minimizes vehicle emissions during design of routes in congested environments with time-dependent travel speeds, hard time windows,  

E-print Network

-dependent travel speeds, hard time windows, andcapacityconstraints.ThiscreatesanewtypeofVRP,theemissions vehicle as a primary objective and distance traveled as a secondary objective without violating time windows, routethat minimizes vehicle emissions during design of routes in congested environments with time

Bertini, Robert L.

254

The design and evaluation of a hydraulic actuation system for a legged rough-terrain vehicle  

NASA Astrophysics Data System (ADS)

One of the causes of low efficiency of legged vehicles is the type of actuation system used. This paper describes the overall design and the evaluation of some aspects of a proposed hydraulic actuation system for a six-legged vehicle intended for use in rough terrain. Features of the hydraulic actuation system designed to improve mechanical efficiency are described. A combination of linearized dynamic system analysis and computer simulation of the nonlinear dynamic system equations is used to evaluate some aspects of the proposed design. The tradeoff between energy efficient operation and the dynamic performance of the actuation system is investigated. Some criteria for controller design are enumerated.

Srinivasan, K.; Waldron, K. J.; Dworak, J. A.

255

The design of an airfoil for a high-altitude, long-endurance remotely piloted vehicle  

NASA Technical Reports Server (NTRS)

Airfoil design efforts are studied. The importance of integrating airfoil and aircraft designs was demonstrated. Realistic airfoil data was provided to aid future high altitude, long endurance aircraft preliminary design. Test cases were developed for further validation of the Eppler program. Boundary layer, not pressure distribution or shape, was designed. Substantial improvement was achieved in vehicle performance through mission specific airfoil designed utilizing the multipoint capability of the Eppler program.

Maughmer, Mark D.; Somers, Dan M.

1987-01-01

256

Side slope design based on human tolerance to vehicle response  

E-print Network

committee, who was instrumental in convincing me to leave private industry and enter the field of transportation research. His encouragement, direction, and assistance throughout this research and my entire graduate program are sincerely appreciated... of Tolerable Deceleration (Tentative) 33 3. Tolerable Acceleration Limits Established For Ditch Traversal Study (Tentative) 41 4. Summary of Full-Scale Vehicle Tests 5. K-Values For Ditch Profile Evaluation 6. Maximum and Average Accelerations ? Profile 1...

Weaver, Graeme Douglas

1970-01-01

257

Estimating Logistics Support of Reusable Launch Vehicles During Conceptual Design  

NASA Technical Reports Server (NTRS)

Methods exist to define the logistics support requirements for new aircraft concepts but are not directly applicable to new launch vehicle concepts. In order to define the support requirements and to discriminate among new technologies and processing choices for these systems, NASA Langley Research Center (LaRC) is developing new analysis methods. This paper describes several methods under development, gives their current status, and discusses the benefits and limitations associated with their use.

Morris, W. D.; White, N. H.; Davies, W. T.; Ebeling, C. E.

1997-01-01

258

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

259

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

260

A New Handbook for the Development of Space Vehicle Terrestrial Environment Design Requirements  

NASA Technical Reports Server (NTRS)

A new NASA document entitled "Terrestrial Environment (Climatic) Criteria Handbook for Use in Aerospace Vehicle Development (NASA-HDBK-IOO1A) has been developed. The Handbook provides terrestrial environment information, data bases, models, recommendations, etc. for use in the design, development, trade studies, testing, and mission analyses for space (or launch) vehicles. This document is organized into fourteen specific natural environment disciplines of which some are winds, atmospheric models, thermal radiation, precipitation-for-icing, cloud cover, atmospheric electricity, geologic hazards, toxic chemical release by propulsion systems, and sea state. Atmospheric phenomena play a significant role in the design and flight of aerospace vehicles and in the integrity of the associated aerospace systems and structures. Environmental design criteria guidelines in this document are based on measurements and observations of atmospheric and climatic phenomena relative to various aerospace development, operational, and vehicle launch locations. The natural environment criteria guidelines data presented in this Handbook were formulated based on discussions with and requests from engineers involved in aerospace vehicle development and operations. Therefore, they represent responses to actual engineering problems and are not just a general compilation of environmental data. The Handbook addresses the basis for the information presented, the interpretations of the terrestrial environment guideline given in the Handbook, and its application to the development of aerospace vehicle design requirements. Specific examples of the Handbook content and associated "lessons lenmed" are given in this paper.

Johnson, Dale L.; Vaughan, William W.

2008-01-01

261

A New Handbook for the Development of Space Vehicle Terrestrial Environment Design Requirements.  

NASA Technical Reports Server (NTRS)

A new NASA document entitled "Terrestrial Environment (Climatic) Criteria Handbook for Use in Aerospace Vehicle Development (NASA-HDBK-1001A) has been developed. The Handbook provides terrestrial environment information, data bases, models, recommendations, etc. for use in the design, development, trade studies, testing, and mission analyses for space (or launch) .vehicles. This document is organized into fourteen specific natural environment disciplines of which some are winds, atmospheric models, thermal radiation, precipitation-for-icing, cloud cover, atmospheric electricity, geologic hazards, toxic chemical release by propulsion systems, and sea state. Atmospheric phenomena play a significant role in the design and flight of aerospace vehicles and in the integrity of the associated aerospace systems and structures. Environmental design criteria guidelines in this document are based on measurements and observations of atmospheric and climatic phenomena relative to various aerospace development, operational, and vehicle launch locations. The natural environment criteria guidelines data presented in this Handbook were formulated based on discussions with and requests from engineers involved in aerospace vehicle development and operations. Therefore, they represent responses to actual engineering problems and are not just a general compilation of environmental data. The Handbook addresses the basis for the information presented, the interpretations of the terrestrial environment guideline given in the Handbook, and its application to the development of aerospace vehicle design requirements. Specific examples of the Handbook content and associated "lessons lenmed" are given in this paper.

Johnson, Dale L.; Vaughan, William W.

2008-01-01

262

HASA: 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, electral 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.

1988-01-01

263

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

264

Modeling and Simulation of Reliability & Maintainability Parameters for Reusable Launch Vehicles using Design of Experiments  

NASA Technical Reports Server (NTRS)

This paper describes the development of a methodology for estimating reliability and maintainability distribution parameters for a reusable launch vehicle. A disciplinary analysis code and experimental designs are used to construct approximation models for performance characteristics. These models are then used in a simulation study to estimate performance characteristic distributions efficiently. The effectiveness and limitations of the developed methodology for launch vehicle operations simulations are also discussed.

Unal, Resit; Morris, W. Douglas; White, Nancy H.; Lepsch, Roger A.

2004-01-01

265

Adaptive guidance law design based on characteristic model for reentry vehicles  

Microsoft Academic Search

In this paper an adaptive guidance law based on the characteristic model is designed to track a reference drag acceleration\\u000a for reentry vehicles like the Shuttle. The characteristic modeling method of linear constant systems is extended for single-input\\u000a and single-output (SISO) linear time-varying systems so that the characteristic model can be established for reentry vehicles.\\u000a A new nonlinear differential golden-section

Junchun Yang; Jun Hu; Maolin Ni

2008-01-01

266

Design and analysis of an Extended Kalman Filter based navigator for an autonomous underwater vehicle  

E-print Network

senses, thinks. and then acts. & All of these functions require a knowledge of how the vehicle is relating to its real world environment. For guidance and control functions, this knowledge can be quantitatively defined in terms of the vehicle states... navigation system, providing an error check for the inertial measurements as well as being available to act as a back-up navigation system in case of a failure of the inertial system. METHOD OF APPROACH The Kalman filter navigator designed within...

Just, Bradley Eugene

1994-01-01

267

A conceptual design of an unmanned test vehicle using an airbreathing propulsion system  

NASA Technical Reports Server (NTRS)

According to Aviation Week and Space Technology (Nov. 16, 1992), without a redefined approach to the problem of achieving single stage-to-orbit flight, the X-30 program is virtually assured of cancellation. One of the significant design goals of the X-30 program is to achieve single stage to low-earth orbit using airbreathing propulsion systems. In an attempt to avoid cancellation, the NASP Program has decided to design a test vehicle to achieve these goals. This report recommends a conceptual design of an unmanned test vehicle using an airbreathing propulsion system.

1992-01-01

268

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

269

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

270

Theory and Design of Flight-Vehicle Engines  

NASA Technical Reports Server (NTRS)

Papers are presented on such topics as the testing of aircraft engines, errors in the experimental determination of the parameters of scramjet engines, the effect of the nonuniformity of supersonic flow with shocks on friction and heat transfer in the channel of a hypersonic ramjet engine, and the selection of the basic parameters of cooled GTE turbines. Consideration is also given to the choice of optimal total wedge angle for the acceleration of aerospace vehicles, the theory of an electromagnetic-resonator engine, the dynamic characteristics of the pumps and turbines of liquid propellant rocket engines in transition regimes, and a hierarchy of mathematical models for spacecraft control engines.

Zhdanov, V. T. (editor); Kurziner, R. I. (editor)

1987-01-01

271

Engineering and design of vehicles for long distance road transport of livestock (ruminants, pigs and poultry).  

PubMed

During road transportation, livestock are subjected to a number of concurrent potential stressors that can increase mortality and morbidity and compromise welfare status and production efficiency. A major concern is the thermal micro-environment within the vehicle with both heat stress and cold stress constituting major problems. It is possible to mitigate the effects of external climatic conditions by improving vehicle design and operation using engineering solutions that match 'on-board' environmental conditions with the biological requirements of the animals. This review describes an investigative approach that targets four elements. These are the thermal conditions on commercial transport vehicles under a range of climatic conditions, the 'thermal comfort zones' or target conditions for different livestock species, the heat and moisture loads upon vehicles that must be dissipated and the thermodynamic characteristics of animal transport vehicles that affect the design of mechanical or active ventilation systems able to function at maximum efficiency under everyday commercial conditions. Results of research around these four elements can provide the sound scientific basis for improved vehicle design and operation and for legislation and codes of practice aimed at optimising animal welfare and productivity in relation to transportation of livestock on journeys of both long and short duration. PMID:20405426

Mitchell, Malcolm A; Kettlewell, Peter J

2008-01-01

272

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

273

332: 418 --Project 3 --Spring 2006 Design of a Controller for a Vehicle Lateral Dynamics Control  

E-print Network

PART A: CONTROLLER ANALYTICAL DESIGN AND MATLAB SIMULATION (10 points) The error of the lateral a control engineering point of view: a) Find the open-loop transfer function and make a conclusion about332: 418 --Project 3 -- Spring 2006 Design of a Controller for a Vehicle Lateral Dynamics Control

Gajic, Zoran

274

Modern electrical machine analysis and design techniques applied to hybrid vehicle drive machines  

Microsoft Academic Search

In this paper a review is made of the different analysis and design techniques that can be used in modern electrical machine design, and references them to the developing area of hybrid vehicle drives. These machines are characterized by high transient torque requirement, compactness and forced cooling. While rare-earth magnet machines are commonly used in these applications, there is an

D. G. Dorrell; M. Popescu; L. Evans; D. A. Staton; A. M. Knight

2010-01-01

275

Rotor Slots Design of Induction Machine for Hybrid Electric Vehicle Drives  

Microsoft Academic Search

Rotor slot design of the induction motor for hybrid electric vehicle drives is investigated in the paper. Rotor slot types of the induction machine for variable frequency drives are deferent from that of the induction machine for industry applications. Improper rotor slot design will lead to bad torque performance and unwished noise of the induction machine. Three common rotor slot

Chu Shumei; Dai Ying; Song Liwei

2006-01-01

276

A Conceptual Aerospace Vehicle Structural System Modeling, Analysis and Design Process  

NASA Technical Reports Server (NTRS)

A process for aerospace structural concept analysis and design is presented, with examples of a blended-wing-body fuselage, a multi-bubble fuselage concept, a notional crew exploration vehicle, and a high altitude long endurance aircraft. Aerospace vehicle structures must withstand all anticipated mission loads, yet must be designed to have optimal structural weight with the required safety margins. For a viable systems study of advanced concepts, these conflicting requirements must be imposed and analyzed early in the conceptual design cycle, preferably with a high degree of fidelity. In this design process, integrated multidisciplinary analysis tools are used in a collaborative engineering environment. First, parametric solid and surface models including the internal structural layout are developed for detailed finite element analyses. Multiple design scenarios are generated for analyzing several structural configurations and material alternatives. The structural stress, deflection, strain, and margins of safety distributions are visualized and the design is improved. Over several design cycles, the refined vehicle parts and assembly models are generated. The accumulated design data is used for the structural mass comparison and concept ranking. The present application focus on the blended-wing-body vehicle structure and advanced composite material are also discussed.

Mukhopadhyay, Vivek

2007-01-01

277

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

278

CONCEPTUAL DESIGN ISSUE: DEVELOPING A NEW HIGHWAY VEHICLE EMISSION ESTIMATION METHODOLOGY  

EPA Science Inventory

The paper reports on EPA's effort to define the design of an ideal methodology for estimating emissions from highway vehicles. The design concept will be used by EPA to focus research and promote the availability of accurate, cost effective inventory procedures within 5 to 10 yea...

279

A Design Approach for a GPS User Segment for Aerospace Vehicles  

Microsoft Academic Search

As new applications for the use of the Global Positioning System (GPS) on aerospace vehicles emerge, more attention is being paid to the design of the user segment, which comprises the hardware and software employed by the user to obtain navigation information from GPS. The complexity of the design of the user segment, as well as the performance demanded of

John J. Dougherty; Hossny El-Sherief; Daniel J. Simon; Gary A. Whitmer

1993-01-01

280

Requirements for multidisciplinary design of aerospace vehicles on high performance computers  

NASA Technical Reports Server (NTRS)

The design of aerospace vehicles is becoming increasingly complex as the various contributing disciplines and physical components become more tightly coupled. This coupling leads to computational problems that will be tractable only if significant advances in high performance computing systems are made. Some of the modeling, algorithmic and software requirements generated by the design problem are discussed.

Voigt, Robert G.

1989-01-01

281

Assessment and preliminary design of an energy buffer for regenerative breaking in electric vehicles  

Microsoft Academic Search

The original objectives of this program were to: provide an assessment of electric vehicle energy buffers with currently available state of the art, off-the-shelf components, and design, fabricate, and test an engineering model of a selected buffer. The selected buffer was not to include flywheel or electrochemical concepts. A hydropneumatic (liquid and gas) buffer concept was selected for design. The

R. Buchholz; A. Mathur

1979-01-01

282

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

283

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

284

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

285

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

286

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

287

Rocket-powered single-stage vehicle configuration selection and design  

NASA Technical Reports Server (NTRS)

A reusable rocket-powered, single-stage launch vehicle has been designed as a part of NASA's Advanced Manned Launch System (AMLS) study to examine options for a next-generation manned space transportation system. The configuration selection process utilized a response surface methodology for multidisciplinary optimization. The methodology was utilized to determine the minimum dry weight entry vehicle to meet constraints on landing velocity and on subsonic, supersonic, and hypersonic trim and stability. Once the optimum configuration was determined, a multidisciplinary conceptual vehicle design was performed. This paper presents the results of the configuration selection methodology and summarizes the overall conceptual design process with special attention given to the individual disciplines of weights/ sizing, structures/materials, configuration, flight mechanics, aerodynamics, aeroheating, propulsion, and operations.

Stanley, Douglas O.; Engelund, Walter C.; Lepsch, Roger A.; Mcmillin, Mark; Wurster, Kathryn E.; Powell, Richard W.; Guinta, Anthony A.; Unal, Resit

1993-01-01

288

Resilient design of recharging station networks for electric transportation vehicles  

SciTech Connect

As societies shift to 'greener' means of transportation using electricity-driven vehicles one critical challenge we face is the creation of a robust and resilient infrastructure of recharging stations. A particular issue here is the optimal location of service stations. In this work, we consider the placement of battery replacing service station in a city network for which the normal traffic flow is known. For such known traffic flow, the service stations are placed such that the expected performance is maximized without changing the traffic flow. This is done for different scenarios in which roads, road junctions and service stations can fail with a given probability. To account for such failure probabilities, the previously developed facility interception model is extended. Results show that service station failures have a minimal impact on the performance following robust placement while road and road junction failures have larger impacts which are not mitigated easily by robust placement.

Kris Villez; Akshya Gupta; Venkat Venkatasubramanian

2011-08-01

289

Launch Vehicle Design and Optimization Methods and Priority for the Advanced Engineering Environment  

NASA Technical Reports Server (NTRS)

NASA's Advanced Engineering Environment (AEE) is a research and development program that will improve collaboration among design engineers for launch vehicle conceptual design and provide the infrastructure (methods and framework) necessary to enable that environment. In this paper, three major technical challenges facing the AEE program are identified, and three specific design problems are selected to demonstrate how advanced methods can improve current design activities. References are made to studies that demonstrate these design problems and methods, and these studies will provide the detailed information and check cases to support incorporation of these methods into the AEE. This paper provides background and terminology for discussing the launch vehicle conceptual design problem so that the diverse AEE user community can participate in prioritizing the AEE development effort.

Rowell, Lawrence F.; Korte, John J.

2003-01-01

290

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

291

Improving Conceptual Design for Launch Vehicles. The Bimese Concept: A Study of Mission and Economic Options  

NASA Technical Reports Server (NTRS)

This report summarizes key activities conducted in the third and final year of the cooperative agreement NCC1-229 entitled "Improving Conceptual Design for Launch Vehicles." This project has been funded by the Vehicle Analysis Branch at NASA's Langley Research Center in Hampton, VA. Work has been performed by the Space Systems Design Lab (SSDL) at the Georgia Institute of Technology, Atlanta, GA. Accomplishments during the first and second years of this project have been previously reported in annual progress reports. This report will focus on the third and final year of the three year activity.

Olds, John R.; Tooley, Jeffrey

1999-01-01

292

Vehicle occupancy detection camera position optimization using design of experiments and standard image references  

NASA Astrophysics Data System (ADS)

Camera positioning and orientation is important to applications in domains such as transportation since the objects to be imaged vary greatly in shape and size. In a typical transportation application that requires capturing still images, inductive loops buried in the ground or laser trigger sensors are used when a vehicle reaches the image capture zone to trigger the image capture system. The camera in such a system is in a fixed position pointed at the roadway and at a fixed orientation. Thus the problem is to determine the optimal location and orientation of the camera when capturing images from a wide variety of vehicles. Methods from Design for Six Sigma, including identifying important parameters and noise sources and performing systematically designed experiments (DOE) can be used to determine an effective set of parameter settings for the camera position and orientation under these conditions. In the transportation application of high occupancy vehicle lane enforcement, the number of passengers in the vehicle is to be counted. Past work has described front seat vehicle occupant counting using a camera mounted on an overhead gantry looking through the front windshield in order to capture images of vehicle occupants. However, viewing rear seat passengers is more problematic due to obstructions including the vehicle body frame structures and seats. One approach is to view the rear seats through the side window. In this situation the problem of optimally positioning and orienting the camera to adequately capture the rear seats through the side window can be addressed through a designed experiment. In any automated traffic enforcement system it is necessary for humans to be able to review any automatically captured digital imagery in order to verify detected infractions. Thus for defining an output to be optimized for the designed experiment, a human defined standard image reference (SIR) was used to quantify the quality of the line-of-sight to the rear seats of the vehicle. The DOE-SIR method was exercised for determining the optimal camera position and orientation for viewing vehicle rear seats over a variety of vehicle types. The resulting camera geometry was used on public roadway image capture resulting in over 95% acceptable rear seat images for human viewing.

Paul, Peter; Hoover, Martin; Rabbani, Mojgan

2013-03-01

293

A Loop Material Flow System Design for Automated Guided Vehicles  

E-print Network

to a 1 #12;A Loop Material Flow System Design for AGVs 2 half of the total manufacturing costs the modern material handling equipment in manufacturing plants. They are preferred to conveyors due to their exibility, and to robots due to their mobility. The design of the material ow system and its simplicity

Dessouky, Maged

294

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

NASA Technical Reports Server (NTRS)

Results of a requirements analysis task for Integrated Programs for Aerospace Vehicle Design (IPAD) are presented. User requirements which, in part, will shape the IPAD system design are given. Requirements considered were: generation, modification, storage, retrieval, communication, reporting, and protection of information. Data manipulation and controls on the system and the information were also considered. Specific needs relative to the product design process are also discussed.

Anderton, G. L.

1979-01-01

295

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

296

Design of a remotely piloted vehicle for a low Reynolds number station keeping mission  

NASA Technical Reports Server (NTRS)

Six teams of senior level Aerospace Engineering undergraduates were given a request for proposal, asking for a design concept for a remotely piloted vehicle (RPV). This RPV was to be designed to fly at a target Reynolds number of 1 times 10(exp 5). The craft was to maximize loiter time and perform an indoor, closed course flight. As part of the proposal, each team was required to construct a prototype and validate their design with a flight demonstration.

1990-01-01

297

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

298

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

299

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

300

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

301

Decomposition-Based Decision Making for Aerospace Vehicle Design  

NASA Technical Reports Server (NTRS)

Most practical engineering systems design problems have multiple and conflicting objectives. Furthermore, the satisfactory attainment level for each objective ( requirement ) is likely uncertain early in the design process. Systems with long design cycle times will exhibit more of this uncertainty throughout the design process. This is further complicated if the system is expected to perform for a relatively long period of time, as now it will need to grow as new requirements are identified and new technologies are introduced. These points identify a need for a systems design technique that enables decision making amongst multiple objectives in the presence of uncertainty. Traditional design techniques deal with a single objective or a small number of objectives that are often aggregates of the overarching goals sought through the generation of a new system. Other requirements, although uncertain, are viewed as static constraints to this single or multiple objective optimization problem. With either of these formulations, enabling tradeoffs between the requirements, objectives, or combinations thereof is a slow, serial process that becomes increasingly complex as more criteria are added. This research proposal outlines a technique that attempts to address these and other idiosyncrasies associated with modern aerospace systems design. The proposed formulation first recasts systems design into a multiple criteria decision making problem. The now multiple objectives are decomposed to discover the critical characteristics of the objective space. Tradeoffs between the objectives are considered amongst these critical characteristics by comparison to a probabilistic ideal tradeoff solution. The proposed formulation represents a radical departure from traditional methods. A pitfall of this technique is in the validation of the solution: in a multi-objective sense, how can a decision maker justify a choice between non-dominated alternatives? A series of examples help the reader to observe how this technique can be applied to aerospace systems design and compare the results of this so-called Decomposition-Based Decision Making to more traditional design approaches.

Borer, Nicholas K.; Mavris, DImitri N.

2005-01-01

302

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

303

Electric vehicle design, racing and distance to empty algorithms  

E-print Network

This research began with the goal of designing and building an electric motorcycle to compete in the Isle of Man TT Zero race. A set of parametric physics-based models was derived to size the batteries and motors, predict ...

Rodgers, Lennon Patrick

2013-01-01

304

Integrated structural and thermal design of an entry vehicle aeroshell  

E-print Network

of ACC, GFRP, and 7075 Al 19 EAective Properties of the Assumed Laminate . . . . . 35 Laminate Allowable Stresses (Design Factor of 2 5 Included) 38 Phase I Design Summary (costs of insulators are constant across all comparisons, and are not included..., Ohlhorst, and Martin, 1989) are presented in Table 1 below. The properties of graphite / epoxy (Vinson, and Sierakowski, 1987) and 7075 aluminum (Flinn and Trojan, 1990) are presented for comparison. Table 1 Material properties of ACC, GFRP, and 7075 AI...

Cochran, David Brian

1996-01-01

305

ODIN - Optimal Design Integration system for synthesis of aerospace vehicles  

NASA Technical Reports Server (NTRS)

The ODIN system is a new design synthesis procedure for solving multiple discipline design problems. In ODIN an unlimited number of independent technology codes can be linked together in the computer in any desired sequence. This paper describes the ODIN system, the executive program DIALOG, the data management technique, and the program library. The use of ODIN is illustrated with an application drawn from space system studies.

Rau, T. R.; Decker, J. P.

1974-01-01

306

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

307

Bioresearch Module Design Definition and Space Shuttle Vehicle Integration Study. Volume 1: Basic Report  

NASA Technical Reports Server (NTRS)

Preliminary designs of the Bioexplorer spacecraft, developed in an earlier study program, are analyzed and updated to conform to a new specification which includes use of both the Scout and the space shuttle vehicle for launch. The updated spacecraft is referred to as bioresearch module. It is capable of supporting a variety of small biological experiments in near-earth and highly elliptical earth orbits. The baseline spacecraft design is compatible with the Scout launch vehicle. Inboard profile drawings, weight statements, interface drawings, and spacecraft parts and aerospace ground equipment lists are provided to document the design. The baseline design was analyzed to determine the design and cost impact of a set of optional features. These include reduced experiment power and thermal load, addition of an experiment television monitor, and replacement of VHF with S-band communications. The impact of these options on power required, weight change and cost is defined.

Lang, A. L., Jr.

1971-01-01

308

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

E-print Network

of the work. The two years of working with him have given me much insight into many aspects in the field of hybrid vehicles and motor drives, far beyond the scope of my thesis work. I also take this opportunity to thank my committee members Dr... members of the Motor Drives and Advanced Vehicle System Research Program is gratefully acknowledged. vi TABLE OF CONTENTS...

Shidore, Neeraj Shripad

2005-02-17

309

LifeSat engineering in-house vehicle design  

NASA Technical Reports Server (NTRS)

The LifeSat program was initiated to research the effects of microgravity and cosmic radiation on living organisms. The effects of long-term human exposure to free-space radiation fields over a range of gravitational environments has long been recognized as one of the primary design uncertainties for human space exploration. A critical design issue in the radiation biology requirements was the lack of definition of the minimum radiation absorbed dosage required to produce statistically meaningful data. The Phase A study produced a spacecraft conceptual design resembling a Discoverer configuration with a total weight of approximately 2800 pounds that would carry a 525-pound payload module (45 inches in diameter and 36 inches long) and support up to 12 rodents and a general biology module supporting lower life forms for an on-orbit duration of up to 60 days. The phase B conceptual designs focused on gravitational biology requirements and only briefly addressed the design impacts of the shift toward radiobiological science that occurred during the latter half of the Phase B studies.

Adkins, A.; Badhwar, G.; Bryant, L.; Caram, J.; Conley, G.; Crull, T.; Cuthbert, P.; Darcy, E.; Delaune, P.; Edeen, M.

1992-01-01

310

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

311

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

312

Noise, vibration and harshness (NVH) criteria as functions of vehicle design and consumer expectations  

NASA Astrophysics Data System (ADS)

The criteria for NVH design are to a large degree determined by the types of vehicles and the perceived desires of the purchasers of vehicles, as well as the cost of incorporating NVH measures. Vehicles may be classified into specific types, e.g., economy car, midsize passenger, near-luxury and luxury passenger cars, sports cars, vans, minivans, and sports utility vehicles of varying sizes. The owner of a luxury sedan would expect a quiet ride with minimal vibration and harshness-however, if that sedan is to display sporting characteristics, some aspects of NVH may actually have to be increased in order to enhance a feeling of driver exhilaration. A discussion of the requirements for specific types of vehicles is provided, with due regard for effects on the usability of installed sound/video systems, driver and passenger fatigue, feel of steering mechanisms and other mechanical components, consumer market research, etc. A number of examples of vehicles on the market are cited.

Raichel, Daniel R.

2005-09-01

313

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

314

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

315

Design Process of Flight Vehicle Structures for a Common Bulkhead and an MPCV Spacecraft Adapter  

NASA Technical Reports Server (NTRS)

Design and manufacturing space flight vehicle structures is a skillset that has grown considerably at NASA during that last several years. Beginning with the Ares program and followed by the Space Launch System (SLS); in-house designs were produced for both the Upper Stage and the SLS Multipurpose crew vehicle (MPCV) spacecraft adapter. Specifically, critical design review (CDR) level analysis and flight production drawing were produced for the above mentioned hardware. In particular, the experience of this in-house design work led to increased manufacturing infrastructure for both Marshal Space Flight Center (MSFC) and Michoud Assembly Facility (MAF), improved skillsets in both analysis and design, and hands on experience in building and testing (MSA) full scale hardware. The hardware design and development processes from initiation to CDR and finally flight; resulted in many challenges and experiences that produced valuable lessons. This paper builds on these experiences of NASA in recent years on designing and fabricating flight hardware and examines the design/development processes used, as well as the challenges and lessons learned, i.e. from the initial design, loads estimation and mass constraints to structural optimization/affordability to release of production drawing to hardware manufacturing. While there are many documented design processes which a design engineer can follow, these unique experiences can offer insight into designing hardware in current program environments and present solutions to many of the challenges experienced by the engineering team.

Aggarwal, Pravin; Hull, Patrick V.

2015-01-01

316

ME 410 Flight Vehicle Design II Spring 2012 Information Sheet  

E-print Network

, and the mock-up with a short video report. A single composite grade will be assigned. 6. Design Review the following activities: o Status Report: A summary of the status of the team's progress and any outstanding Meeting Leader responsibilities for more details. o DEW Q&A after Status Report. o Open discussion

317

Setting initial targets in vehicle side impact safety design using regression-based modeling  

Microsoft Academic Search

The performance of a vehicle in a side impact safety assessment test can be influenced by a number of parameters which can be categorized under structural, packaging, and restraint system-related areas. One way of setting design variable targets in initial stages for desirable side impact safety performance is to use reliable regression-based relations developed with the aid of test data.

A Deb; K S Cheruvu

2007-01-01

318

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

319

Autonomous controller design for unmanned aerial vehicles using multi-objective genetic programming  

Microsoft Academic Search

Autonomous navigation controllers were developed for fixed wing unmanned aerial vehicle (UAV) applications using multiobjective genetic programming (GP). We designed four fitness functions derived from flight simulations and used multiobjective GP to evolve controllers able to locate a radar source, navigate the UAV to the source efficiently using on-board sensor measurements, and circle closely around the emitter. Controllers were evolved

Choong K. Oh; Gregory J. Barlow

2004-01-01

320

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

321

Nano Air Vehicle wing concepts design and experimental study of nano rotor hovering performance  

Microsoft Academic Search

Nano Air Vehicles (NAVs) were proposed as unmanned aerial robots to fulfill the missions in cluster environment. This study designs two types of wing concept as rotary wing and flapping wing for NAV based on the minimum energy loss theory and biologically inspired theory. The hovering performance of the two concepts is compared each other to demonstrate the concept superiority.

Zhen Liu; Min Xu

2010-01-01

322

Design of a Mechanism for Biaxial Rotation of a Wing for a Hovering Vehicle  

Microsoft Academic Search

This paper presents a novel mechanism to actuate the wings of a hovering micro air vehicle (MAV). The mechanism uses a single actuator, but each wing can rotate about two orthogonal axes. The goal of this work is to design a light-weight compact mechanism that flaps the wings, inspired from the wing motion of hummingbird and hovering insects, to generate

Sean H. McIntosh; Sunil K. Agrawal; Zaeem Khan

2006-01-01

323

Design of a 100 kW switched reluctance motor for electric vehicle propulsion  

Microsoft Academic Search

Low cost, high reliability, and competitive weight and efficiency combine to make the switched reluctance (SR) motor drive a strong candidate for application in future electric vehicle (EV) propulsion systems. This paper presents methods and results of a prototype SR motor design study. Finite element analysis and transient simulation results predict performance, efficiency, and weight that are competitive with existing

Tatsuya Uematsu; Richard S. Wallace

1995-01-01

324

Future Armored Resupply Vehicle (FARV) conceptual fuel system design. Final report  

Microsoft Academic Search

This document presents an idealized automated fuel system applicable to unique requirements. The system accepts fuel at high rates, transports fuel in a battlefield environment, and supplies fuel to a vehicle equipped to receive it without exposing the crew to small arms fire. The fuel system design incorporates controls and mechanisms which compensate for battle damage and irregularities found in

R. R. Daubert; E. C. Fisher; W. K. Moore; N. C. Munro

1995-01-01

325

A Capability to Generate Physics-based Mass Estimating Relationships for Conceptual Space Vehicle Design  

NASA Technical Reports Server (NTRS)

This paper is written in support of the on-going research into conceptual space vehicle design conducted at the Space Systems Design Laboratory (SSDL) at the Georgia Institute of Technology. Research at the SSDL follows a sequence of a number of the traditional aerospace disciplines. The sequence of disciplines and interrelationship among them is shown in the Design Structure Matrix (DSM). The discipline of Weights and Sizing occupies a central location in the design of a new space vehicle. Weights and Sizing interact, either in a feed forward or feed back manner, with every other discipline in the DSM. Because of this principle location, accuracy in Weights and Sizing is integral to producing an accurate model of a space vehicle concept. Instead of using conceptual level techniques, a simplified Finite Element Analysis (FEA) technique is described as applied to the problem of the Liquid Oxygen (LOX) tank bending loads applied to the forward Liquid Hydrogen (LH2) tank of the Georgia Tech Air Breathing Launch Vehicle (ABLV).

Olds, John R.; Marcus, Leland

2002-01-01

326

Design of Sliding Mode Autopilot with Steady-State Error Elimination for Autonomous Underwater Vehicles  

Microsoft Academic Search

Autonomous underwater vehicles (AUVs) have nonlinear and time-varying behaviour and unmodelled dynamics. This paper describes the design, development and evaluation of nonlinear sliding mode autopilot system for an AUV to control the speed, steering and depth of the nonlinear AUV. It has also been observed by some researchers that the sliding mode controller is unable to eliminate the steady-state error.

Juan Shi

2006-01-01

327

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

E-print Network

Modelling and Design Optimization of Low Speed Fuel Cell Hybrid Electric Vehicles by Matthew Blair of emissions to global climate change. Although electric cars and buses have been the focus of much of electric for a fuel cell - battery hybrid electric scooter. The modelling and simulation of the fuel cell electric

Victoria, University of

328

DESIGN OF POWER-SPLIT HYBRID VEHICLES WITH A SINGLE PLANETARY GEAR Chiao-Ting Li  

E-print Network

DESIGN OF POWER-SPLIT HYBRID VEHICLES WITH A SINGLE PLANETARY GEAR Chiao-Ting Li Department between gears on the planetary gearset K Final drive gear ratio on output shaft R Gear radius of the ring gear S Gear radius of the sun gear e (subscript) Engine MG (subscript) Electric machine out (subscript

Peng, Huei

329

Design and construction of an Autonomous Underwater Vehicle for the launch of a small UAV  

Microsoft Academic Search

This paper describes the design and construction of a low cost Autonomous Underwater Vehicle (AUV) prototype that can work as launch platform of a small UAV. The AUV can travel in a determined path to reach the launch AUV point. The AUV length is less than 2 m. The max operation depth is 20 m. It is composed of eight

A. Cadena

2009-01-01

330

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

331

Hydraulic system design and vehicle dynamic modeling for the analysis and development of tire roller  

Microsoft Academic Search

In this research, the authors attempt hydraulic system design and vehicle dynamic modeling for the development of the tire roller. The tire roller is one of the most useful machines for road construction sites and applications with other construction equipment. The authors conceptualize the new hydraulic system, derive the equations of motion for dynamic analysis and investigate system modeling by

Jun-Ho Kim; Chun-Sik Park; Sang-Gyum Kim; Jung-Ha Kim

2001-01-01

332

Hydraulic System Design and Vehicle Dynamic Modeling for the Development of a Tire Roller  

Microsoft Academic Search

In this paper, we describe a hydraulic system design and vehicle dynamic modeling for development of tire roller traction, an essential aspect in the system analysis of tire rollers. Generally, tire rollers are one of the most useful types of machines employed in road construction, technically applied to many construction fields. We also conceptualize a new hydraulic and driving system

Sang-Gyum Kim; Jung-Ha Kim; Woon-Sung Lee

2003-01-01

333

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

334

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

335

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

336

Conceptual Design of a Vertical Takeoff and Landing Unmanned Aerial Vehicle with 24-HR Endurance  

NASA Technical Reports Server (NTRS)

This paper describes a conceptual design study for a vertical takeoff and landing (VTOL) unmanned aerial vehicle (UAV) that is able to carry a 25-lb science payload for 24 hr and is able to land and take off at elevations as high as 15,000 ft without human intervention. In addition to the science payload, this vehicle must be able to carry a satellite communication system, and the vehicle must be able to be transported in a standard full-size pickup truck and assembled by only two operators. This project started with a brainstorming phase to devise possible vehicle configurations that might satisfy the requirements. A down select was performed to select a near-term solution and two advanced vehicle concepts that are better suited to the intent of the mission. Sensitivity analyses were also performed on the requirements and the technology levels to obtain a better understanding of the design space. This study found that within the study assumptions the mission is feasible; the selected concepts are recommended for further development.

Fredericks, William J.

2010-01-01

337

Int. J. Vehicle Design, Vol. 59, No. 4, 2012 315 Combined design and robust control of a vehicle  

E-print Network

Engineering, College of Engineering and Petroleum, Kuwait University P.O. Box: 5969, Safat 13060, Kuwait E of Mechanical Engineering, Kuwait University, Kuwait. His research interests include robust design, robust

Papalambros, Panos

338

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

339

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

340

A New Battery\\/Ultracapacitor Energy Storage System Design and Its Motor Drive Integration for Hybrid Electric Vehicles  

Microsoft Academic Search

This paper proposes a new energy storage system (ESS) design, including both batteries and ultracapacitors (UCs) in hybrid electric vehicle (HEV) and electric vehicle applications. The conventional designs require a DC-DC converter to interface the UC unit. Herein, the UC can be directly switched across the motor drive DC link during the peak power demands. The resulting wide voltage variation

Shuai Lu; Keith A. Corzine; Mehdi Ferdowsi

2007-01-01

341

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

342

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 Zo, a solar-powered robot designed to explore the Mars-like landscapes of the Atacama Desert in Chile. We are developing the Zo chassis as an alternative to the traditional six-wheeled, rocker-bogie system used by Mars rovers flown in the past ten years. Zo travels over rough terrain

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

2005-01-01

343

Computational Design Principles for Multiple Autonomous Vehicle Organization  

Microsoft Academic Search

In Distributed Artificial Intelligence (AI), a bifurcation in design principles can be observed. On the one hand there seems to be a resurgence of the 'classical' AI approach of bestowing agents with human-like intelligent capacities and on the other hand there is an anti-representational school emerging. Classical AI has had to endure severe criti cisms while anti-representational approaches fall short

Alfred D. M. Wan; Peter J. Braspenning

1995-01-01

344

Design of high-efficiency and high-torque-density switched reluctance motor for vehicle propulsion  

Microsoft Academic Search

A high-density and high-efficiency switched reluctance (SR) motor has been designed and built for vehicle propulsion. Extensive finite-element analyses have been carried out to optimize the geometry for high density. Steady-state performance of the drive has been simulated to ensure good efficiency at all speeds. Special attention has been given during machine design to lower the acoustic noise. Direct liquid

Khwaja M. Rahman; Steven E. Schulz

2002-01-01

345

On Design and Development of an Intelligent Mobile Robotic Vehicle for StairCase Navigation  

Microsoft Academic Search

\\u000a The present chapter focuses on the study of different features of stair-climbing mechanisms for transporting materials autonomously.\\u000a The authors finally concentrate on arm wheel-based design for stair climbing. An attempt is made to design, develop and construct\\u000a a mobile robotic vehicle for stair navigation with the following functional attributes: (i) motion on plane surface, (ii)\\u000a navigation on stair- case, i.e.,

Ranjit Ray; Bikash Bepari; Subhasis Bhaumik

2010-01-01

346

NASA Ares I Launch Vehicle Roll and Reaction Control Systems Design Status  

NASA Technical Reports Server (NTRS)

This paper provides an update of design status following the preliminary design review of NASA s Ares I first stage roll and upper stage reaction control systems. The Ares I launch vehicle has been chosen to return humans to the moon, mars, and beyond. It consists of a first stage five segment solid rocket booster and an upper stage liquid bi-propellant J-2X engine. Similar to many launch vehicles, the Ares I has reaction control systems used to provide the vehicle with three degrees of freedom stabilization during the mission. During launch, the first stage roll control system will provide the Ares I with the ability to counteract induced roll torque. After first stage booster separation, the upper stage reaction control system will provide the upper stage element with three degrees of freedom control as needed. Trade studies and design assessments conducted on the roll and reaction control systems include: propellant selection, thruster arrangement, pressurization system configuration, and system component trades. Since successful completion of the preliminary design review, work has progressed towards the critical design review with accomplishments made in the following areas: pressurant / propellant tank, thruster assembly, and other component configurations, as well as thruster module design, and waterhammer mitigation approach. Also, results from early development testing are discussed along with plans for upcoming system testing. This paper concludes by summarizing the process of down selecting to the current baseline configuration for the Ares I roll and reaction control systems.

Butt, Adam; Popp, Chris G.; Pitts, Hank M.; Sharp, David J.

2009-01-01

347

Development of a conceptual flight vehicle design weight estimation method library and documentation  

NASA Astrophysics Data System (ADS)

The state of the art in estimating the volumetric size and mass of flight vehicles is held today by an elite group of engineers in the Aerospace Conceptual Design Industry. This is not a skill readily accessible or taught in academia. To estimate flight vehicle mass properties, many aerospace engineering students are encouraged to read the latest design textbooks, learn how to use a few basic statistical equations, and plunge into the details of parametric mass properties analysis. Specifications for and a prototype of a standardized engineering "tool-box" of conceptual and preliminary design weight estimation methods were developed to manage the growing and ever-changing body of weight estimation knowledge. This also bridges the gap in Mass Properties education for aerospace engineering students. The Weight Method Library will also be used as a living document for use by future aerospace students. This "tool-box" consists of a weight estimation method bibliography containing unclassified, open-source literature for conceptual and preliminary flight vehicle design phases. Transport aircraft validation cases have been applied to each entry in the AVD Weight Method Library in order to provide a sense of context and applicability to each method. The weight methodology validation results indicate consensus and agreement of the individual methods. This generic specification of a method library will be applicable for use by other disciplines within the AVD Lab, Post-Graduate design labs, or engineering design professionals.

Walker, Andrew S.

348

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

349

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

NASA Astrophysics Data System (ADS)

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.; Tinker, Michael L.

2005-02-01

350

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

351

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

NASA Technical Reports Server (NTRS)

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.; Tinker, Michael L.

2005-01-01

352

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

353

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

354

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

355

Concept Design of a Crash Management System for Goods Vehicles  

NSDL National Science Digital Library

In this study by the European Aluminium Association and FKA (Forschungsgesellschaft Kraftfahrwesen Aachen), a concept crash system for 40t trucks is developed based on the front end design used in the APROSYS study. The concept was built around European safety regulations in CAD software and simulated with an FE model using aluminum and steel. It was found that using an octagon shaped aluminum crush box would be the safest due to its characteristics of low weight, high energy absorption, and low technical complexity. Through additional testing it was also found if EU directive 96/53/EC could be modified to exclude cabin dimensions from its requirements, safer collisions for both parties would result.

2013-07-10

356

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

357

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

358

Design for Reliability and Safety Approach for the New NASA 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 intended for sending crew and cargo to the international Space Station (ISS), to the moon, and beyond. This program is called Constellation. As part of the Constellation program, NASA is developing new launch vehicles aimed at significantly increase safety and reliability, reduce the cost of accessing space, and provide a growth path for manned space exploration. Achieving these goals requires a rigorous process that addresses reliability, safety, and cost upfront and throughout all the phases of the life cycle of the program. This paper discusses the "Design for Reliability and Safety" approach for the NASA new launch vehicles, the ARES I and ARES V. Specifically, the paper addresses the use of an integrated probabilistic functional analysis to support the design analysis cycle and a probabilistic risk assessment (PRA) to support the preliminary design and beyond.

Safie, Fayssal M.; Weldon, Danny M.

2007-01-01

359

Evaluation of Separation Mechanism Design for the Orion/Ares Launch Vehicle  

NASA Technical Reports Server (NTRS)

As a part of the preliminary design work being performed for the Orion vehicle, the Orion to Spacecraft Adaptor (SA) separation mechanism mechanism was analyzed and sized, with findings presented here. Sizing is based on worst case abort condition as a result of an anomaly driving the launch vehicle engine thrust vector control hard-over causing a severe vehicle pitch over. This worst case scenario occurs just before Upper Stage Main Engine Cut-Off (MECO) when the vehicle is the lightest and the damping effect due to propellant slosh has been reduced to a minimum. To address this scenario and others, two modeling approaches were invoked. The first approach was a detailed Simulink model to quickly assess the Service Module Engine nozzle to SA clearance for a given separation mechanism. The second approach involved the generation of an Automatic Dynamic Analysis of Mechanical Systems (ADAMS) model to assess secondary effects due to mass centers of gravity that were slightly off the vehicle centerline. It also captured any interference between the Solar Arrays and the Spacecraft Adapter. A comparison of modeling results and accuracy are discussed. Most notably, incorporating a larger SA flange diameter allowed for a natural separation of the Orion and its engine nozzle even at relatively large pitch rates minimizing the kickoff force. Advantages and disadvantages of the Simulink model vs. a full geometric ADAMS model are discussed as well.

Konno, Kevin E.; Catalano, Daniel A.; Krivanek, Thomas M.

2008-01-01

360

Evaluation of Separation Mechanism Design for the Orion/Ares Launch Vehicle  

NASA Technical Reports Server (NTRS)

As a part of the preliminary design work being performed for the Orion vehicle, the Orion to Spacecraft Adaptor (SA) separation mechanism was analyzed and sized, with findings presented here. Sizing is based on worst case abort condition as a result of an anomaly driving the launch vehicle engine thrust vector control hard-over causing a severe vehicle pitch over. This worst case scenario occurs just before Upper Stage Main Engine Cut-Off (MECO) when the vehicle is the lightest and the damping effect due to propellant slosh has been reduced to a minimum. To address this scenario and others, two modeling approaches were invoked. The first approach was a detailed Simulink model to quickly assess the Service Module Engine nozzle to SA clearance for a given separation mechanism. The second approach involved the generation of an Automatic Dynamic Analysis of Mechanical Systems (ADAMS) model to assess secondary effects due to mass centers of gravity that were slightly off the vehicle centerline. It also captured any interference between the Solar Arrays and the Spacecraft Adapter. A comparison of modeling results and accuracy are discussed. Most notably, incorporating a larger SA flange diameter allowed for a natural separation of the Orion and it's engine nozzle even at relatively large pitch rates minimizing the kickoff force. Advantages and disadvantages of the Simulink model vs. a full geometric ADAMS model are discussed as well.

Konno, Kevin E.; Catalano, Daniel A.; Krivanek, Thomas M.

2008-01-01

361

Evaluation of Separation Mechanism Design for the Orion/Ares Launch Vehicle  

NASA Technical Reports Server (NTRS)

As a part of the preliminary design work being performed for the Orion vehicle, the Orion to Spacecraft Adaptor (SA) separation mechanism was analyzed and sized, with findings presented here. Sizing is based on worst case abort condition as a result of an anomaly driving the launch vehicle engine thrust vector control hard-over causing a severe vehicle pitch over. This worst case scenario occurs just before Upper Stage Main Engine Cut-Off (MECO) when the vehicle is the lightest and the damping effect due to propellant slosh has been reduced to a minimum. To address this scenario and others, two modeling approaches were invoked. The first approach was a detailed 2-D (Simulink) model to quickly assess the Service Module Engine nozzle to SA clearance for a given separation mechanism. The second approach involved the generation of an Automatic Dynamic Analysis of Mechanical Systems (ADAMS) model to assess secondary effects due to mass centers of gravity that were slightly off the vehicle centerline. It also captured any interference between the Solar Arrays and the Spacecraft Adapter. A comparison of modeling results and accuracy are discussed. Most notably, incorporating a larger SA flange diameter allowed for a natural separation of the Orion and its engine nozzle even at relatively large pitch rates minimizing the kickoff force. Advantages and disadvantages of the 2-D model vs. a full 3-D (ADAMS) model are discussed as well.

Konno, Kevin E.; Catalano, Daniel A.; Krivanek, Thomas M.

2008-01-01

362

Task-based vehicle interior layout design using optimization method to enhance safety  

NASA Astrophysics Data System (ADS)

This paper presents a virtual environment for conducting vehicle interior layout design. A virtual human called Santos that is biomechanically correct, has realistic musculoskeletal system, and natural motion/posture is created to live in this virtual world. One of the objectives of this virtual environment is to allow Santos to explore the interior package design such that one designs new defense and security vehicles without having to create a physical prototype to enhance safety, save time and cost. Different controls require different tasks, for example, pulling a clutch lever, pushing a button, turning a knob, and so on. Therefore, different tasks correspond to different human upper-body motions and hand loads, which in turn correspond to different displacement and torque at each joint. This is a dynamics problem for interior layout design with external loads. The formulation of dynamic equations of motion is implemented within optimization algorithm to predict joint profiles. This methodology allows Santos to help vehicle interior layout design while executing various tasks.

Kim, Joo; Yang, Jingzhou; Abdel-Malek, Karim; Nebel, Kyle

2005-05-01

363

Innovative Structural and Joining Concepts for Lightweight Design of Heavy Vehicle Systems  

SciTech Connect

Recent advances in the area of Metal Matrix Composites (MMC's) have brought these materials to a maturity stage where the technology is ready for transition to large-volume production and commercialization. The new materials seem to allow the fabrication of higher quality parts at less than 50 percent of the weight as compared to steel, especially when they are selectively reinforced with carbon, silicon carbide, or aluminum oxide fibers. Most of the developments in the MMC materials have been spurred, mainly by applications that require high structural performance at elevated temperatures, the heavy vehicle industry could also benefit from this emerging technology. Increasing requirements of weight savings and extended durability are the main drivers for potential insertion of MMC technology into the heavy vehicle market. Critical elements of a typical tractor-trailer combination, such as highly loaded sections of the structure, engine components, brakes, suspensions, joints and bearings could be improved through judicious use of MMC materials. Such an outcome would promote the DOE's programmatic objectives of increasing the fuel efficiency of heavy vehicles and reducing their life cycle costs and pollution levels. However, significant technical and economical barriers are likely to hinder or even prevent broad applications of MMC materials in heavy vehicles. The tradeoffs between such expected benefits (lower weights and longer durability) and penalties (higher costs, brittle behavior, and difficult to machine) must be thoroughly investigated both from the performance and cost viewpoints, before the transfer of MMC technology to heavy vehicle systems can be properly assessed and implemented. MMC materials are considered to form one element of the comprehensive, multi-faceted strategy pursued by the High Strength/Weight Reduction (HS/WR) Materials program of the U.S. Department of Energy (DOE) for structural weight savings and quality enhancements in heavy vehicles. The research work planed for the first year of this project (June 1, 2003 through May 30, 2004) focused on a theoretical investigation of weight benefits and structural performance tradeoffs associated with the design, fabrication, and joining of MMC components for heavy-duty vehicles. This early research work conducted at West Virginia University yielded the development of integrated material-structural models that predicted marginal benefits and significant barriers to MMC applications in heavy trailers. The results also indicated that potential applications of MMC materials in heavy vehicles are limited to components identified as critical for either loadings or weight savings. Therefore, the scope of the project was expanded in the following year (June 1, 2004 through May 30, 2005) focused on expanding the lightweight material-structural design concepts for heavy vehicles from the component to the system level. Thus, the following objectives were set: (1) Devise and evaluate lightweight structural configurations for heavy vehicles. (2) Study the feasibility of using Metal Matrix Composites (MMC) for critical structural components and joints in heavy vehicles. (3) Develop analysis tools, methods, and validated test data for comparative assessments of innovative design and joining concepts. (4) Develop analytical models and software for durability predictions of typical heavy vehicle components made of particulate MMC or fiber-reinforced composites. This report summarizes the results of the research work conducted during the past two years in this projects.

Jacky C. Prucz; Samir N. Shoukry; Gergis W. William

2005-08-31

364

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

365

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

366

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

367

Simulation of Wind Profile Perturbations for Launch Vehicle Ascent Flight Systems Design Assessments  

NASA Technical Reports Server (NTRS)

Ideally, a statistically representative sample of measured high-resolution wind profiles with wavelengths as small as tens of meters is required for assessment of launch vehicle ascent flight systems component capability and vehicle operability for a selected launch site. At most potential launch sites a sample of high-resolution measured wind profiles may not exist. Representative samples of Rawinsonde wind profiles are more likely to be available because of the extensive network of measurement sites established for routine measurements at 12-hr intervals in support of national and international weather observing and forecasting activity. Such a sample, although large enough to statistically represent relatively large wavelength perturbations, would be inadequate for launch system design assessment applications because the Rawinsonde system can accurately measure wind perturbations with wavelengths no smaller than 2000m (1000m altitude increment). Wavelengths less than 2000m in the raw Rawinsonde data, which tend to be dominated by un-damped spurious balloon motion and radar tracking system noise, are filtered within the data processing scheme. The Kennedy Space Center (KSC) Jimsphere wind profiles (150/month and seasonal pairs) are the only adequate high resolution (approximately 150 to 300m effective resolution, but over-sampled at 25m intervals) data that have been used extensively in launch vehicle design, operability assessments and operational protection of vehicle systems for wind perturbation uncertainty. Jimsphere wind profiles have been measured at a few other potential launch sites but the number of profiles is relatively small and the samples are not statistically representative of the site dependent wind profile variability. A simulation process has been developed for enhancement of measured low-resolution Rawinsonde profiles that are more likely to be available in the vicinity of potential launch sites and are a statistically representative sample of wind profile perturbation wavelengths greater than 2000m. The enhancement produces perturbed wind profiles with wavelengths as small as desired for application in launch vehicle ascent flight simulations and design assessments.

Adelfang, S. I.

2003-01-01

368

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

369

Preliminary structural design of a lunar transfer vehicle aerobrake. M.S. Thesis  

NASA Technical Reports Server (NTRS)

An aerobrake concept for a Lunar transfer vehicle was weight optimized through the use of the Taguchi design method, structural finite element analyses and structural sizing routines. Six design parameters were chosen to represent the aerobrake structural configuration. The design parameters included honeycomb core thickness, diameter to depth ratio, shape, material, number of concentric ring frames, and number of radial frames. Each parameter was assigned three levels. The minimum weight aerobrake configuration resulting from the study was approx. half the weight of the average of all twenty seven experimental configurations. The parameters having the most significant impact on the aerobrake structural weight were identified.

Bush, Lance B.

1992-01-01

370

Conceptual design of the AE481 Demon Remotely Piloted Vehicle (RPV)  

NASA Technical Reports Server (NTRS)

This project report presents a conceptual design for a high speed remotely piloted vehicle (RPV). The AE481 Demon RPV is capable of performing video reconnaissance missions and electronic jamming over hostile territory. The RPV cruises at a speed of Mach 0.8 and an altitude of 300 feet above the ground throughout its mission. It incorporates a rocket assisted takeoff and a parachute-airbag landing. Missions are preprogrammed, but in-flight changes are possible. The Demon is the answer to a military need for a high speed, low altitude RPV. The design methods, onboard systems, and avionics payload are discussed in this conceptual design report along with economic viability.

Hailes, Chris; Kolver, Jill; Nestor, Julie; Patterson, Mike; Selow, Jan; Sagdeo, Pradip; Katz, Kenneth

1994-01-01

371

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

372

Practices in adequate structural design. [of space vehicles and space systems  

NASA Technical Reports Server (NTRS)

An account is given of the guidelines for safe and reliable space vehicle design, especially in the structural engineering area, which have been formulated by NASA in the aftermath of the Space Shuttle Challenger accident in 1986. Illustrative examples are presented from state-of-the-art, performance-driven hardware whose design ineluctably gives rise to a high sensitivity to small variations and uncertainties. It is recommended that such hardware be designed with a view to easy inspectability and manufacturability, with emphasis on the role played in system structures by fracture mechanics. Static and dynamic coupling effects must be precluded wherever possible.

Ryan, Robert S.

1989-01-01

373

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

374

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

375

Quantum dots as a platform for nanoparticle drug delivery vehicle design  

PubMed Central

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

2012-01-01

376

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

377

Concept Design of High Power Solar Electric Propulsion Vehicles for Human Exploration  

NASA Technical Reports Server (NTRS)

Human exploration beyond low Earth orbit will require enabling capabilities that are efficient, affordable and reliable. Solar electric propulsion (SEP) has been proposed by NASA s Human Exploration Framework Team as one option to achieve human exploration missions beyond Earth orbit because of its favorable mass efficiency compared to traditional chemical propulsion systems. This paper describes the unique challenges associated with developing a large-scale high-power (300-kWe class) SEP vehicle and design concepts that have potential to meet those challenges. An assessment of factors at the subsystem level that must be considered in developing an SEP vehicle for future exploration missions is presented. Overall concepts, design tradeoffs and pathways to achieve development readiness are discussed.

Hoffman, David J.; Kerslake, Thomas W.; Hojnicki, Jeffrey S.; Manzella, David H.; Falck, Robert D.; Cikanek, Harry A., III; Klem, Mark D.; Free, James M.

2011-01-01

378

Vertical Lift Planetary Aerial Vehicles: Three Planetary Bodies and Four Conceptual Design Cases  

NASA Technical Reports Server (NTRS)

NASA Ames Research Center has been studying the feasibility of vertical lift aerial vehicles to support planetary science and exploration missions. Besides Earth, it appears that there are three planetary bodies within our solar system where vertical flight might not only be theoretically feasible, but would also have unique mission capabilities that no other platform (ground-based, aerial, or orbital) could provide. Several vertical lift vehicle configurations might be applicable for planetary science missions. This paper presents a few representative conceptual design cases and the design challenges inherent in their development. Finally, more detailed comments are directed to the issues inherent in developing a NASA Mars Scout mission employing the use of a Martian autonomous rotorcraft.

Young, Larry A.; Aiken, Edwin W.

2001-01-01

379

Development of Integrated Programs for Aerospace-vehicle design (IPAD): Integrated information processing requirements  

NASA Technical Reports Server (NTRS)

The engineering-specified requirements for integrated information processing by means of the Integrated Programs for Aerospace-Vehicle Design (IPAD) system are presented. A data model is described and is based on the design process of a typical aerospace vehicle. General data management requirements are specified for data storage, retrieval, generation, communication, and maintenance. Information management requirements are specified for a two-component data model. In the general portion, data sets are managed as entities, and in the specific portion, data elements and the relationships between elements are managed by the system, allowing user access to individual elements for the purpose of query. Computer program management requirements are specified for support of a computer program library, control of computer programs, and installation of computer programs into IPAD.

Southall, J. W.

1979-01-01

380

A graphical weather system design for the NASA transport systems research vehicle B-737  

NASA Technical Reports Server (NTRS)

A graphical weather system was designed for testing in the NASA Transport Systems Research Vehicle B-737 airplane and simulator. The purpose of these tests was to measure the impact of graphical weather products on aircrew decision processes, weather situation awareness, reroute clearances, workload, and weather monitoring. The flight crew graphical weather interface is described along with integration of the weather system with the flight navigation system, and data link transmission methods for sending weather data to the airplane.

Scanlon, Charles H.

1992-01-01

381

Control system design for rotorcraft-based unmanned aerial vehicles using time-domain system identification  

Microsoft Academic Search

This paper introduces the development of flight control system for rotorcraft-based unmanned aerial vehicle (RUAV). In this research, the linear time-invariant model valid for hover is sought. The system response data is acquired in carefully devised experiment procedure and then a linear time-invariant system model is obtained using the time-domain analysis method. The acquired model is used to design feedback

David Hyunchul Shim; Hyoun Jin Kim; Shankar Sastry

2000-01-01

382

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

E-print Network

Battery life and cost are intimately related · Batteries are substantially oversized to meet power for battery aging · Worst-case duty cycles and environments drive the need to oversize batteries · Systems with vehicle simulations under realistic driving cycles and environments ASTR 2010 Oct 6 ­ 8, Denver. Colorado

383

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

384

Optimal design and allocation of electrified vehicles and dedicated charging infrastructure for minimum life cycle greenhouse gas emissions and cost  

E-print Network

reduce greenhouse gas (GHG) emissions by shifting energy demand from gasoline to electricity. GHG for minimum life cycle greenhouse gas emissions and cost Elizabeth Traut a,n , Chris Hendrickson b,1 , Erica and GHG emissions of electrified vehicles. c We design PHEVs and BEVs and assign vehicles and charging

Michalek, Jeremy J.

385

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

386

Conceptual design of a flight validation mission for a Hypervelocity Asteroid Intercept Vehicle  

NASA Astrophysics Data System (ADS)

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

2015-01-01

387

Multidisciplinary Design Optimization of a Full Vehicle with High Performance Computing  

NASA Technical Reports Server (NTRS)

Multidisciplinary design optimization (MDO) of a full vehicle under the constraints of crashworthiness, NVH (Noise, Vibration and Harshness), durability, and other performance attributes is one of the imperative goals for automotive industry. However, it is often infeasible due to the lack of computational resources, robust simulation capabilities, and efficient optimization methodologies. This paper intends to move closer towards that goal by using parallel computers for the intensive computation and combining different approximations for dissimilar analyses in the MDO process. The MDO process presented in this paper is an extension of the previous work reported by Sobieski et al. In addition to the roof crush, two full vehicle crash modes are added: full frontal impact and 50% frontal offset crash. Instead of using an adaptive polynomial response surface method, this paper employs a DOE/RSM method for exploring the design space and constructing highly nonlinear crash functions. Two NMO strategies are used and results are compared. This paper demonstrates that with high performance computing, a conventionally intractable real world full vehicle multidisciplinary optimization problem considering all performance attributes with large number of design variables become feasible.

Yang, R. J.; Gu, L.; Tho, C. H.; Sobieszczanski-Sobieski, Jaroslaw

2001-01-01

388

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

389

Environmental Controls and Life Support System (ECLSS) Design for a Multi-Mission Space Exploration Vehicle (MMSEV)  

NASA Technical Reports Server (NTRS)

Engineers at Johnson Space Center (JSC) are developing an Environmental Control and Life Support System (ECLSS) design for the Multi-Mission Space Exploration Vehicle (MMSEV). The purpose of the MMSEV is to extend the human exploration envelope for Lunar, Near Earth Object (NEO), or Deep Space missions by using pressurized exploration vehicles. The MMSEV, formerly known as the Space Exploration Vehicle (SEV), employs ground prototype hardware for various systems and tests it in manned and unmanned configurations. Eventually, the system hardware will evolve and become part of a flight vehicle capable of supporting different design reference missions. This paper will discuss the latest MMSEV ECLSS architectures developed for a variety of design reference missions, any work contributed toward the development of the ECLSS design, lessons learned from testing prototype hardware, and the plan to advance the ECLSS toward a flight design.

Stambaugh, Imelda; Baccus, Shelley; Naids, Adam; Hanford, Anthony

2012-01-01

390

Environmental Controls and Life Support System (ECLSS) Design for a Multi-Mission Space Exploration Vehicle (MMSEV)  

NASA Technical Reports Server (NTRS)

Engineers at Johnson Space Center (JSC) are developing an Environmental Control and Life Support System (ECLSS) design for the Multi-Mission Space Exploration Vehicle (MMSEV). The purpose of the MMSEV is to extend the human exploration envelope for Lunar, Near Earth Object (NEO), or Deep Space missions by using pressurized exploration vehicles. The MMSEV, formerly known as the Space Exploration Vehicle (SEV), employs ground prototype hardware for various systems and tests it in manned and unmanned configurations. Eventually, the system hardware will evolve and become part of a flight vehicle capable of supporting different design reference missions. This paper will discuss the latest MMSEV ECLSS architectures developed for a variety of design reference missions, any work contributed toward the development of the ECLSS design, lessons learned from testing prototype hardware, and the plan to advance the ECLSS toward a flight design.

Stambaugh, Imelda; Baccus, Shelley; Buffington, Jessie; Hood, Andrew; Naids, Adam; Borrego, Melissa; Hanford, Anthony J.; Eckhardt, Brad; Allada, Rama Kumar; Yagoda, Evan

2013-01-01

391

The acoustical design of vehicles: A new tool for benchmarking and target sound  

NASA Astrophysics Data System (ADS)

Evaluating sound quality leads to difficulties. Conventional tests neglect the context-sensitivity of human perception evaluation; they only reflect artificial realities which do not correspond with perceptual authenticity. Since the subjective evaluation is influenced by different modifiers, it is necessary to extend methods in order to be able to survey and represent various objective variables as well as subjective variables sufficiently. It is known that experiments in laboratories only constitute artificial realities and disregard important parameters like context, relevance, or external validity. The test design lacks the consideration of the usual interaction between the self-stimulated sound and the driver as well as the context, in which the driver experiences and evaluates the perceived sound. A 3-D sound simulation system (H3S) has been developed for the realistic reproduction of airborne sound in driving simulators. Mobile H3S is capable of simulating a vehicle soundscape-consisting of engine sound, tire, and wind noise-according to a real driving situation. A vehicle equipped with this interactive technique can be driven regularly on the road while the acoustic impression for the driver originates from a different or modified vehicle. The soundscape adapts online to changes in speed, engine rpm, and load caused by the vehicle controls.

Genuit, Klaus; Schulte-Fortkamp, Brigitte

2005-09-01

392

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

393

Design for Reliability and Safety Approach for the NASA New 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 intended for sending crew and cargo to the international Space Station (ISS), to the moon, and beyond. This program is called Constellation. As part of the Constellation program, NASA is developing new launch vehicles aimed at significantly increase safety and reliability, reduce the cost of accessing space, and provide a growth path for manned space exploration. Achieving these goals requires a rigorous process that addresses reliability, safety, and cost upfront and throughout all the phases of the life cycle of the program. This paper discusses the "Design for Reliability and Safety" approach for the NASA new crew launch vehicle called ARES I. The ARES I is being developed by NASA Marshall Space Flight Center (MSFC) in support of the Constellation program. The ARES I consists of three major Elements: A solid First Stage (FS), an Upper Stage (US), and liquid Upper Stage Engine (USE). Stacked on top of the ARES I is the Crew exploration vehicle (CEV). The CEV consists of a Launch Abort System (LAS), Crew Module (CM), Service Module (SM), and a Spacecraft Adapter (SA). The CEV development is being led by NASA Johnson Space Center (JSC). Designing for high reliability and safety require a good integrated working environment and a sound technical design approach. The "Design for Reliability and Safety" approach addressed in this paper discusses both the environment and the technical process put in place to support the ARES I design. To address the integrated working environment, the ARES I project office has established a risk based design group called "Operability Design and Analysis" (OD&A) group. This group is an integrated group intended to bring together the engineering, design, and safety organizations together to optimize the system design for safety, reliability, and cost. On the technical side, the ARES I project has, through the OD&A environment, implemented a probabilistic approach to analyze and evaluate design uncertainties and understand their impact on safety, reliability, and cost. This paper focuses on the use of the various probabilistic approaches that have been pursued by the ARES I project. Specifically, the paper discusses an integrated functional probabilistic analysis approach that addresses upffont some key areas to support the ARES I Design Analysis Cycle (DAC) pre Preliminary Design (PD) Phase. This functional approach is a probabilistic physics based approach that combines failure probabilities with system dynamics and engineering failure impact models to identify key system risk drivers and potential system design requirements. The paper also discusses other probabilistic risk assessment approaches planned by the ARES I project to support the PD phase and beyond.

Safie, Fayssal, M.; Weldon, Danny M.

2007-01-01

394

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

395

Designing cathodic protection systems for marine structures and vehicles. ASTM special technical publication 1370  

SciTech Connect

Cathodic protection is an important method of protecting structures and ships from the corrosive effects of seawater. Poor designs can be far more costly to implement than optimal designs, Improper design can cause overprotection, with resulting paint blistering and accelerated corrosion of some alloys, underprotection, with resultant structure corrosion, or stray current corrosion of nearby structures. The first ASTM symposium specifically aimed at cathodic protection in seawater was intended to compile all the criteria and philosophy for designing both sacrificial and impressed current cathodic protection systems for structures and vehicles in seawater. The papers which are included in this STP are significant in that they summarize the major seawater cathodic protection system design philosophies. Papers have been processed separately for inclusion on the database.

Hack, H.P. [ed.

1999-07-01

396

Overview of the Integrated Programs for Aerospace Vehicle Design (IPAD) project  

NASA Technical Reports Server (NTRS)

To respond to national needs for improved productivity in engineering design and manufacturing, a NASA supported joint industry/government project is underway denoted Integrated Programs for Aerospace Vehicle Design (IPAD). The objective is to improve engineering productivity through better use of computer technology. It focuses on development of data base management technology and associated software for integrated company wide management of engineering and manufacturing information. Results to date on the IPAD project include an in depth documentation of a representative design process for a large engineering project, the definition and design of computer aided design software needed to support that process, and the release of prototype software to manage engineering information. This paper provides an overview of the IPAD project and summarizes progress to date and future plans.

Venneri, S. L.

1983-01-01

397

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

398

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

399

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

400

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

401

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

402

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

403

Biconic cargo return vehicle with an advanced recovery system. Volume 1: Conceptual design  

NASA Technical Reports Server (NTRS)

The conceptual design of the biconic Cargo Return Vehicle (CRV) is presented. The CRV will be able to meet all of the Space Station Freedom (SSF's) resupply needs. Worth note is the absence of a backup recovery chute in case of Advanced Recovery System (ARS) failure. The high reliability of ram-air parachutes does not warrant the penalty weight that such a system would create on successful missions. The CRV will launch vertically integrated with an Liquid Rocket Booster (LRB) vehicle and meets all NASA restrictions on fuel type for all phases of the mission. Because of the downscaled Orbital Maneuvering Vehicle (OMV) program, the CRV has been designed to be able to transfer cargo by docking directly to the Space Station Freedom as well as with OMV assistance. The CRV will cover enough crossrange to reach its primary landing site, Edwards Airforce Base, and all secondary landing sites with the exception of one orbit. Transportation back to KSC will be via the Boeing Super Guppy. Due to difficulties with man-rating the CRV, it will not be used in a CERV role. A brief summary of the CRV's specifications is given.

1990-01-01

404

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

405

Design and vibration control of military vehicle suspension system using magnetorheological damper and disc spring  

NASA Astrophysics Data System (ADS)

This paper proposes a new type of magnetorheological (MR) fluid based suspension system and applies it to military vehicles for vibration control. The suspension system consists of a gas spring, a MR damper and a safety passive damper (disc spring). Firstly, a dynamic model of the MR damper is derived by considering the pressure drop due to the viscosity and the yield stress of the MR fluid. A dynamic model of the disc spring is then established for its evaluation as a safety damper with respect to load and pressure. Secondly, a full military vehicle is adopted for the integration of the MR suspension system. A skyhook controller associated with a semi-active actuating condition is then designed to reduce the imposed vibration. In order to demonstrate the effectiveness of the proposed MR suspension system, a computer simulation is undertaken showing the vibration control performance of such properties as vertical displacement and pitch angle, evaluated for a bumpy road profile.

Ha, Sung Hoon; Seong, Min-Sang; Choi, Seung-Bok

2013-06-01

406

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

407

Design of an autonomous teleoperated cargo transporting vehicle for lunar base operations  

NASA Technical Reports Server (NTRS)

At the turn of the century NASA plans to begin construction of a lunar base. The base will likely consist of developed areas (i.e., habitation, laboratory, landing and launching sites, power plant) separated from each other due to safety considerations. The Self-Repositioning Track Vehicle (SRTV) was designed to transport cargo between these base facilities. The SRTV operates by using two robotic arms to raise and position segments of track upon which the vehicle travels. The SRTV utilizes the semiautonomous mobility (SAM) method of teleoperation; actuator-controlled interlocking track sections; two robotic arms each with five degrees of freedom; and these materials: titanium for structural members and aluminum for shell members, with the possible use of light-weight, high-strength composites.

Holt, James; Lao, Tom; Monali, Nkoy

1989-01-01

408

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

409

DUKSUP: A Computer Program for High Thrust Launch Vehicle Trajectory Design and Optimization  

NASA Technical Reports Server (NTRS)

From the late 1960's through 1997, the leadership of NASA's Intermediate and Large class unmanned expendable launch vehicle projects resided at the NASA Lewis (now Glenn) Research Center (LeRC). One of LeRC's primary responsibilities --- trajectory design and performance analysis --- was accomplished by an internally-developed analytic three dimensional computer program called DUKSUP. Because of its Calculus of Variations-based optimization routine, this code was generally more capable of finding optimal solutions than its contemporaries. A derivation of optimal control using the Calculus of Variations is summarized including transversality, intermediate, and final conditions. The two point boundary value problem is explained. A brief summary of the code's operation is provided, including iteration via the Newton-Raphson scheme and integration of variational and motion equations via a 4th order Runge-Kutta scheme. Main subroutines are discussed. The history of the LeRC trajectory design efforts in the early 1960's is explained within the context of supporting the Centaur upper stage program. How the code was constructed based on the operation of the Atlas/Centaur launch vehicle, the limits of the computers of that era, the limits of the computer programming languages, and the missions it supported are discussed. The vehicles DUKSUP supported (Atlas/Centaur, Titan/Centaur, and Shuttle/Centaur) are briefly described. The types of missions, including Earth orbital and interplanetary, are described. The roles of flight constraints and their impact on launch operations are detailed (such as jettisoning hardware on heating, Range Safety, ground station tracking, and elliptical parking orbits). The computer main frames on which the code was hosted are described. The applications of the code are detailed, including independent check of contractor analysis, benchmarking, leading edge analysis, and vehicle performance improvement assessments. Several of DUKSUP's many major impacts on launches are discussed including Intelsat, Voyager, Pioneer Venus, HEAO, Galileo, and Cassini.

Williams, C. H.; Spurlock, O. F.

2014-01-01

410

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

411

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

412

Ares I Crew Launch Vehicle Project: Forward Plan to Preliminary Design Review  

NASA Technical Reports Server (NTRS)

The Exploration Launch Projects Office, located at NASA's Marshall Space Flight Center, conducted the Ares I Crew Launch Vehicle System Requirements Review (SRR) at the end of 2006, a mere year after the project team was assembled. In Ares' first year, extensive trade studies and evaluations were conducted to refine the design initially recommended by the Exploration Systems Architecture Study, conceptual designs were analyzed for fitness, and the contractual framework was assembled to enable a development effort unparalleled in American space flight since the Space Shuttle. Now, the project turns its focus to the Preliminary Design Review (PDR), scheduled for 2008. Taking into consideration the findings of the SRR, the design of the Ares I is being tightened and refined to meet the operability, reliability, and affordability goals outlined by the Constellation Program. As directed in NASA Procedure and Regulation (NPR) 7123, NASA Systems Engineering Procedural Requirements, the Ares I SRR examined "the functional and performance requirements defined for the system and the preliminary program or project plan and ensures that the requirements and the selected concept will satisfy the mission." The SRR was conducted to ensure the system- and element-level design and interface requirements are defined prior to proceeding into the project's design phase. The Exploration Launch Projects Control Board convened on December 19,2006, and accepted the findings of the SRR and the go-forward plan proceeding to PDR. Based upon these findings, the Ares project believes that operability must drive the vehicle's design, and that a number of design challenges, including system mass and reliability, must be addressed as part of the progress to PDR.

Dumbacher, Daniel L.; Reuter, James L.

2007-01-01

413

Aeroassisted manned transfer vehicle (TAXI) for advanced Mars Transportation: NASA/USRA 1987 Senior Design Project  

NASA Technical Reports Server (NTRS)

A conceptual design study of an aeroassisted orbital transfer vehicle is discussed. Nicknamed TAXI, it will ferry personnel and cargo: (1) between low Earth orbit and a spacecraft circling around the Sun in permanent orbit intersecting gravitational fields of Earth and Mars, and (2) between the cycling spacecraft and a Mars orbiting station, co-orbiting with Phobos. Crew safety and mission flexibility (in terms of ability to provide a wide range of delta-V) were given high priority. Three versions were considered, using the same overall configuration based on a low L/D aerobrake with the geometry of a raked off elliptical cone with ellipsoidal nose and a toroidal skirt. The propulsion system consists of three gimballed LOX/LH2 engines firing away from the aerobrake. The versions differ mainly in the size of the aeroshields and propellant tanks. TAXI A version resulted from an initial effort to design a single transfer vehicle able to meet all delta-V requirements during the 15-year period (2025 to 2040) of Mars mission operations. TAXI B is designed to function with the cycling spacecraft moving in a simplified, nominal trajectory. On Mars missions, TAXI B would be able to meet the requirements of all the missions with a relative approach velocity near Mars of less than 9.3 km/sec. Finally, TAXI C is a revision of TAXI A, a transfer vehicle designed for missions with a relative velocity near Mars larger than 9.3 km/sec. All versions carry a crew of 9 (11 with modifications) and a cargo of 10000 lbm. Trip duration varies from 1 day for transfer from LEO to the cycling ship to nearly 5 days for transfer from the ship to the Phobos orbit.

1987-01-01

414

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

415

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

416

The design and performance estimates for the propulsion module for the booster of a TSTO vehicle  

NASA Technical Reports Server (NTRS)

A NASA study of the propulsion systems for possible low-risk replacements for the Space Shuttle is presented. Results of preliminary studies to define the USAF two-stage-to-orbit (TSTO) concept to deliver 10,000 pounds to low polar orbit are described. The booster engine module consists of an over/under turbine bypass engines/ramjet engine design for acceleration from takeoff to the staging point of Mach 6.5 and approximately 100,000 feet altitude. Propulsion system performance and weight are presented with preliminary mission study results of vehicle size.

Snyder, Christopher A.; Maldonado, Jaime J.

1991-01-01

417

Design of an airborne launch vehicle for an air launched space booster  

NASA Technical Reports Server (NTRS)

A conceptual design is presented for a carrier vehicle for an air launched space booster. This airplane is capable of carrying a 500,000 pound satellite launch system to an altitude over 40,000 feet for launch. The airplane features a twin fuselage configuration for improved payload and landing gear integration, a high aspect ratio wing for maneuverability at altitude, and is powered by six General Electric GE-90 engines. The analysis methods used and the systems employed in the airplane are discussed. Launch costs are expected to be competitive with existing launch systems.

Chao, Chin; Choi, Rich; Cohen, Scott; Dumont, Brian; Gibin, Mauricius; Jorden, Rob; Poth, Stefan

1993-01-01

418

Evolutionary computing for the design search and optimization of space vehicle power subsystems  

NASA Technical Reports Server (NTRS)

Evolutionary computing has proven to be a straightforward and robust approach for optimizing a wide range of difficult analysis and design problems. This paper discusses the application of these techniques to an existing space vehicle power subsystem resource and performance analysis simulation in a parallel processing environment. Out preliminary results demonstrate that this approach has the potential to improve the space system trade study process by allowing engineers to statistically weight subsystem goals of mass, cost and performance then automatically size power elements based on anticipated performance of the subsystem rather than on worst-case estimates.

Kordon, Mark; Klimeck, Gerhard; Hanks, David; Hua, Hook

2004-01-01

419

The design and performance estimates for the propulsion module for the booster of a TSTO vehicle  

NASA Technical Reports Server (NTRS)

A NASA study of propulsion systems for possible low-risk replacements for the Space Shuttle is presented. Results of preliminary studies to define the USAF two-stage-to-orbit (TSTO) concept to deliver 10,000 pounds to low polar orbit are described. The booster engine module consists of an over/under turbine bypass engines/ramjet engine design for acceleration from takeoff to the staging point of Mach 6.5 and approximately 100,000 feet altitude. Propulsion system performance and weight are presented with preliminary mission study results of vehicle size.

Snyder, Christopher A.; Maldonado, Jaime J.

1991-01-01

420

PM Motor Parametric Design Analyses for Hybrid Electric Vehicle Traction Drive Application: Interim Report  

SciTech Connect

The Department of Energy's (DOE) Office of FreedomCAR (Cooperative Automotive Research) and Vehicle Technologies has a strong interest in making rapid progress in permanent magnet (PM) machine development. The program is directing various technology development projects that will advance the technology and lead to request for proposals (RFP) for manufacturer prototypes. This aggressive approach is possible because the technology is clearly within reach and the approach is deemed essential, based on strong market demand, escalating fuel prices, and competitive considerations. In response, this study began parallel development paths that included a literature search/review, development and utilization of multiple parametric models to determine the effects of design parameters, verification of the modeling methodology, development of an interior PM (IPM) machine baseline design, development of alternative machine baseline designs, and cost analyses for several candidate machines. This interim progress report summarizes the results of these activities as of June 2004. This report provides background and summary information for recent machine parametric studies and testing programs that demonstrate both the potential capabilities and technical limitations of brushless PM machines (axial gap and radial gap), the IPM machine, the surface-mount PM machines (interior or exterior rotor), induction machines, and switched reluctance machines. The FreedomCAR program, while acknowledging the progress made by Oak Ridge National Laboratory, Delphi, Delco-Remy International, and others in these programs, has redirected efforts toward a ''short path'' to a marketable and competitive PM motor for hybrid electric vehicle traction applications. The program has developed a set of performance targets for the type of traction machine desired. The short-path approach entails a comprehensive design effort focusing on the IPM machine and meeting the performance targets. The selection of the IPM machine reflects industry's confidence in this market-proven design that exhibits a power density surpassed by no other machine design.

Staunton, R.H.

2004-08-11

421

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

422

Innovative Structural and Joining Concepts for Lightweight Design of Heavy Vehicle Systems  

SciTech Connect

The extensive research and development effort was initiated by the U.S. Department of Energy (DOE) in 2002 at West Virginia University (WVU) in order to investigate practical ways of reducing the structural weight and increasing the durability of heavy vehicles through the judicious use of lightweight composite materials. While this project was initially focused on specific Metal Matrix Composite (MMC) material, namely Aluminum/Silicon Carbide (Al/SiC) commercially referenced as ''LANXIDE'', the current research effort was expanded from the component level to the system level and from MMC to other composite material systems. Broadening the scope of this research is warranted not only by the structural and economical deficiencies of the ''LANXIDE'' MMC material, but also by the strong coupling that exists between the material and the geometric characteristics of the structure. Such coupling requires a truly integrated design approach, focused on the heaviest sections of a van trailer. Obviously, the lightweight design methods developed in this study will not be implemented by the commercial industry unless the weight savings are indeed impressive and proven to be economically beneficial in the context of Life Cycle Costs (LCC). ''Bulk Haul'' carriers run their vehicles at maximum certified weight, so that each pound saved in structural weight would translate into additional pound of cargo, and fewer vehicles necessary to transport a given amount of freight. It is reasonable to ascertain that a typical operator would be ready to pay a premium of about $3-4 for every additional pound of cargo, or every pound saved in structural weight. The overall scope of this project is to devise innovative, lightweight design and joining concepts for heavy vehicle structures, including cost effective applications of components made of metal matrix composite (MMC) and other composite materials in selected sections of such systems. The major findings generated by this research effort in its first two years have been summarized in the 2003 and 2004 Annual Progress Reports of DOE's Freedom Car and Vehicle Technologies Program. Consistent interactions with producers of heavy trailers, such as Great Dane and Wabash, as well as with their users, such as Old Dominion Freight Lines, have continued during this period to ensure that the research conducted at WVU will yield practical results that will benefit the industry in the near future. Furthermore, Dr. Gergis William and Mr. Thomas Evans participated in the 2005 Technology and Maintenance Council (TMC) annual meeting held in Tampa, Florida, in February 2005. This event offered the WVU researchers an effective opportunity to explore various technical needs and concerns of the industry, both from the performance and maintenance viewpoints, as well as to assess realistically potential benefits and barriers associated with practical implementation of lightweight materials and design technologies in heavy vehicle structures.

Prucz, Jacky C; Shoukry, Samir N; William, Gergis W; Evans, Thomas H

2006-09-30

423

Design of a nonlinear robust controller for a complete unmanned aerial vehicle mission  

NASA Astrophysics Data System (ADS)

Unmanned Aerial Vehicle (UAV) flight control systems must be capable of delivering the required performance while handling nonlinearities and uncertainties in the vehicle model, the atmosphere, and ambient wind. These factors necessitate the development of nonlinear flight control system design methods that can handle large nonlinearities and uncertainties. Variable approaches to the linear control of UAVs have been discussed in the recent literature. However, the development of a nonlinear robust autopilot has not been addressed to any significant degree. The development of a nonlinear autopilot based on robust control methods will be discussed in this dissertation. In this design technique, the nonlinear UAV model is not linearized. The control law is designed using the Hinfinity technique. This dissertation presents the results of an exploratory study to examine robust autopilot nonlinear design methods for the UAV and compare this new approach with existing PID, LQR, and linear Hinfinity techniques. Since the method must then be verified, its flight simulation will be done using MATLAB/SIMULINK. Verification, validation and robustness tests are documented at the end of this dissertation. The airplane examined is called the Hawkeye. It was designed and built by KU students in the fall of 2004. It is a small, 14 foot wingspan, remotely controlled airplane made from composite materials with a maximum takeoff weight of 90 lbs. It will be used in the future as a small UAV for research programs at KU. The mission includes take-off, climb, cruise, a one and a half circle accomplished in a level turn, and a return back to its original airfield accomplished by cruising back, descending, and completing an approach and landing. After take-off, the airplane is required to climb to 1,000 ft altitude, and then it travels 5,000 ft over the ground into the target area. It will then take some photos of that target using its camera. The complete mission for the UAV lasts about 180 seconds.

Sadraey, Mohammad Hashem

424

Human Factors in the Design of the Crew Exploration Vehicle (CEV)  

NASA Technical Reports Server (NTRS)

NASA s Space Exploration vision for humans to venture to the moon and beyond provides interesting human factors opportunities and challenges. The Human Engineering group at NASA has been involved in the initial phases of development of the Crew Exploration Vehicle (CEV), Orion. Getting involved at the ground level, Human Factors engineers are beginning to influence design; this involvement is expected to continue throughout the development lifecycle. The information presented here describes what has been done to date, what is currently going on, and what is expected in the future. During Phase 1, prior to the contract award to Lockheed Martin, the Human Engineering group was involved in generating requirements, conducting preliminary task analyses based on interviews with subject matter experts in all vehicle systems areas, and developing preliminary concepts of operations based on the task analysis results. In addition, some early evaluations to look at CEV net habitable volume were also conducted. The program is currently in Phase 2, which is broken down into design cycles, including System Readiness Review, Preliminary Design Review, and Critical Design Review. Currently, there are ongoing Human Engineering Technical Interchange Meetings being held with both NASA and Lockheed Martin in order to establish processes, desired products, and schedules. Multiple design trades and quick-look evaluations (e.g. display device layout and external window size) are also in progress. Future Human Engineering activities include requirement verification assessments and crew/stakeholder evaluations of increasing fidelity. During actual flights of the CEV, the Human Engineering group is expected to be involved in in-situ testing and lessons learned reporting, in order to benefit human space flight beyond the initial CEV program.

Whitmore, Mihriban; Byrne, Vicky; Holden, Kritina

2007-01-01

425

Design and Performance of Insect-Scale Flapping-Wing Vehicles  

NASA Astrophysics Data System (ADS)

Micro-air vehicles (MAVs)---small versions of full-scale aircraft---are the product of a continued path of miniaturization which extends across many fields of engineering. Increasingly, MAVs approach the scale of small birds, and most recently, their sizes have dipped into the realm of hummingbirds and flying insects. However, these non-traditional biologically-inspired designs are without well-established design methods, and manufacturing complex devices at these tiny scales is not feasible using conventional manufacturing methods. This thesis presents a comprehensive investigation of new MAV design and manufacturing methods, as applicable to insect-scale hovering flight. New design methods combine an energy-based accounting of propulsion and aerodynamics with a one degree-of-freedom dynamic flapping model. Important results include analytical expressions for maximum flight endurance and range, and predictions for maximum feasible wing size and body mass. To meet manufacturing constraints, the use of passive wing dynamics to simplify vehicle design and control was investigated; supporting tests included the first synchronized measurements of real-time forces and three-dimensional kinematics generated by insect-scale flapping wings. These experimental methods were then expanded to study optimal wing shapes and high-efficiency flapping kinematics. To support the development of high-fidelity test devices and fully-functional flight hardware, a new class of manufacturing methods was developed, combining elements of rigid-flex printed circuit board fabrication with "pop-up book" folding mechanisms. In addition to their current and future support of insect-scale MAV development, these new manufacturing techniques are likely to prove an essential element to future advances in micro-optomechanics, micro-surgery, and many other fields.

Whitney, John Peter

426

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

427

Structural analysis and topology optimization design for a sweeper vehicle frame  

Microsoft Academic Search

To improve the mechanical performance and reduce the weight of a sweeper vehicle frame, a finite element model for a dump sweeper vehicle frame is established to analyze strength stiffness and modal of vehicle. By using Ls-dyna software, displacement and time curve for vehicle rectangular frame under external force incentives is solved. Based on the analysis results, topological optimization is

Zhou Bing; Wu Chonghui; Wei-ping Li

2010-01-01

428

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 driving vehicle The electric vehicle was prepared in order to make noise outside. 50 mm loudspeaker's characteristics Compact loudspeaker performance shows that the [500;4000] Hz band is achievable: The vehicles were

Boyer, Edmond

429

Influence of operating conditions on the optimum design of electric vehicle battery cooling plates  

NASA Astrophysics Data System (ADS)

The efficiency of cooling plates for electric vehicle batteries can be improved by optimizing the geometry of internal fluid channels. In practical operation, a cooling plate is exposed to a range of operating conditions dictated by the battery, environment, and driving behaviour. To formulate an efficient cooling plate design process, the optimum design sensitivity with respect to each boundary condition is desired. This determines which operating conditions must be represented in the design process, and therefore the complexity of designing for multiple operating conditions. The objective of this study is to determine the influence of different operating conditions on the optimum cooling plate design. Three important performance measures were considered: temperature uniformity, mean temperature, and pressure drop. It was found that of these three, temperature uniformity was most sensitive to the operating conditions, especially with respect to the distribution of the input heat flux, and also to the coolant flow rate. An additional focus of the study was the distribution of heat generated by the battery cell: while it is easier to assume that heat is generated uniformly, by using an accurate distribution for design optimization, this study found that cooling plate performance could be significantly improved.

Jarrett, Anthony; Kim, Il Yong

2014-01-01

430

Design of Field Experiments for Adaptive Sampling of the Ocean with Autonomous Vehicles  

NASA Astrophysics Data System (ADS)

Due to the highly non-linear and dynamical nature of oceanic phenomena, the predictive capability of various ocean models depends on the availability of operational data. A practical method to improve the accuracy of the ocean forecast is to use a data assimilation methodology to combine in-situ measured and remotely acquired data with numerical forecast models of the physical environment. Autonomous surface and underwater vehicles with various sensors are economic and efficient tools for exploring and sampling the ocean for data assimilation; however there is an energy limitation to such vehicles, and thus effective resource allocation for adaptive sampling is required to optimize the efficiency of exploration. In this paper, we use physical oceanography forecasts of the coastal zone of Singapore for the design of a set of field experiments to acquire useful data for model calibration and data assimilation. The design process of our experiments relied on the oceanography forecast including the current speed, its gradient, and vorticity in a given region of interest for which permits for field experiments could be obtained and for time intervals that correspond to strong tidal currents. Based on these maps, resources available to our experimental team, including Autonomous Surface Craft (ASC) are allocated so as to capture the oceanic features that result from jets and vortices behind bluff bodies (e.g., islands) in the tidal current. Results are summarized from this resource allocation process and field experiments conducted in January 2009.

Zheng, H.; Ooi, B. H.; Cho, W.; Dao, M. H.; Tkalich, P.; Patrikalakis, N. M.

2010-05-01

431

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

432

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

433

The effect of engine design characteristics on orbital transfer vehicle performance  

NASA Technical Reports Server (NTRS)

The objective in maximizing performance for a space-based Orbital Transfer Vehicle (OTV) is to minimize the propellant required to successfully complete a given reference mission and thereby reduce launch and storage costs. Engine sizing studies were conducted which examined the effect of engine design characteristics on the total propellant required to accomplish the manned and unmanned OTV missions anticipated for the 1995 to 2010 time period. Two propellant combinations, O2/H2 and N2O4/MMH, were selected as baselines. Exotic combinations such as F2/H2 and O2/CH4 were also studied to identify potential benefits and growth capabilities. Parametric results showing the effects of engine thrust, number of engines, nozzle area ratio and payload requirements are presented for various reference missions. The results indicate that the optimum engine size and thrust are not significantly affected by detailed engine design characteristics.

Schmidt, G. R.

1985-01-01

434

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