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1

Entrainment and vehicle following controllers design for autonomous intelligent vehicles  

Microsoft Academic Search

Entrainment and vehicle following controllers are proposed for autonomous intelligent vehicles in both non-tight and tight vehicle following manoeuvres. A nonlinear vehicle model is used for designing the controllers. The proposed vehicle following controller is designed based on a constant time headway policy; whereas, the proposed entrainment controller is designed based on a k-factor headway policy. The proposed vehicle following

C. C. Chien; P. Ioannou; M. C. Lai

1994-01-01

2

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

3

Hybrid Vehicle Design Challenge  

NSDL National Science Digital Library

This module is written for a first-year algebra-based physics class, though it could easily be modified for conceptual physics. It is intended to provide hands-on activities 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 utilize these scientific concepts to solve the following problem: "The rising price of gasoline has many effects on the US economy and the environment. You have been contracted as by an engineering firm to help with the design of a physical energy storage system to be used on 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 make a sales pitch to Nissan with a small prototype with your idea 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.

Vu Bioengineering Ret Program

4

Designing a Crew Exploration Vehicle  

NSDL National Science Digital Library

In this activity, students will design a model Crew Exploration Vehicle (CEV) for future space exploration, develop a conclusion based upon the results of their designs, and compare individual results to class results by looking for patterns. The activity is designed to accompany the Kids' Science News Network (KSNN) 21st Century Explorer 30-second news break entitled 'What Will Replace the Space Shuttle?' The activity includes a teacher's guide and instructions for students, and a Spanish translation is available.

5

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

6

Advanced concepts in electric vehicle design  

Microsoft Academic Search

In 1994, the Eco-Vehicle Project was begun to develop an electric vehicle (EV) using a ground-up design approach that incorporates unique designs specific to an EV. The Eco-Vehicle will be a high-performance, but ultrasmall, battery-powered vehicle. New designs for the Eco-Vehicle include an in-wheel motor drive system, a hollow load floor which will house the batteries, and a new battery

Hiroshi Shimizu; Junji Harada; Colby Bland; Kiyomoto Kawakami; Lam Chan

1997-01-01

7

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

8

Conceptual design for aerospace vehicles  

NASA Technical Reports Server (NTRS)

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

Gratzer, Louis B.

1989-01-01

9

Preliminary aerothermodynamic design method for hypersonic vehicles  

NASA Technical Reports Server (NTRS)

Preliminary design methods are presented for vehicle aerothermodynamics. Predictions are made for Shuttle orbiter, a Mach 6 transport vehicle and a high-speed missile configuration. Rapid and accurate methods are discussed for obtaining aerodynamic coefficients and heat transfer rates for laminar and turbulent flows for vehicles at high angles of attack and hypersonic Mach numbers.

Harloff, G. J.; Petrie, S. L.

1987-01-01

10

Atlas vehicle and mission design enhancements  

NASA Astrophysics Data System (ADS)

The paper discusses the vehicle configuration and performance capability of Atlas launch vehicles I, II, IIA, and IIAS. It is pointed out that the higher performance of Atlas IIA and Atlas IIAS vehicles was achieved by improving the software and hardware systems on the vehicle, by introducing two enhancement systems known as the Block I and Block II enhancement packages. The paper describes these enhancement packages and discusses the trajectory design options for Atlas launch vehicle as well as other aspects of Atlas mission.

Dunbar, Dennis R.; White, Robert C.; Waterman, R. C.

1992-08-01

11

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

12

Wind. [and space vehicle design criteria  

NASA Technical Reports Server (NTRS)

A space vehicle's response to atmospheric disturbances includes many parameters, the choice of criteria (parameters) depending upon the vehicle configuration and the specific mission. Response calculation methods for all phases of vehicle design are separated into their various phases and parts, using different approaches and methods of evaluation, as the particular phase demands. Although not independent, these phases include: (1) preliminary design; (2) final structural design; (3) guidance and control system design and optimization (preliminary and final); and (4) establishment of limits and procedures for launch and flight operations. Thus, the proper selection, representation, and use of wind information require the skillfully coordinated efforts of aerospace meteorologists and engineers.

Alexander, M. B.; Brown, S. C.; Camp, D. W.; Daniels, G. E.; Falls, L. W.; Fichtl, G. H.; Hill, K.; Kaufman, J.; Smith, O. E.; Vaughan, W. W.

1973-01-01

13

Design of pedestrian friendly vehicle bumper  

Microsoft Academic Search

Car-pedestrian accidents take thousands of lives worldwide annually. Therefore, pedestrian protection is an important issue\\u000a in traffic safety. How to consider a pedestrian friendliness vehicle and then propose pedestrian protection methods are urgent\\u000a works for minimizing pedestrian injury. For designing a pedestrian friendly vehicle bumper, this study adopts the European\\u000a Enhanced Vehicle-safety Committee\\/ Working Group 17 (EEVC\\/WG17) regulations of legform

Tso-Liang Teng; Van-Luc Ngo; Trong-Hai Nguyen

2010-01-01

14

Control of road noise by vehicle design  

NASA Astrophysics Data System (ADS)

The task of reducing the noise emitted by commercial vehicles is complicated; not only are the mechano-acoustic aspects complex but there are serious commercial limitations arising from the cost of noise reduction in a very competitive industry. Noise radiated by the engine is the principal source on present-day commercial vehicles. The principles of design of enclosures to attenuate the noise are presented. The work of vehicle noise reduction is illustrated by an example in which the effects of exhaust silencing and various designs of engine enclosure are illustrated. It is concluded that it is possible, but not necessarily practicable, to get down to an I.S.O. test level of about 80 dBA with the appropriate amount of engine enclosure at a weight penalty of 9 Ib/dBA. However, space limitations on vehicles fitted with larger engines than those used in this work may make the fitting of an enclosure extremely difficult, and may necessitate considerable redesign of the vehicle. 80 dBA is probably the lower limit of commercial vehicle nosie and is set by type rolling noise. The vehicle manufacturer can make use of the techniques described above to make vehicles considerably quieter, but any acoustical treatment involves penalties in weight, cost, space, etc. For this reason it is cheaper and more effective to plan noise control treatments at the design stage than it is to modify existing vehicles.

Aspinall, D. T.

1970-12-01

15

Advances in fuel cell vehicle design  

NASA Astrophysics Data System (ADS)

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 obstacles to overcome before attaining the widespread commercialization of fuel cell vehicles, such as improvements in fuel cell and battery durability, development of a hydrogen infrastructure, and reduction of high costs, the fundamental concept of the fuel cell vehicle is strong: it is efficient, emits zero harmful emissions, and the hydrogen fuel can be produced from various renewable sources. Therefore, research on fuel cell vehicle design is imperative in order to improve vehicle performance and durability, increase efficiency, and reduce costs. This thesis makes a number of key contributions to the advancement of fuel cell vehicle design within two main research areas: powertrain design and DC/DC converters. With regards to powertrain design, this research first analyzes various powertrain topologies and energy storage system types. Then, a novel fuel cell-battery-ultracapacitor topology is presented which shows reduced mass and cost, and increased efficiency, over other promising topologies found in the literature. A detailed vehicle simulator is created in MATLAB/Simulink in order to simulate and compare the novel topology with other fuel cell vehicle powertrain options. A parametric study is performed to optimize each powertrain and general conclusions for optimal topologies, as well as component types and sizes, for fuel cell vehicles are presented. Next, an analytical method to optimize the novel battery-ultracapacitor energy storage system based on maximizing efficiency, and minimizing cost and mass, is developed. This method can be applied to any system utilizing the novel battery-ultracapacitor energy storage system and is not limited in application to only fuel cell vehicles. With regards to DC/DC converters, it is important to design efficient and light-weight converters for use in fuel cell and other electric vehicles to improve overall vehicle fuel economy. Thus, this research presents a novel soft-switching method, the capacitor-switched regenerative snubber, for the high-power DC/DC boost converters commonly used in fuel cell vehicles. This circuit is shown to increase the efficiency and reduce the overall mass of the DC/DC boost converter.

Bauman, Jennifer

16

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

17

Design of power controller for hybrid vehicle  

Microsoft Academic Search

In this paper a new solution for the design of a control system of a hybrid vehicle is presented using game model approaches. Hybrid vehicles combined the benefits of a gasoline engine and an electric motor, which can be utilized in parallel through a mechanical transmission. Players are considered to be the electric motor and the gasoline engine. Payoff matrices

Hubert H. Chin; Ayat A. Jafari

2010-01-01

18

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

19

Designing an autonomous robot vehicle  

Microsoft Academic Search

In the fall of 1996, at Texas Tech University, a class of 32 EE students was asked to build a mobile robot vehicle. It would, under Region 3 Student Conference robotics competition guidelines: 1) complete three laps around a wooden track, and 2) at the beginning of each lap, drop a coin in a toll slot in an order specified

R. D'Souza

1998-01-01

20

Multidisciplinary design optimization for space vehicle  

NASA Astrophysics Data System (ADS)

The paper presents the ongoing research activity on Multidisciplinary Design Optimization (MDO) of the ESA PRESTIGE Program (PRrogram in Education for Space, Technology, Innovation and knowledGE), which is aimed at providing the European Space Agency with a new software technology for assisting in the early design phases of space vehicles. During the research, a software called SVAGO (Space Vehicles Analysis and Global Optimization) for future space transportation systems will be developed for the conceptual and early preliminary design of launch and re-entry vehicles, exploiting the synergies of the different interacting disciplines through the MDO methodology. First results of the research, namely the conceptual level modelling and optimization of classical expendable launch vehicles, will be presented in the paper, together with an overview of the complete software under development and its capabilities. Particular attention will be paid to the launcher subsystems analysis architecture, to the global and local optimization algorithms and the MDO architectures selected for this purpose.

Riccardi, Annalisa; Castellini, Francesco; Bueskens, Christof; Lavagna, Michèle Roberta

21

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

22

Design rationale for a remote work vehicle  

SciTech Connect

The remote work vehicle (RWV) is a mobile, teleoperated, electrohydraulic robot designed for aggressive, radiological decontamination work. The RWV performs tasks such as washdown, sampling, material packaging and transport, surfacing, and demolition. This paper discusses the design rationale that shaped the development of the RWV with respect to capability, reliability, operability, decontaminability, extensibility, and maintainability. To meet an important subset of nuclear damage recovery tasks, the design embraced these often competing ideals.

Whittaker, W.L.

1986-01-01

23

Motor controller design for hybrid electric vehicles  

Microsoft Academic Search

Motor and its control technology is one of main components of Hybrid Electric Vehicles (HEV). To meet the fast torque response demands of HEV, rotor flux-oriented based vector control algorithm with simulation model is concerned and modular design for hardware and software of controller is present in the paper. Series of anti-jamming and vibration isolation measurements are taken especially to

Yafu Zhou; Jing Lian; Dianting Cao; Wei Wang

2009-01-01

24

Advanced control design for hybrid turboelectric vehicle  

NASA Technical Reports Server (NTRS)

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.

1995-01-01

25

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

26

Human Factors in space vehicle design  

NASA Astrophysics Data System (ADS)

Proper consideration of human needs in the design of space vehicles results in a safe and productive environment for crewmembers. This is particularly important for crew interfaces that are used during ascent and entry due to the demanding environmental conditions. The involvement of Human Factors (HF) engineers in the design and evaluation process ensures that Human-Systems Integration (HSI) begins early, and continues throughout the lifecycle of a vehicle. This paper highlights various aspects of the HSI process: establishment of HSI standards, the use of research to develop and refine challenging requirements and verification methods, partnering with research projects to drive evidence-based designs, and the value of applying HF methods and principles to design.

Holden, Kritina L.; Boyer, Jennifer L.; Ezer, Neta; Holubec, Keith; Sándor, Anikó; Stephens, John-Paul

2013-11-01

27

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

28

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

29

Vehicle design for low cost operations  

NASA Astrophysics Data System (ADS)

Based on considerations derived from a study examining transportation systems for drivers of operational costs, a near term expendable launch vehicle (ELV) is proposed. The largest single factor projected to decrease cost for the STS is an increase in the degree of reusability and a reduction in the maintenance and refurbishment of that reusable hardware. The proposed candidate ELV system has an assessed reliability value of 0.985, and it offers dual redundant avionics. The conservative design approach incorporates existing qualified Saturn V and Shuttle technology for Stages 1 and 2, and Leasat and multimission bus integral propulsion technology for the transfer vehicle, an all liquid engine using storable propellants.

Bangsund, E.; Caluori, V.

1986-10-01

30

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

31

Conceptual design of flapping-wing micro air vehicles  

Microsoft Academic Search

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

J P Whitney; R J Wood

2012-01-01

32

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

33

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

34

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

35

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

36

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

37

Design Studies of Continuously Variable Transmissions for Electric Vehicles.  

National Technical Information Service (NTIS)

Preliminary design studies were performed on four continuously variable transmission (CVT) concepts for use in advanced electric vehicles. A 1700 kg (3750 lb) vehicle with an energy storage flywheel was specified. Requirements of the CVTs were a maximum t...

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

1981-01-01

38

Atlas vehicle and mission design enhancements  

Microsoft Academic Search

The paper discusses the vehicle configuration and performance capability of Atlas launch vehicles I, II, IIA, and IIAS. It is pointed out that the higher performance of Atlas IIA and Atlas IIAS vehicles was achieved by improving the software and hardware systems on the vehicle, by introducing two enhancement systems known as the Block I and Block II enhancement packages.

Dennis R. Dunbar; Robert C. White; R. C. Waterman

1992-01-01

39

Configuration Design of the Adaptive Suspension Vehicle  

Microsoft Academic Search

The selection of vehicle and leg configuration and of power transmission and actuation system configuration for the adaptive suspension vehicle (ASV) are discussed. The ASV will be a proof-of-concept prototype of a proposed class of transportation vehicles for use in terrain that is not passable for conventional vehicles. It uses a legged locomotion princi ple. The machine will not be

Kenneth J. Waldron; Vincent J. Vohnout; Arrie Pery; Robert B. McGhee

1984-01-01

40

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

41

Orbital Maneuvering Vehicle space station communications design  

NASA Technical Reports Server (NTRS)

The authors present an Orbital Maneuvering Vehicle space station communications systems design approach which is intended to satisfy the stringent link requirements. The operational scenario, system configuration, signal design, antenna system management, and link performance analysis are discussed in detail. It is shown that the return link can transmit up to 21.6 Mb/s and maintain at least a 3-dB link margin through proper power and antenna management control at a maximum distance of 37 km. It is suggested that the proposed system, which is compatible with the space station multiple-access system, can be a model for other space station interoperating elements or users to save the development cost and reduce the technical and schedule risks.

Arndt, D.; Novosad, S. W.; Tu, K.; Loh, Y. C.; Kuo, Y. S.

1988-01-01

42

Orbital Maneuvering Vehicle space station communications design  

NASA Astrophysics Data System (ADS)

The authors present an Orbital Maneuvering Vehicle space station communications systems design approach which is intended to satisfy the stringent link requirements. The operational scenario, system configuration, signal design, antenna system management, and link performance analysis are discussed in detail. It is shown that the return link can transmit up to 21.6 Mb/s and maintain at least a 3-dB link margin through proper power and antenna management control at a maximum distance of 37 km. It is suggested that the proposed system, which is compatible with the space station multiple-access system, can be a model for other space station interoperating elements or users to save the development cost and reduce the technical and schedule risks.

Arndt, D.; Novosad, S. W.; Tu, K.; Loh, Y. C.; Kuo, Y. S.

43

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

44

Accelerating the Design of Space Vehicles  

NASA Technical Reports Server (NTRS)

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

Laufenberg, Larry (Editor)

2003-01-01

45

Robust platoon-stable controller design for autonomous intelligent vehicles  

Microsoft Academic Search

A new variable structure longitudinal controller is designed and analyzed for an autonomous intelligent vehicle. The proposed controller not only guarantees individual vehicle stability but also platoon stability. Moreover, the achieved platoon stability is proven to be robust with respect to vehicle parameter uncertainties and unknown time varying disturbances. Explicit transient bounds are obtained which indicate ways of choosing controller

A. Stotsky; C. C. Chien; P. Ioannou

1994-01-01

46

Optimal configuration design for hydraulic split hybrid vehicles  

Microsoft Academic Search

Hydraulic hybrid vehicles are more suitable for heavy-duty applications in urban driving than hybrid electric vehicles because of the high power density and low cost of hydraulic devices. However, the low rotational speeds of hydraulic pump\\/motor and the low energy density of the accumulator impose severe constraints on the design and control for these vehicles. The split configuration is an

Chiao-Ting Li; Huei Peng

2010-01-01

47

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

48

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

49

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

50

Research overview : design specifications for hybrid vehicles  

Microsoft Academic Search

In this paper a method is proposed for determination of the de- sign specifications regarding the energy exchange systems for dierent charge- sustaining hybrid vehicles of dierent vehicle classes. Hybrid drivetrains for vehicles combine multiple power sources in order to increase the driving func- tions. The function can enhance the fuel consumption, emissions, comfort, driving performance and safety. In this

THEO HOFMAN; Druten van RM

2004-01-01

51

Methods for designing the trajectories of launch vehicles and satellites  

Microsoft Academic Search

This book examines the theoretical principles underlying the ballistic analysis of long-range missiles, launch vehicles, and satellites. Particular emphasis is placed on methods for the solution of ballistic problems, employed in the design of the vehicles themselves as well as in trajectory design. Orbital motion is considered with reference to the theory of unperturbed Keplerian motion, the ballistic design of

Refat Fazylovich Appazov; Oleg Georgievich Sytin

1987-01-01

52

Design of vehicle bus data acquisition and fault diagnosis system  

Microsoft Academic Search

This paper introduces the overall design of vehicle bus data acquisition and fault diagnosis system on the basis of OBD, focusing on its lower computer system and the upper computer system design principles. This system is based on the widely used CAN bus technology, to extract the vehicle's status or fault information. The CAN bus adopts the SAE J1939 protocol

Wang Quanqi; Wang Jian; Wang Yanyan

2011-01-01

53

MODELING CUSTOMER PERCEPTIONS OF CRAFTSMANSHIP IN VEHICLE INTERIOR DESIGN  

Microsoft Academic Search

The craftsmanship concept in vehicle interior design is explored in a quantitative manner. A proprietary process by Johnson Controls, Inc. was used as a basis to investigate customer perceptions through surveys. A list of vehicle interior characteristics and perceived craftsmanship attributes was developed and analyzed using multidimensional scaling, cluster analysis, and decomposition. Designers can use this list to guide their

Ilkin Hossoy; Panos Papalambros; Richard Gonzalez; Thomas J. Aitken

2004-01-01

54

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

55

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

56

Design diversity of HEVs with example vehicles from HEV competitions  

SciTech Connect

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

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

1996-12-31

57

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

58

Defining Support Requirements During Conceptual Design of Reusable Launch Vehicles  

NASA Technical Reports Server (NTRS)

Current methods for defining the operational support requirements of new systems are data intensive and require significant design information. Methods are being developed to aid in the analysis process of defining support requirements for new launch vehicles during their conceptual design phase that work with the level of information available during this phase. These methods will provide support assessments based on the vehicle design and the operating scenarios. The results can be used both to define expected support requirements for new launch vehicle designs and to help evaluate the benefits of using new technologies. This paper describes the models, their current status, and provides examples of their use.

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

1995-01-01

59

Two designs for an orbital transfer vehicle  

NASA Technical Reports Server (NTRS)

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

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

1988-01-01

60

Thermo-acoustic fatigue design for hypersonic vehicle skin panels  

NASA Astrophysics Data System (ADS)

Thermo-vibro-acoustic analysis and test of skin panels for airbreathing hypersonic vehicles is made for a generic vehicle and trajectory. Aerothermal analysis shows that impingement of the bow shock wave on the vehicle and engine noise produce high fluctuating pressures and local heat fluxes. Maximum temperatures will exceed 2700 F (1480 C) at the top of the ascent trajectory and engine sound levels will exceed 170 dB at takeoff. As a result, loads due to engine acoustics and shock impingement dominate the design of many transatmospheric vehicle skin panels.

Wentz, Kenneth R.; Blevins, Robert D.; Holehouse, Ian

1994-09-01

61

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

Federal Register 2010, 2011, 2012, 2013

...Certain Automotive Vehicles and Designs Therefore; Notice of Investigation...certain automotive vehicles and designs therefore by reason of infringement...certain automotive vehicles and designs therefore that infringe U...Industrial Co., Ltd., 53 Building, 3297 Hong Mei Road,...

2010-06-17

62

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

63

Orbit design for a space ambulance vehicle  

NASA Astrophysics Data System (ADS)

A number of rendezvous maneuvers between space stations in geocentric orbits at altitudes ranging between 200 km and geosynchronous altitude are examined. Minimum time to complete rendezvous is studied for purposes of expediting crew patient transfer to an orbiting medical base station (MBS) for the stabilization of trauma and definitive care. The vehicle to be used for the crew patient transfer to the MBS is the space ambulance vehicle (SAV). The SAV is assumed to use two velocity impulses to complete rendezvous maneuvers between an SS and the MBS: an accelerating impulse when departing the SS and a second decelerating impulse prior to docking with the MBS. Recommendations are made concerning the planning of space operations which will reduce both time and propulsive energy for rendezvous maneuvers. It is suggested that throttleable engines be used when transferring a crew patient whose trauma could be exacerbated by excessive acceleration of the carrier vehicle.

Nelson, Walter C.

64

Mars reconnaissance lander: Vehicle and mission design  

NASA Astrophysics Data System (ADS)

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

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

2011-10-01

65

Concept design of a new generation military vehicle  

NASA Astrophysics Data System (ADS)

This paper presents the development of an advanced concept for a next generation military vehicle based on state of the art technologies. The vehicle's platform will be directly suitable for high mobility applications for instance: Special Forces missions, Marine reconnaissance missions, and commercial racing in events such as Bajas and the Paris - Dakar. The platform will be a 10000 -14000 lbs high-speed multi-purpose vehicle, designed for extreme off-road operation. A completely new suspension concept is expected to be developed and the new vehicle topology will accommodate a new generation hybrid-electric power train. The dynamic performance targets are 125 mph off-road and 0-60 in 7 seconds. The concept design will focus also on survivability mainly through the use of a new vehicle topology (herein referred to as "island") specifically designed to enhance crew protection. The "island" topology consists in locating the powertrain and other vehicle equipment and subsystems around the crew compartment. Thus, even in the event of an external shield penetration the crew compartment remains protected by the surrounding equipment which serves in an additional role as a secondary shield. The paper presents vehicle specifications, performance capabilities, simulation models and virtual models of the vehicle.

Cantemir, Codrin-Gruie; Ursescu, Gabriel; Serrao, Lorenzo; Rizzoni, Giorgio; Bechtel, James; Udvare, Thomas; Letherwood, Mike

2006-06-01

66

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

67

Aeroassisted-Vehicle Design Studies for a Manned Mars Mission,  

National Technical Information Service (NTIS)

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...

G. P. Menees

1987-01-01

68

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

69

Design of a Low Cost Avionics System for Launch Vehicles  

NASA Technical Reports Server (NTRS)

Marshall Space Flight Center has long been one of the leaders in development of propulsion systems. Due to current launch vehicle costs, Marshall Space Flight Centers (MSFC) Advanced Space Transportation Program (ASTP) office has emphasized the development of low cost launch vehicles. The Bantam launch vehicle is one of the primary programs that has low cost as a requirement. One of the driving factors for a low cost launch vehicle is a low cost avionics system. This paper will summarize MSFC's Astrionics Laboratories efforts in designing a low cost avionics system. MSFC has done Phase A avionics system design and has been working with various contractors on a Phase B preliminary avionics design. Deriving the major requirements, trade studies and cost drivers are some of the topics to be discussed.

Crawford, Kevin; Wallace, Shawn

1998-01-01

70

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

71

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

72

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

73

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

74

Spacecraft rendezvous operational considerations affecting vehicle systems design and configuration  

NASA Technical Reports Server (NTRS)

One lesson learned from Orbiting Maneuvering Vehicle (OMV) program experience is that Design Reference Missions must include an appropriate balance of operations and performance inputs to effectively drive vehicle systems design and configuration. Rendezvous trajectory design is based on vehicle characteristics (e.g., mass, propellant tank size, and mission duration capability) and operational requirements, which have evolved through the Gemini, Apollo, and STS programs. Operational constraints affecting the rendezvous final approach are summarized. The two major objectives of operational rendezvous design are vehicle/crew safety and mission success. Operational requirements on the final approach which support these objectives include: tracking/targeting/communications; trajectory dispersion and navigation uncertainty handling; contingency protection; favorable sunlight conditions; acceptable relative state for proximity operations handover; and compliance with target vehicle constraints. A discussion of the ways each of these requirements may constrain the rendezvous trajectory follows. Although the constraints discussed apply to all rendezvous, the trajectory presented in 'Cargo Transfer Vehicle Preliminary Reference Definition' (MSFC, May 1991) was used as the basis for the comments below.

Prust, Ellen E.

1991-01-01

75

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

76

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

77

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

78

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

79

Aerothermodynamic Design Problems of Winged Re-Entry Vehicles  

Microsoft Academic Search

In this chapter, we consider selected aerothermodynamic design problems of winged re-entry vehicles (RV-W’s, Section 1.1).\\u000a Of these vehicles the Space Shuttle Orbiter so far is the only operational vehicle. The other ones are conceptual studies\\u000a or projects, which have reached different degrees of maturity.\\u000a \\u000a RV-W’s are either launched vertically with the help of rockets or, in the case of

Ernst Heinrich Hirschel; Claus Weiland

80

Design of multiple-input power converter for hybrid vehicles  

Microsoft Academic Search

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

Luca Solero; Alessandro Lidozzi; Josè Antenor Pomilio

2005-01-01

81

Influence of structural dynamics on vehicle design - Government view. [of aerospace vehicles  

NASA Technical Reports Server (NTRS)

Dynamic design considerations for aerospace vehicles are discussed, taking into account fixed wing aircraft, rotary wing aircraft, and launch, space, and reentry vehicles. It is pointed out that space vehicles have probably had the most significant design problems from the standpoint of structural dynamics, because their large lightweight structures are highly nonlinear. Examples of problems in the case of conventional aircraft include the flutter encountered by high performance military aircraft with external stores. A description is presented of a number of examples which illustrate the direction of present efforts for improving aircraft efficiency. Attention is given to the results of studies on the structural design concepts for the arrow-wing supersonic cruise aircraft configuration and a system study on low-wing-loading, short haul transports.

Kordes, E. E.

1977-01-01

82

Advanced lead acid battery designs for hybrid electric vehicles  

Microsoft Academic Search

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

Dean B. Edwards; Charles Kinney

2001-01-01

83

Rotor Design of Permanent Magnet Synchronous Motor for Railway Vehicle  

NASA Astrophysics Data System (ADS)

The permanent magnet synchronous motor (PMSM) is an efficient machine, which has found application over wide power and speed ranges. This paper presents the optimal rotor design of a PMSM for use on a railway vehicle. This design utilizes reluctance torque in order to develop higher torque at starting with low open circuit voltage at high speed.

Kondo, Minoru; Kondo, Keiichiro; Fujishima, Yasushi; Wakao, Shinji

84

An Optimal System Design Process for a MARS Roving Vehicle.  

National Technical Information Service (NTIS)

The problem of determining the optimal design for a Mars roving vehicle is considered. A system model is generated by consideration of the physical constraints on the design parameters and the requirement that the system be deliverable to the Mars surface...

C. Pavarini J. Baker A. Goldberg

1971-01-01

85

Control Design for Autonomous Vehicles: A Dynamic Optimization Perspective  

Microsoft Academic Search

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

Fernando Lobo Pereira

2001-01-01

86

Design for Safety - The Ares Launch Vehicles Paradigm Change  

NASA Technical Reports Server (NTRS)

The lessons learned from the S&MA early involvement in the Ares I launch vehicle design phases proved that performing an in-line function jointly with engineering is critical for S&MA to have an effective role in supporting the system, element, and component design. These lessons learned were used to effectively support the Ares V conceptual design phase and planning for post conceptual design phases. The Top level Conceptual LOM assessment for Ares V performed by the S&MA community jointly with the engineering Advanced Concept Office (ACO) was influential in the final selection of the Ares V system configuration. Post conceptual phase, extensive reliability effort should be planned to support future Heavy Lift Launch Vehicles (HLLV) design. In-depth reliability analysis involving the design, manufacturing, and system engineering communities is critical to understand design and process uncertainties and system integrated failures.

Safie, Fayssal M.; Maggio, Gaspare

2010-01-01

87

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

88

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

89

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

90

INTELLIGENT DESIGN OF VEHICLE PACKAGE USING ONTOLOGY AND CASEBASED REASONING  

Microsoft Academic Search

\\u000a The similarity of varied vehicle package is a critical design feature that affects method selection, optimized design and\\u000a driver performance. However there is limited understanding of what constitutes similarity in package design and limited computer-based\\u000a support to identify this feature in a layout model. This paper contributes a case-based framework for representing and reasoning\\u000a about layout similarity that builds on

Xiaoping Jin; Enrong Mao; Bo Cheng

2009-01-01

91

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

92

Analysis Method for Quantifying Vehicle Design Goals  

NASA Technical Reports Server (NTRS)

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

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

2007-01-01

93

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

94

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

Microsoft Academic Search

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

Xiao Huang

2006-01-01

95

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

96

Off-road perception testbed vehicle design and evaluation  

NASA Astrophysics Data System (ADS)

Off-road robotics efforts such as DARPA"s PerceptOR program have motivated the development of testbed vehicles capable of sustained operation in a variety of terrain and environments. This paper describes the retrofitting of a minimally-modified ATV chassis into such a testbed which has been used by multiple programs for autonomous mobility development and sensor characterization. Modular mechanical interfaces for sensors and equipment enclosures enabled integration of multiple payload configurations. The electric power subsystem was capable of short-term operation on batteries with refueled generation for continuous operation. Processing subsystems were mounted in sealed, shock-dampened enclosures with heat exchangers for internal cooling to protect against external dust and moisture. The computational architecture was divided into a real-time vehicle control layer and an expandable high level processing and perception layer. The navigation subsystem integrated real time kinematic GPS with a three-axis IMU for accurate vehicle localization and sensor registration. The vehicle software system was based on the MarsScape architecture developed under DARPA"s MARS program. Vehicle mobility software capabilities included route planning, waypoint navigation, teleoperation, and obstacle detection and avoidance. The paper describes the vehicle design in detail and summarizes its performance during field testing.

Spofford, John R.; Herron, Jennifer B.; Anhalt, David J.; Morgenthaler, Matthew K.; DeHerrera, Clinton

2003-09-01

97

Design of an instrumented vehicle test bed for developing a human centered driver support system  

Microsoft Academic Search

We introduce a new type of intelligent vehicle test-bed that is enabling new research in the field. This new test-bed is designed to capture not just a portion of the vehicle surround, but rather the entire vehicle surround as well as the vehicle interior and vehicle state for extended periods of time. This is accomplished using multiple modalities of sensor

Joel C. McCall; Ofer Achler; Mohan M. Trivedi

2004-01-01

98

Conception, design, and development of the RRV (remote reconnaissance vehicle) and the RWV (remote work vehicle)  

SciTech Connect

Remote technology is sought for a variety of activities in the nuclear industry where radiation and other aspects of the work environment pose hazards to or preclude a human work force. Exposure-related costs and instances of necessity motivate the use and development of remote technology. The remote work vehicle (RWV) and the remote reconnaissance vehicle (RRV) are teleoperated systems developed for such uses. This paper considers design and development of these systems with emphasis on responding to a specific need: recovery of the Three Mile Island Unit 2 (TMI-2) containment basement.

Champeny, L.; Whittaker, W.L.

1988-01-01

99

Design tradeoffs on engine-integrated hypersonic vehicles  

NASA Technical Reports Server (NTRS)

Two classes of airbreathing hypersonic vehicle concepts, one for primarily cruise missions and the other for accelerator type missions, are presented. Both are designed with waverider airframes and hydrogen-fueled scramjet engine modules. Cruise configurations are optimized for the product of I(sp) and L/D while matching lift to weight and thrust to drag at some equivalence ratio. Accelerator configurations are optimized for effective specific impulse while matching lift to weight at an equivalence ratio of one. The method and computer code developed to optimize the configurations are discussed. The features and design tradeoffs for each class of vehicles are described. Recently available weight estimates for all-body waveriders have had a significant impact on the integrated configurations. Mach 8 vehicles at 40 km altitude optimized with the cruise objective function have L/Ds of 2.55 to 2.92 and I(sp)s of 2850 to 2940 sec. A Mach 14 vehicle at 40-km altitude optimized with the accelerator objective function has an I(sp) sub eff of 189 sec, and a Mach 10 vehicle an I(sp) sub eff of 880 sec.

O'Neill, Mary Kae L.; Lewis, Mark J.

1992-01-01

100

Emerging CFD technologies and aerospace vehicle design  

NASA Astrophysics Data System (ADS)

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.

1995-03-01

101

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

102

Cost Engineering – The new paradigm for space launch vehicle design  

Microsoft Academic Search

The paper describes the basic definition and application of 'Cost Engineering' which means to design a vehicle system for minimum development cost and\\/or for minimum operations cost. This is important now and for the future since space transportation has become primarily a commercial business in contrast to the past where it has been mainly a subject of military power and

Dietrich E. Koelle

1998-01-01

103

Design Study of Toroidal Traction Cvt for Electric Vehicles.  

National Technical Information Service (NTIS)

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 exi...

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

1980-01-01

104

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

105

Conceptual designing — Unmanned aerial vehicle flight control system  

Microsoft Academic Search

Conceptual design procedure of Unmanned Aerial Vehicle (UAV) flight control system is discussed in this paper. Detailed discussion of important aspects of UAV relating to its role, mission, capabilities and their implications on the flight control system are discussed. This leads to the basic requirements for the flight control and then translates to the type of controller to be used

Tahir Hameed; Wang Wei; Ren Zhang

2009-01-01

106

MDO approach for early design of aerobraking orbital transfer vehicles  

NASA Astrophysics Data System (ADS)

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

Bérend, N.; Bertrand, S.

2009-12-01

107

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

108

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

109

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

110

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

111

Intelligent Design of Vehicle Package Using Ontology and Casebased Reasoning  

NASA Astrophysics Data System (ADS)

The similarity of varied vehicle package is a critical design feature that affects method selection, optimized design and driver performance. However there is limited understanding of what constitutes similarity in package design and limited computer-based support to identify this feature in a layout model. This paper contributes a case-based framework for representing and reasoning about layout similarity that builds on domain-specific ontological modeling and case-based reasoning techniques. Validation study of the system provides evidence that the framework is general and enables a more efficient package layout design process.

Jin, Xiaoping; Mao, Enrong; Cheng, Bo

112

Usability heuristics and their role in designing vehicles - A case study of an electric-hybrid vehicle body design  

Microsoft Academic Search

Morphologies for designing vehicles and their bodies traditionally rely on engineering optimization of variables such as strength of materials, structural rigidity, loading characteristics and manufactur ing constraints, to name a few. Combined with automotive engineering and ergonomic safety standards such methodologies have limited scope for incorporating user-desired or utility -led innovations, especially during conceptualization. Often local utility-based requirements and usage

PRADEEP YAMMIYAVAR

2005-01-01

113

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

114

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

115

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

116

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

117

Kistler reusable vehicle facility design and operational approach  

NASA Astrophysics Data System (ADS)

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

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

118

An active emergency stop design and protocol for unmanned vehicles  

NASA Astrophysics Data System (ADS)

Emergency stop systems are an integral and lifesaving component of large unmanned vehicles. Some E-stop designs may require their own separate data radio link, and passive listening designs can fail due to false carrier signals, or be delayed by buffering of data if no protocol handshake is required. This paper describes an active emergency stop architecture with data handshake that can share a radio data link with primary command and control communications such as using JAUS. Given a data link where packet delivery latency is well below E-stop timeout time, the OCU and vehicle can exchange E-stop keepalive messages actively, with sequence numbers to guard against the possibility of old data deceiving the vehicle and keeping the E-stop from triggering. Since the vehicle and OCU are addressing each other and not merely looking for a carrier signal, E-stop communications can coexist with other data traffic so long as packet delivery time is well below E-stop timeout time. An example implementation is over a computer network link supporting TCP/IP, such as using common off-the-shelf 802.11 equipment, or similar radios that might achieve longer range with somewhat lower data rate. With 802.11, round-trip delivery times are generally below 10 milliseconds, providing margin for many retransmissions within a typical 500 millisecond E-stop timeout time. Another benefit of this active E-stop design is immediate triggering of a stop using an E-stop button. Rather than waiting for an E-stop timeout time to expire, an explicit message triggering a stop can be sent from the OCU-side E-stop button device to the vehicle E-stop circuitry (which can still be independent from the VCU). This will trigger a stop within the packet network delivery time, just 10 milliseconds in our example.

Crum, Gary L.

2006-06-01

119

Aerothermal Protuberance Heating Design and Test Configurations for Ascent Vehicle Design.  

National Technical Information Service (NTIS)

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 t...

C. E. Martin D. Freeman R. D. Neumann

2010-01-01

120

The design of two-stage-to-orbit vehicles  

NASA Technical Reports Server (NTRS)

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

1991-01-01

121

Conceptual design of a manned orbital transfer vehicle  

NASA Technical Reports Server (NTRS)

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

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

1988-01-01

122

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

123

Response spectrum methods in tank-vehicle design  

Microsoft Academic Search

Existing design rules for tank vehicles have proved insufficient, because vibrations often cause fatigue cracks. Measurements\\u000a have been performed on the tank to provide a picture of the influence of different road types and filling ratios.\\u000a \\u000a Shock response spectrum analysis (SRS) was used to obtain a measure of single-dynamic events. To get a basis for dimensioning\\u000a against fatigue a calculation

U. Olofsson; T. Svensson; H. Torstensson

1995-01-01

124

Modeling and simulation of autonomous underwater vehicles: design and implementation  

Microsoft Academic Search

Autonomous underwater vehicles (AUVs) have many scientific, military, and commercial applications because of their potential capabilities and significant cost-performance improvements over traditional means for performing search and survey. The development of a reliable sampling platform requires a thorough system design and many costly at-sea trials during which systems specifications can be validated. Modeling and simulation provides a cost-effective measure to

Feijun Song; P. Edgar An; Andres Folleco

2003-01-01

125

Zinc-bromine battery design for electric vehicles  

Microsoft Academic Search

Design projections for zinc-bromine batteries are attractive for electric vehicle applications in terms of low manufacturing costs ($28\\/kWh) and good performance characteristics. Zinc-bromine battery projections (60-80 Wh\\/kg, 130-200 W\\/kg) compare favorably to both current lead acid batteries and proposed advanced battery candidates. The performance of recently developed battery components with 1200 cm2electrodes in a 120V, 10 kWh module is described.

RICHARD J. BELLOWS; PATRICK GRIMES; HARRY EINSTEIN; EDWARD KANTNER; PAUL MALACHESKY; KENNETH NEWBY

1983-01-01

126

Zinc-bromine battery design for electric vehicles  

Microsoft Academic Search

Design projections for zinc-bromine batteries are attractive for electric vehicle applications in terms of low manufacturing costs ($28\\/kWh) and good performance characteristics. Zinc-bromine batery projections (60 to 80 Wh\\/kg, 130 to 200 W\\/kg) compare favorably to both current lead acid batteries and proposed advanced battery candidates. The performance of recently developed battery components with 1200 cm² electrodes in a 120V,

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

1982-01-01

127

The vehicle design evaluation program - A computer-aided design procedure for transport aircraft  

NASA Technical Reports Server (NTRS)

The vehicle design evaluation program is described. This program is a computer-aided design procedure that provides a vehicle synthesis capability for vehicle sizing, external load analysis, structural analysis, and cost evaluation. The vehicle sizing subprogram provides geometry, weight, and balance data for aircraft using JP, hydrogen, or methane fuels. The structural synthesis subprogram uses a multistation analysis for aerodynamic surfaces and fuselages to develop theoretical weights and geometric dimensions. The parts definition subprogram uses the geometric data from the structural analysis and develops the predicted fabrication dimensions, parts material raw stock buy requirements, and predicted actual weights. The cost analysis subprogram uses detail part data in conjunction with standard hours, realization factors, labor rates, and material data to develop the manufacturing costs. The program is used to evaluate overall design effects on subsonic commercial type aircraft due to parameter variations.

Oman, B. H.; Kruse, G. S.; Schrader, O. E.

1977-01-01

128

43 CFR 420.21 - Procedure for designating areas for off-road vehicle use.  

Code of Federal Regulations, 2013 CFR

...designating areas for off-road vehicle use. 420...Section 420.21 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF...INTERIOR OFF-ROAD VEHICLE USE Designated...designating areas for off-road vehicle use. ...practicable, hold public hearings to...

2013-10-01

129

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

Code of Federal Regulations, 2013 CFR

...requirements for road vehicles by design type. 115.65 Section...Approval of Road Vehicles by Design Type § 115.65 Technical requirements for road vehicles by design type. The plans and...U.S. Customs Service, Office of Field Operations, 1300...

2013-04-01

130

NASA advanced aeronautics design solar powered remotely piloted vehicle  

NASA Technical Reports Server (NTRS)

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

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

1991-01-01

131

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

132

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

133

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

134

Small thermal optics design for UAV (unmanned aerial vehicle) system  

NASA Astrophysics Data System (ADS)

Now, Military demands focused attention on small and light-weight system development. Above all, UAV(Unmanned Aerial Vehicle) is necessary to reduce weight of equipments. Therefore, we invest some expense in many years so that it might design more light optical system for UAV. Consequently, we can build new miniaturization and light-weight system. The most important thing is the system using just two motors for continuous zoom(x3 ~ x20), NUC(nonuniformity correction), Narcissus, Athermalization, and auto-focus functions. An MTF (modulation transfer function) and a detection range are also satisfied by the demands. We use CODE V and NVTherm program for design and analysis.

Lee, Sun Kyu; Na, Jun Hee; Yoon, Chang Jun; Oh, Seung Eun; Choi, Joongkyu; Pyo, Hyo Jin

2010-08-01

135

Design Guidelines for Quiet Fans and Pumps for Space Vehicles  

NASA Technical Reports Server (NTRS)

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

Lovell, John S.; Magliozzi, Bernard

2008-01-01

136

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

137

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

138

Mobile large-vehicle inspection system design issues  

NASA Astrophysics Data System (ADS)

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

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

1998-12-01

139

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

140

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

141

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

142

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

143

Analysis and design of a multi-wheeled vehicle with variable geometry suspension  

NASA Astrophysics Data System (ADS)

In most field robots, go or no-go decision depends on the maximum height of a bump. For combat vehicles, however, much advanced capability of the vehicle is required to pass over a higher bump compared to its wheel radius. For this purpose, many combat vehicles are using variable geometry suspension (VGS). In this paper, a 6x6 vehicle with a rotating VGS was designed. Computer simulations of the designed vehicle were carried out with the ADAMS program to estimate motor capacity and the required torque. The suspension was designed to rotate 360 degrees about the swing axis, thus, the vehicle could climb a higher bump by rotating its suspension.

Noh, Tae-Bum; Yoo, Wan-Suk; Kim, Min-Ho; Noh, Hyun-Woo; Kim, Hyun-Woo; Huh, Nam; Park, Hee-Young; Park, Se-Jin

2006-06-01

144

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

145

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

146

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

147

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

148

Integrated Design System (IDS) Tools for the Spacecraft Aeroassist/Entry Vehicle Design Process  

NASA Technical Reports Server (NTRS)

The definition of the Integrated Design System technology focus area as presented in the NASA Information Technology center of excellence strategic plan is described. The need for IDS tools in the aeroassist/entry vehicle design process is illustrated. Initial and future plans for spacecraft IDS tool development are discussed.

Olynick, David; Braun, Robert; Langhoff, Steven R. (Technical Monitor)

1997-01-01

149

The ground surveillance robot (GSR): An autonomous vehicle designed to transit unknown terrain  

Microsoft Academic Search

The Ground Surveillance Robot (GSR) project has proceeded continuously since the Fall of 1980, and in that time an autonomous vehicle design and some degree of implementation has been achieved. The vehicle design has been partitioned into sensor, control, and planning subsystems. A distributed blackboard scheme has been developed which provides the mechanism by which these subsystems are coordinated. Vehicle

S. Harmon

1987-01-01

150

Multidisciplinary Design of Air-launched Satellite Launch Vehicle Using Particle Swarm Optimization  

Microsoft Academic Search

Launch vehicle design is a complex, multidisciplinary engineering activity that requires making difficult compromises to achieve a balance among competing objectives for the vehicle, including safety, reliability, performance, operability, and cost. Significant work has been done in recent years to advance the design, analysis and optimization of launch vehicles. In the present research effort we propose the application of Particle

Amer Farhan Rafique; He LinShu; Qasim Zeeshan; Ali Kamran

151

Design, simulation and fabrication of a fuel efficient urban class series hybrid vehicle  

Microsoft Academic Search

While designing all the attributes of a Hybrid vehicle, the most important factor is the fuel economy. Reduced aerodynamic drag and light weight vehicle chassis are major factors for improving the fuel economy. The series hybrid vehicle designed utilizes gasoline to generate electricity which is then stabilized and stored in the super capacitor banks. This stored electrical energy is then

Syed Hassaan Ali; Humza Akhtar; Shuja Munir; Umair bin Ikram

2011-01-01

152

Mission, technologies and design of planetary mobile vehicle  

NASA Astrophysics Data System (ADS)

The French Space Agency (CNES) started a study in late 1992 of an autonomous rover VAP (for Planetary Autonomous Vehicle). The aim of this study was to investigate multimission mobile platform design. The focus was placed on a martian mission for several reasons: (1) there is a very high scientific interest for Mars surface exploration leading to a better understanding of the solar system and Earth evolution; (2) roving on the planet is one mandatory and preliminary step before the conquest of the 'red planet' by manned mission; and (3) it is a necessary complement to fixed networks and sample return, in order to get data relevant to very large areas. The overall system concept including launch, cruise, deboost from Mars orbit, Mars atmosphere entry, and landing is not part of the study but is only kept in mind, as these phases of the mission induce several constraints. The main results of the study are given, showing the two possibilities: a large vehicle of 450 kg as the baseline and a smaller vehicle of 250 kg as an option. The various subsystems are described and the choices justified. The expected performances are summarized.

Hayard, Michel

1994-06-01

153

Design sounding rocket payload system to study vehicle charging phenomena  

NASA Astrophysics Data System (ADS)

The objectives of this contract are the following: (1) reassemble and test the A31.603 rocket payload, previously flown at WSMR in January of 1978. Conduct spacecraft charging tests in a plasma using the vacuum chamber at Johnson Space Flight Center, Texas; (2) design a sounding rocket payload for the measurement of vehicle charging due to charge ejection in accordance with the results of the reassembly and retest of the A31.603 payload, and in accordance with specifications for the instrumentation for the instrumentation for the spacecraft charging rocket-2 payload; (3) fabricate and test a negative charge ejection system; (4) fabricate and test rocket payload sensor systems to measure the vehicle-to-plasma potential difference; (5) fabricate and test sensor systems to measure and identify charged particle return to the payload; (6) fabricate and test sensor systems to measure rapid changes in vehicle potential; (7) fabricate and test a microprocessor-based sounding rocket experiment controller. (8) fabricate and test one set of ground support equipment; (9) integrate at contractor's facility the above sensor systems with a rocket payload structure and instrumentation provided by the government.

Hills, R. S.

1985-05-01

154

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

155

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

156

Trajectory Design for Autonomous Underwater Vehicles Based on Ocean Model Predictions for Feature Tracking.  

National Technical Information Service (NTIS)

Trajectory design for Autonomous Underwater Vehicles (AUVs) is of great importance to the oceanographic research community. Intelligent planning is required to maneuver a vehicle to high-valued locations for data collection. We consider the use of ocean m...

B. H. Jones, D. A. Caron, P. P. Li R. N. Smith, Y. Chao

2009-01-01

157

Multiobjective Static Output Feedback Control Design for Vehicle Suspensions  

NASA Astrophysics Data System (ADS)

This paper presents an approach to design multiobjective static output feedback H2/H?/GH2 controller for vehicle suspensions by using linear matrix inequalities (LMIs) and genetic algorithms (GAs). A quarter-car model with active suspension system is studied in this paper and three main performance requirements for an advanced vehicle suspension are considered. Among these requirements, the ride comfort performance is optimized by minimizing the H2 norm from the road disturbance to the sprung mass acceleration, the road holding performance is improved by constraining the H? norm from the road disturbance to the tyre deflection to be less than a given value, and the suspension deflection is guaranteed to be less than its hard limit by constraining the generalized H2 norm from the road disturbance to the suspension deflection. In addition, the controller gain can be constrained naturally in GAs, which can avoid the actuator saturation problem. A static output feedback controller, which only uses the available sprung velocity and suspension deflection signals as feedback signals, is obtained. This multiobjective controller is realized by using GAs to search for the possible control gain matrix and then to resolve the LMIs together with the minimization optimization problem. The approach is validated by numerical simulation which shows that the designed static output feedback controller can achieve good active suspension performances in spite of its simplicity.

Du, Haiping; Zhang, Nong

158

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

159

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

NASA Astrophysics Data System (ADS)

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

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

160

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

161

Identification of vehicle design requirements for older drivers.  

PubMed

The proportion of older people in the population is rising, as is the proportion of older women driving licence holders. The needs and abilities of older drivers therefore need to be considered in vehicle design. Following some initial focus groups an extensive nation-wide postal survey was conducted to ascertain the type and degree of problems associated with automotive design for older drivers and to guide further research into the most appropriate areas. Over a thousand questionnaires were received. Findings indicate that particular difficulties are experienced significantly more often by older drivers than younger drivers, in particular turning to look out of the rear window and getting in and out of the car. Reasons for these were ascertained and are reported here. The findings have guided a subsequent research project into the factors affecting ease of entry and exit by older drivers. PMID:15854568

Herriotts, Paul

2005-05-01

162

Optimal design of a magnetorheological fluid suspension for tracked vehicle  

NASA Astrophysics Data System (ADS)

This paper presents optimal design of controllable magnetorheological suspension system (MRSS) for a tracked vehicle. As a first step, a double-rod type MRSS is designed on the basis of the Bingham model of commercially available MR fluid, and its damping characteristics are evaluated with respect to the intensity of the magnetic field. Subsequently, the governing equation of motion of the MRSS featuring the MR valve is established Then, the optimization problem to find optimal geometric dimensions of the MRSS is formulated by considering an objective function which is related to damping torque and control energy. The first order optimization method intergrated with a commercial finite element method(FEM) software is adopted to obtain optimal solution of the system. The performance characteristics of the optimized MRSS are then evaluated and compared with initial ones.

Ha, S. H.; Choi, S. B.; Rhee, E. J.; Kang, P. S.

2009-02-01

163

Loligomers: design of de novo peptide-based intracellular vehicles.  

PubMed Central

Defined branched peptides (loligomers) incorporating cytoplasmic translocation signals, nuclear localization sequences, and fluorescent probes were designed and synthesized to demonstrate the feasibility and simplicity of creating novel classes of intracellular vehicles. Loligomers containing all the above signals were rapidly internalized by Chinese hamster ovary (CHO) cells and accumulated in their nucleus. At 4 degrees C, the interaction of peptide constructs with CHO cells was limited to membrane association. Loligomers entered cells at higher temperatures by adsorptive endocytosis. Inhibitors of ATP synthesis affected cytoplasmic import only weakly but abolished nuclear uptake. The peptide signals guided both cytoplasmic and nuclear localization events. The properties exhibited by loligomers suggest a strategy for the facile design of "guided" classes of intracellular agents. Images Fig. 3

Sheldon, K; Liu, D; Ferguson, J; Gariepy, J

1995-01-01

164

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

165

Series hybrid vehicles and optimized hydrogen engine design  

NASA Astrophysics Data System (ADS)

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

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

1995-05-01

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

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

National Technical Information Service (NTIS)

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

2003-01-01

168

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

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

Robust stabilization of a wheeled vehicle: Hybrid feedback control design and experimental validation  

Microsoft Academic Search

In this paper, the problem of robust stabilization of a wheeled vehicle is addressed. The configuration (position and orientation)\\u000a set of the vehicle is divided into two parts: global and local configuration sets. The novelty of this paper is the design\\u000a of a hybrid feedback controller that assigns different objectives in the vehicle’s global and local behaviors. Two Lyapunov\\u000a functions

Augie Widyotriatmo; Keum-Shik Hong; Lafin H. Prayudhi

2010-01-01

171

Feasibility Study of an Integrated Program for Aerospace Vehicle Design (Ipad). Volume 1. Summary.  

National Technical Information Service (NTIS)

The development and characteristics of an Integrated Program for Aerospace Vehicle Design (IPAD) System are discussed. The principal characteristic of the design philosophy is its consistency in treating the various aspects of the design with a uniform de...

C. A. Garrocq M. J. Hurley

1973-01-01

172

Man-vehicle systems research facility: Design and operating characteristics  

NASA Technical Reports Server (NTRS)

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

1983-01-01

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

OPTIMAL DESIGN AND DYNAMIC SIMULATION OF A HYBRID SOLAR VEHICLE  

Microsoft Academic Search

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

Ivan Arsie; Gianfranco Rizzo; Marco Sorrentino

175

Design of Flight Service Vehicle Dispatching Management System  

Microsoft Academic Search

Interphone is used to dispatch vehicle in flight service at many airports in China. Former service manners have the advantages of low speed, poor real time ability, etc., which make the manager can not acquire every vehicle's working state in time. Therefore, a powerful flight service vehicle dispatching management system becomes necessary. Firstly, the wireless local area networks (WLAN) around

Lei Deng; De-yuan Gao

2009-01-01

176

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

177

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

178

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

179

Intelligent design of mechanical parameters of the joint in vehicle body concept design model  

NASA Astrophysics Data System (ADS)

In order to estimate the mechanical properties of the overall structure of the body accurately and quickly in conceptual design phase of the body, the beam and shell mixing elements was used to build simplified finite element model of the body. Through the BP neural network algorithm, the parameters of the mechanical property of joints element which had more affection on calculation accuracy were calculated and the joint finite element model based on the parameters was also constructed. The case shown that the method can improve the accuracy of the vehicle simulation results, while not too many design details were needed, which was fit to the demand in the vehicle body conceptual design phase.

Hou, Wen-bin; Zhang, Hong-zhe; Hou, Da-jun; Hu, Ping

2013-05-01

180

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

181

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

National Technical Information Service (NTIS)

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 a...

Y. S. P. Shiue

2005-01-01

182

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

183

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

184

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

NASA Technical Reports Server (NTRS)

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

1988-01-01

185

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

Microsoft Academic Search

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

Fan Xin; Hu Chun

2010-01-01

186

Critical engine system design characteristics for SSTO vehicles  

NASA Astrophysics Data System (ADS)

Engine system design characteristics are summarized for typical vertical take-off and landing (VTOL) and vertical take-off and horizontal landing (VTHL) Strategic Defense Initiative Organization (SDIO) single stage to orbit (SSTO) vehicles utilizing plug nozzle configurations. Power cycle selection trades involved the unique modular platelet engine (MPE) with the use of (1) LO2 and LH2 at fixed and variable mixture ratios, (2) LO2 and propane or RP-1, and (3) dual fuels (LO2 with LH2 and C3H8). The number of thrust cells and modules were optimized. Dual chamber bell and a cluster of conventional bell nozzle configurations were examined for comparison with the plug configuration. Thrust modulation (throttling) was selected for thrust vector control. Installed thrust ratings were established to provide an additional 20 percent overthrust capability for engine out operation. Turbopumps were designed to operate at subcritical speeds to facilitate a wide range of throttling and long life. A unique dual spool arrangement with hydrostatic bearings was selected for the LH2 turbopump. Controls and health monitoring with expert systems for diagnostics are critical subsystems to ensure minimum maintenance and supportability for a less than seven day turnaround. The use of an idle mode start, in conjunction with automated health condition monitoring, allows the rocket propulsion system to operate reliably in the manner of present day aircraft propulsion.

Fanciullo, Thomas J.; Judd, D. C.; Obrien, C. J.

1992-02-01

187

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

188

Adjustment of Design Limited Imperfections for Transportation Vehicles  

NASA Astrophysics Data System (ADS)

The realization of light weight-construction without loss of passive safety in transportation vehicles is a big challenge for the next years. Considering the requirements on an automobile from consumer view a modern car should combine a high quality of comfort and standard with low operating expenses and a high safety standard. The use of lightweight design enables reductions in fuel consumption and CO2 emissions which are leading to a decrease of operating costs. The increase in passive safety is mainly characterized by an increase in strength and weight due to a concerted material selection, an enhancement of sheet metal thickness and additional compensating elements, e.g. patches. Especially for limited imperfections like cataphoretic drain holes or accesses for joining operations the strength adjustment without additional compensating elements and increasing weight possesses very much potential. The presented research investigate the possibility to reinforce local imperfections considering the material TRIP780 by combining different approaches on light-weight design. The reinforcements are realized by additional forming elements and enhance the moment of inertia. Different investigations were carried out to assess the placement and arrangement of the reinforcements in the deep drawing parts

Voges-Schwieger, Kathrin; Hübner, Sven; Behrens, Bernd-Arno

2011-05-01

189

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

190

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

191

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

192

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

193

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

194

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

195

Design of an agile unmanned combat vehicle: a product of the DARPA UGCV program  

Microsoft Academic Search

The unmanned ground compat vehicle (UGCV) design evolved by the SAIC team on the DARPA UGCV Program is summarized in this paper. This UGCV design provides exceptional performance against all of the program metrics and incorporates key attributes essential for high performance robotic combat vehicles. This performance includes protection against 7.62 mm threats, C130 and CH47 transportability, and the ability

Lindsey D. Thornhill; Alan Walls; Ronald C. Arkin; Joseph H. Beno; Chuck Bergh; Don Bresie; Anthony Giovannetti; Benny M. Gothard; Larry H. Matthies; Porfirio Nogueiro; Jim Scanlon; Ron Scott; Miguel Simon; Wilford Smith; Kenneth J. Waldron

2003-01-01

196

Design of an In-Wheel Axial Flux Brushless DC Motor for Electric Vehicle  

Microsoft Academic Search

The hybrid electric vehicles has gained increasing importance in automobile manufacturing due to their high efficiency and environmental friendliness. The main components of hybrid electric vehicles are electric power source, electric motor and control system. The electric motor used should have a high torque density and compact design. This paper presents a design of an electric motor for direct drive

N. A. Rahim; Hew Wooi Ping; M. Tadjuddin

2006-01-01

197

A new digital human environment and assessment of vehicle interior design  

Microsoft Academic Search

Abstract Vehicle interior design directly relates to driver performance measures such as comfort, efficiency, risk of injury, and vehicle safety. A digital human,is a convenient tool for satisfying the need to reduce the design cycle in order to save time and money. This paper presents a digital human environment, Santos,, developed at The University of Iowa, and its assessment as

Jingzhou Yang; Joo H. Kim; Karim Abdel-malek; Timothy Marler; Steven Beck; Gregory R. Kopp

2007-01-01

198

Particle Swarm Optimization for optimal powertrain component sizing and design of fuel cell hybrid electric vehicle  

Microsoft Academic Search

In this paper, an optimal design to minimize the cost, mass and volume of the fuel cell (FC) and supercapacitor (SC) in a fuel cell hybrid electric vehicle is presented. Because of the hybrid powertrain, component sizing significantly affects vehicle performance, cost and fuel economy. Hence, during sizing, various design and control constraints should also be satisfied simultaneously. In this

Omar Hegazy; Joeri Van Mierlo

2010-01-01

199

Impact of empty vehicle flow on optimal flow path design for unidirectional AGV systems  

Microsoft Academic Search

This paper addresses the flow path design issue of automated material handling systems. We concentrate on the design of unidirectional guide path for automated guided vehicle systems. We present a modelling approach to determine the optimal flow path, which takes into account the impact of empty and loaded vehicle flows on the objective function to be minimized. We suggest a

X.-C. SUN; N. TCHERNEV

1996-01-01

200

Design Guidelines for Prevention of Corrosion in Combat and Tactical Vehicles,  

National Technical Information Service (NTIS)

This report was prepared to provide guidelines for the military design engineer in developing improved corrosion control techniques for military combat and tactical vehicles. It covers basic corrosion theory, principles of proper design and protective coa...

A. R. Kovant

1988-01-01

201

Concept design of a new generation military vehicle  

Microsoft Academic Search

This paper presents the development of an advanced concept for a next generation military vehicle based on state of the art technologies. The vehicle's platform will be directly suitable for high mobility applications for instance: Special Forces missions, Marine reconnaissance missions, and commercial racing in events such as Bajas and the Paris - Dakar. The platform will be a 10000

Codrin-Gruie Cantemir; Gabriel Ursescu; Lorenzo Serrao; Giorgio Rizzoni; James Bechtel; Thomas Udvare; Mike Letherwood

2006-01-01

202

Design of flight control law for underwater supercavitating vehicle  

Microsoft Academic Search

In high-speed flight, the surfaces of an underwater vehicle are enveloped by cavity entirely or mostly, and there is only a small portion of the body contacting with water. Due to the existence of hydrodynamic force and surrounding environment disturbances, the tail of body interacts with vehicle wall and generates planing force, which leads to system having great nonlinearity and

Han Yuntao; Sun Yao; Mo Hongwei; Bai Tao

2008-01-01

203

Fuzzy CMAC control design for an airbreathing hypersonic cruise vehicle  

Microsoft Academic Search

This paper proposes the implementation of fuzzy cerebellar model arithmetic computer (FCMAC) neural network for altitude and velocity tracking control of the longitudinal model of an airbreathing hypersonic cruise vehicle (AHCV) which has an integrated airframe-propulsion system configuration. A set of nonlinear longitudinal equations of motion for the vehicle which include the CFD-generated aerodynamic, propulsion, and coupled aero propulsion data

Yan Binbin; Lu Cunkan; Yu Weiwei; Yan Jie

2009-01-01

204

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

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 and Fuel Consumption Optimization for a Bio-Inspired Semi-floating Hybrid Vehicle  

Microsoft Academic Search

Based on a bionic concept and combing air-cushion techniques and track driving mechanisms, a novel semi-floating hybrid concept vehicle is proposed to meet the transportation requirements on soft terrain. First, the vehicle scheme and its improved duel-spring flexible suspension design are described. Then, its fuel consumption model is proposed accordingly with respect to two vehicle operating parameters. Aiming at minimizing

Jiannan Luo; Yansong Zhang

2011-01-01

207

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

208

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

Code of Federal Regulations, 2010 CFR

...2009-07-01 false Monitoring of effects of motor vehicle use on designated roads and trails and in designated...MANAGEMENT Designation of Roads, Trails, and Areas...Vehicle Use § 212.57 Monitoring of effects of motor vehicle use on designated roads and trails and in...

2009-07-01

209

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

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Monitoring of effects of motor vehicle use on designated roads and trails and in designated...MANAGEMENT Designation of Roads, Trails, and Areas...Vehicle Use § 212.57 Monitoring of effects of motor vehicle use on designated roads and trails and in...

2010-07-01

210

Design Considerations for an Urban Freeway Vehicle Detection System.  

National Technical Information Service (NTIS)

Urban freeways are undergoing significant changes due to reconstruction and rehabilitation of roadways to increase the capacities, to provide for High Occupancy Vehicle (HOV) operations, and to repair damaged and worn-out pavements and structures. There i...

W. R. McCasland

1982-01-01

211

Design of Genetic Algorithms for Topology Control of Unmanned Vehicles.  

National Technical Information Service (NTIS)

We present genetic algorithms (GAs) as a decentralised topology control mechanism distributed among active running software agents to achieve a uniform spread of terrestrial unmanned vehicles (UVs) over an unknown geographical area. This problem becomes m...

C. S. Sahin E. Urrea G. Bertoli M. Conner M. U. Uyar

2010-01-01

212

Design and Control of Flapping Wing Micro Air Vehicles.  

National Technical Information Service (NTIS)

Flapping wing Micro Air Vehicles (MAVs) continues to be a growing field, with ongoing research into unsteady, low Re aerodynamics, micro- fabrication, and fluid-structure interaction. However, research into flapping wing control of such MAVs continues to ...

M. L. Anderson

2011-01-01

213

Design Study of Flat Belt CVT for Electric Vehicles.  

National Technical Information Service (NTIS)

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 recommende...

E. L. Kumm

1980-01-01

214

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

215

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

216

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

217

Integrated design of trajectory planning and control for micro air vehicles  

Microsoft Academic Search

Effective trajectory planning and feedback control are important for an autonomous micro air vehicle (MAV) to accomplish a flight task of going across several target points. This paper presents a novel method to generate an optimal trajectory for a MAV based on criteria of minimum energy consumptions and lowest difficulties in reorienting the vehicle, via designing feasible turning rates and

Rong Zhu; Dong Sun; Zhaoying Zhou

2007-01-01

218

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

219

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

Microsoft Academic Search

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

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

2010-01-01

220

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

Microsoft Academic Search

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

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

2004-01-01

221

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

Microsoft Academic Search

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

Xiaohu Fan; Yulin Zhang

2009-01-01

222

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

NASA Technical Reports Server (NTRS)

A number of problems related to the design, construction and evaluation of an autonomous roving planetary vehicle and its control and operating systems intended for an unmanned exploration of Mars are studied. Vehicle configuration, dynamics, control, systems and propulsion; systems analysis; terrain sensing and modeling and path selection; and chemical analysis of samples are included.

1974-01-01

223

Design and realization of expressway vehicle path recognition and ETC system based on RFID  

Microsoft Academic Search

With the development of expressway, the vehicle path recognition based on RFID is designed and an Electronic Toll Collection system of expressway will be implemented. It uses a passive RFID tag as carrier to identify Actual vehicle path in loop road. The ETC system will toll collection without parking, also census traffic flow and audit road maintenance fees. It is

Zhihui Feng; Yanjie Zhu; Pengtao Xue; Mingjie Li

2010-01-01

224

Design trade space for a Mars ascent vehicle for a Mars sample return mission  

Microsoft Academic Search

The design of an ascent vehicle for Mars sample return is one of the most challenging problems to be addressed for this type of mission. This paper identifies the spectrum of performance requirements that could be required of a Mars ascent vehicle for a sample return mission. With this understanding of performance requirements, an investigation of technology requirements is presented.

Ronald W. Humble

1999-01-01

225

Design of an Adaptive Cruise Control \\/ Collision Avoidance with lane change support for vehicle autonomous driving  

Microsoft Academic Search

This paper presents an adaptive cruise control (ACC) and collision avoidance (CA) system for vehicle autonomous driving. The control scheme is designed to improve drivers' comfort during multi-vehicle driving situations and to completely avoid rear-end collision using severe braking and lane change maneuver. In order to create such an application, the proposed system consists of a longitudinal control strategy for

Dongwook Kim; Seungwuk Moon; H. J. Kim; Kyongsu Yi

2009-01-01

226

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

NASA Astrophysics Data System (ADS)

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

1988-06-01

227

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

228

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

229

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

230

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

231

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

232

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

233

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

234

Design Study of Steel V-Belt CVT for Electric Vehicles.  

National Technical Information Service (NTIS)

A continuously variable transmission (CVT) design layout was completed. The intended application was for coupling the flywheel to the driveline of a flywheel battery hybrid electric vehicle. The requirements were that the CVT accommodate flywheel speeds f...

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

1980-01-01

235

HASA: Hypersonic Aerospace Sizing Analysis for the Preliminary Design of Aerospace Vehicles.  

National Technical Information Service (NTIS)

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 veh...

G. J. Harloff B. M. Berkowitz

1988-01-01

236

Theoretical aerothermal concepts for configuration design of hypersonic vehicles  

Microsoft Academic Search

Convection coefficients and heat fluxes due to aerodynamic heating on critical surfaces of hypersonic vehicle are obtained analytically. The applicability of recovery temperature for stagnation regions is discussed. Convection coefficient for the bicurvature forward stagnation region is obtained directly from 2-D stagnation region correlation, using the two principal radii of curvatures. Convective heat flux to swept-back leading edge (SBLE) surface

Shripad P. Mahulikar

2005-01-01

237

Red Warning Triangles. Vehicle Perceptibility 3. Function, Design and Application.  

National Technical Information Service (NTIS)

The document reports on the warning system for vehicles stationary on the highway in Europe--the red warning triangle. Standards to be given for perceptibility and wind stability of the red warning triangles. The report analyses the practical conditions o...

1970-01-01

238

Enhanced Armored Vehicle Fire Control System Design Modifications  

Microsoft Academic Search

This paper discusses a technique which promises to significantly enhance the capability of many existing armored vehicle fire control systems to better service maneuvering targets. The basic technique described in this paper allows for the transformation of existing driven reticle systems to emulate a gun director system by relatively simple signal flow changes which do not require any additional hardware.

Toney R. Perkins; John N. Groff

1986-01-01

239

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

240

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

241

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 control of a mobile planetary vehicle according to a systematic plan for the exploration of Mars has been undertaken. Problem areas receiving attention include: (1) overall systems analysis; (2) vehicle configuration and dynamics; (3) toroidal wheel design and evaluation; (4) on-board navigation systems; (5) satellite-vehicle navigation systems; (6) obstacle detection systems; (7) terrain sensing, interpretation and modeling; (8) computer simulation of terrain sensor-path selection systems; and (9) chromatographic systems design concept studies. The specific tasks which have been undertaken are defined and the progress which has been achieved during the period July 1, 1971 to December 31, 1971 is summarized.

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

1971-01-01

242

Novel approach for designing a hypersonic gliding-cruising dual waverider vehicle  

NASA Astrophysics Data System (ADS)

For a hypersonic gliding-cruising vehicle, the gliding Mach number is larger than the cruising Mach number. It may be useful to design the inlet shroud to act as the compression surface of the waverider, to ensure that the vehicle rides on the shock wave, during both the gliding and cruising phases. A new design concept, namely a gliding-cruising dual waverider, is proposed in the current study. During the gliding phase, the hypersonic vehicle rides on the shock wave at the design gliding Mach number, as the inlet shroud is designed to act as waverider?s compression surface. During the cruising phase, when the inlet shroud is cast away or jettisoned, the hypersonic vehicle rides on the shock wave at the design cruising Mach number, as the forebody is designed to act as waverider?s compression surface. Thus, the design methodology of the dual-cone-derived waverider is described based on the theory of conical flow. Finally, the numerical methods are utilized to verify the new design method of the aerodynamic configuration. This methodology proposed is useful to design a hypersonic vehicle for two regimes of flight.

Liu, Jun; Ding, Feng; Huang, Wei; Jin, Liang

2014-09-01

243

Expert system for vehicle body assembly conceptual design  

Microsoft Academic Search

The paper introduces the architecture of conceptual assembly expert system, which makes fuzzy and qualitative presentation of design knowledge in the conceptual assembly design stage. Qualitative simulation approach in the expert system is a new approach to designing assemblies' tolerance design and joint configuration in the conceptual design. Also, qualitative analysis assists designers to determine feasible assembly sequences. The system

Yubing Li; Guanlong Chen; Xinming Lai; Cheng Zheng; Yanfeng Xing

2006-01-01

244

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

245

Dual throat engine design for a SSTO launch vehicle  

NASA Technical Reports Server (NTRS)

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

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

1980-01-01

246

Design of digital load torque observer in hybrid electric vehicle  

NASA Astrophysics Data System (ADS)

In hybrid electric vehicle, engine begain to work only when motor was in high speed in order to decrease tail gas emission. However, permanent magnet motor was sensitive to its load, adding engine to the system always made its speed drop sharply, which caused engine to work in low efficiency again and produced much more environment pollution. Dynamic load torque model of permanent magnet synchronous motor is established on the basic of motor mechanical equation and permanent magnet synchronous motor vector control theory, Full- digital load torque observer and compensation control system is made based on TMS320F2407A. Experiment results prove load torque observer and compensation control system can detect and compensate torque disturbing effectively, which can solve load torque disturbing and decrease gas pollution of hybrid electric vehicle.

Sun, Yukun; Zhang, Haoming; Wang, Yinghai

2008-12-01

247

The automated lane-keeping design for an intelligent vehicle  

Microsoft Academic Search

In this paper, a vision-based lane-keeping automated steering system is proposed and is successfully verified in our vehicle platform, TAIWAN iTS-1. The proposed steering system can achieve the accurate detection of the complicated road environment information; and more, the closed-loop automated lane-keeping steering system with virtual look-ahead is stable under varying speed operation. Furthermore, to achieve more manlike driving behavior

Shinq-Jen Wu; Hsin-Han Chiang; Jau-Woei Perng; Tsu-Tian Lee; Chao-Jung Chen

2005-01-01

248

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

249

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

NASA Astrophysics Data System (ADS)

Problems associated with the aerodynamic design of space vehicles with emphasis of the role of hypersonic wind tunnel facilities in the development of the vehicle are considered. At first, to identify wind tunnel and computational fluid dynamics (CFD) requirements, operational environments are postulated for hypervelocity vehicles. Typical flight corridors are shown with the associated flow density: real gas effects, low density flow, and non-equilibrium flow. Based on an evaluation of these flight regimes and consideration of the operational requirements, the wind tunnel testing requirements for the aerodynamic design are examined. Then, the aerodynamic design logic and optimization techniques to develop and refine the configurations in a traditional phased approach based on the programmatic design of space vehicle are considered. Current design methodology for the determination of aerodynamic characteristics for designing the space vehicle, i.e., (1) ground test data, (2) numerical flow field solutions and (3) flight test data, are also discussed. Based on these considerations and by identifying capabilities and limits of experimental and computational methods, the role of a large conventional hypersonic wind tunnel and the high enthalpy tunnel and the interrelationship of the wind tunnels and CFD methods in actual aerodynamic design and analysis are discussed.

Sakakibara, Seizou; Hozumi, Kouichi; Soga, Kunio; Nomura, Shigeaki

250

Design and evaluation of side slip angle-based vehicle stability control scheme on a virtual test track  

Microsoft Academic Search

This paper describes the development of side slip angle-based vehicle stability control (VSC) schemes and the evaluation of the control schemes on a virtual test track. A differential braking control law based on vehicle planar motion has been designed using a three-degree-of-freedom yaw plane vehicle model. The control threshold for the VSC is designed based on the vehicle body side

Taeyoung Chung; Kyongsu Yi

2006-01-01

251

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

252

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

253

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

254

The Application of the NASA Advanced Concepts Office, Launch Vehicle Team Design Process and Tools for Modeling Small Responsive Launch Vehicles  

NASA Technical Reports Server (NTRS)

The Advanced Concepts Office (ACO) Launch Vehicle Team at the NASA Marshall Space Flight Center (MSFC) is recognized throughout NASA for launch vehicle conceptual definition and pre-phase A concept design evaluation. The Launch Vehicle Team has been instrumental in defining the vehicle trade space for many of NASA s high level launch system studies from the Exploration Systems Architecture Study (ESAS) through the Augustine Report, Constellation, and now Space Launch System (SLS). The Launch Vehicle Team s approach to rapid turn-around and comparative analysis of multiple launch vehicle architectures has played a large role in narrowing the design options for future vehicle development. Recently the Launch Vehicle Team has been developing versions of their vetted tools used on large launch vehicles and repackaged the process and capability to apply to smaller more responsive launch vehicles. Along this development path the LV Team has evaluated trajectory tools and assumptions against sounding rocket trajectories and air launch systems, begun altering subsystem mass estimating relationships to handle smaller vehicle components, and as an additional development driver, have begun an in-house small launch vehicle study. With the recent interest in small responsive launch systems and the known capability and response time of the ACO LV Team, ACO s launch vehicle assessment capability can be utilized to rapidly evaluate the vast and opportune trade space that small launch vehicles currently encompass. This would provide a great benefit to the customer in order to reduce that large trade space to a select few alternatives that should best fit the customer s payload needs.

Threet, Grady E.; Waters, Eric D.; Creech, Dennis M.

2012-01-01

255

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

256

Hypersonic aerospace sizing analysis for the preliminary design of aerospace vehicles  

NASA Technical Reports Server (NTRS)

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

Harloff, Gary J.; Berkowitz, Brian M.

1990-01-01

257

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

258

Design of an agile unmanned combat vehicle: a product of the DARPA UGCV program  

NASA Astrophysics Data System (ADS)

The unmanned ground compat vehicle (UGCV) design evolved by the SAIC team on the DARPA UGCV Program is summarized in this paper. This UGCV design provides exceptional performance against all of the program metrics and incorporates key attributes essential for high performance robotic combat vehicles. This performance includes protection against 7.62 mm threats, C130 and CH47 transportability, and the ability to accept several relevant weapons payloads, as well as advanced sensors and perception algorithms evolving from the PerceptOR program. The UGCV design incorporates a combination of technologies and design features, carefully selected through detailed trade studies, which provide optimum performance against mobility, payload, and endurance goals without sacrificing transportability, survivability, or life cycle cost. The design was optimized to maximize performance against all Category I metrics. In each case, the performance of this design was validated with detailed simulations, indicating that the vehicle exceeded the Category I metrics. Mobility metrics were analyzed using high fidelity VisualNastran vehicle models, which incorporate the suspension control algorithms and controller cycle times. DADS/Easy 5 3-D models and ADAMS simulations were also used to validate vehicle dynamics and control algorithms during obstacle negotiation.

Thornhill, Lindsey D.; Walls, Alan; Arkin, Ronald C.; Beno, Joseph H.; Bergh, Chuck; Bresie, Don; Giovannetti, Anthony; Gothard, Benny M.; Matthies, Larry H.; Nogueiro, Porfirio; Scanlon, Jim; Scott, Ron; Simon, Miguel; Smith, Wilford; Waldron, Kenneth J.

2003-09-01

259

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

NASA Technical Reports Server (NTRS)

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

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

2012-01-01

260

Design and optimization for the occupant restraint system of vehicle based on a single freedom model  

NASA Astrophysics Data System (ADS)

Throughout the vehicle crash event, the interactions between vehicle, occupant, restraint system (VOR) are complicated and highly non-linear. CAE and physical tests are the most widely used in vehicle passive safety development, but they can only be done with the detailed 3D model or physical samples. Often some design errors and imperfections are difficult to correct at that time, and a large amount of time will be needed. A restraint system concept design approach which based on single-degree-of-freedom occupant-vehicle model (SDOF) is proposed in this paper. The interactions between the restraint system parameters and the occupant responses in a crash are studied from the view of mechanics and energy. The discrete input and the iterative algorithm method are applied to the SDOF model to get the occupant responses quickly for arbitrary excitations (impact pulse) by MATLAB. By studying the relationships between the ridedown efficiency, the restraint stiffness, and the occupant response, the design principle of the restraint stiffness aiming to reduce occupant injury level during conceptual design is represented. Higher ridedown efficiency means more occupant energy absorbed by the vehicle, but the research result shows that higher ridedown efficiency does not mean lower occupant injury level. A proper restraint system design principle depends on two aspects. On one hand, the restraint system should lead to as high ridedown efficiency as possible, and at the same time, the restraint system should maximize use of the survival space to reduce the occupant deceleration level. As an example, an optimization of a passenger vehicle restraint system is designed by the concept design method above, and the final results are validated by MADYMO, which is the most widely used software in restraint system design, and the sled test. Consequently, a guideline and method for the occupant restraint system concept design is established in this paper.

Zhang, Junyuan; Ma, Yue; Chen, Chao; Zhang, Yan

2013-05-01

261

Advanced design of valve-regulated lead–acid battery for hybrid electric vehicles  

Microsoft Academic Search

A novel design of lead-acid battery has been developed for use in hybrid electric vehicles HEVs . The battery has current take-offs at both ends of each of the positive and negative plates. This feature markedly reduces battery operating temperatures, improves battery . capacity, and extends cycle-life under HEV duty. The battery also performs well under partial-state-of-charge PSoC rfast-charge, electric-vehicle

L. T. Lam; R. H. Newnham; H. Ozgun; F. A. Fleming

2000-01-01

262

Saliency-Based Sensorless Drive of an Adequately Designed IPM Motor for Robot Vehicle Application  

NASA Astrophysics Data System (ADS)

Technology fusion between motor design and control can produce new applications. This paper introduces a saliency-based sensorless drive of adequate designed IPM motor for a specific application in a robot vehicle. The motor is deliberately designed to meet the requirements of robot application and lend itself better for saliency based sensorless control. The speed and position of multiple wheel-motors are synchronously controlled by the drive amplifiers and a single motion controller over the speed range from zero to maximum speed for the robot vehicle application. Finally, two types of robot vehicles, one being a two-wheeled differential drive and the other being an omni directional drive, are developed to transport objects and human. This paper mainly focuses on the concept of motor design and its control. Some analysis and test data are given in this paper.

Ide, Kozo; Takaki, Mamoru; Morimoto, Shinya; Kawazoe, Yosuke; Maemura, Akihiko; Ohto, Motomichi

263

Multidisciplinary design of a rocket-based combined cycle SSTO launch vehicle using Taguchi methods  

NASA Technical Reports Server (NTRS)

Results are presented from the optimization process of a winged-cone configuration SSTO launch vehicle that employs a rocket-based ejector/ramjet/scramjet/rocket operational mode variable-cycle engine. The Taguchi multidisciplinary parametric-design method was used to evaluate the effects of simultaneously changing a total of eight design variables, rather than changing them one at a time as in conventional tradeoff studies. A combination of design variables was in this way identified which yields very attractive vehicle dry and gross weights.

Olds, John R.; Walberg, Gerald D.

1993-01-01

264

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

265

Optimum Structural Design Concepts for Aerospace Vehicles: Bibliography and Assessment.  

National Technical Information Service (NTIS)

Minimum weight design of aerospace structures has evolved during the past two decades into a rather rigorous scientific discipline that permits the rational selection of structural configurations and materials for various design requirements. Because of t...

G. Gerard

1965-01-01

266

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

267

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

268

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

269

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

270

Conceptual design of two-stage-to-orbit hybrid launch vehicle  

NASA Technical Reports Server (NTRS)

The object of this design class was to design an earth-to orbit vehicle to replace the present NASA space shuttle. The major motivations for designing a new vehicle were to reduce the cost of putting payloads into orbit and to design a vehicle that could better service the space station with a faster turn-around time. Another factor considered in the design was that near-term technology was to be used. Materials, engines and other important technologies were to be realized in the next 10 to 15 years. The first concept put forth by NASA to meet these objectives was the National Aerospace Plane (NASP). The NASP is a single-stage earth-to-orbit air-breathing vehicle. This concept ran into problems with the air-breathing engine providing enough thrust in the upper atmosphere, among other things. The solution of this design class is a two-stage-to-orbit vehicle. The first stage is air-breathing and the second stage is rocket-powered, similar to the space shuttle. The second stage is mounted on the top of the first stage in a piggy-back style. The vehicle takes off horizontally using only air-breathing engines, flies to Mach six at 100,000 feet, and launches the second stage towards its orbital path. The first stage, or booster, will weigh approximately 800,000 pounds and the second stage, or orbiter will weigh approximately 300,000 pounds. The major advantage of this design is the full recoverability of the first stage compared with the present solid rocket booster that are only partially recoverable and used only a few times. This reduces the cost as well as providing a more reliable and more readily available design for servicing the space station. The booster can fly an orbiter up, turn around, land, refuel, and be ready to launch another orbiter in a matter of hours.

1991-01-01

271

Development of design tool for hybrid power systems of hybrid electric military combat vehicles  

Microsoft Academic Search

This paper introduces a developed hybrid power modeling and simulation tool for series hybrid electric military combat vehicles. A simulation tool for determining optimal hybrid power in hybrid components such as motor, engine, generator, and storages and for evaluating designed driving control strategy and energy management strategy is essential in designing a hybrid system. The developed tool is based on

Dong Hwan Choi; Seong Jun Lee; Bo-Hyung Cho; Yeo Giel Yoon

2010-01-01

272

Design considerations for a low altitude long endurance solar powered unmanned aerial vehicle  

Microsoft Academic Search

This paper presents design considerations for a low altitude long endurance solar powered unmanned aerial vehicle (LALE UAV). The considerations addressed include the determination of the available solar power, the design of the UAV wing for long endurance flights and the determination of the electrical power and energy balance of the UAV. Using these considerations, a solar powered UAV was

J. Meyer; J. A. F. du Plessis; P. Ellis; W. Clark

2007-01-01

273

The scalable design of flapping micro air vehicles inspired by insect flight  

Microsoft Academic Search

Here we explain how flapping micro air vehicles (MAVs) can be designed at different scales, from bird to insect size. The common believe is that micro fixed wing airplanes and helicopters outperform MAVs at bird scale, but become inferior to flapping MAVs at the scale of insects as small as fruit flies. Here we present our experience with designing and

D. Lentink; S. R. Jongerius; N. L. Bradshaw

2008-01-01

274

Using simulation in design of a cellular assembly plant with automatic guided vehicles  

Microsoft Academic Search

The paper has two main purposes. The first purpose is to give a comprehensive summary of previous research done in design and analysis of Automatic Guided Vehicle Systems (AGVS) and present a hierarchical taxonomy of the factors to be used in design of AGVS. The second purpose is to analyze the main and interaction effects of a large number of

Omur M. Ülgen; Pankaj Kedia

1990-01-01

275

Design of intelligent real-time hierarchical control architecture for combat vehicle fire control system  

Microsoft Academic Search

According to intelligence development requirement of combat vehicle fire control system, it is important to research the intelligent control architecture. The design principles of intelligent real-time hierarchical control architecture are put forward first, and then the architecture of the entire system and the architecture of each control layer are designed and illustrated in detail, at last the main characters of

Han Yang; Chang Tianqing; Qiu Xiaobo

2010-01-01

276

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

National Technical Information Service (NTIS)

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 tradi...

J. R. Olds L. Marcus

2002-01-01

277

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

278

Two Designs for an Orbital Transfer Vehicle: A Comparison of Two OTVS.  

National Technical Information Service (NTIS)

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

1988-01-01

279

Human driving data-based design of a vehicle adaptive cruise control algorithm  

Microsoft Academic Search

This paper presents a vehicle adaptive cruise control algorithm design with human factors considerations. Adaptive cruise control (ACC) systems should be acceptable to drivers. In order to be acceptable to drivers, the ACC systems need to be designed based on the analysis of human driver driving behaviour. Manual driving characteristics are investigated using real-world driving test data. The goal of

Seungwuk Moon; Kyongsu Yi

2008-01-01

280

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

281

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

282

Design Refinement and Modeling Methods for Highly-Integrated Hypersonic Vehicles  

NASA Astrophysics Data System (ADS)

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

Torrez, Sean Michael

283

Flight control system design for a micro aerial vehicle  

Microsoft Academic Search

Purpose – The purpose of this paper is to present an original design procedure for a flight control system. Design\\/methodology\\/approach – An optimization process, based on a genetic algorithm (GA), is used to meet the frequency domain handling qualities requirements in the longitudinal plane for an unconventional platform characterized by nonlinear aerodynamics. The parameters are implemented in the search process

Giorgio Guglieri; Barbara Pralio; Fulvia Quagliotti

2006-01-01

284

A machine-to-loop assignment and layout design methodology for tandem AGV systems with multiple-load vehicles  

Microsoft Academic Search

In this paper, we propose a design methodology for tandem Automated Guided Vehicle (AGV) systems with multiple-load vehicles. Our goal is to devise a design methodology that can achieve the following objectives in multiple-load tandem AGV designs. The first objective is to achieve the workload-balance between vehicles of different loops. The second objective is to minimize the inter-loop flow. The

Ying-Chin Ho; Ping-Fong Hsieh

2004-01-01

285

Topology, Design, Analysis, and Thermal Management of Power Electronics for Hybrid Electric Vehicle Applications  

SciTech Connect

Power electronics circuits play 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 topologies, such as buck converters, voltage source inverters and bidirectional boost converters are challenged by system cost, efficiency, controllability, thermal management, voltage and current capability, and packaging issues. Novel topologies, such as isolated bidirectional DC/DC converters, multilevel converters, and Z-source inverters, offer potential improvement to hybrid vehicle system performance, extended controllability and power capabilities. This paper gives an overview of the topologies, design, and thermal management, and control of power electronics circuits in hybrid vehicle applications.

Mi, C.; Peng, F. Z.; Kelly, K. J.; O'Keefe, M.; Hassani, V.

2008-01-01

286

Overview of the Beta II Two-Stage-To-Orbit vehicle design  

NASA Technical Reports Server (NTRS)

A study of a near-term, low risk two-stage-to-orbit (TSTO) vehicle was undertaken. The goal of the study was to assess a fully reusable TSTO vehicle with horizontal takeoff and landing capability that could deliver 10,000 pounds to a 120 nm polar orbit. The configuration analysis was based on the Beta vehicle design. A cooperative study was performed to redesign and refine the Beta concept to meet the mission requirements. The vehicle resulting from this study was named Beta II. It has an all-airbreathing first stage and a staging Mach number of 6.5. The second stage is a conventional wing-body configuration with a single SSME.

Plencner, Robert M.

1991-01-01

287

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

288

Design and Analysis of Subscale and Full-Scale Buckling-Critical Cylinders for Launch Vehicle Technology Development.  

National Technical Information Service (NTIS)

NASA s Shell Buckling Knockdown Factor (SBKF) project has the goal of developing new analysis-based shell buckling design factors (knockdown factors) and design and analysis technologies for launch vehicle structures. Preliminary design studies indicate t...

A. E. Lovejoy, C. Rankin, M. W. Hilburger, R. P. Thornburgh

2012-01-01

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

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

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

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

293

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

294

Integrated vs decoupled fault detection filter & flight control law designs for a re-entry vehicle  

Microsoft Academic Search

An integrated design of a robust fault detection filter and control system for a re-entry vehicle is presented. The integrated architecture is based on the four-block Youla parametrization which allows to better and directly trade-off filter and control design objectives in the face of disturbances and uncertainties. Hinfin -optimization techniques are used to design the integrated controller\\/filter system for a

Helena Castro; Samir Bennani; Andres Marcos

2006-01-01

295

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

296

System modeling and optimal design of a Mars-roving vehicle.  

NASA Technical Reports Server (NTRS)

The problem of systematically determining the optimal design for an unmanned Mars-roving vehicle is considered. A system model, identifying all feasible designs, is generated by consideration of the physical constraints on the design parameters, and the requirement that the system be deliverable to the Mars surface. An expression which evaluates system performance relative to mission goals is developed. The model and objective function together allow simulation of the effects of design trade-offs upon system performance for all feasible designs. Nonlinear programming techniques are utilized to identify the optimal design.

Smith, E. J.; Pavarini, C.; Vandenburg, N.

1972-01-01

297

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

NASA Technical Reports Server (NTRS)

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

Gollan, Rowan J.; Smart, Michael K.

2010-01-01

298

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

299

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

300

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

Code of Federal Regulations, 2013 CFR

36 Parks, Forests, and Public Property 2 2013-07-01...motor vehicle use on designated roads and trails and in designated...57 Parks, Forests, and Public Property FOREST SERVICE...MANAGEMENT Designation of Roads, Trails, and Areas for...

2013-07-01

301

Integrating Human Factors into Crew Exploration Vehicle (CEV) Design  

NASA Technical Reports Server (NTRS)

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

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

2007-01-01

302

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

303

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

304

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

305

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

306

A DESIGN FOR COMPOSING AND EXTENDING VEHICLE MODELS  

Microsoft Academic Search

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 its aircraft model design with the following goals: 1. Avoid polluting the aircraft model with experiment

Michael M. Madden; Jason R. Neuhaus

307

Design of a Dynamic Weighbridge for Recording Vehicle Wheel Loads.  

National Technical Information Service (NTIS)

A description is given of the apparatus developed for weighing the axle loads carried by traffic travelling along roads at normal speeds, classifying the loads into various preselected weight groups, and counting the number in each group. The design of th...

J. J. Trott J. W. Grainger

1968-01-01

308

Series hybrid vehicles and optimized hydrogen engine design  

Microsoft Academic Search

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

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

1995-01-01

309

Suntrakker-a student-designed solar vehicle  

Microsoft Academic Search

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

B. Rogow

1997-01-01

310

Applying Monte Carlo Simulation to Launch Vehicle Design and Requirements Verification  

NASA Technical Reports Server (NTRS)

This paper is focused on applying Monte Carlo simulation to probabilistic launch vehicle design and requirements verification. The approaches developed in this paper can be applied to other complex design efforts as well. Typically the verification must show that requirement "x" is met for at least "y" % of cases, with, say, 10% consumer risk or 90% confidence. Two particular aspects of making these runs for requirements verification will be explored in this paper. First, there are several types of uncertainties that should be handled in different ways, depending on when they become known (or not). The paper describes how to handle different types of uncertainties and how to develop vehicle models that can be used to examine their characteristics. This includes items that are not known exactly during the design phase but that will be known for each assembled vehicle (can be used to determine the payload capability and overall behavior of that vehicle), other items that become known before or on flight day (can be used for flight day trajectory design and go/no go decision), and items that remain unknown on flight day. Second, this paper explains a method (order statistics) for determining whether certain probabilistic requirements are met or not and enables the user to determine how many Monte Carlo samples are required. Order statistics is not new, but may not be known in general to the GN&C community. The methods also apply to determining the design values of parameters of interest in driving the vehicle design. The paper briefly discusses when it is desirable to fit a distribution to the experimental Monte Carlo results rather than using order statistics.

Hanson, John M.; Beard, Bernard B.

2010-01-01

311

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

SciTech Connect

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

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

1995-02-01

312

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

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

Optimal design for hybrid rocket engine for air launch vehicle  

Microsoft Academic Search

A feasibility study and the optimal design was conducted for the application of a hybrid motor with HTPB\\/LOX combination to\\u000a the first stage of an air launch system. The feasibility analysis showed that the hybrid motor could successfully be used\\u000a as a substitute for the solid rocket motor of the first stage of the Pegasus XL if the average specific

Ihnseok Rhee; Changjin Lee; Jae-Woo Lee

2008-01-01

315

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

ERIC Educational Resources Information Center

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

Hubbard, Guy

1999-01-01

316

FPGA based signal processing module design and implementation for FMCW vehicle radar systems  

Microsoft Academic Search

In this paper, we design the signal processing module based on FPGA for vehicle FMCW radar systems. We employ the detection algorithms based on two-step FFT (Fast Fourier Transform) using the several fast ramps in order to resolve radar range-velocity ambiguities. We implement the detection algorithms including the first FFT, DBF (Digital Beam Forming), the second FFT, and CFAR (Constant

Eugin Hyun; Sang-Dong Kim; Yeong-Hwan Ju; Jong-Hun Lee; Eung-Noh You; Jeong-Ho Park; Dong-Jin Yeom; Sang-Hyun Park; Seung-Gak Kim

2011-01-01

317

Assessment and Preliminary Design of an Energy Buffer for Regenerative Breaking in Electric Vehicles.  

National Technical Information Service (NTIS)

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 s...

R. Buchholz A. Mathur

1979-01-01

318

Logic-Based, Performance-Driven Electric Vehicle Software Design Tool.  

National Technical Information Service (NTIS)

The goal of this research was to develop computer-based logic algorithms and build them into SmartHEV, a series hybrid electric vehicle software design program. Computer-based logic algorithms were developed to improve the success and rate of convergence ...

D. M. Blackketter D. G. Alexander

2001-01-01

319

NASA advanced-aeronautics design solar-powered remotely piloted vehicle  

Microsoft Academic Search

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

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

1991-01-01

320

Design and implementation of HILS system for ABS ECU of commercial vehicles  

Microsoft Academic Search

The hardware in-the-loop simulation (HILS) system has historically been used in the development and testing of complex and costly systems such as military tactical missiles, aircraft flight control system, satellite control systems, and automotive systems. Especially in the automotive industry, HILS is an effective tool for design, performance evaluation and test of vehicle subsystems such as antilock brake system (ABS),

J. M. Cho; D. H. Hwang; K. C. Lee; J. W. Jeon; D. Y. Park; Y. J. Kim; J. S. Joh

2001-01-01

321

Methods and means of the computer-aided design of unmanned aerial vehicle model  

Microsoft Academic Search

The work contains the analysis of the design methodology of an unmanned aerial vehicle (UAV), which is able to carry out environmental monitoring, define the location of various objects and targets with high accuracy, map the seats of fire and areas of environmental contamination, fulfil patrolling functions to solve the tasks of the National Armed Forces and police, carry out

A. Urbahs; M. Urbaha; V. Petrovs; A. Jakovlevs

2009-01-01

322

An application of robust control techniques to control law design of unmanned air vehicle  

Microsoft Academic Search

This paper applies robust control techniques (RCTs) to the control law design of an unmanned air vehicle (UAV) which is modeled with parameter uncertainties. Firstly, physical modeling approach is used to develop a Linear Fraction Transformation (LFT) based model. Upon this, sensitivities of uncertain parameters are investigated. Then both H? and ? approaches are used to synthesize controllers and ?

Dai Hansu; Zhu Jihong

2010-01-01

323

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

NASA Technical Reports Server (NTRS)

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

Mellish, J. A.

1980-01-01

324

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

325

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

Microsoft Academic Search

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

Yukio Honda; Tomokazu Nakamura; Toshiro Higaki; Yoji Takeda

1997-01-01

326

Further Studies on the Enhancement of Armored Vehicle Fire Control System Design  

Microsoft Academic Search

This paper summarizes the follow-on analysis performed by the US Army Ballistic Research Laboratory in evaluating an armored vehicle fire control modification designed to enhance performance against maneuvering targets. The original work was presented at the 1986 American Control Conference in Seattle, Wa. and dealt with a redesign concept intended to convert a driven reticle fire control to one emulating

Toney R. Perkins; John N. Groff

1987-01-01

327

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

328

Development of software testbed using parametric design approaches for a series hybrid military vehicle  

Microsoft Academic Search

This paper deals with the component sizing of a series hybrid electric vehicle (HEV). Since the component sizes are interrelated with the power-train structures and power control algorithm, the optimal sizing cannot be determined in a simple manner. Thus, in order to simplify the sizing problem for the HEV, this paper presents parametric design approaches which identifies the sizing effects

S. J. Lee; J. C. Kim; H. S. Bae; D. H. Choi; B. H. Cho

2010-01-01

329

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

330

Design of rocker switches for work-vehicles—an application of Kansei Engineering  

Microsoft Academic Search

Rocker switches used in vehicles meet high demands partly due to the increased focus on customer satisfaction. Previous studies focused on ergonomics and usability rather than design for emotions and affection. The aim of this study was to determine how and to what extent engineering properties influence the perception of rocker switches. Secondary aims were to compare two types of

Simon Schütte; Jörgen Eklund

2005-01-01

331

A Method of Integrating Aeroheating into Conceptual Reusable Launch Vehicle Design: Evaluation of Advanced Thermal Protection Techniques for Future Reusable Launch Vehicles  

NASA Technical Reports Server (NTRS)

A method for integrating Aeroheating analysis into conceptual reusable launch vehicle (RLV) design is presented in this thesis. This process allows for faster turn-around time to converge a RLV design through the advent of designing an optimized thermal protection system (TPS). It consists of the coupling and automation of four computer software packages: MINIVER, TPSX, TCAT, and ADS. MINIVER is an Aeroheating code that produces centerline radiation equilibrium temperatures, convective heating rates, and heat loads over simplified vehicle geometries. These include flat plates and swept cylinders that model wings and leading edges, respectively. TPSX is a NASA Ames material properties database that is available on the World Wide Web. The newly developed Thermal Calculation Analysis Tool (TCAT) uses finite difference methods to carry out a transient in-depth 1-D conduction analysis over the center mold line of the vehicle. This is used along with the Automated Design Synthesis (ADS) code to correctly size the vehicle's thermal protection system (TPS). The numerical optimizer ADS uses algorithms that solve constrained and unconstrained design problems. The resulting outputs for this process are TPS material types, unit thicknesses, and acreage percentages. TCAT was developed for several purposes. First, it provides a means to calculate the transient in-depth conduction seen by the surface of the TPS material that protects a vehicle during ascent and reentry. Along with the in-depth conduction, radiation from the surface of the material is calculated along with the temperatures at the backface and interior parts of the TPS material. Secondly, TCAT contributes added speed and automation to the overall design process. Another motivation in the development of TCAT is optimization. In some vehicles, the TPS accounts for a high percentage of the overall vehicle dry weight. Optimizing the weight of the TPS will thereby lower the percentage of the dry weight accounted for by the TPS. Also, this will lower the cost of the TPS and the overall cost of the vehicle.

Olds, John R.; Cowart, Kris

2001-01-01

332

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

333

A Study of Fuel Efficiency and Emission Policy Impact on Optimal Vehicle Design Decisions  

Microsoft Academic Search

Recent environmental legislation, such as the European Union Directive on End-of- Life Vehicles and the Japanese Home Electric Appliances Recycling law, has had a major influence on product design from both an engineering and an economic perspective. This article presents a methodology for studying the effects of automobile fuel efficiency and emission policies on the long-term design decisions of profit-seeking

Jeremy J. Michalek; Panos Y. Papalambros; Steven J. Skerlos

2004-01-01

334

Conceptual Design of a Personal Aerial Vehicle Using Co Flow Jet Airfoil  

Microsoft Academic Search

A flying wing personal aerial vehicle (PAV) is designed using a co-flow jet airfoil (CFJ); it is designed to take-off and land on regular roads and highways, at take-off speed of 60mph. The advantages of using CFJ throughout the entire PAV are the enhanced lift\\/stall margin and thrust generation. It has a targeted range of 500miles, at a cruise mach

Patricia X. Coronado; Brandon Cuffie; Diego Saer; Ge-Cheng Zha

335

Design and fabrication of elevon cove thermal protection systems for aerospace vehicles  

NASA Technical Reports Server (NTRS)

The design study of a lightweight, effective, reuseable seal for use along the elevon cove of shuttle-type reentry and hypersonic cruise vehicles is presented. The study deals primarily with membrane seals, both metallic and non-metallic. This type of seal spans the cove gap between the wing and elevon, and does not depend on spring tension to maintain contact along a flexing wing span. Technical requirements and criteria were generally derived from the space shuttle and utilized for seal design.

Varisco, A.; Borysewiez, A.; Wolter, W.

1979-01-01

336

Interplanetary charged particle models (1974). NASA space vehicle design criteria (environment)  

Microsoft Academic Search

The design of space vehicles for operation in interplanetary space is given, based on descriptions of solar wind, solar particle events, and galactic cosmic rays. A state-of-the-art review is presented and design criteria are developed from experiment findings aboard interplanetary and high-altitude earth-orbiting spacecraft. Solar cells were found to be particularly sensitive. Solar protons may also impact the reliability of

1975-01-01

337

Modular design and testing for anti-lock brake actuation and control using a scaled vehicle system  

Microsoft Academic Search

A unique decoupling feature in frictional disk brake mechanisms, derived through kinematic analysis, enables modularised design of an Anti-lock Braking System (ABS) into a sliding mode system that specifies reference brake torque and a tracking brake actuator controller. Modelling of brake actuation, vehicle dynamics, and control design are described for a scaled vehicle system. The overall control scheme is evaluated

Chinmaya B. Patil; Raul G. Longoria

2007-01-01

338

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

339

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 âAPROSYSâ 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.

Association, European A.

340

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

341

Linear Induction Motor Research: Linear Induction Motor and Test Vehicle Design and Fabrication. Volume II, Book 2.  

National Technical Information Service (NTIS)

A 2500-hp linear induction motor (LIM), a complete test vehicle, a propulsion control system, test instrumentation, and an onboard auxiliary power supply have been designed, fabricated, and checked out. The system was designed to operate at test speeds up...

1971-01-01

342

Linear Induction Motor Research: Linear Induction Motor and Test Vehicle Design and Fabrication. Volume II, Book 1.  

National Technical Information Service (NTIS)

A 2500-hp linear induction motor (LIM), a complete test vehicle, a propulsion control system, test instrumentation, and an onboard auxiliary power supply have been designed, fabricated, and checked out. The system was designed to operate at test speeds up...

1971-01-01

343

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

344

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

345

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

346

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

347

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

348

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

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

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

351

Optimal trajectory designs and systems engineering analyses of reusable launch vehicles  

NASA Astrophysics Data System (ADS)

Realizing a reusable launch vehicle (RLU) that is low cost with highly effective launch capability has become the "Holy Grail" within the aerospace community world-wide. Clear understanding of the vehicle's operational limitations and flight characteristics in all phases of the flight are preponderant components in developing such a launch system. This dissertation focuses on characterizing and designing the RLU optimal trajectories in order to aid in strategic decision making during mission planning in four areas: (1) nominal ascent phase, (2) abort scenarios and trajectories during ascent phase including abort-to-orbit (ATO), transoceanic-abort-landing (TAL) and return-to-launch-site (RTLS), (3) entry phase (including footprint), and (4) systems engineering aspects of such flight trajectory design. The vehicle chosen for this study is the Lockheed Martin X-33 lifting-body design that lifts off vertically with two linear aerospike rocket engines and lands horizontally. An in-depth investigation of the optimal endo-atmospheric ascent guidance parameters such as earliest abort time, engine throttle setting, number of flight phases, flight characteristics and structural design limitations will be performed and analyzed to establish a set of benchmarks for making better trade-off decisions. Parametric analysis of the entry guidance will also be investigated to allow the trajectory designer to pinpoint relevant parameters and to generate optimal constrained trajectories. Optimal ascent and entry trajectories will be generated using a direct transcription method to cast the optimal control problem as a nonlinear programming problem. The solution to the sparse nonlinear programming problem is then solved using sequential quadratic programming. Finally, guidance system hierarchy studies such as work breakdown structure, functional analysis, fault-tree analysis, and configuration management will be developed to ensure that the guidance system meets the definition of vehicle design requirements and constraints.

Tsai, Hung-I. Bruce

352

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

NASA Astrophysics Data System (ADS)

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

Beyer, Eric W.

353

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

SciTech Connect

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

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

2010-08-01

354

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

355

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

356

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

357

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

358

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

359

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

360

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

NASA Technical Reports Server (NTRS)

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

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

1994-01-01

361

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.

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

2012-01-01

362

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

363

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

364

Robust Yaw Stability Controller Design for a Light Commercial Vehicle Using a Hardware in the Loop Steering Test Rig  

Microsoft Academic Search

This paper is on designing a multi-objective, robust parameter space steering controller for yaw stability improvement of a light commercial vehicle and its testing on a hardware-in-the-loop steering test rig. A linear single track model of the light commercial vehicle is used for controller design while its nonlinear version is used during hardware-in-the-loop simulations. The multi-objective design method used here

Sinan Oncu; Sertac Karaman; Levent Guvenc; S. S. Ersolmaz; E. S. Ozturk; E. Cetin; M. Sinai

2007-01-01

365

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

Microsoft Academic Search

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

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

1983-01-01

366

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

367

Application of fleet ballistic missile components/designs for expendable launch vehicles  

NASA Astrophysics Data System (ADS)

This paper describes the orbital performance and configuration attributes of an expendable launch vehicle (ELV) derived from flight-qualified components. Representative logistical and programmatic data are also provided. The backbone of the ELV program described is the cost-effective use of proven Fleet Ballistic Missile components/designs coupled with other high confidence 'off-the-shelf' equipment. The ELV defined can place over a thousand pounds (1000 lb) of spacecraft (payload) into Low Earth Orbit.

Grizzell, Norman E.

368

Design of decimation filter for real-time signal processing of micro-air-vehicles  

Microsoft Academic Search

This paper reports a digital decimation filter chip for real-time signal processing of micro-air-vehicles (MAVs), which is composed of cascade integrator comb (CIC) filter, half-band filter and CIC compensation filter. To obtain low power, low hardware cost and efficient area, optimization was performed at behavioral level modeling and register transfer level (RTL) design. A mathematical framework was presented to perform

Ying-tao Ding; Shun-an Zhong; Jing Chen

2011-01-01

369

Achieving Efficient Designs for Energy and Power Systems of Electric Vehicles  

Microsoft Academic Search

\\u000a With the advent of the electric car as a new transport model for the twenty-first century, this paper attempts to give an\\u000a analysis of this technology and justify the need for efficient energetic designs for this kind of vehicles. It is necessary\\u000a to reach the best compromise of performance with the least waste energy possible. This is the reason why

Emilio Larrodé; Jesús Gallego; Sara Sánchez

370

Design and Implementation of a New Thermoelectric-Photovoltaic Hybrid Energy System for Hybrid Electric Vehicles  

Microsoft Academic Search

In this article, a new thermoelectric-photovoltaic hybrid energy system is proposed for hybrid electric vehicles. The key is to newly develop the multiple-input single-ended primary inductor converter to simultaneously regulate the thermoelectric and photovoltaic generators in such a way that the total output power can be maximized. Both design and implementation of the proposed system are discussed. Experimental results are

Xiaodong Zhang; K. T. Chau

2011-01-01

371

Design features of portable wheelchair ramps and their implications for curb and vehicle access.  

PubMed

This study evaluated a range of portable wheelchair ramps to highlight the effect of different product features on ease of use when wheelchair users climb curbs or access vehicles. Twelve portable ramps were evaluated. Although all the ramps were designed to load powered wheelchairs into motor vehicles, they were manufactured in different designs. The ramps were based on a "singlewide" platform or "channel" design. Some ramps had fixed dimensions, whereas others could be reduced in size because they were telescopic or designed to allow folding. Overall, the ramps could be divided into four subgroups on the basis of their key features. These were horizontally and longitudinally folding ramps, telescopic ramps, and ramps with fixed dimensions. The telescopic ramps could be subdivided into "U"-shaped gutter ramps and reverse profile ramps. Product appraisals and trials involving wheelchair users and caregivers of wheelchair users were done to evaluate each of these ramp designs. Although wheelchair ramps are available in a wide range of designs and configurations, we found that no single ramp design successfully met the needs of all wheelchair users or their caregivers. The evaluation highlighted a number of specific problems and potential hazards. Some ramps were found to move during a maneuver, showed poor stability when used with some vehicles, or were too narrow to allow wheelchair castors to pass through the channel without jamming. Some features, such as handles and locking mechanisms, influenced the ease with which the caregivers could use the ramps. Wheelchair users preferred the wide platform ramps because they were able to drive up these with ease and little preparation. The caregivers preferred folding or telescopic channel ramps because these were easier to handle and store. PMID:15543462

Storr, Tim; Spicer, Julie; Frost, Peggy; Attfield, Steve; Ward, Christopher D; Pinnington, Lorraine L

2004-05-01

372

Hybrid Vehicles.  

National Technical Information Service (NTIS)

This TOP provides standardized tests recommended for evaluating hybrid vehicles. Because of the development of hybrid propulsion techniques for military wheeled and tracked vehicles new testing procedures to assess the automotive and safety design of thes...

2008-01-01

373

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

374

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

375

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

376

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

377

NASA advanced-aeronautics design solar-powered remotely piloted vehicle  

SciTech Connect

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

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

1991-04-01

378

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

379

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

NASA Technical Reports Server (NTRS)

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

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

1973-01-01

380

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

381

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

382

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

NASA Technical Reports Server (NTRS)

A number of problems related to unmanned exploration of planets or other extraterrestrial bodies with Mars as a case in point were investigated. The design and evaluation of a prototype rover concept with emphasis on mobility, maneuverability, stability, control and propulsion is described along with the development of terrain sensor concepts and associated software for the autonomous control of any planetary rover. Results are applicable not only to the design of a mission rover but the vehicle is used as a test bed for the rigorous evaluation of alternative autonomous control systems.

Gisser, D. G.; Frederick, D. K.; Yerazunis, S. W.

1977-01-01

383

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

384

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

385

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

386

Aerodynamic characteristics of some lifting reentry concepts applicable to transatmospheric vehicle design studies  

NASA Technical Reports Server (NTRS)

The aerodynamic characteristics of some lifting reentry concepts are examined with a view to the applicability of such concepts to the design of possible transatmospheric vehicles (TAV). A considerable amount of research has been done in past years with vehicle concepts suitable for manned atmospheric-entry, atmospheric flight, and landing. Some of the features of these concepts that permit flight in or out of the atmosphere with maneuver capability should be useful in the mission requirements of TAV's. The concepts illustrated include some hypersonic-body shapes with and without variable geometry surfaces, and a blunt lifting-body configuration. The merits of these concepts relative to the aerodynamic behavior of a TAV are discussed.

Spearman, M. L.

1984-01-01

387

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

388

Integrated Hypersonic Aerothermoelastic Methodology for Transatmospheric Vehicle (TAV)/Thermal Protection System (TPS) Structural Design and Optimization.  

National Technical Information Service (NTIS)

The adaptation of ZONA unified hypersonic/supersonic method ZONA7U and its integration/development into a ZONA aerothermoelastic software system for transatmospheric vehicle (TAV)/thermal protection system (TPS) design/ analysis was proven a successful to...

D. D. Liu P. C. Chen L. Tang K. T. Chang A. Chemaly

2002-01-01

389

System Design Optimization for a MARS-Roving Vehicle and Perturbed-Optimal Solutions in Nonlinear Programming.  

National Technical Information Service (NTIS)

Work in two somewhat distinct areas is presented. First, the optimal system design problem for a Mars-roving vehicle is attacked by creating static system models and a system evaluation function and optimizing via nonlinear programming techniques. The sec...

C. Pavarini

1974-01-01

390

On-road assessment of in-vehicle driving workload for older drivers: Design guidelines for intelligent vehicles  

Microsoft Academic Search

There has been recent interest in intelligent vehicle technologies, such as advanced driver assistance systems (ADASs) or\\u000a in-vehicle information systems (IVISs), that offer a significant enhancement of safety and convenience to drivers and passengers.\\u000a However, the use of ADAS- and IVIS-based information devices may increase driver distraction and workload, which in turn can\\u000a increase the chance of traffic accidents. The

M. H. Kim; J. Son

2011-01-01

391

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

Microsoft Academic Search

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

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

2010-01-01

392

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

393

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

394

Estimation of payload loads using rigid body interface accelerations. [in structural design of launch vehicle systems  

NASA Technical Reports Server (NTRS)

In the design/analysis process of a payload structural system, the accelerations at the payload/launch vehicle interface obtained from a system analysis using a rigid payload are often used as the input forcing function to the elastic payload to obtain structural design loads. Such an analysis is at best an approximation since the elastic coupling effects are neglected. This paper develops a method wherein the launch vehicle/rigid payload interface accelerations are modified to account for the payload elasticity. The advantage of the proposed method, which is exact to the extent that the physical system can be described by a truncated set of generalized coordinates, is that the complete design/analysis process can be performed within the organization responsible for the payload design. The method requires the updating of the system normal modes to account for payload changes, but does not require a complete transient solution using the composite system model. An application to a real complex structure, the Viking Spacecraft System, is given.

Chen, J. C.; Garba, J. A.; Wada, B. K.

1978-01-01

395

Unexpected discoveries and S-invention of design requirements: important vehicles for a design process  

Microsoft Academic Search

Designers, during a conceptual design process, do not just synthesize solutions that satisfy initially given requirements, but also invent design issues or requirements that capture important aspects of the given problem. How do they do this? What becomes the impetus for the invention of important issues or requirements? So-called `unexpected discoveries', the acts of attending to visuo-spatial features in sketches

Masaki Suwa; John Gero; Terry Purcell

2000-01-01

396

Scale-model vehicle analysis for the design of a steering controller  

Microsoft Academic Search

A scale-model vehicle is developed that is dynamically similar to a full-size vehicle through application of the Buckingham-Pi theorem. Specifically, the vehicle is modified to match the corresponding Pi groups of the scale-model vehicle and the average of a number of full-size vehicles. The modifications require the mass of the vehicle and its distribution to be changed. Furthermore, an experimental

Phillip Hoblet; J. A. Piepmeier

2003-01-01

397

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

NASA Technical Reports Server (NTRS)

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

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

2010-01-01

398

An Approach to Integrated Design, Analysis and Data Management for Rapid Air Vehicle Design  

NASA Astrophysics Data System (ADS)

An integrated system based on the fusion of proven legacy system and modern PIDO technology has been developed for aircraft configuration development in conceptual and preliminary design phase of aircraft development. KAI-RAVSIM proved successfully the feasibility of new integrated configuration development system by reducing design cycle time and enhancing the design capability. KAI-RAVSIM is currently expanding to be utilized with simulation data management system.

Kim, Ji Hong

399

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

NASA Technical Reports Server (NTRS)

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

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

1994-01-01

400

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

401

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

402

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

403

Control and design of multiple unmanned air vehicles for persistent surveillance  

NASA Astrophysics Data System (ADS)

Control of multiple autonomous aircraft for search and exploration, is a topic of current research interest for applications such as weather monitoring, geographical surveys, search and rescue, tactical reconnaissance, and extra-terrestrial exploration, and the need to distribute sensing is driven by considerations of efficiency, reliability, cost and scalability. Hence, this problem has been extensively studied in the fields of controls and artificial intelligence. The task of persistent surveillance is different from a coverage/exploration problem, in that all areas need to be continuously searched, minimizing the time between visitations to each region in the target space. This distinction does not allow a straightforward application of most exploration techniques to the problem, although ideas from these methods can still be used. The use of aerial vehicles is motivated by their ability to cover larger spaces and their relative insensitivity to terrain. However, the dynamics of Unmanned Air Vehicles (UAVs) adds complexity to the control problem. Most of the work in the literature decouples the vehicle dynamics and control policies, but their interaction is particularly interesting for a surveillance mission. Stochastic environments and UAV failures further enrich the problem by requiring the control policies to be robust, and this aspect is particularly important for hardware implementations. For a persistent mission, it becomes imperative to consider the range/endurance constraints of the vehicles. The coupling of the control policy with the endurance constraints of the vehicles is an aspect that has not been sufficiently explored. Design of UAVs for desirable mission performance is also an issue of considerable significance. The use of a single monolithic optimization for such a problem has practical limitations, and decomposition-based design is a potential alternative. In this research high-level control policies are devised, that are scalable, reliable, efficient, and robust to changes in the environment. Most of the existing techniques that carry performance guarantees are not scalable or robust to changes. The scalable techniques are often heuristic in nature, resulting in lack of reliability and performance. Our policies are tested in a multi-UAV simulation environment developed for this problem, and shown to be near-optimal in spite of being completely reactive in nature. We explicitly account for the coupling between aircraft dynamics and control policies as well, and suggest modifications to improve performance under dynamic constraints. A smart refueling policy is also developed to account for limited endurance, and large performance benefits are observed. The method is based on the solution of a linear program that can be efficiently solved online in a distributed setting, unlike previous work. The Vehicle Swarm Technology Laboratory (VSTL), a hardware testbed developed at Boeing Research and Technology for evaluating swarm of UAVs, is described next and used to test the control strategy in a real-world scenario. The simplicity and robustness of the strategy allows easy implementation and near replication of the performance observed in simulation. Finally, an architecture for system-of-systems design based on Collaborative Optimization (CO) is presented. Earlier work coupling operations and design has used frameworks that make certain assumptions not valid for this problem. The efficacy of our approach is illustrated through preliminary design results, and extension to more realistic settings is also demonstrated.

Nigam, Nikhil

404

Hybrid Vehicle Simulation.  

National Technical Information Service (NTIS)

Interest in nonpetroleum fueled ground vehicles led Stafford to develop the computer code, Electric Vehicle Simulation (EVSIM). EVSIM was designed to predict the performance of current electric vehicles or to be used in the design of electric/hybrid vehic...

D. B. Founds

1983-01-01

405

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

NASA Technical Reports Server (NTRS)

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

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

1999-01-01

406

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

407

A design and characteristic analysis of the motion base for vehicle driving simulator  

Microsoft Academic Search

The main procedures of development of the motion system for a vehicle driving simulator are classified in 3 parts: 1) development of the motion base system which can be generated by the motion cues; 2) the construction of a real-time vehicle software which can afford the vehicle dynamics; and 3) the integration of vehicle driving simulator, which can be interconnected

Jung-Ha Kim; Woon-Sung Lee; Il-Kyeong Park; Kyung-Kyun Park; Jun-Hee Cho

1997-01-01

408

Design of a master device for the teleoperation of wheeled and tracked vehicles  

Microsoft Academic Search

This paper presents a novel interface for the intuitive teleoperation of wheeled and tracked vehicles. The key contributions are a new mechanism of proposed interface and matching strategies. The new mechanism not only allows human operator to easily give command to a target vehicle in teleoperation of wheeled and tracked vehicles, but also improve the operators' perception of target vehicle

Ba-Hai Nguyen; Jee-Hwan Ryu

2010-01-01

409

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

NASA Astrophysics Data System (ADS)

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

Grujicic, M.; Cheeseman, B. A.

2014-01-01

410

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

411

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

412

Design of a toy submarine using underwater vehicle design optimization framework  

Microsoft Academic Search

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

Khairul Alam; Tapabrata Ray; Sreenatha G. Anavatti

2011-01-01

413

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

NASA Technical Reports Server (NTRS)

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

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

1998-01-01

414

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

NASA Astrophysics Data System (ADS)

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

Jones, Kevin D.; Platzer, Max F.

415

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

NASA Astrophysics Data System (ADS)

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

Jones, Kevin D.; Platzer, Max F.

2009-05-01

416

A Generic Model Driven Approach for Safer Mission and Vehicle Management Software Design  

NASA Astrophysics Data System (ADS)

The purpose of a spacecraft, whether an observation or telecommunication satellite, a lander, a chaser as the ATV (Automated Transfer Vehicle) or a launcher is to perform a mission. A mission is composed of several modes, the number of modes being generally representative of the complexity of the mission assigned to the spacecraft. The Mission and Vehicle Management Software (MVMS) plays the role of an orchestra conductor that will internally control the proper behaviour of the spacecraft and all its avionics element inter-cooperation during its lifetime, and therefore the safety of the mission. The MVMS can either be one function of the main onboard software, or a fully piece of segregated software running on a dedicated processing unit or distributed on several hardware or functional nodes. This paper presents a generic design that can be used for low to medium complexity system, or, in case of highly complex systems, for the most critical MVMS functions. The design is model based oriented. SCADE Suite (from Esterel Technologies) has being selected for its very high adequacy for MVMS implementation and its capability to satisfy high safety requirements: The purpose is to make use of the autocoding facility offered by SCADE, knowing that a Criticality A (DO178B standard) certification kit is available for the generator.

Boudillet, O.; Person, T.; Genevoix, M.

2012-01-01

417

Habitability as a Tier One Criterion in Exploration Mission and Vehicle Design. Part 1; Habitability  

NASA Technical Reports Server (NTRS)

Habitability and human factors are necessary criteria to include in the iterative process of Tier I mission design. Bringing these criteria in at the first, conceptual stage of design for exploration and other human-rated missions can greatly reduce mission development costs, raise the level of efficiency and viability, and improve the chances of success. In offering a rationale for this argument, the authors give an example of how the habitability expert can contribute to early mission and vehicle architecture by defining the formal implications of a habitable vehicle, assessing the viability of units already proposed for exploration missions on the basis of these criteria, and finally, by offering an optimal set of solutions for an example mission. In this, the first of three papers, we summarize the basic factors associated with habitability, delineate their formal implications for crew accommodations in a long-duration environment, and show examples of how these principles have been applied in two projects at NASA's Johnson Space Center: the BIO-Plex test facility, and TransHab.

Adams, Constance M.; McCurdy, Matthew Riegel

1999-01-01

418

The acoustical design of vehicles-a challenge for qualitative evaluation  

NASA Astrophysics Data System (ADS)

Whenever the acoustical design of vehicles is explored, the crucial question about the appropriate method of evaluation arises. Research shows that not only acoustic but also non-acoustic parameters have a major influence on the way sounds are evaluated. Therefore, new methods of evaluation have to be implemented. Methods are needed which give the opportunity to test the quality of the given ambience and to register the effects and evaluations in their functional interdependence as well as the influence of personal and contextual factors. Moreover, new methods have to give insight into processes of evaluation and their contextual parameters. In other words, the task of evaluating acoustical ambiences consists of designating a set of social, psychological, and cultural conditions which are important to determine particular individual and collective behavior, attitudes, and also emotions relative to the given ambience. However, no specific recommendations exist yet which comprise particular descriptions of how to assess those specific sound effects. That is why there is a need to develop alternative methods of evaluation with whose help effects of acoustical ambiences can be better predicted. A method of evaluation will be presented which incorporates a new sensitive approach for the evaluation of vehicle sounds.

Schulte-Fortkamp, Brigitte; Genuit, Klaus; Fiebig, Andre

2005-09-01

419

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

420

Design and test of a situation-augmented display for an unmanned aerial vehicle monitoring task.  

PubMed

In this study, a situation-augmented display for unmanned aerial vehicle (UAV) monitoring was designed, and its effects on operator performance and mental workload were examined. The display design was augmented with the knowledge that there is an invariant flight trajectory (formed by the relationship between altitude and velocity) for every flight, from takeoff to landing. 56 participants were randomly assigned to the situation-augmented display or a conventional display condition to work on 4 (number of abnormalities) x 2 (noise level) UAV monitoring tasks three times. Results showed that the effects of situation-augmented display on flight completion time and time to detect abnormalities were robust under various workload conditions, but error rate and perceived mental workload were unaffected by the display type. Results suggest that the UAV monitoring task is extremely difficult, and that display devices providing high-level situation-awareness may improve operator monitoring performance. PMID:24422345

Lu, Jen-Li; Horng, Ruey-Yun; Chao, Chin-Jung

2013-08-01

421

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

422

Design of permanent magnet brushless motors with asymmetric air gap for electric vehicles  

NASA Astrophysics Data System (ADS)

This paper proposes a cost-effective approach to design permanent magnet brushless dc motors for electric vehicles. The key is to shape the pole arc in such a way that the air gap length is at a maximum at the leading edge of each rotor pole arc and at a minimum at the trailing edge of the same pole arc, hence resulting in an asymmetric air gap. Thus, for a specified rotational direction, the distortion of air gap flux density and hence the torque ripple can be significantly suppressed. Also, with the use of advanced conduction angle control, the motor can achieve a wide speed range. The proposed motor drive is designed and implemented for a low-voltage battery-powered electric motorcycle.

Chau, K. T.; Cui, Wei; Jiang, J. Z.; Wang, Zheng

2006-04-01

423

Conceptual Design of a Hypervelocity Asteroid Intercept Vehicle (HAIV) Flight Validation Mission  

NASA Technical Reports Server (NTRS)

In this paper we present a detailed overview of the MDL study results and subsequent advances in the design of GNC algorithms for accurate terminal guidance during hypervelocity NEO intercept. The MDL study produced a conceptual con guration of the two-body HAIV and its subsystems; a mission scenario and trajectory design for a notional flight validation mission to a selected candidate target NEO; GNC results regarding the ability of the HAIV to reliably intercept small (50 m) NEOs at hypervelocity (t