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1

Nuclear air cushion vehicles  

NASA Technical Reports Server (NTRS)

The state-of-the-art of the still-conceptual nuclear air cushion vehicle, particularly the nuclear powerplant is identified. Using mission studies and cost estimates, some of the advantages of nuclear power for large air cushion vehicles are described. The technology studies on mobile nuclear powerplants and conceptual ACV systems/missions studies are summarized.

Anderson, J. L.

1973-01-01

2

Air cushion vehicles: A briefing  

NASA Technical Reports Server (NTRS)

Experience and characteristics; the powering, uses, and implications of large air cushion vehicles (ACV); and the conceptual design and operation of a nuclear powered ACV freighter and supporting facilities are described.

Anderson, J. L.; Finnegan, P. M.

1971-01-01

3

Heave Stability of Air Cushion Vehicles Hovering over Deep Water.  

National Technical Information Service (NTIS)

The heave stability of air cushion vehicles hovering over infinitely deep water is examined theoretically. When applied to the Canadian National Research Council craft, HEX-5, the theory predicts that the volume modulation produced by the spatially averag...

M. J. Hinchey

1982-01-01

4

Heave stability of air cushion vehicles hovering over deep water  

Microsoft Academic Search

The heave stability of air cushion vehicles hovering over infinitely deep water is examined theoretically. When applied to the Canadian National Research Council craft, HEX-5, the theory predicts that the volume modulation produced by the spatially averaged deflection of the plenum water free surface would increase the stable operating region relative to overland operation. The air flow modulation produced by

M. J. Hinchey

1982-01-01

5

Heave stability of air cushion vehicles hovering over deep water  

NASA Astrophysics Data System (ADS)

The heave stability of air cushion vehicles hovering over infinitely deep water is examined theoretically. When applied to the Canadian National Research Council craft, HEX-5, the theory predicts that the volume modulation produced by the spatially averaged deflection of the plenum water free surface would increase the stable operating region relative to overland operation. The air flow modulation produced by deflection of the water free surface at the lip of the plenum on the other hand would cause unstable behavior at low cushion pressures.

Hinchey, M. J.

1982-08-01

6

Developments in skirt systems for air cushion vehicles  

NASA Astrophysics Data System (ADS)

The present evaluation of the development status of air-cushion vehicle (ACV) skirts emphasizes the materials employed, with a view to the formulation of materials-performance requirements for next-generation AVCs and, in particular, an 'air-cushion catamaran' surface-effect ship (SES). Attention is given to novel skirt-design features which furnish substantial savings in maintenance costs. The employment of extant test rig data and the use of CAD methods are discussed, and the features of a novel system for the direct fixing of a bow finger onto an SES structure are noted.

Inch, Peter; Prentice, Mark E.; Lewis, Carol Jean

7

Northwest passage: Trade route for large air cushion vehicles  

NASA Technical Reports Server (NTRS)

A conceptual vehicle and powerplant (10,000-ton) nuclear-powered air-cushion vehicle (ACV) that could open the Northwest Passage and other Arctic passages to commercial traffic is identified. The report contains a description of the conceptual vehicle, including the powerplant and operations, an assessment of technical feasibility, estimates of capital and operating costs, and identification of eligible cargo and markets. A comparison of the nuclear ACV freighter with nuclear container ships shows that for containerized or roll-on/roll-off cargo the ACV would provide greatly reduced transit time between North Atlantic and North Pacific ports at a competitive cost.

Anderson, J. L.

1973-01-01

8

Creating new cities through the large air-cushion vehicle.  

NASA Technical Reports Server (NTRS)

The air-cushion vehicle (ACV) can travel over concrete roads, grass, sand, mud, swamp, snow, ice, and water. This mobility makes possible a totally new geographical freedom in choosing transportation routes, locating ports, and laying out a city. By the 1980s fleets of large ACV freighters could begin carrying ocean-going cargo. The mobility of an ACV fleet would allow placing hoverports away from areas now crowded. New cities could rise along shallow or reef-bound seacoasts and rivers, just as cities once rose around deep-water seaports.

Anderson, J. L.; Finnegan, P. M.

1972-01-01

9

Effect of Ground Board Boundary Layer on Air Cushion Vehicle Wind Tunnel Tests.  

National Technical Information Service (NTIS)

Forward speed tests were performed on an Air Cushion Vehicle in the subsonic wind tunnel using a fixed ground board. The effect of the ground board boundary layer on the reactions of the vehicle was determined by comparing the test results with previous t...

E. K. Garay

1967-01-01

10

The Wave Resistance of an Air-Cushion Vehicle in Accelerated Motion.  

National Technical Information Service (NTIS)

The report is concerned with the theoretical wave resistance of an air-cushion vehicle (ACV) traveling over water of uniform finite or infinite depth, in steady or unsteady motion. Referring first to steady motion, it is shown that the unrealistic oscilla...

L. J. Doctors S. D. Sharma

1970-01-01

11

Test and Demonstration Prototype Tracked Air Cushion Vehicle (PTACV) - Phase IIIC.  

National Technical Information Service (NTIS)

A six year multi-phased program for design, development and test of a prototype tracked air cushion vehicle was culminated in a six month test and demonstration under Phase IIIC. Descriptions of the various major sub-systems are presented with design and ...

A. K. Smith J. Dallas L. Samusson R. Dynes R. Stott

1977-01-01

12

An Analysis of Skill Requirements for Operators of Amphibious Air Cushion Vehicles (ACVs).  

ERIC Educational Resources Information Center

This report describes the skills required in the operation of an amphibious air cushion vehicle (ACV) in Army tactical and logistic missions. The research involved analyzing ACV characteristics, operating requirements, environmental effects, and results of a simulation experiment. The analysis indicates that ACV operation is complicated by an…

McKnight, A. James; And Others

13

Feasibility report: Operation of light air cushion vehicle at McMurdo Sound, Antarctica  

NASA Astrophysics Data System (ADS)

This report explores the viability of the use of an air cushion vehicle (ACV) or hovercraft to perform logistic and scientific support in the area of McMurdo Station, Antarctica. After a review of personnel assets and facilities at McMurdo Station to support the ACV plus a reconnaissance of the five major routes selected, it appears that an air cushion vehicle in the 1 to 1 1/2 ton payload class would be of significant value to support operations. It would reduce transit times for surface vehicle traverses on the routes selected and reduce requirements for expenditure of helicopter flight time in others. Of major significance is the ability to handle passenger/shuttle requirements between the Scott Base transition and Williams Field Skiway. Use of the ACV for high frequency passenger operations would help preserve the snow road for cargo operations during periods of road deterioration.

Dibbern, J. S.

1987-02-01

14

A Preliminary Study of Actively Controlled Air Cushion Vehicle Suspensions.  

National Technical Information Service (NTIS)

The primitive vehicle suspension system coupling a simple vehicle model in point contact with a two-dimensional guideway having random irregularities is defined. The optimum linear suspension which minimizes a linear combination of vehicle heave accelerat...

D. A. Hullender D. N. Wormley H. H. Richardson

1970-01-01

15

Study of fuel economy optimization for a semi-track air-cushion vehicle based on genetic algorithms and fuzzy control  

Microsoft Academic Search

A semi-track air-cushion vehicle (STACV) which combines an air-cushion lifting system with a semi-track propulsion system is an efficient solution for heavy-duty vehicles working on soft terrain, such as the vehicles for agricultural, oil industrial and military purposes. Focusing on optimizing fuel economy of the vehicle, five main issues are studied in this paper. Firstly, based on the analyses of

Shuo Xu; Zhe Luo; Fan Yu

2008-01-01

16

A Study of Requirements, Model Configurations, and Test Plans for Air Cushion System Comparison Tests.  

National Technical Information Service (NTIS)

The Navy plans to test several models of air cushion vehicles with different cushion systems. A set of model design requirements suitable for all the models was developed by the Navy with the assistance of Bell Aerospace Textron and other contractors. The...

J. Ryken

1979-01-01

17

Air cushion landing gear applications study  

NASA Technical Reports Server (NTRS)

A series of air cushion landing gear (ACLG) applications was studied and potential benefits analyzed in order to identify the most attractive of these. The selected applications are new integrated designs (not retrofits) and employ a modified design approach with improved characteristics and performance. To aid the study, a survey of potential users was made. Applications were evaluated in the light of comments received. A technology scenario is developed, with discussion of problem areas, current technology level and future needs. Feasible development timetables are suggested. It is concluded that near-term development of small-size ACLG trunks, exploration of flight effects and braking are key items. The most attractive applications are amphibious with very large cargo aircraft and small general aviation having the greatest potential.

Earl, T. D.

1979-01-01

18

1986 CACTS International Conference on Air Cushion Technology, Toronto, Canada, Sept. 16-18, 1986, Preprints  

NASA Astrophysics Data System (ADS)

The present conference on the design and development, innovative configurational concepts, test result analyses and operational characteristics of ACVs gives attention to design criteria for light, high-speed ACVs in desert environments, preliminary over-water tests of linear propellers, tests on high speed hovercraft icebreaking, and the performance of an air cushion crawler all-terrain vehicle. Also discussed are the use of ACVs as high speed ASW vehicles, performance criteria for air cushion heave dynamics, the bounce characteristics of an ACV's responsive skirt, and the use of hovercraft in ice enforcement.

MacEwen, W. R.

19

Air-cushion tankers for Alaskan North Slope oil  

NASA Technical Reports Server (NTRS)

A concept is described for transporting oil from the Arctic to southern markets in 10,000-ton, chemically fueled air-cushion vehicles (ACV's) configured as tankers. Based on preliminary cost estimates the conceptual ACV tanker system as tailored to the transportation of Alaskan North Slope oil could deliver the oil for about the same price per barrel as the proposed trans-Alaska pipeline with only one-third of the capital investment. The report includes the description of the conceptual system and its operation; preliminary cost estimates; an appraisal of ACV tanker development; and a comparison of system costs, versatility, vulnerability, and ecological effect with those of the trans-Alaska pipeline.

Anderson, J. L.

1973-01-01

20

A new design of an alternating-pressure air cushion  

Microsoft Academic Search

In this study, a new alternating-pressure air cushion (APAC) is designed and fabricated to render, for pressure ulcer prevention, a sufficient rest for the skin tissue in contact with the user's body pressure. The APAC designed comprises six cylindrical air bags and conforms to human factors or ergonomics. The inflation\\/ deflation system adopts a microcontroller IC chip to drive the

John Yanhao Chen; Andy Wenxian Luo

2010-01-01

21

Experimental and analytical studies of advanced air cushion landing systems  

NASA Technical Reports Server (NTRS)

Several concepts are developed for air cushion landing systems (ACLS) which have the potential for improving performance characteristics (roll stiffness, heave damping, and trunk flutter), and reducing fabrication cost and complexity. After an initial screening, the following five concepts were evaluated in detail: damped trunk, filled trunk, compartmented trunk, segmented trunk, and roll feedback control. The evaluation was based on tests performed on scale models. An ACLS dynamic simulation developed earlier is updated so that it can be used to predict the performance of full-scale ACLS incorporating these refinements. The simulation was validated through scale-model tests. A full-scale ACLS based on the segmented trunk concept was fabricated and installed on the NASA ACLS test vehicle, where it is used to support advanced system development. A geometrically-scaled model (one third full scale) of the NASA test vehicle was fabricated and tested. This model, evaluated by means of a series of static and dynamic tests, is used to investigate scaling relationships between reduced and full-scale models. The analytical model developed earlier is applied to simulate both the one third scale and the full scale response.

Lee, E. G. S.; Boghani, A. B.; Captain, K. M.; Rutishauser, H. J.; Farley, H. L.; Fish, R. B.; Jeffcoat, R. L.

1981-01-01

22

DRAC (Driver Air Cushion) User's Manual, Revision B.  

National Technical Information Service (NTIS)

This manual was written to give the Potential user of the DRAC computer program the specific information he will need to: set up the input file; run the program; and interpret the results. DRAC is an acronym for DRiver Air Cushion and was written to descr...

M. Fitzpatrick

1981-01-01

23

Dynamic heave-pitch analysis of air cushion landing systems  

NASA Technical Reports Server (NTRS)

A program to develop analytical tools for evaluating the dynamic performance of Air Cushion Landing Systems (ACLS) is described. The heave (vertical) motion of the ACLS was analyzed, and the analysis was extended to cover coupled heave-pitch motions. The mathematical models developed are based on a fundamental analysis of the body dynamics and fluid mechanics of the aircraft-cushion-runway interaction. The air source characteristics, flow losses in the feeding ducts, trunk and cushion, the effects of fluid compressibility, and dynamic trunk deflections, including ground contact are considered. A computer program, based on the heave-pitch analysis, was developed to simulate the dynamic behavior of an ACLS during landing impact and taxi over an irregular runway. The program outputs include ACLS motions, loadings, pressures, and flows as a function of time. To illustrate program use, three basic types of simulations were carried out. The results provide an initial indication of ACLS performance during (1) a static drop, (2) landing impact, and (3) taxi over a runway irregularity.

Captain, K. M.; Boghani, A. B.; Wormley, D. N.

1975-01-01

24

Reduced energy and volume air pump for a seat cushion  

DOEpatents

An efficient pump system is described for transferring air between sets of bladders in a cushion. The pump system utilizes a reversible piston within a cylinder in conjunction with an equalizing valve in the piston which opens when the piston reaches the end of travel in one direction. The weight of a seated user then forces air back across the piston from an inflated bladder to the previously deflated bladder until the pressure is equalized. In this fashion the work done by the pump is cut in half. The inflation and deflation of the different bladders is controlled to vary the pressure on the several pressure points of a seated user. A principal application is for wheel chair use to prevent pressure ulcers. 12 figs.

Vaughn, M.R.; Constantineau, E.J.; Groves, G.E.

1997-08-19

25

Simulation of an Air Cushion Vehicle.  

National Technical Information Service (NTIS)

This report describes the components, architecture, and operations of the ACV-LC real-time digital simulation. The system configuration is described in detail, including the pilot station controls and displays. The mathematical model of the equations of m...

J. F. Loud

1977-01-01

26

A review on the aviation piston engine power assembly for the air cushion boat  

NASA Astrophysics Data System (ADS)

The aviation piston engine has a suitable power rating. The weight of the air cushion boat developed early was rather small, mostly ranging from 2 to 4 tons. The power rating of the air cushion boat is about 100 to 135 horsepower/ton. According to this, a single engine's power rating ranges from 200 to 500 horsepower. It is well known that this is exactly the most common power rating of an aviation piston engine (and an air-cooled diesel engine).

Jianzhang, Zhu

1986-09-01

27

Effect of a Dynamic Air Cushion on the Development of Leg Edema during Wheelchair Sitting  

PubMed Central

[Purpose] To clarify how a novel dynamic cushion affects the leg edema evoked by wheelchair sitting, we measured the changes in leg volume induced during wheelchair sitting with the dynamic air cushion or a static cushion. [Subjects and Methods] Nine healthy male subjects participated in this study. Leg edema during wheelchair sitting was evaluated with strain gauge plethysmography (the gauge was placed around the middle portion of the lower thigh). Following a period of rest, each subject was asked to sit on a wheelchair containing the dynamic cushion for 15?min. Then, the protocol was repeated with a static cushion. The angles of the knee and ankle joints were set to 90 degrees, and no footrests were used. [Results] The change in leg volume observed during sitting on the dynamic cushion (0.00 ± 0.03?mL/100?mL) was smaller than that observed during sitting on the static cushion (0.02 ± 0.02?mL/100?mL). [Conclusion] These results suggested that the dynamic cushion relieved leg edema during wheelchair sitting.

Murata, Jun; Murata, Shin; Ohyama, Michie; Kogo, Haruki; Matsubara, Shohzo

2014-01-01

28

Comprehensive Documentation of Driver (DRACR) (Driver Air Cushion - Rotation) and Passenger (PAC) (Passenger Air Cushion) Computer Models.  

National Technical Information Service (NTIS)

This manual is written to give the user of the DRACR computer model the specific information he will need to set up the input file, run the program, and interpret the results. This model describes the interaction between the driver of a vehicle and an air...

M. U. Fitzpatrick

1982-01-01

29

Heave instabilities of amphibious air cushion suspension systems  

NASA Astrophysics Data System (ADS)

Attempts to ascertain the accuracy with which analytical models can be used to predict the onset of heave instabilities are described with emphasis on relatively simple configurations in which important effects are uncoupled. For the basic element of multicell systems, even relatively short supply ducting can have a very large effect, especially at low flows or hover-gaps where the duct-cushion system tends to behave as a Helmholtz resonator. For loop and segment systems, it is concluded that duct effects would be small. Internal flow effects associated with jets and vortices within the basic cushion volume are shown to be relatively unimportant at practical flow rates, although they are important at very high flow rates. Nonlinear phenomena, and procedures for controlling or quenching limit cycle amplitudes are explored. Suggestions for future work are included.

Hinchey, M. J.

1980-11-01

30

Experimental Investigation of Air Cushion Flutter Using a Two- Dimensional Trunk Model.  

National Technical Information Service (NTIS)

This program was an in-house project, to test the effectiveness of flutter control elements on an air cushion trunk. A single inelastic trunk carcass was used throughout the program. Individual elements were added to change the stiffness or mass of the fa...

P. C. Vorum

1984-01-01

31

Control systems for platform landings cushioned by air bags  

NASA Astrophysics Data System (ADS)

This report presents an exploratory mathematical study of control systems for airdrop platform landings cushioned by airbags. The basic theory of airbags is reviewed and solutions to special cases are noted. A computer program is presented, which calculates the time-dependence of the principal variables during a landing under the action of various control systems. Two existing control systems of open-loop type are compared with a conceptual feedback (closed-loop) system for a fairly typical set of landing conditions. The feedback controller is shown to have performance much superior to the other systems. The feedback system undergoes an interesting oscillation not present in the other systems, the source of which is investigated. Recommendations for future work are included.

Ross, Edward W.

1987-07-01

32

Inflation pressure effect on performance of air-filled wheelchair cushions.  

PubMed

Air-filled wheelchair cushions are frequently used in the prevention of pressure sores. Their effectiveness in reducing interface pressures and in redistributing body weight (BW) appears dependent on their internal inflation pressure. This pilot study examines and defines this relationship. Interface pressures were measured with the TIPE (Texas Interface Pressure Evaluator) system for 14 subjects while sitting on each of three commercially available air-filled wheelchair cushions. This relationship between interface pressure and internal pressure was then determined for each of the three body-build categories. In each category the interface pressure displayed a higher degree of sensitivity to underinflation than to overinflation. A high correlation found between BW and internal air pressure (IAP), may be useful in the design of a customized pressure indicator system. The study documents the influence of IAP on seating pressure and supports the need for further research in the development of an indicator system that alerts users to under- or overinflation of the cushion. PMID:3954563

Krouskop, T A; Williams, R; Noble, P; Brown, J

1986-02-01

33

Speed control with end cushion for high speed air cylinder  

DOEpatents

A high speed air cylinder in which the longitudinal movement of the piston within the air cylinder tube is controlled by pressurizing the air cylinder tube on the accelerating side of the piston and releasing pressure at a controlled rate on the decelerating side of the piston. The invention also includes a method for determining the pressure required on both the accelerating and decelerating sides of the piston to move the piston with a given load through a predetermined distance at the desired velocity, bringing the piston to rest safely without piston bounce at the end of its complete stroke.

Stevens, Wayne W. (Idaho Falls, ID); Solbrig, Charles W. (Idaho Falls, ID)

1991-01-01

34

Heave-pitch-roll analysis and testing of air cushion landing systems  

NASA Technical Reports Server (NTRS)

The analytical tools (analysis and computer simulation) needed to explain and predict the dynamic operation of air cushion landing systems (ACLS) is described. The following tasks were performed: the development of improved analytical models for the fan and the trunk; formulation of a heave pitch roll analysis for the complete ACLS; development of a general purpose computer simulation to evaluate landing and taxi performance of an ACLS equipped aircraft; and the verification and refinement of the analysis by comparison with test data obtained through lab testing of a prototype cushion. Demonstration of simulation capabilities through typical landing and taxi simulation of an ACLS aircraft are given. Initial results show that fan dynamics have a major effect on system performance. Comparison with lab test data (zero forward speed) indicates that the analysis can predict most of the key static and dynamic parameters (pressure, deflection, acceleration, etc.) within a margin of a 10 to 25 percent.

Boghani, A. B.; Captain, K. M.; Wormley, D. N.

1978-01-01

35

Air Vehicle Path Planning.  

National Technical Information Service (NTIS)

This dissertation explores optimal path planning for air vehicles. An air vehicle exposed to illumination by a tracking radar is considered and the problem of determining an optimal planar trajectory connecting two prespecified points is addressed. An ana...

J. M. Hebert

2001-01-01

36

Numerical simulation of the flow in a conduit, in the presence of a confined air cushion  

NASA Astrophysics Data System (ADS)

A rectangular conduit with a closed end has water flowing in/out at the other end. The water level at the open end has an imposed sinusoidal movement. When this level is higher than the ceiling of the conduit, a certain mass of air is trapped under the ceiling. In a previous article (T.D. Nguyen, La Houille Blanche, No. 2, 1990), it was supposed that this air is flowing out freely through the ceiling, so the relative pressure at the water surface is zero, and the water hammer at the dead end of the conduit was calculated when the conduit was thoroughly filled. In this article, it is supposed that the trapped air is compressed isothermally or adiabatically. The set of equations is resolved (water continuity and movement equations, air state equation) by supposing a regime of flow at each section (section submerged or not), a certain value for the air pressure and by using the sweep method to determine the water flow characteristics. The air volume calculated by iteration must converge, and the calculated regimes at each section (submerged or free) must agree with the supposed regimes. The simulation is performed first with a horizontal conduit then with an inclined conduit. As expected, adiabatic compression gives higher pressure than isothermal compression. The simulation shows also that when there is an air cushion, compared with the case when air is flowing out freely, the shock of the water hammer at the closed end of the conduit is significantly reduced. This method is aimed at calculating the flow with entrapped air in the inlet/outlet tunnel of a hydroelectric plant, or in sewer system pipe when a sudden discharge surge (due to turbin opening/closing or to urban storm) changes a previously free-surface flow in a mostly full-pipe flow, but with some air entrapped under the ceiling. Copyright

Nguyen, Trieu Dong

1999-02-01

37

Effect of a responsive skirt on air cushion vehicle seakeeping  

Microsoft Academic Search

The skirt system, which will be excited to make a response motion under the outer disturbance, is treated as a passive control system, and the longitudinal motion equations of ACV are derived according to the control principle. The influence of the skirt response in waves on ACVs seaworthiness is analyzed in the paper. Some results are gotten that the greater

W. L. Zhou; T. Ma

1985-01-01

38

Effect of a responsive skirt on air cushion vehicle seakeeping  

NASA Astrophysics Data System (ADS)

The skirt system, which will be excited to make a response motion under the outer disturbance, is treated as a passive control system, and the longitudinal motion equations of ACV are derived according to the control principle. The influence of the skirt response in waves on ACVs seaworthiness is analyzed in the paper. Some results are gotten that the greater vertical deflexion of skirt will make the response of heave, pitch motion and acceleration of the craft decreased a lot, but the horizontal deflexion will go the opposite way. The natural frequency of skirt plays an important role in seaworthiness improvement, the adoption of lower frequency skirt can make the frequency band of craft motion response narrower effectively. The matching of skirt parameters of bow and stern has a certain effect too.

Zhou, W. L.; Ma, T.

39

1985 Joint International Conference on Air Cushion Technology, Rockville, MD, September 24-26, 1985, Preprints and Late Papers  

NASA Astrophysics Data System (ADS)

Papers are presented on the effect of a resonant skirt on ACV seakeeping, aerodynamic characteristics of a bag-cone skirt, and a calculation of the static forces acting on ACV bag-finger skirts. Also considered are tactical problems relating to the hovercraft application of marine gas turbines, development of the Air Cushion Equipment Transporter, prevention of propeller Foreign Object Damage, and air propellers and their environmental problems on ACVs. Other topics include the maneuvering simulation of an Antarctic hovercraft, computer-aided conceptual design of air ACVs, the use of model-test data for predicting full-scale ACV resistance, and passive control of air cushion heave dynamics. Papers are also presented on hovercraft in low enforcement, managing LCAC in the evolving acquisition environment, and SES and ACV for naval mission.

Amyot, J. R.

1985-12-01

40

Air Cushioned Landing Craft (LCAC) Based Ship to Shore Movement Simulation: A Decision Aid for the Amphibious Commander. A (SMMAT) Application.  

National Technical Information Service (NTIS)

Amphibious forces are the enabling force of choice to globally project rapid and sustainable combat power in the littoral. Whether delivering supplies and equipment for military operations or for humanitarian or disaster relief, the Air Cushioned Landing ...

E. P. Kearns

1994-01-01

41

A Comparative Study Between an Improved Novel Air-Cushion Sensor and a Wheeled Probe for Minimally Invasive Surgery  

PubMed Central

Abstract Purpose We describe a comparative study between an enhanced air-cushion tactile sensor and a wheeled indentation probe. These laparoscopic tools are designed to rapidly locate soft-tissue abnormalities during minimally invasive surgery (MIS). Materials and Methods The air-cushion tactile sensor consists of an optically based sensor with a 7.8?mm sphere “floating” on a cushion of air at the tip of a shaft. The wheeled indentation probe is a 10?mm wide and 5?mm in diameter wheel mounted to a force/torque sensor. A continuous rolling indentation technique is used to pass the sensors over the soft-tissue surfaces. The variations in stiffness of the viscoelastic materials that are detected during the rolling indentations are illustrated by stiffness maps that can be used for tissue diagnosis. The probes were tested by having to detect four embedded nodules in a silicone phantom. Each probe was attached to a robotic manipulator and rolled over the silicone phantom in parallel paths. The readings of each probe collected during the process of rolling indentation were used to achieve the final results. Results The results show that both sensors reliably detected the areas of variable stiffness by accurately identifying the location of each nodule. These are illustrated in the form of two three-dimensional spatiomechanical maps. Conclusions These probes have the potential to be used in MIS because they could provide surgeons with information on the mechanical properties of soft tissue, consequently enhancing the reduction in haptic feedback.

Challacombe, Benjamin; Li, Jichun; Seneviratne, Lakmal; Althoefer, Kaspar; Dasgupta, Prokar; Murphy, Declan

2010-01-01

42

Static and Drop Tests of a Quarter Scale Model of the CC-115 Aircraft Equipped with an Air Cushion Landing System.  

National Technical Information Service (NTIS)

Static load deflection tests and vertical drop tests were performed on a quarter scale model of a Canadian CC-115 (Buffalo) aircraft equipped with an Air Cushion Landing System (ACLS). The model weighed 610 lbs and the ACLS air supply was furnished by two...

J. C. Vaughn S. Campbell D. J. Pool

1972-01-01

43

Calibration of an Axial Fan at Various Power Settings for Use on a Quarter Scale XC-8A Air Cushion Model.  

National Technical Information Service (NTIS)

A method was developed to measure volume flow from electrically powered fans during model testing of a dynamically scaled, quarter-scale XC-8A air cushion model. To measure the volume flow during model operation, the static pressure at a point along the f...

D. L. Fischer

1980-01-01

44

Wheelchair Seat Cushion Guide.  

National Technical Information Service (NTIS)

The Guide includes extensive information about wheelchair cushions from choosing the correct size cushion to skin breakdown and other seating issues. Of particular use might be the patient evaluation checklist and seat cushion selection algorithm. Informa...

C. M. Gilker

1994-01-01

45

Vantage (trademark) Unmanned Air Vehicle.  

National Technical Information Service (NTIS)

The Vehicle Research Section (VRS) at the Naval Research Laboratory (NRL) in Washington, DC, has been developing airborne unmanned air platforms to support electronic warfare (EW) and intelligence, surveillance, and reconnaissance (ISR) missions for over ...

J. R. Southwick

2008-01-01

46

Foam Cushioning  

NASA Technical Reports Server (NTRS)

One innovation developed by a contractor at Ames Research Center was an open cell polymeric foam material with unusual properties. Intended as padding for aircraft seats the material offered better impact protection against accidents, and also enhanced passenger comfort because it distributed body weight evenly over the entire contact area. Called a slow springback foam, it flows to match the contour of the body pressing against it, and returns to its original shape once the pressure is removed. It has many applications including aircraft cushions and padding, dental stools, and athletic equipment. Now it's used by Dynamic Systems, Inc. for medical applications such as wheel chairs for severely disabled people which allow them to sit for 3-8 hours where they used to be uncomfortable in 15-30 minutes.

1988-01-01

47

THE NRL MITE AIR VEHICLE  

Microsoft Academic Search

Micro Air Vehicles (MAVs) offer the promise of affordably expendable, covert sensor platforms for a range of close-in situational awareness activities. Since 1996, the US Naval Research Laboratory (NRL) has been developing technologies that will enable Navy-relevant missions with the smallest practical MAVs. This effort includes the development and integration of sensors, avionics, and advanced intelligent autopilots for flight control,

James Kellogg; Christopher Bovais; Jill Dahlburg; Richard Foch; John Gardner; Adam Sciambi; William Spears; Donald Srull; Carol Sullivan

2001-01-01

48

Compressed air propulsion system for a vehicle  

Microsoft Academic Search

A compressed air propulsion system for a vehicle is described which consists of: an engine including cylinders reciprocatingly receiving therein a respective plurality of pistons, and an exhaust means connected to the cylinders, the engine drivingly connected to an axle of the vehicle to propel the vehicle; a transaxle operatively mounted on and rotatably driven by the vehicle; air compressing

Johnson

1986-01-01

49

Modification of an Aquila Unmanned Air Vehicle.  

National Technical Information Service (NTIS)

The requirement exists at the Naval Postgraduate School Unmanned Air Vehicle Laboratory for an air vehicle capable of carrying a 60 pound payload. To that end, an air vehicle from the canceled Army Aquila program was modified to become the payload carrier...

J. E. Stewart

1995-01-01

50

System safety engineering in the development of advanced surface transportation vehicles  

NASA Technical Reports Server (NTRS)

Applications of system safety engineering to the development of advanced surface transportation vehicles are described. As a pertinent example, the paper describes a safety engineering efforts tailored to the particular design and test requirements of the Tracked Air Cushion Research Vehicle (TACRV). The test results obtained from this unique research vehicle provide significant design data directly applicable to the development of future tracked air cushion vehicles that will carry passengers in comfort and safety at speeds up to 300 miles per hour.

Arnzen, H. E.

1971-01-01

51

Intelligence Applied to Air Vehicles  

NASA Technical Reports Server (NTRS)

The exponential growth in information technology has provided the potential for air vehicle capabilities that were previously unavailable to mission and vehicle designers. The increasing capabilities of computer hardware and software, including new developments such as neural networks, provide a new balance of work between humans and machines. This paper will describe several NASA projects, and review results and conclusions from ground and flight investigations where vehicle intelligence was developed and applied to aeronautical and space systems. In the first example, flight results from a neural network flight control demonstration will be reviewed. Using, a highly-modified F-15 aircraft, a NASA/Dryden experimental flight test program has demonstrated how the neural network software can correctly identify and respond to changes in aircraft stability and control characteristics. Using its on-line learning capability, the neural net software would identify that something in the vehicle has changed, then reconfigure the flight control computer system to adapt to those changes. The results of the Remote Agent software project will be presented. This capability will reduce the cost of future spacecraft operations as computers become "thinking" partners along with humans. In addition, the paper will describe the objectives and plans for the autonomous airplane program and the autonomous rotorcraft project. Technologies will also be developed.

Rosen, Robert; Gross, Anthony R.; Fletcher, L. Skip; Zornetzer, Steven (Technical Monitor)

2000-01-01

52

Operation of an Untethered, Unmanned Air Vehicle.  

National Technical Information Service (NTIS)

The goal of the Avionics lab at the Naval Postgraduate School is to develop an unmanned air vehicle that can be mass produced frugally with items readily available in the commercial marketplace. The Archytas vehicle under concurrent production and develop...

M. G. Hakun

1995-01-01

53

Aeroelastic Fixed Wing Micro Air Vehicle  

NASA Technical Reports Server (NTRS)

Wind tunnel testing of the University of Florida Aeroelastic Fixed Wing Micro Air Vehicle, biologically inspired flight systems. Photographed in building 1214, Basic Aerodynamics Research Tunnel (BART).

2000-01-01

54

Friction brake cushions acceleration and vibration loads  

NASA Technical Reports Server (NTRS)

Friction brake cushions an object in a vehicle from axially applied vibration and steady-state acceleration forces. The brake incorporates a doubly tapered piston that applies a controlled radial force to friction brake segments bearing against the walls of a cylinder.

Fraser, G. F.; Zawadski, G. Z.

1966-01-01

55

Enabling Technologies for Nano Air Vehicles.  

National Technical Information Service (NTIS)

This project investigated several areas with the aim of improving performance and operational use of nano air vehicles (NAVs) by understanding fundamental operating principles and developing key technologies. The project developed plasma actuators for thr...

J. D. Jacob

2009-01-01

56

Intelligent Unmanned Air Vehicle Flight Systems  

Microsoft Academic Search

This paper describes an intelligent autonomous airborne flight capability that is being used as a test bed for future technology development. The unmanned air vehicles (UAVs) fly under autonomous control of both an onboard computer and an autopilot. The onboard computer provides the mission control and runs the autonomous Intelligent Controller (IC) software while the autopilot controls the vehicle navigation

Jodi A. Miller; Paul D. Minear; Albert F. Niessner; Anthony M. DeLullo; Brian R. Geiger; Lyle N. Long; Joseph F. Horn

2007-01-01

57

Cooperative Control for Autonomous Air Vehicles  

Microsoft Academic Search

The main objective of this research is to develop and evaluate the performance of strategies for cooperative control of autonomous\\u000a air vehicles that seek to gather information about a dynamic target environment, evade threats, and coordinate strikes against\\u000a targets. The air vehicles are equipped with sensors to view a limited region of the environment they are visiting, and are\\u000a able

Kevin Passino; Marios Polycarpou; David Jacques; Meir Pachter; Yang Liu; Yanli Yang; Matt Flint; Michael Baum

58

Zinc air battery development for electric vehicles  

Microsoft Academic Search

This report summarizes the results of research conducted during the sixteen month continuation of a program to develop rechargeable zinc-air batteries for electric vehicles. The zinc-air technology under development incorporates a metal foam substrate for the zinc electrode, with flow of electrolyte through the foam during battery operation. In this 'soluble' zinc electrode the zincate discharge product dissolves completely in

R. A. Putt; G. W. Merry

1991-01-01

59

Aluminum-air batteries for vehicles  

Microsoft Academic Search

The aluminum-air battery is an advanced electrochemical energy source in the early stages of development. The battery is potentially capable of providing an electric vehicle with the range, acceleration, and rapid refueling capability of today's automobile. The Lawrence Livermore National Laboratory leads this DOE-funded program with a major part of the research being conducted by industrial laboratories. Peak cell energy

E. Behrin; J. F. Cooper

1981-01-01

60

Zinc air battery development for electric vehicles  

Microsoft Academic Search

This document reports the progress and accomplishments of a 16 month program to develop a rechargeable zinc-air battery for electric vehicle propulsion, from October 1988 through January 1990. The program was the first stage in the transition of alkaline zinc electrode technology, invented at Lawrence Berkeley Laboratory, to private industry. The LBL invention teaches the use of a copper metal

Ronald A. Putt

1990-01-01

61

Optimal Trajectories for an Unmanned Air Vehicle.  

National Technical Information Service (NTIS)

Time-optimal trajectories for the Delilah Unmanned Air Vehicle (UAV) were studied. Delilah is a 400-lb, turbojet-powered decoy carrying active and passive radio-frequency (RF) payloads; its dash speed is 770 kt and its flight ceiling is 30,000 ft. The Pon...

J. Z. Ben-Asher

1990-01-01

62

Nano Air Vehicles: A Technology Forecast.  

National Technical Information Service (NTIS)

This paper documents the result of a future technology forecast study to determine when operationally useful nano-air vehicles (NAVs) will be achieved. This was accomplished as part of the Blue Horizons Research Team tasked by the Chief of Staff of the Un...

W. A. Davis

2007-01-01

63

Analysis for SNF Multi Canister Overpack (MCO) Drop into the Cask from the MCO Handling Machine (MHM) with Air Cushion  

SciTech Connect

The purpose of this report is to investigate the potential for damage to the MCO during impact from an accidental drop from the MHM into the shipping cask. The MCO is dropped from a height of 8.2 feet above the cask enters the cask concentrically and falls the additional 12.83 feet to the cask bottom. Because of the interface fit between the MCO and the cask and the air entrapment the MCO fall velocity is slowed. The shipping cask is resting on an impact absorber at the time of impact. The energy absorbing properties of the impact absorber are included in this analysis.

RAINS, D.J.

2000-01-12

64

Motor Vehicles, Air Pollution, and Climate Change  

NASA Astrophysics Data System (ADS)

Despite years of technical progress, motor vehicles continue to be a leading cause of environmental damage in the United States. For example, today's cars and trucks are the largest source of air pollution in many urban areas. US motor vehicles also account for 25 percent of the nation's carbon emissions, more than most countries emit from all sources combined. Fortunately, a host of technical improvements are emerging that could go a long ways towards taking vehicles out of the pollution picture. In the near-term, improving on the century-old internal combustion engine can deliver much-needed incremental gains. But electric drive vehicles--whether powered by batteries, small engines in hybrid configuration, or fuel cells--ultimately offer the greatest promise. Such technologies could dramatically reduce energy use, greenhouse gas emissions, and key air pollutants. The bulk of technical attention in recent years has been focused on improving the passenger vehicle, which will be the dominant energy consumer in the transportation sector for years to come. But freight trucks are also of growing concern, both because their contribution to global warming is on the rise and because serious questions are being raised about the public health impact of diesel technology. As a result, heavy trucks are emerging as a priority issue. Capitalizing on the opportunity presented by new technologies will not only require continued technical innovation but also policy action. As research into improved engines, fuels, and drive systems bears fruit over the coming years, aggressive and prudent policies will ensure that these new options make it onto the road and deliver on their environmental promise.

Mark, Jason

2000-04-01

65

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

66

Adsorption air conditioner for electric vehicle applications. Revision 1.  

National Technical Information Service (NTIS)

This paper shows an analysis of the applicability of an adsorption system for electric vehicle (EV) air conditioning. Adsorption systems are designed and optimized to provide the required cooling for four combinations of vehicle characteristics and drivin...

S. M. Aceves

1994-01-01

67

Nonlinear dynamics of biomimetic micro air vehicles  

NASA Astrophysics Data System (ADS)

Flapping-wing micro air vehicles (FMAV) are new conceptual air vehicles that mimic the flying modes of birds and insects. They surpass the research fields of traditional airplane design and aerodynamics on application technologies, and initiate the applications of MEMS technologies on aviation fields. This paper studies a micro flapping mechanism that based upon insect thorax and actuated by electrostatic force. Because there are strong nonlinear coupling between the two physical domains, electrical and mechanical, the static and dynamic characteristics of this system are very complicated. Firstly, the nonlinear dynamic model of the electromechanical coupling system is set up according to the physical model of the flapping mechanism. The dynamic response of the system in constant voltage is studied by numerical method. Then the effect of damping and initial condition on dynamic characteristics of the system is analyzed in phase space. In addition, the dynamic responses of the system in sine voltage excitation are discussed. The results of research are helpful to the design, fabrication and application of the micro flapping mechanism of FMAV, and also to other micro electromechanical system that actuated by electrostatic force.

Hou, Y.; Kong, J.

2008-02-01

68

Zinc air battery development for electric vehicles. Final report.  

National Technical Information Service (NTIS)

This report summarizes the results of research conducted during the sixteen month continuation of a program to develop rechargeable zinc-air batteries for electric vehicles. The zinc-air technology under development incorporates a metal foam substrate for...

R. A. Putt G. W. Merry

1991-01-01

69

Zinc air battery development for electric vehicles  

NASA Astrophysics Data System (ADS)

This report summarizes the results of research conducted during the sixteen month continuation of a program to develop rechargeable zinc-air batteries for electric vehicles. The zinc-air technology under development incorporates a metal foam substrate for the zinc electrode, with flow of electrolyte through the foam during battery operation. In this 'soluble' zinc electrode the zincate discharge product dissolves completely in the electrolyte stream. Cycle testing at Lawrence Berkeley Laboratory, where the electrode was invented, and at MATSI showed that this approach avoids the zinc electrode shape change phenomenon. Further, electrolyte flow has been shown to be necessary to achieve significant cycle life (greater than 25 cycles) in this open system. Without it, water loss through the oxygen electrode results in high resistance failure of the cell. The Phase 1 program, which focused entirely on the zinc electrode, elucidated the conditions necessary to increase electrode capacity from 75 to as much as 300 mAh/sq cm. By the end of the Phase 1 program over 500 cycles had accrued on one of the zinc-zinc half cells undergoing continuous cycle testing. The Phase 2 program continued the half cell cycle testing and separator development, further refined the foam preplate process, and launched into performance and cycle life testing of zinc-air cells.

Putt, R. A.; Merry, G. W.

1991-07-01

70

Zinc air battery development for electric vehicles  

SciTech Connect

This report summarizes the results of research conducted during the sixteen month continuation of a program to develop rechargeable zinc-air batteries for electric vehicles. The zinc-air technology under development incorporates a metal foam substrate for the zinc electrode, with flow of electrolyte through the foam during battery operation. In this soluble'' zinc electrode the zincate discharge product dissolves completely in the electrolyte stream. Cycle testing at Lawrence Berkeley Laboratory, where the electrode was invented, and at MATSI showed that this approach avoids the zinc electrode shape change phenomenon. Further, electrolyte flow has been shown to be necessary to achieve significant cycle life (> 25 cycles) in this open system. Without it, water loss through the oxygen electrode results in high-resistance failure of the cell. The Phase I program, which focused entirely on the zinc electrode, elucidated the conditions necessary to increase electrode capacity from 75 to as much as 300 mAh/cm{sup 2}. By the end of the Phase I program over 500 cycles had accrued on one of the zinc-zinc half cells undergoing continuous cycle testing. The Phase II program continued the half cell cycle testing and separator development, further refined the foam preplate process, and launched into performance and cycle life testing of zinc-air cells.

Putt, R.A.; Merry, G.W. (MATSI, Inc., Atlanta, GA (United States))

1991-07-01

71

Evaluation of 'Sorbothane' Cushioning Material.  

National Technical Information Service (NTIS)

Sorbothane, a high density polyurethane material with unusual displacement properties, is presently used extensively as a cushioning material for the human body in medical and sporting applications. This study was undertaken to consider possible packaging...

M. T. Wyderski

1984-01-01

72

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

73

Air-Conditioning for Electric Vehicles  

NASA Technical Reports Server (NTRS)

Combination of ammonia-absorption refrigerator, roof-mounted solar collectors, and 200 degrees C service electric-vehicle motor provides evaporative space-heating/space cooling system for electric-powered and hybrid fuel/electric vehicles.

Popinski, Z.

1984-01-01

74

Zinc air battery development for electric vehicles  

NASA Astrophysics Data System (ADS)

This document reports the progress and accomplishments of a 16 month program to develop a rechargeable zinc-air battery for electric vehicle propulsion, from October 1988 through January 1990. The program was the first stage in the transition of alkaline zinc electrode technology, invented at Lawrence Berkeley Laboratory, to private industry. The LBL invention teaches the use of a copper metal foam substrate for the zinc electrode, in combination with forced convection of electrolyte through the foam during battery operation. Research at LBL showed promise that this approach would avoid shape change (densification and dendrite growth), the primary failure mode of this electrode. The program comprised five tasks: (1) cell design, (2) capacity maximization, (3) cycle testing, (4) materials qualification, and (5) a cost/design study. The cell design contemplates a plate and frame stack, with alternating zinc and oxygen electrode frame assemblies between rigid end plates. A 200 Ah cell, as may be required for the EV application, would comprise a stack of five zinc and six oxygen electrode frame/assemblies.

Putt, Ronald A.

1990-05-01

75

Performance Analysis of 'Star' Pack Cushion Inserts.  

National Technical Information Service (NTIS)

The objectives of the study were two-fold: (1) Modify 'Star' pack cushion inserts to provide more uniform cushioning protection and most cost effective pack; and (2) determine adequacy of previously published 'Star' pack performance data for representing ...

R. V. Brown

1974-01-01

76

Interior view Beale Air Force Base, Perimeter Acquisition Vehicle ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Interior view - Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Satellite Communications Terminal, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

77

On-Line Trajectory Optimization for Autonomous Air Vehicles.  

National Technical Information Service (NTIS)

Successful operation of next-generation unmanned air vehicles will demand a high level of autonomy. Autonomous low-level operation in a complex environment dictates a need for onboard, robust, reliable and efficient trajectory optimization. In this report...

B. Yang E. Johnson J. E. Corban S. Twigg T. Ries

2007-01-01

78

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

79

Looking north Beale Air Force Base, Perimeter Acquisition Vehicle ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Looking north - Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Electric Substation, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

80

Motor Vehicle Emissions Control. Book Two. Thermostatic Air Cleaner Systems.  

National Technical Information Service (NTIS)

The next emissions control system we will examine is the Thermostatic Air Cleaner system, abbreviated TAC. The TAC system helps in controlling auto emissions and also increases vehicle performance and driveability. This book contains: Introduction to emis...

B. D. Hayes M. T. Maness R. A. Ragazzi R. A. Barrett

1977-01-01

81

Gust Mitigation of Micro Air Vehicles Using Passive Articulated Wings  

PubMed Central

Birds and insects naturally use passive flexing of their wings to augment their stability in uncertain aerodynamic environments. In a similar manner, micro air vehicle designers have been investigating using wing articulation to take advantage of this phenomenon. The result is a class of articulated micro air vehicles where artificial passive joints are designed into the lifting surfaces. In order to analyze how passive articulation affects performance of micro air vehicles in gusty environments, an efficient 8 degree-of-freedom model is developed. Experimental validation of the proposed mathematical model was accomplished using flight test data of an articulated micro air vehicle obtained from a high resolution indoor tracking facility. Analytical investigation of the gust alleviation properties of the articulated micro air vehicle model was carried out using simulations with varying crosswind gust magnitudes. Simulations show that passive articulation in micro air vehicles can increase their robustness to gusts within a range of joint compliance. It is also shown that if articulation joints are made too compliant that gust mitigation performance is degraded when compared to a rigid system.

Slegers, Nathan

2014-01-01

82

Gust mitigation of micro air vehicles using passive articulated wings.  

PubMed

Birds and insects naturally use passive flexing of their wings to augment their stability in uncertain aerodynamic environments. In a similar manner, micro air vehicle designers have been investigating using wing articulation to take advantage of this phenomenon. The result is a class of articulated micro air vehicles where artificial passive joints are designed into the lifting surfaces. In order to analyze how passive articulation affects performance of micro air vehicles in gusty environments, an efficient 8 degree-of-freedom model is developed. Experimental validation of the proposed mathematical model was accomplished using flight test data of an articulated micro air vehicle obtained from a high resolution indoor tracking facility. Analytical investigation of the gust alleviation properties of the articulated micro air vehicle model was carried out using simulations with varying crosswind gust magnitudes. Simulations show that passive articulation in micro air vehicles can increase their robustness to gusts within a range of joint compliance. It is also shown that if articulation joints are made too compliant that gust mitigation performance is degraded when compared to a rigid system. PMID:24516368

Oduyela, Adetunji; Slegers, Nathan

2014-01-01

83

Honeywell's organic air vehicle chemical-biological sensing platform  

NASA Astrophysics Data System (ADS)

Unmanned air vehicles (UAVs) today are mostly used for reconnaissance and sometimes weapons delivery. Remote sensing of chemical-biological (CB) agents is another beneficial use of UAVs. While remote sensing of CB agents can be done by LIDAR spectroscopy, this technology is less spatially precise and less sensitive than actual measurements on a collected sample. One family of UAVs of particularly unique benefit for CB sampling and in-flight analysis is the Honeywell family of Organic Air Vehicles (OAVs). This vehicle with its ability to hover and stare has the unique ability among UAVs to collect and analyze chem-bio samples from a specific location over extended periods of time. Such collections are not possible with other micro-air-vehicles (MAVs) that only operate in fly-by mode. This paper describes some of the Honeywell OAV features that are conducive to CB detection.

Cole, Barry E.; Krafthefer, Brian; Knee, Daniel; Fulton, Vaughn M.; Law, Kristen

2004-12-01

84

Missions and vehicle concepts for modern, propelled, lighter-than-air vehicles  

NASA Technical Reports Server (NTRS)

The results of studies conducted over the last 15 years to assess missions and vehicle concepts for modern, propelled, lighter-than-air vehicles (airships) were surveyed. Rigid and non-rigid airship concepts are considered. The use of airships for ocean patrol and surveillance is discussed along with vertical heavy lift airships. Military and civilian needs for high altitude platforms are addressed.

Ardema, M. D.

1984-01-01

85

Zinc air battery development for electric vehicles. Final report  

Microsoft Academic Search

This report summarizes the results of research conducted during the sixteen month continuation of a program to develop rechargeable zinc-air batteries for electric vehicles. The zinc-air technology under development incorporates a metal foam substrate for the zinc electrode, with flow of electrolyte through the foam during battery operation. In this ``soluble`` zinc electrode the zincate discharge product dissolves completely in

R. A. Putt; G. W. Merry

1991-01-01

86

Dioxin-receptor Ligands in Urban Air and Vehicle Exhaust  

Microsoft Academic Search

The ability of extracts of urban air and vehicle exhaust particulates to bind to the dioxin receptor has been determined. It was shown that such extracts do contain significant amounts of dioxin-receptor binding activity. The level of dioxin-receptor binding found in ambient air reflects its pollution level as determined by mutagenic activity. Furthermore, it was shown that the extracts of

Grant G. F. Mason

87

Flexible Wing Base Micro Aerial Vehicles: Assessment of Controllability of Micro Air Vehicles  

NASA Technical Reports Server (NTRS)

In the last several years, we have developed unique types of micro air vehicles that utilize flexible structures and extensible covering materials. These MAVs can be operated with maximum dimensions as small as 6 inches and carry reasonable payloads, such as video cameras and transmitters. We recently demonstrated the potential of these vehicles by winning the Fourth International Micro Air Vehicle Competition, held at Ft. Huachucha, Arizona in May 2000. The pilots report that these vehicles have unusually smooth flying characteristics and are relatively easy to fly, both in the standard RC mode and "through the camera" when at greater distances. In comparison, they find that similar sized vehicles with more conventional rigid construction require much more input from the pilot just to maintain control. To make these subjective observations more quantitative, we have devised a system that can conveniently record a complete history of all the RC transmitter stick movements during a flight. Post-flight processing of the stick movement data allows for direct comparisons between different types of MAVs when flown by the same pilot, and also comparisons between pilots. Eventually, practical micro air vehicles will be autonomously controlled, but we feel that the smoothest flying and easiest to fly embodiments will also be the most successful in the long run. Comparisons between several types of micro air vehicles will be presented, along with interpretations of the data.

Jenkins, David A.; Ifju, Peter G.; Abdulrahim, Mujahid; Olipra, Scott

2002-01-01

88

Air conditioner for automotive vehicles capable of cooling intake air supplied to an internal combustion engine  

Microsoft Academic Search

An air conditioner is described for use in an automotive vehicle having an internal combustion engine with an intake air system, an intake port and an intake passage, means is arranged in the intake system for compressing intake air, and a passenger compartment, comprising a refrigerant cycle means where a refrigerant is circulated. The refrigerant cycle means comprises: a compressor

Sugiura

1987-01-01

89

Prototype air bag restraint for use in patrol vehicles  

SciTech Connect

An air bag has been designed and laboratory tested for use in existing police vehicles that will restrain a person if he or she becomes violent. The device will prevent self-injury and protect the vehicle and officer. The device does not pose a suffocation hazard and can be quickly and easily inflated or deflated by the officer from the front seat. The device is ready for field testing.

Marts, D.J.; Barker, S.G.

1995-03-01

90

Attachment device for an inflatable protective cushion  

DOEpatents

An inflatable cushion assembly for use with an inflator comprises an inflatable cushion having an inner surface, outer surface, and at least one protrusion extending from one of the inner or outer surfaces. The inflatable cushion defines an opening between the inner surface and the outer surface for receiving the inflator. An attachment member contacts the one of the inner or outer surfaces adjacent the opening and includes a groove for receiving the protrusion, the attachment member securing the inflator within the opening.

Nelsen, James M. (Albuquerque, NM); Luna, Daniel A. (Los Lunas, NM); Gwinn, Kenneth W. (Cedar Crest, NM)

1998-01-01

91

Air breathing space transport vehicles with wings  

NASA Astrophysics Data System (ADS)

It is pointed out that the currently available space transportation systems of the Western World will not be able to satisfy demands expected for the turn of the century. The development of new systems is, therefore, necessary. Studies of suitable concepts for space transportation systems have already been conducted. Key technologies for future space transportation systems are based on new structural and propulsion concepts. The present investigation is concerned with the employment of a combined rocket-ramjet engine in a single-stage vehicle with wings, taking into account vehicles with vertical or horizontal launching capabilities. Questions of feasibility are explored exclusively under considerations of technological implementation. The considered combined rocket-ramjet propulsion unit is compared with propulsion systems based entirely on the use of rockets. The propellants are liquid hydrogen and liquid oxygen. It is found that the single-stage rocket-ramjet engine vehicle is feasible on the basis of the technological assumptions discussed by Haefeli et al. (1977).

Schoettle, U. M.

92

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

93

Air-Breathing Launch Vehicle Technology Being Developed  

NASA Technical Reports Server (NTRS)

Of the technical factors that would contribute to lowering the cost of space access, reusability has high potential. The primary objective of the GTX program is to determine whether or not air-breathing propulsion can enable reusable single-stage-to-orbit (SSTO) operations. The approach is based on maturation of a reference vehicle design with focus on the integration and flight-weight construction of its air-breathing rocket-based combined-cycle (RBCC) propulsion system.

Trefny, Charles J.

2003-01-01

94

Collaborative tactical behaviors for autonomous ground and air vehicles  

NASA Astrophysics Data System (ADS)

Tactical behaviors for autonomous ground and air vehicles are an area of high interest to the Army. They are critical for the inclusion of robots in the Future Combat System (FCS). Tactical behaviors can be defined at multiple levels: at the Company, Platoon, Section, and Vehicle echelons. They are currently being defined by the Army for the FCS Unit of Action. At all of these echelons, unmanned ground vehicles, unmanned air vehicles, and unattended ground sensors must collaborate with each other and with manned systems. Research being conducted at the National Institute of Standards and Technology (NIST) and sponsored by the Army Research Lab is focused on defining the Four Dimensional Real-time Controls System (4D/RCS) reference model architecture for intelligent systems and developing a software engineering methodology for system design, integration, test and evaluation. This methodology generates detailed design requirements for perception, knowledge representation, decision making, and behavior generation processes that enable complex military tactics to be planned and executed by unmanned ground and air vehicles working in collaboration with manned systems.

Albus, James; Barbera, Anthony; Scott, Harry; Balakirsky, Stephen

2005-05-01

95

Flush Air Data Sensing System for Trans-Atmospheric Vehicles  

NASA Astrophysics Data System (ADS)

With the emergence of multiple companies attempting to tap the space tourism market, as well as NASA's return to the moon initiative, an inexpensive but reliable means of determining wind relative vehicle attitude is becoming a necessity. The traditional means of obtaining air data (altitude, Mach number, angles of attack and sideslip) using fixed pitot probes and directional flow vanes is not viable for collecting data on high supersonic and hypersonic vehicles, due to the high temperatures and dynamic pressures. The solution is to use a matrix of flush mounted pressure ports on the vehicle nose or on an outboard wing leading edge. Since the ports will be located behind a detached shock wave at supersonic velocities, the temperatures will remain substantially lower. A Flush Air Data Sensing (FADS) system can also be used for subsonic conditions, although it must be calibrated for the effects of the vehicle geometry. The physics of air behavior and the mathematics of the solution algorithm will be presented. Several relevant examples of planned vehicles will be presented.

Ellsworth, Joel

2006-10-01

96

Mechanically refuelable zinc/air electric vehicle cells  

NASA Astrophysics Data System (ADS)

Refuelable zinc/air batteries have long been considered for motive as well as stationary power because of a combination of high specific energy, low initial cost, and the possibility of mechanical recharge by electrolyte exchange and additions of metallic zinc. In this context, advanced slurry batteries, stationary packed bed cells, and batteries offering replaceable cassettes have been reported recently. The authors are developing self-feeding, particulate-zinc/air batteries for electric vehicle applications. Emissionless vehicle legislation in California motivated efforts to consider a new approach to providing an electric vehicle with long range (400 km), rapid refueling (10 minutes) and highway safe acceleration - factors which define the essential functions of common automobiles. Such an electric vehicle would not compete with emerging secondary battery vehicles in specialized applications (commuting vehicles, delivery trucks). Rather, different markets would be sought where long range or rapid range extension are important. Examples are: taxis, continuous-duty fork-lift trucks and shuttle busses, and general purpose automobiles having modest acceleration capabilities. In the long range, a mature fleet would best use regional plants to efficiently recover zinc from battery reaction products. One option would be to use chemical/thermal reduction to recover the zinc. The work described focuses on development of battery configurations which efficiently and completely consume zinc particles, without clogging or changing discharge characteristics.

Noring, J.; Gordon, S.; Maimoni, A.; Spragge, M.; Cooper, J. F.

1992-12-01

97

Mechanically refuelable zinc/air electric vehicle cells  

SciTech Connect

Refuelable zinc/air batteries have long been considered for motive as well as stationary power because of a combination of high specific energy, low initial cost, and the possibility of mechanical recharge by electrolyte exchange and additions of metallic zinc. In this context, advanced slurry batteries, stationary packed bed cells and batteries offering replaceable cassettes have been reported recently. The authors are developing self-feeding, particulate-zinc/air batteries for electric vehicle applications. Emissionless vehicle legislation in California motivated efforts to consider a new approach to providing an electric vehicle with long range (400 km), rapid refueling (10 minutes) and highway safe acceleration -- factors which define the essential functions of common automobiles. Such a electric vehicle would not compete with emerging secondary battery vehicles in specialized applications (commuting vehicles, delivery trucks). Rather, different markets would be sought where long range or rapid range extension are important. Examples are: taxis, continuous-duty fork-lift trucks and shuttle busses, and general purpose automobiles having modest acceleration capabilities. In the long range, a mature fleet would best use regional plants to efficiently recover zinc from battery reaction products. One option would be to use chemical/thermal reduction to recover the zinc. The work described in this report focuses on development of battery configurations which efficiently and completely consume zinc particles, without clogging or changing discharge characteristics.

Noring, J.; Gordon, S.; Maimoni, A.; Spragge, M.; Cooper, J.F.

1992-12-01

98

Simple Active Aerodynamic Suspension Systems for High-Speed Ground Vehicles.  

National Technical Information Service (NTIS)

The feasibility of using active aerodynamic surfaces to improve the vertical ride quality of a tracked air cushion vehicle is investigated analytically with a six-degree-of-freedom linear model. Two aerodynamic fins actively control the pitch and plunge s...

R. O. Stearman P. E. Russell E. P. Nolte

1973-01-01

99

Zinc air battery development for electric vehicles. Final report.  

National Technical Information Service (NTIS)

This document reports the progress and accomplishments of a 16 month program to develop a rechargeable zinc-air battery for electric vehicle propulsion, from October 1988 through January 1990. The program was the first stage in the transition of alkaline ...

R. A. Putt

1990-01-01

100

On-Line Trajectory Optimization for Autonomous Air Vehicles.  

National Technical Information Service (NTIS)

Successful operation of next-generation unmanned air vehicles will demand a high level of autonomy. Autonomous low-level operation in a high-threat environment dictates a need for on-hoard, robust, reliable and efficient trajectory optimization. in this r...

J. E. Corban E. N. Johnson A. J. Calise S. Twigg

2003-01-01

101

Smart remote sensing of environmental systems using Unmanned Air Vehicles  

Microsoft Academic Search

Remote sensing of environmental systems is getting more and more attention as the amount of applications and platform increases and costs are going down. Early applications were taking advantage of manned aircrafts and satellites to gather data but the trend is currently shifting to cheaper platforms: Unmanned Air Vehicles (UAVs). UAVs have tremendous advantages thanks to their on-board processing and

C. Tricaud; YangQuan Chen

2010-01-01

102

Cooperative task scheduling for networked uninhabited air vehicles  

Microsoft Academic Search

In the work presented here, we study a cooperative control problem for a network of uninhabited air vehicles (UAVs) where it is assumed that after deployment a set of tasks is given to a group of UAVs and the UAVs must cooperate to decide which UAV should process each task. The cooperation must occur during real-time operation due to a

ALVARO E. GIL; KEVIN M. PASSINO; SRIRAM GANAPATHY; ANDREW SPARKS

2008-01-01

103

The Challenges of Flight-Testing Unmanned Air Vehicles  

Microsoft Academic Search

Unmanned Air Vehicles (UAVs) remain a developing technology of keen interest to the military as well as certain commercial enterprises (such as mining exploration companies), with over 200 UAV types in use throughout the world. UAVs present a difficult challenge for the T&E community as well, with present military UAV interest focussed on total autonomy to reduce operator skill requirements

Warren Williams; Michael Harris

104

Super Maneuverable, Flapping Wing Micro-Air-Vehicles.  

National Technical Information Service (NTIS)

Interest in the development of super-maneuverable, micro-air- vehicles has led to the re-examination of basic flight modes, particularly, those that are inspired by biological observations. The majority of experimental and numerical studies related to fla...

B. Balachandran E. Balaras M. Vanella S. Preidikman T. Fitzgerald

2009-01-01

105

78 FR 20881 - Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards...  

Federal Register 2010, 2011, 2012, 2013

...Tier 3 Motor Vehicle Emission and Fuel Standards'' (the proposed rule...the impacts of motor vehicles and fuels on air quality and public health...timeframe as the greenhouse gas/fuel efficiency standards for light-duty...

2013-04-08

106

Prospects for future hypersonic air-breathing vehicles  

NASA Technical Reports Server (NTRS)

The age of hypersonics is (almost) here. This is evident from the amount of activity in the United States, Europe, the USSR and Japan; this activity is a reflection of technical progress in key areas which will enable new vehicle systems, as well as renewed interest in the utilization of these systems. The current situation, at least in the United States, is the product of an interesting history which is briefly reviewed here. The context for hypersonic applications is discussed, but the emphasis is on hypersonic technology issues and needs, particularly for propulsion and technology integration. The paper concludes with prospects for accomplishing the objective of air-breathing hypersonic vehicle systems.

Beach, H. L., Jr.; Blankson, Isaiah M.

1991-01-01

107

[Motor vehicle source contributions to air pollutants in Beijing].  

PubMed

Beijing's motor vehicle emission inventory based on GIS technology was developed, and used to estimate the contribution rate of different types of vehicles and different areas of vehicles to the total vehicular emissions in the urban area of Beijing. ISCST3, a gaussian dispersion air quality model, was modified at low wind speed condition, and then used to facilitate the study of the spatial and temporal distribution of CO and NOx concentrations in Beijing. It was shown that vehicle source emissions of CO and NOx accounted for 76.8% and 40.2%, respectively, of the total emissions in 1995. The simulation results also showed that emissions from the vehicle sources had contributed 76.5% and 68.4% of the total CO and NOx concentrations in urban atmosphere of Beijing in 1995, and were even higher at down-town and near the arteries. Therefore, strategies for CO and NOx pollution control will of necessity need to focus on the vehicle sources. PMID:11769211

Hao, J; Wu, Y; Fu, L; He, K; He, D

2001-09-01

108

Powering future vehicles with the refuelable zinc/air battery  

SciTech Connect

A recent road test at LLNL underscored the zinc/air battery`s capacity to give electric vehicles some of the attractive features of gas-driven cars: a 400-km range between refueling, 10-minute refueling, and highway-safe acceleration. Developed at Lawrence Livermore National Laboratory, the battery weights only one-sixth as much as standard lead/acid batteries and occupies one-third the space, yet costs less per mile to operate. What`s more, because the battery is easily refuelable, it promises trouble-free, nearly 24-hour-a-day operation for numerous kinds of electric vehicles, from forklifts to delivery vans and possibly, one day, personal automobiles. The test of a Santa Barbara Municipal Transit bus with a hybrid of zinc/air and lead/acid batteries capped a short development period for the zinc/air battery. The test run indicated the zinc/air battery`s potential savings in vehicle weight from 5.7 to 4.0 metric tons, in battery weight from 2.0 to 0.3 metric tons, in battery volume from 0.79 to 0.25 m{sup 3}, and in electricity cost from 5.6 cents per mile to 4.7 cents per mile. The power, however, remains the same.

NONE

1995-10-01

109

Discussion of Aerodynamic Control Effectors (ACEs) for Unmanned Air Vehicles (UAVs).  

National Technical Information Service (NTIS)

A Reynolds number based, unmanned air vehicle classification structure has been developed which identifies four classes of unmanned air vehicle concepts. The four unmanned air vehicle (UAV) classes are; Micro UAV, Meso UAV, Macro UAV, and Mega UAV. In a s...

R. M. Wood

2002-01-01

110

Specialized cockpit displays, symbology, and control mechanization for air vehicle weapons aiming and employment  

NASA Astrophysics Data System (ADS)

Throughout the history of aviation, air vehicles have been developed for military applications in a number of roles, especially the use of weapons to attack targets on the ground and in the air. The complex dynamics of weapons aiming and employment from air vehicles has driven the design of a wide variety of specialized software and operator interfaces. The task of weapons employment in an air vehicle is particularly challenging when the target is itself an air vehicle. This paper examines specialized implementations in cockpit display symbology for weapons employment of modern air-to-air missiles.

Greeley, Kevin W.

2001-09-01

111

A Compact Millimeter Wave Radar Sensor for Unmanned Air Vehicles  

Microsoft Academic Search

This paper presents a compact Millimeter Wave (MMW) radar unit that has been developed to be used as a Range, Bearing and\\u000a Elevation (RBE) sensor on the Brumby Mk III Unmanned Air Vehicles (UAV). The Brumby MkIII is the flight platform used in the\\u000a Autonomous Navigation and Sensing Experimental Research (ANSER) project which is focused on the development and demonstration

Ali Göktogan; Graham Brooker; Salah Sukkarieh

2003-01-01

112

Real-time dynamic trajectory smoothing for unmanned air vehicles  

Microsoft Academic Search

This brief presents a real-time, feasible trajectory generation algorithm for unmanned air vehicles (UAVs) flying through a sequence of waypoints. The algorithm produces extremal trajectories that transition between straight-line path segments in a time-optimal fashion. In addition, the algorithm can be configured so that the dynamically feasible trajectory has the same path length as the straight-line waypoint path. Implementation issues

Erik P. Anderson; Randal W. Beard; Timothy W. McLain

2005-01-01

113

Attachment device for an inflatable protective cushion  

DOEpatents

An inflatable cushion assembly for use with an inflator comprises an inflatable cushion having an inner surface, outer surface, and at least one protrusion extending from one of the inner or outer surfaces. The inflatable cushion defines an opening between the inner surface and the outer surface for receiving the inflator. An attachment member contacts the one of the inner or outer surfaces adjacent the opening and includes a groove for receiving the protrusion, the attachment member securing the inflator within the opening. 22 figs.

Nelsen, J.M.; Luna, D.A.; Gwinn, K.W.

1998-12-08

114

Comparative analysis of aluminum-air battery propulsion systems for passenger vehicles  

NASA Astrophysics Data System (ADS)

Three electric propulsion systems using an aluminum air battery were analyzed and compared to the internal combustion engine (ICE) vehicle. The engine and fuel systems of a representative five passenger highway vehicle were replaced conceptually by each of the three electric propulsion systems. The electrical vehicles were constrained by the computer simulation to be equivalent to the ICE vehicle in range and acceleration performance. The vehicle masses and aluminum consumption rates were then calculated for the electric vehicles and these data were used as figures of merit. The Al-air vehicles analyzed were (1) an Al-air battery only electric vehicle; (2) an Al-air battery combined with a nickel zinc secondary battery for power leveling and regenerative braking; and (3) an Al-air battery combined with a flywheel for power leveling and regenerative braking. All three electric systems compared favorably with the ICE vehicle.

Salisbury, J. D.; Behrin, E.; Kong, M. K.; Whisler, D. J.

1980-02-01

115

Modular disposable can (MODCAN) crash cushion: A concept investigation  

NASA Technical Reports Server (NTRS)

A conceptual design investigation of an improved highway crash cushion system is presented. The system is referred to as a modular disposable can (MODCAN) crash system. It is composed of a modular arrangement of disposable metal beverage cans configured to serve as an effective highway impact attenuation system. Experimental data, design considerations, and engineering calculations supporting the design development are presented. Design performance is compared to that of a conventional steel drum system. It is shown that the MODCAN concepts offers the potential for smoother and safer occupant deceleration for a larger class of vehicle impact weights than the steel drum device.

Knoell, A.; Wilson, A.

1976-01-01

116

Foam-filled cushions for sliding trays  

NASA Technical Reports Server (NTRS)

Polytetrafluoroethylene tube filled with polyurethane foam forms low friction sliding surface that cushions vibrations and absorbs manufacturing tolerances and misalignment. Possible uses include packaging of components for shipping and seals for doors in lockers, cars, and refrigerators.

Nahin, S. B.; Robb, P. H.

1980-01-01

117

9 CFR 3.88 - Primary conveyances (motor vehicle, rail, air, and marine).  

...motor vehicle, rail, air, and marine). ...primary conveyances used to transport nonhuman primates...nonhuman primate enough air for normal breathing. (d) During air transportation, the...primary conveyance used to transport nonhuman primates...

2014-01-01

118

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

119

Air velocity characteristics within vented pallets loaded in a refrigerated vehicle with and without air ducts  

Microsoft Academic Search

During transport using refrigerated vehicles, this being a vital link in the cold chain, the maintaining of even temperature throughout the cargo is essential in order to preserve the quality, safety and shelf life of perishable food. Within the refrigerated container, the temperature level and its homogeneity are directly governed by airflow patterns. The design of the air-distribution system should

J. Moureh; S. Tapsoba; E. Derens; D. Flick

2009-01-01

120

Projection Moire Interferometry Measurements of Micro Air Vehicle Wings  

NASA Technical Reports Server (NTRS)

Projection Moire Interferometry (PMI) has been used to measure the structural deformation of micro air vehicle (MAV) wings during a series of wind tunnel tests. The MAV wings had a highly flexible wing structure, generically reminiscent of a bat s wing, which resulted in significant changes in wing shape as a function of MAV angle-of-attack and simulated flight speed. This flow-adaptable wing deformation is thought to provide enhanced vehicle stability and wind gust alleviation compared to rigid wing designs. Investigation of the potential aerodynamic benefits of a flexible MAV wing required measurement of the wing shape under aerodynamic loads. PMI was used to quantify the aerodynamically induced changes in wing shape for three MAV wings having different structural designs and stiffness characteristics. This paper describes the PMI technique, its application to MAV testing, and presents a portion of the PMI data acquired for the three different MAV wings tested.

Fleming, Gary A.; Bartram, Scott M.; Waszak, Martin R.; Jenkins, Luther N.

2001-01-01

121

Comparative analysis of aluminum-air battery propulsion systems for passenger vehicles  

Microsoft Academic Search

Three electric propulsion systems using an aluminum air battery were analyzed and compared to the internal combustion engine (ICE) vehicle. The engine and fuel systems of a representative five passenger highway vehicle were replaced conceptually by each of the three electric propulsion systems. The electrical vehicles were constrained by the computer simulation to be equivalent to the ICE vehicle in

J. D. Salisbury; E. Behrin; M. K. Kong; D. J. Whisler

1980-01-01

122

Electrospinning of a Micro-air Vehicle Wing Skin  

NASA Technical Reports Server (NTRS)

Electrospinning was utilized to create lightweight, electrically responsive wing skins for micro-air vehicle (MAV) wing frame designs. Various compositions of an electroactive polymer were investigated to determine the appropriate electrospinning conditions for these materials. Electrospun mats of these materials were characterized via optical microscopy and scanning electron microscopy. Tensile properties of the electrospun fibers were also measured. An optimal polymer composition was electrospun onto MAV wing frames to create a bird wing-like texture. Preliminary testing of electroactivity of these prototype MAV wings is reported here.

Pawlowski, K. J.; Belvin, H. L.; Raney, D. L.; Su, J.; Harrison, J. S.; Siochi, E. J.

2003-01-01

123

Analysis and optimization of an adsorption air conditioner for electric vehicle applications.  

National Technical Information Service (NTIS)

This paper shows an analysis of the applicability of an adsorption system for electric vehicle (EV) air conditioning. Adsorption systems are designed and optimized to provide the required cooling for four combinations of vehicle characteristics and drivin...

S. M. Aceves

1994-01-01

124

Effect of Intake Air Filter Condition on Light-Duty Gasoline Vehicles.  

National Technical Information Service (NTIS)

Proper maintenance can help vehicles perform as designed, positively affecting fuel economy, emissions, and the overall drivability. This effort investigates the effect of one maintenance factor, intake air filter replacement, with primary focus on vehicl...

B. West J. Thomas K. Norman S. Huff

2012-01-01

125

Coevolution of Form and Function in the Design of Micro Air Vehicles.  

National Technical Information Service (NTIS)

This paper discusses approaches to cooperative coevolution of form and function for autonomous vehicles, specifically evolving morphology and control for an autonomous micro air vehicle (MAV). The evolution of a sensor suite with minimal size, weight, and...

A. C. Schultz M. D. Bugajska

2002-01-01

126

Low Earth Orbit Raider (LER) winged air launch vehicle concept  

NASA Technical Reports Server (NTRS)

The need to launch small payloads into low earth orbit has increased dramatically during the past several years. The Low Earth orbit Raider (LER) is an answer to this need. The LER is an air-launched, winged vehicle designed to carry a 1500 pound payload into a 250 nautical mile orbit. The LER is launched from the back of a 747-100B at 35,000 feet and a Mach number of 0.8. Three staged solid propellant motors offer safe ground and flight handling, reliable operation, and decreased fabrication cost. The wing provides lift for 747 separation and during the first stage burn. Also, aerodynamic controls are provided to simplify first stage maneuvers. The air-launch concept offers many advantages to the consumer compared to conventional methods. Launching at 35,000 feet lowers atmospheric drag and other loads on the vehicle considerably. Since the 747 is a mobile launch pad, flexibility in orbit selection and launch time is unparalleled. Even polar orbits are accessible with a decreased payload. Most importantly, the LER launch service can come to the customer, satellites and experiments need not be transported to ground based launch facilities. The LER is designed to offer increased consumer freedom at a lower cost over existing launch systems. Simplistic design emphasizing reliability at low cost allows for the light payloads of the LER.

Feaux, Karl; Jordan, William; Killough, Graham; Miller, Robert; Plunk, Vonn

1989-01-01

127

Updraft Model for Development of Autonomous Soaring Uninhabited Air Vehicles  

NASA Technical Reports Server (NTRS)

Large birds and glider pilots commonly use updrafts caused by convection in the lower atmosphere to extend flight duration, increase cross-country speed, improve range, or simply to conserve energy. Uninhabited air vehicles may also have the ability to exploit updrafts to improve performance. An updraft model was developed at NASA Dryden Flight Research Center (Edwards, California) to investigate the use of convective lift for uninhabited air vehicles in desert regions. Balloon and surface measurements obtained at the National Oceanic and Atmospheric Administration Surface Radiation station (Desert Rock, Nevada) enabled the model development. The data were used to create a statistical representation of the convective velocity scale, w*, and the convective mixing-layer thickness, zi. These parameters were then used to determine updraft size, vertical velocity profile, spacing, and maximum height. This paper gives a complete description of the updraft model and its derivation. Computer code for running the model is also given in conjunction with a check case for model verification.

Allen, Michael J.

2006-01-01

128

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

129

Toward a Morphing Micro-Air Vehicle Wing  

NASA Astrophysics Data System (ADS)

In 2004 Schmit and Glauser applied the POD, LSE, and Global POD techniques to a flow-structure interaction problem in which a MAV wing experienced flow induced vibrations. During this flow-structure interaction, the strain, measured by dynamic strain gauges mounted on the wing, was used to estimate the velocity field in the wake of the MAV wing. For comparison, a stereo PIV system was also simultaneously used to capture images of the velocity field in the wake of the MAV wing. The purpose of the experiment was to develop feedback flow/structure methods for Micro Air Vehicles. While Schmit and Glauser successfully show that the velocity field can be estimated by using dynamic strain gauges, their work captures only the sensing aspect of the control problem. The present work aims toward the development of a MAV wing that has sensing and morphing capabilities. By using strategically placed piezoelectric actuators, along with the strain gauges, the MAV wing will not only be able to sense the flow conditions, but respond to them as well. Schmit, R.F. and Glauser, M.N. (2004), "Low-Dimensional Tools for Flow-Structure Interaction Problems: Application to Micro-Air Vehicles'', To Appear AIAA Journal.

Martin, Tamanika; Schmit, Ryan; Glauser, Mark

2004-11-01

130

Improving the aluminum-air battery system for use in electrical vehicles  

Microsoft Academic Search

The objectives of this study include improvement of the efficiency of the aluminum\\/air battery system and demonstration of its ability for vehicle applications. The aluminum\\/air battery system can generate enough energy and power for driving ranges and acceleration similar to that of gasoline powered cars. Therefore has the potential to be a power source for electrical vehicles. Aluminum\\/air battery vehicle

Shaohua Yang

2003-01-01

131

Review on operation concepts and separation simulation of M-5 rocket vehicle air-launch program  

NASA Astrophysics Data System (ADS)

This report reviews the methods to load and separate the M-5 air-launched rocket vehicle from the mother plane. Comparison of the features, merits, demerits, and separation profiles of the M-5 air-launched rocket vehicle with those of the U.S. air-launched rocket vehicle 'Pegasus' are made. The feasibility of separation from the mother plane is verified by simulation.

Ishikawa, Tadashi; Hirose, Hidehiro; Tani, Yasuhiro; Nagao, Yousuke

1991-07-01

132

Design Analysis of an Aluminum-Air Battery for Vehicle Operations. Transportation Systems Research.  

National Technical Information Service (NTIS)

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 t...

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

1983-01-01

133

Vehicle expectations in air transportation for the year 2000  

NASA Technical Reports Server (NTRS)

This paper is intended to provide an overview of the air transportation system for the year 2000 in terms of vehicle expectations. Emphasis is placed on civil air transportation with the time period approached from the standpoint of evolutionary changes for the near term and also with the assumption of more revolutionary changes for the far term. The view along the evolutionary path begins with a historical review of airline market growth and the impact that technologies have had on airplane designs. Projections of the life expectancy of existing, derivative, and new airplanes are examined in terms of their productivity and fuel efficiency in view of the present and projected fuel usage and availability. The factors influencing airline growth are outlined and some views on whether another new generation of subsonic airplanes are in the offing are given along with an assessment of the economic viability of an advanced commercial supersonic transport in terms of its higher speed, higher productivity, and higher fuel usage. With regard to revolutionary changes, major technology breakthroughs are assumed to occur at a specified date. As an example, the impact of a dramatic reduction in skin friction drag is examined in terms of its effect on the airplane configuration, its propulsion systems, it projected fuel usage, and the air transportation system in which it must operate.

Hearth, D. P.

1980-01-01

134

Zinc air battery development for electric vehicles. Final report  

SciTech Connect

This report summarizes the results of research conducted during the sixteen month continuation of a program to develop rechargeable zinc-air batteries for electric vehicles. The zinc-air technology under development incorporates a metal foam substrate for the zinc electrode, with flow of electrolyte through the foam during battery operation. In this ``soluble`` zinc electrode the zincate discharge product dissolves completely in the electrolyte stream. Cycle testing at Lawrence Berkeley Laboratory, where the electrode was invented, and at MATSI showed that this approach avoids the zinc electrode shape change phenomenon. Further, electrolyte flow has been shown to be necessary to achieve significant cycle life (> 25 cycles) in this open system. Without it, water loss through the oxygen electrode results in high-resistance failure of the cell. The Phase I program, which focused entirely on the zinc electrode, elucidated the conditions necessary to increase electrode capacity from 75 to as much as 300 mAh/cm{sup 2}. By the end of the Phase I program over 500 cycles had accrued on one of the zinc-zinc half cells undergoing continuous cycle testing. The Phase II program continued the half cell cycle testing and separator development, further refined the foam preplate process, and launched into performance and cycle life testing of zinc-air cells.

Putt, R.A.; Merry, G.W. [MATSI, Inc., Atlanta, GA (United States)

1991-07-01

135

Flexible Wing Base Micro Aerial Vehicles: Composite Materials for Micro Air Vehicles  

NASA Technical Reports Server (NTRS)

This paper will discuss the development of the University of Florida's Micro Air Vehicle concept. A series of flexible wing based aircraft that possess highly desirable flight characteristics were developed. Since computational methods to accurately model flight at the low Reynolds numbers associated with this scale are still under development, our effort has relied heavily on trial and error. Hence a time efficient method was developed to rapidly produce prototype designs. The airframe and wings are fabricated using a unique process that incorporates carbon fiber composite construction. Prototypes can be fabricated in around five man-hours, allowing many design revisions to be tested in a short period of time. The resulting aircraft are far more durable, yet lighter, than their conventional counterparts. This process allows for thorough testing of each design in order to determine what changes were required on the next prototype. The use of carbon fiber allows for wing flexibility without sacrificing durability. The construction methods developed for this project were the enabling technology that allowed us to implement our designs. The resulting aircraft were the winning entries in the International Micro Air Vehicle Competition for the past two years. Details of the construction method are provided in this paper along with a background on our flexible wing concept.

Ifju, Peter G.; Ettinger, Scott; Jenkins, David; Martinez, Luis

2002-01-01

136

Resonance Type Flapping Wing for Micro Air Vehicle  

NASA Astrophysics Data System (ADS)

A resonance type flapping wing, which is suitable for an insect-like Micro Air Vehicle, is presented. It utilizes the resonance phenomenon of a two-degrees-of-freedom elastic system, that is, the wing is supported by the springs for flapping and feathering motions, and is oscillated at the resonance frequency of the system only by the torque in flapping motion. The amplitudes of flapping and feathering motions and the phase angle between them are controlled by changing the amount of damping. An optimum design method is applied to determine the structural parameters of the wing, the amount of applied torque and damping. Using these determined optimum quantities, arbitrary control of the flapping and feathering motions is possible. This paper presents the theoretical bases of the concept. The results of the numerical simulation using a Navier-Stokes code that takes into account the aeroelastic effects are also presented to verify the concept.

Isogai, Koji; Kamisawa, Yuichi; Sato, Hiroyuki

137

Pioneer unmanned air vehicle accomplishments during Operation Desert Storm  

NASA Astrophysics Data System (ADS)

This paper will describe the accomplishments and lessons learned of the Pioneer Unmanned Air Vehicle (UAV) during Operations Desert Shield and Desert Storm. The Pioneer UAV has been deployed with three branches of the U.S. military (USA, USN, and USMC) for the past four years. Although the system has compiled over 6,000 flight hours, the recent conflict in the Gulf is the first opportunity to demonstrate its true value in a combat scenario. In a relatively short time (42 days), 307 flights and 1,011 flight hours were completed on Operation Desert Storm. This, coupled with the accuracy of various weapons systems that Pioneer observed/cued for, resulted in timely target engagements. This paper will chronicle the Pioneer deployment and accomplishments on Operations Desert Shield and Desert Storm. Various employment methods, tactics, doctrine, and lessons learned will be presented.

Christner, James H.

1991-12-01

138

Air pollution and health risks due to vehicle traffic.  

PubMed

Traffic congestion increases vehicle emissions and degrades ambient air quality, and recent studies have shown excess morbidity and mortality for drivers, commuters and individuals living near major roadways. Presently, our understanding of the air pollution impacts from congestion on roads is very limited. This study demonstrates an approach to characterize risks of traffic for on- and near-road populations. Simulation modeling was used to estimate on- and near-road NO2 concentrations and health risks for freeway and arterial scenarios attributable to traffic for different traffic volumes during rush hour periods. The modeling used emission factors from two different models (Comprehensive Modal Emissions Model and Motor Vehicle Emissions Factor Model version 6.2), an empirical traffic speed-volume relationship, the California Line Source Dispersion Model, an empirical NO2-NOx relationship, estimated travel time changes during congestion, and concentration-response relationships from the literature, which give emergency doctor visits, hospital admissions and mortality attributed to NO2 exposure. An incremental analysis, which expresses the change in health risks for small increases in traffic volume, showed non-linear effects. For a freeway, "U" shaped trends of incremental risks were predicted for on-road populations, and incremental risks are flat at low traffic volumes for near-road populations. For an arterial road, incremental risks increased sharply for both on- and near-road populations as traffic increased. These patterns result from changes in emission factors, the NO2-NOx relationship, the travel delay for the on-road population, and the extended duration of rush hour for the near-road population. This study suggests that health risks from congestion are potentially significant, and that additional traffic can significantly increase risks, depending on the type of road and other factors. Further, evaluations of risk associated with congestion must consider travel time, the duration of rush-hour, congestion-specific emission estimates, and uncertainties. PMID:23500830

Zhang, Kai; Batterman, Stuart

2013-04-15

139

Integration of an Autopilot for a Micro Air Vehicle  

NASA Technical Reports Server (NTRS)

Two autopilots providing autonomous flight capabilities are presented herein. The first is the Pico-Pilot, demonstrated for the 12-inch size class of micro air vehicles. The second is the MicroPilot MP2028(sup g), where its integration into a 36-inch Zagi airframe (tailless, elevons only configuration) is investigated and is the main focus of the report. Analytical methods, which include the use of the Advanced Aircraft Analysis software from DARCorp, were used to determine the stability and control derivatives, which were then validated through wind tunnel experiments. From the aerodynamic data, the linear, perturbed equations of motion from steady-state flight conditions may be cast in terms of these derivatives. Using these linear equations, transfer functions for the control and navigation systems were developed and feedback control laws based on Proportional, Integral, and Derivative (PID) control design were developed to control the aircraft. The PID gains may then be programmed into the autopilot software and uploaded to the microprocessor of the autopilot. The Pico-Pilot system was flight tested and shown to be successful in navigating a 12-inch MAV through a course defined by a number of waypoints with a high degree of accuracy, and in 20 mph winds. The system, though, showed problems with control authority in the roll and pitch motion of the aircraft: causing oscillations in these directions, but the aircraft maintained its heading while following the prescribed course. Flight tests were performed in remote control mode to evaluate handling, adjust trim, and test data logging for the Zagi with integrated MP2028(sup g). Ground testing was performed to test GPS acquisition, data logging, and control response in autonomous mode. Technical difficulties and integration limitations with the autopilot prevented fully autonomous flight from taking place, but the integration methodologies developed for this autopilot are, in general, applicable for unmanned air vehicles within the 36-inch size class or larger that use a PID control based autopilot.

Platanitis, George; Shkarayev, Sergey

2005-01-01

140

Investigation of Heat-Activated Cushioning Material.  

National Technical Information Service (NTIS)

A study was initiated to determine the feasibility of obtaining a solid urethane system which could be foamed-in-place, by the application of heat, in order to provide a cushioning material for ship-to-shore transfers. The best formulation obtained contai...

D. Minuti

1967-01-01

141

Alternative Methods for Flotation Seat Cushion Use.  

National Technical Information Service (NTIS)

Alternative methods of using flotation seat cushions for water crash survivors were identified at the Civil Aeromedical Institute (CAMI). These methods, tested in the CAMI survival tank and a theme park wave pool were: (1) two people facing each other, ho...

G. E. Funkhouser M. H. George

1995-01-01

142

On some classes of control-oriented model of air-breathing hypersonic vehicles  

Microsoft Academic Search

The system modeling and controller design for air-breathing hypersonic vehicles have always been one of the most highly challenging tasks to the development of hypersonic flight technologies due to the unique characteristics of the vehicle dynamics. In this paper, we first provide an overview of three major classes of control-oriented models of air-breathing hypersonic vehicles in existing literatures. Moreover, explicitly

Cai Guangbin; Duan Guangren; Hu Changhua

2010-01-01

143

Impact of Solar Control PVB Glass on Vehicle Interior Temperatures, Air-Conditioning Capacity, Fuel Consumption, and Vehicle Range  

SciTech Connect

The objective of the study was to assess the impact of Saflex1 S-series Solar Control PVB (polyvinyl butyral) configurations on conventional vehicle fuel economy and electric vehicle (EV) range. The approach included outdoor vehicle thermal soak testing, RadTherm cool-down analysis, and vehicle simulations. Thermal soak tests were conducted at the National Renewable Energy Laboratory's Vehicle Testing and Integration Facility in Golden, Colorado. The test results quantified interior temperature reductions and were used to generate initial conditions for the RadTherm cool-down analysis. The RadTherm model determined the potential reduction in air-conditioning (A/C) capacity, which was used to calculate the A/C load for the vehicle simulations. The vehicle simulation tool identified the potential reduction in fuel consumption or improvement in EV range between a baseline and modified configurations for the city and highway drive cycles. The thermal analysis determined a potential 4.0% reduction in A/C power for the Saflex Solar PVB solar control configuration. The reduction in A/C power improved the vehicle range of EVs and fuel economy of conventional vehicles and plug-in hybrid electric vehicles.

Rugh, J.; Chaney, L.; Venson, T.; Ramroth, L.; Rose, M.

2013-04-01

144

Ongoing tests of the Electric Fuel(R) zinc-air battery for electric vehicles  

Microsoft Academic Search

The Electric Fuel zinc-air battery system is being tested in fleet programs throughout Europe, with the programs in various stages. In Germany, Sweden and Italy, vehicles powered by the Electric Fuel zinc-air battery system are being tested in demonstration drives. In the Netherlands, a new program is getting underway to utilize the Electric Fuel zinc-air battery system in fleet vehicles.

Jonathan R. Goldstein; Binyamin Koretz

1998-01-01

145

Characterization of vehicle use in fine air quality control regions  

Microsoft Academic Search

Under contract to the Emission Control Technology Division of the U.S. Environmental Protection Agency, Technical Service Corporation (TSC) has compiled data, estimates and projections of vehicle population and use by vehicle age and type, for each of these cities: Chicago, Denver, Los Angeles, Houston, and Phoenix. As motor vehicle emissions are sensitive to temperature, humidity, and barometric pressure, meteorological data

J. A. Eldon; D. B. Hunsaker

1978-01-01

146

Partial camera automation in an unmanned air vehicle.  

PubMed

The present study focused on an intelligent, semiautonomous, interface for a camera operator of a simulated unmanned air vehicle (UAV). This interface used system "knowledge" concerning UAV motion in order to assist a camera operator in tracking an object moving through the landscape below. The semiautomated system compensated for the translations of the UAV relative to the earth. This compensation was accompanied by the appropriate joystick movements ensuring tactile (haptic) feedback of these system interventions. The operator had to superimpose self-initiated joystick manipulations over these system-initiated joystick motions in order to track the motion of a target (a driving truck) relative to the terrain. Tracking data showed that subjects performed substantially better with the active system. Apparently, the subjects had no difficulty in maintaining control, i.e., "following" the active stick while superimposing self-initiated control movements over the system-interventions. Furthermore, tracking performance with an active interface was clearly superior relative to the passive system. The magnitude of this effect was equal to the effect of update-frequency (2-5 Hz) of the monitor image. The benefits of update frequency enhancement and semiautomated tracking were the greatest under difficult steering conditions. Mental workload scores indicated that, for the difficult tracking-dynamics condition, both semiautomation and update frequency increase resulted in less experienced mental effort. For the easier dynamics this effect was only seen for update frequency. PMID:11541093

Korteling, J E; van der Borg, W

1997-03-01

147

Fire resistant resilient foams. [for seat cushions  

NASA Technical Reports Server (NTRS)

Primary program objectives were the formulation, screening, optimization and characterization of open-cell, fire resistant, low-smoke emitting, thermally stable, resilient polyimide foams suitable for seat cushions in commercial aircraft and spacecraft. Secondary program objectives were to obtain maximum improvement of the tension, elongation and tear characteristics of the foams, while maintaining the resiliency, thermal stability, low smoke emission and other desirable attributes of these materials.

Gagliani, J.

1976-01-01

148

Preliminary performance estimates of an oblique, all-wing, remotely piloted vehicle for air-to-air combat  

NASA Technical Reports Server (NTRS)

A computerized aircraft synthesis program has been used to assess the effects of various vehicle and mission parameters on the performance of an oblique, all-wing, remotely piloted vehicle (RPV) for the highly maneuverable, air-to-air combat role. The study mission consists of an outbound cruise, an acceleration phase, a series of subsonic and supersonic turns, and a return cruise. The results are presented in terms of both the required vehicle weight to accomplish this mission and the combat effectiveness as measured by turning and acceleration capability. This report describes the synthesis program, the mission, the vehicle, and results from sensitivity studies. An optimization process has been used to establish the nominal RPV configuration of the oblique, all-wing concept for the specified mission. In comparison to a previously studied conventional wing-body canard design for the same mission, this oblique, all-wing nominal vehicle is lighter in weight and has higher performance.

Nelms, W. P., Jr.; Bailey, R. O.

1974-01-01

149

Zinc\\/air battery R and D zinc\\/air engineering analysis for electrical vehicles: Tasks III, Final report  

Microsoft Academic Search

This report is an examination and analysis of the zinc-air system as the motive power source for electric vehicle propulsion. Various versions of the zinc-air system and operating schemes along with their advantages and disadvantages are discussed. Baseline cost calculations are also presented in order to compare the cost effectiveness of each of the systems. The treatise is conceptual in

M. Klein; S. Viswanathan

1986-01-01

150

Zinc/Air Battery R and D Zinc/Air Engineering Analysis for Electrical Vehicles: Tasks III, Final Report.  

National Technical Information Service (NTIS)

This report is an examination and analysis of the zinc-air system as the motive power source for electric vehicle propulsion. Various versions of the zinc-air system and operating schemes along with their advantages and disadvantages are discussed. Baseli...

M. Klein S. Viswanathan

1986-01-01

151

Zinc\\/air battery R and D. Zinc\\/air engineering analysis for electrical vehicles, task 3  

Microsoft Academic Search

This report is an examination and analysis of the zinc-air system as the motive power source for electric vehicle propulsion. Various versions of the zinc-air system and operating schemes along with their advantages and disadvantages are discussed. Baseline cost calculations are also presented in order to compare the cost effectiveness of each of the systems. The treatise is conceptual in

M. Klein; S. Viswanathan

1986-01-01

152

Membrane and adaptively-shaped wings for micro air vehicles  

NASA Astrophysics Data System (ADS)

Micro air vehicles (MAVs), with wing span of 15 cm or less and flight speed around 10 m/s, have many applications in both civilian and military areas. The Reynolds number based on the given parameters is around 10 4, which often yields insufficient lift-to-drag ratio. Furthermore, one expects the unsteady effect to be noticeable for such flight vehicles. The flexible wing has been demonstrated to exhibit favorable characteristics such as passive adaptation to the flight; environment and delayed stall. The present study focuses on developing computational and modeling capabilities to better understand the MAV aerodynamics. Both flexible wings, utilizing membrane materials, and adaptively-shaped wings, utilizing piezo-actuated flaps, have been studied. In the adaptively-shaped wing study, we use piezo-actuated flaps to actively control the flow. We assess the impacts of the flap geometry, flapping amplitude, and turbulence; modeling on the flow structure with a parallel experimental effort. The membrane wing uses a passive control mechanism to delay the stall angle and to provide a smoother flight platform. Our study focuses on the mutual interactions between the membrane wing and its surrounding viscous flow. We compare the lift-to-drag ratio and the flow structure between the flexible wing and the corresponding rigid wing. We also investigate the aerodynamic characteristics associated with the low Reynolds number and low aspect ratio wing. To assist our study, we propose an automatic and efficient moving grid technique to facilitate the fluid and structure interaction computations; we also present a dynamic membrane model to study the intrinsic large deformation of the flexible membrane wing. Solutions obtained from the three-dimensional Navier-Stokes equations are presented to highlight, the salient features of the wing aerodynamics. Besides the aerodynamic study, we also perform shape optimization to improve the membrane wing performance. Since direct optimization of a membrane wing is too time consuming to be practical, we optimize a surrogate rigid wing model based on an integrated optimization algorithm, which consists of a Navier-Stokes solver, an automatic grid generation tool; and a gradient-based optimizer. Then, we assess the membrane wing performance based on the outcome from the surrogate model. Our numerical results confirm that the membrane wing exhibits consistent improvement in the lift-to-drag ratio with the surrogate model.

Lian, Yongsheng

153

Space robot simulator vehicle  

NASA Technical Reports Server (NTRS)

A Space Robot Simulator Vehicle (SRSV) was constructed to model a free-flying robot capable of doing construction, manipulation and repair work in space. The SRSV is intended as a test bed for development of dynamic and static control methods for space robots. The vehicle is built around a two-foot-diameter air-cushion vehicle that carries batteries, power supplies, gas tanks, computer, reaction jets and radio equipment. It is fitted with one or two two-link manipulators, which may be of many possible designs, including flexible-link versions. Both the vehicle body and its first arm are nearly complete. Inverse dynamic control of the robot's manipulator has been successfully simulated using equations generated by the dynamic simulation package SDEXACT. In this mode, the position of the manipulator tip is controlled not by fixing the vehicle base through thruster operation, but by controlling the manipulator joint torques to achieve the desired tip motion, while allowing for the free motion of the vehicle base. One of the primary goals is to minimize use of the thrusters in favor of intelligent control of the manipulator. Ways to reduce the computational burden of control are described.

Cannon, R. H., Jr.; Alexander, H.

1985-01-01

154

Unmanned air vehicle (UAV) ultra-persitence research  

SciTech Connect

Sandia National Laboratories and Northrop Grumman Corporation Integrated Systems, Unmanned Systems (NGIS UMS) collaborated to further ultra-persistence technologies for unmanned air vehicles (UAVs). The greatest shortfalls in UAV capabilities have been repeatedly identified as (1) insufficient flight persistence or 'hang time,' (2) marginal electrical power for running higher power avionics and payload systems, and (3) inadequate communications bandwidth and reach. NGIS UMS requested support from Sandia to develop an ultra-persistent propulsion and power system (UP3S) for potential incorporation into next generation UAV systems. The team members tried to determine which energy storage and power generation concepts could most effectively push UAV propulsion and electrical power capabilities to increase UAV sortie duration from days to months while increasing available electrical power at least two-fold. Primary research and development areas that were pursued included these goals: perform general system engineering and integration analyses; develop initial thermal and electrical power estimates; provide mass, volume, dimensional, and balance estimates; conduct preliminary safety assessments; assess logistics support requirements; perform, preliminary assessments of any security and safeguards; evaluate options for removal, replacement, and disposition of materials; generally advance the potential of the UP3S concept. The effort contrasted and compared eight heat sources technologies, three power conversion, two dual cycle propulsion system configurations, and a single electrical power generation scheme. Overall performance, specific power parameters, technical complexities, security, safety, and other operational features were successfully investigated. Large and medium sized UAV systems were envisioned and operational flight profiles were developed for each concept. Heat source creation and support challenges for domestic and expeditionary operations were considered. Fundamental cost driver analysis was also performed. System development plans were drafted in order to determine where the technological and programmatic critical paths lay. As a result of this effort, UAVs were to be able to provide far more surveillance time and intelligence information per mission while reducing the high cost of support activities. This technology was intended to create unmatched global capabilities to observe and preempt terrorist and weapon of mass destruction (WMD) activities. Various DOE laboratory and contractor personnel and facilities could have been used to perform detailed engineering, fabrication, assembly and test operations including follow-on operational support. Unfortunately, none of the results will be used in the near-term or mid-term future. NGIS UMS and SNL felt that the technical goals for the project were accomplished. NGIS UMS was quite pleased with the results of analysis and design although it was disappointing to all that the political realities would not allow use of the results. Technology and system designs evaluated under this CRADA had previously never been applied to unmanned air vehicles (UAVs). Based upon logistic support cost predictions, because the UAVs would not have had to refuel as often, forward basing support costs could have been reduced due to a decrease in the number and extent of support systems and personnel being required to operate UAVs in remote areas. Basic application of the advanced propulsion and power approach is well understood and industry now understands the technical, safety, and political issues surrounding implementation of these strategies. However, the overall economic impact was not investigated. The results will not be applied/implemented. No near-term benefit to industry or the taxpayer will be encountered as a result of these studies.

Dron, S. B.

2012-03-01

155

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

156

Beale Air Force Base, Perimeter Acquisition Vehicle Entry PhasedArray Warning ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Satellite Communications Terminal, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

157

Venus Atmospheric Maneuverable Platform (VAMP) — Air Vehicle Concept and Entry CONOPs  

NASA Astrophysics Data System (ADS)

This presentation discusses the continued development of the Northrop Grumman/L’GARDE team’s long-lived, maneuverable platform to explore the Venus upper atmosphere. It focuses on the air vehicle design and entry CONOPs and their interdependencies.

Sokol, D.; Lee, G.; Polidan, R.; Bolisay, L.; Barnes, N.

2014-06-01

158

Comparative Analysis of Aluminum-Air Battery Propulsion Systems for Passenger Vehicles.  

National Technical Information Service (NTIS)

Three electric propulsion systems using an aluminum-air battery were analyzed and compared to the internal-combustion-engine (ICE) vehicle. The analysis used projected battery characteristics extrapolated from laboratory measurements which were obtained i...

J. D. Salisbury E. Behrin M. K. Kong D. J. Whisler

1980-01-01

159

Literature Review on Bounding Flight in Birds With Applications to Micro Uninhabited Air Vehicles.  

National Technical Information Service (NTIS)

Bounding flight is an intermittent flight pattern observed in small birds, in which periods of flapping flight alternate with periods of wings- folded flight. It has been suggested that this flight pattern could be adopted by micro uninhabited air vehicle...

H. A. Keating

2002-01-01

160

Inspection Maintenance of Light Duty Vehicles in the Denver Air Quality Control Region.  

National Technical Information Service (NTIS)

This report summarizes information on inspection/maintenance programs for the reduction and control of automobile emissions. It deals specifically with inspection/maintenance of light duty vehicles in the Denver Air Quality Control Region. The focus is on...

1974-01-01

161

Performance Criteria for Air Brake Component Combinations on In-Use Commercial Motor Vehicles.  

National Technical Information Service (NTIS)

The National Transportation Safety Board (NTSB) recommended that the Federal Highway Administration (FHWA) develop performance criteria for allowable combinations (brake size, lining friction and axle rating) of air brake system components on heavy vehicl...

R. Radlinski

1996-01-01

162

Wing Force & Moment Characterization of Flapping Wings for Micro Air Vehicle Application.  

National Technical Information Service (NTIS)

This paper presents a general method for investigating the unsteady aerodynamics of flapping wings for micro air vehicle application. For this purpose, a dynamically scaled robotic flapper was designed and fabricated which can flap the wings in a desired ...

Z. A. Khan S. K. Agrawal

2005-01-01

163

Fundamental Study in Nonlinear Aeroelastic Phenomena in Flapping Wing Micro Air Vehicles.  

National Technical Information Service (NTIS)

This report describes the development of an aeroelastic model capable of representing in an approximate manner the fundamental nonlinear aeroelastic behavior of flapping wing micro air vehicles in hover. The approximate nature of the model is due to an ap...

P. P. Friedmann W. Shyy

2008-01-01

164

Some Recent Developments in Wireless Power Transmission to Micro Air Vehicles  

NASA Astrophysics Data System (ADS)

Requirements and new techniques are described for wireless power transmission to micro air vehicles. These techniques involve the use of high-density and multiple-function rectennas, pulsed continuous wave transmission, and a move to higher frequencies.

Alden, A.; Bouliane, P.; Zhang, M.

2005-04-01

165

Beale Air Force Base, Perimeter Acquisition Vehicle Entry PhasedArray Warning ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Electric Substation, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

166

Target location by self-organizing autonomous air vehicles  

NASA Astrophysics Data System (ADS)

Target location is a problem where the application of multiple sensors that are geographically distributed can determine or improve the location estimate of a target. If these sensors are capable of cooperative behaviour then the information from each sensor can be autonomously fused to provide an estimate of the target position. The individual sensors may be quite unsophisticated, yet the observation system that is created through cooperation and adaptive networking of these sensors provides sufficient process gain to achieve target location accuracies similar to those of expensive centralized sensor systems. The accuracy of target location estimates depends heavily on the separation distance between the sensors. Large baseline geometry takes advantage of many seemingly unsophisticated bearing measurements that are organised into a coordinated observation system to locate a target. Team formation is one method to address coordination of distributed sensors, data fusion, sensor resource and energy management, and communication link control based on the concept of cooperating machines1,2,3. We apply an algorithm for agent team formation4 inspired by the self-organising behaviour observed in colonies of ants, to the problem of integrating the sensors of a group of networked mini-Autonomous Air Vehicles (AAVs). The mini-AAVs are tasked to locate targets within a region of interest. The challenge we address is to make the location estimation system adaptive to a dynamic environment and robust to failure. Simulation results are presented which address issues in distributed data fusion, sensor resource and energy management, and communication link control, for a group of mini-AAVs.

Brown, Kim; Bowyer, Richard S.; Koks, Don

2002-08-01

167

Design and Development of Autonomous Uninhabited Air Vehicles at ITB: Challenges and Progress Status  

Microsoft Academic Search

An uninhabited air vehicle has found diverse applications for both civil and military missions. To achieve the stated mission, the vehicle needs to have a certain level of autonomy to maintain its stability following a desired path under embedded guidance, navigation and control al- gorithm. To meet the increasingly more stringent operation requirements, the UAVs rely less and less on

A. Budiyono

2005-01-01

168

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

169

Decentralized consensus based control methodology for vehicle formations in air and deep space  

Microsoft Academic Search

In this paper a new methodology is proposed for decentralized overlapping tracking control of autonomous vehicles in air and deep-space. The methodology is based on the application of recently proposed decentralized consensus-based state estimators in conjunction with the globally LQ optimal state feedback control law. In the case of unmanned aerial vehicles (UAVs), a specific formation model is proposed and

M. S. Stankovic?; D. M. Stipanovic?; S. S. Stankovic?

2010-01-01

170

Adaptive sliding mode tracking control for a flexible air-breathing hypersonic vehicle  

Microsoft Academic Search

This paper is concerned with the adaptive sliding mode control (ASMC) design problem for a flexible air-breathing hypersonic vehicle (FAHV). This problem is challenging because of the inherent couplings between the propulsion system, the airframe dynamics and the presence of strong flexibility effects. Due to the enormous complexity of the vehicle dynamics, only the longitudinal model is adopted for control

Xiaoxiang Hu; Ligang Wu; Changhua Hu; Huijun Gao

171

A refuelable zinc\\/air battery for fleet electric vehicle propulsion  

Microsoft Academic Search

We report the development and on-vehicle testing of an engineering prototype zinc\\/air battery. The battery is refueled by periodic exchange of spent electrolyte for zinc particles entrained in fresh electrolyte. The technology is intended to provide a capability for nearly continuous vehicle operation, using the fleet's home base for 10 minute refuelings and zinc recycling instead of commercial infrastructure. In

John F. Cooper; Dennis Fleming; Douglas Hargrove; Ronald Koopman; Keith Peterman

1995-01-01

172

Aerodynamic modelling of insect-like flapping flight for micro air vehicles  

Microsoft Academic Search

Insect-like flapping flight offers a power-efficient and highly manoeuvrable basis for a micro air vehicle capable of indoor flight. The development of such a vehicle requires a careful wing aerodynamic design. This is particularly true since the flapping wings will be responsible for lift, propulsion and manoeuvres, all at the same time. It sets the requirement for an aerodynamic tool

S. A. Ansari; R. ?bikowski; K. Knowles

2006-01-01

173

Altitude Control of a Single Degree of Freedom Flapping Wing Micro Air Vehicle (Postprint).  

National Technical Information Service (NTIS)

A control strategy is proposed for a minimally actuated flapping wing micro air vehicle. The Harvard RoboFly vehicle accomplished the first takeoff of an insect scale flapping wing aircraft. This flight demonstrated the capability of the aircraft to accel...

D. B. Doman D. O. Sigthorsson M. A. Bolender M. W. Oppenheimer

2009-01-01

174

Estimates of the cost and energy consumption of aluminum-air electric vehicles  

Microsoft Academic Search

Economic costs and primary energy consumption are estimated for general purpose electric vehicles using aluminum-air propulsion batteries within the time frame of the 1990's (earliest possible date of introduction). For an aluminum-air fuel economy of 36 tonne\\/km\\/kg-Al (optimized low-gallium alloys), a total refueling cost of 5.6 cents\\/km (1979$) was estimated for a 1.27 tonne vehicle. This is equivalent to $2

J. F. Cooper

1980-01-01

175

An analysis of aluminum-air battery propulsion systems for passenger vehicles  

Microsoft Academic Search

The performance characteristics of three electric-propulsion systems based on the Al-air battery were analyzed and compared to the internal combustion engine (ICE). In this comparison, the engine and fuel systems of a current five-passenger vehicle were conceptually replaced by three Al-air systems: (1) an Al-air battery-only system, (2) an Al-air battery combined with a nickel-zinc secondary battery for power leveling,

J. D. Salisbury; E. Behrin

1980-01-01

176

Segmented tubular cushion springs and spring assembly  

NASA Technical Reports Server (NTRS)

A spring which includes a tube with an elliptical cross section, with the greater axial dimension extending laterally and the lesser axial dimension extending vertically is disclosed. A plurality of cuts in the form of slots passing through most of a wall of the tube extend perpendiculary to a longitudinal axis extending along the tube. An uncut portion of the tube wall extends along the tube for bonding or fastening the tube to a suitable base, such as a bottom of a seat cushion.

Haslim, L. A. (inventor)

1985-01-01

177

Fire blocking systems for aircraft seat cushions  

NASA Technical Reports Server (NTRS)

A configuration and method for reducing the flammability of bodies of organic materials that thermally decompose to give flammable gases comprises covering the body with a flexible matrix that catalytically cracks the flammable gases to less flammable species. Optionally, the matrix is covered with a gas impermeable outer layer. In a preferred embodiment, the invention takes the form of an aircraft seat in which the body is a poly(urethane) seat cushion, the matrix is an aramid fabric or felt and the outer layer is an aluminum film.

Parker, J. A.; Kourtides, D. A. (inventors)

1984-01-01

178

Study of long term options for electric vehicle air conditioning.  

National Technical Information Service (NTIS)

There are strong incentives in terms of national energy and environmental policy to encourage the commercialization of electrically powered vehicles in the U.S. Among these incentives are reduced petroleum consumption, improved electric generation capacit...

J. Dieckmann D. Mallory

1991-01-01

179

Global trends in motor vehicle air pollution control  

SciTech Connect

The purpose of this paper is to survey the adverse environmental impacts resulting from motor vehicles, to review technologies developed to address these problems, and to summarize the current status of pollution control programs around the world.

Walsh, M.P.

1985-01-01

180

Air quality impacts of motor vehicle emissions in the south coast air basin: Current versus more stringent control scenario  

NASA Astrophysics Data System (ADS)

States are working to comply with the ozone National Ambient Air Quality Standards (NAAQS). Often, regulations restricting vehicle emissions are promulgated in order to attain compliance with the NAAQS. Currently, more stringent vehicle emission regulations are being considered by government agencies. This paper compares emissions from passenger cars and light duty trucks under the current California Low Emission Vehicle (LEV II) standards to a control scenario which was anticipated in 2008 to become LEV III (referred to as "more stringent control" in this paper) and determines if the scenario would result in additional improvements to air quality in California's South Coast Air Basin. The air quality modeling was performed using the Community Multi-scale Air Quality Model (CMAQ) for years 2005, 2014 and 2020. The more stringent control sensitivity study simulated a scenario in which all new passenger cars and light duty trucks in the California South Coast Air Basin in year 2016 achieve Super Ultra-Low Emission Vehicle (SULEV) tail pipe emissions, zero evaporative emissions and more stringent aggressive driving requirements. The total on-road vehicles emissions difference when averaged across the South Coast Air Basin showed the more stringent scenario compared to LEV II to have reductions of 1% for oxides of nitrogen (NO x), 1% for as reactive organic gases (ROG) and 5% for carbon monoxide (CO) in 2030. LEV II modeled ozone levels in the western areas of the basin increased in 2014 and 2020 as compared to 2005, because these areas are VOC-sensitive and the reductions in NO x emissions in these regions are larger than the VOC reductions. In other areas of the South Coast Basin, ozone is reduced by 1.5% or less. The more stringent control scenario modeled levels of ozone have a maximum decrease from LEV II levels by 1% or less in 2014 and 1.5% or less in 2020.

Collet, Susan; Kidokoro, Toru; Sonoda, Yukihiro; Lohman, Kristen; Karamchandani, Prakash; Chen, Shu-Yun; Minoura, Hiroaki

2012-02-01

181

A method for reducing exhaust pressure of vehicle compressed air powered engine  

Microsoft Academic Search

Compressed air powered engine is a type of zero-pollution engine, but its conversion efficiency is very low for its high pressure exhaust which causes much exergy loss. In this study, a control system was developed to reduce the exhaust pressure of vehicle compressed air powered engine. The control system is made up of a controller, a pressure sensor, a photoelectric

Zhenggang Xu; Xiaopeng Xie

2009-01-01

182

Separation Flight Tests of a Small Unmanned Air Vehicle from a C-130 Transport Aircraft  

Microsoft Academic Search

Unmanned Air Vehicles (UAVs) are increasingly being considered for various roles in the civilian and military communities. Various launch methods have been explored and have been mostly ground based. The desire to investigate the feasibility of launching a UAV from a larger surrogate air platform existed, but had not been explored. As part of a concept demonstration program, NAVAIR's Test

David W. Roberts; Aaron D. Judy

183

The motor vehicles ? a significant cause for air pollution in big towns of Bulgaria  

Microsoft Academic Search

Taking as an example the Bulgarian capital (Sofia town) an attempt has been made to emphasize on the “contribution”; of motor transport to the air pollution. By comparing the data from air monitiring stations situated in different areas of the town (city centre, industrial regions and residental quarters) it has been estimated that motor vehicles are the major source of

M. Panayotova

1996-01-01

184

Thermal Performance of Aircraft Polyurethane Seat Cushions  

NASA Technical Reports Server (NTRS)

Aircraft seat materials were evaluated in terms of their thermal performance. The materials were evaluated using (a) thermogravimetric analysis, (b) differential scanning calorimetry, (c) a modified NBS smoke chamber to determine the rate of mass loss and (d) the NASA T-3 apparatus to determine the thermal efficiency. In this paper, the modified NBS smoke chamber will be described in detail since it provided the most conclusive results. The NBS smoke chamber was modified to measure the weight loss of material when exposed to a radiant heat source over the range of 2.5 to 7.5 W/sq cm. This chamber has been utilized to evaluate the thermal performance of various heat blocking layers utilized to protect the polyurethane cushioning foam used in aircraft seats. Various kinds of heat blocking layers were evaluated by monitoring the weight loss of miniature seat cushions when exposed to the radiant heat. The effectiveness of aluminized heat blocking systems was demonstrated when compared to conventional heat blocking layers such as neoprene. All heat blocking systems showed good fire protection capabilities when compared to the state-of-the-art, i.e., wool-nylon over polyurethane foam.

Kourtides, D. A.; Parker, J. A.

1982-01-01

185

Zinc/air battery R and D. Zinc/air engineering analysis for electrical vehicles, task 3  

NASA Astrophysics Data System (ADS)

This report is an examination and analysis of the zinc-air system as the motive power source for electric vehicle propulsion. Various versions of the zinc-air system and operating schemes along with their advantages and disadvantages are discussed. Baseline cost calculations are also presented in order to compare the cost effectiveness of each of the systems. The treatise is conceptual in nature and is not based on new experimental work.

Klein, M.; Viswanathan, S.

1986-12-01

186

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

187

A novel zinc-air battery for electric vehicles  

Microsoft Academic Search

A new type of zinc electrode is matched with new bifunctional air electrodes to produce a zinc-air battery of a novel design. The zinc electrode is a flow-thru type made from copper foam-metal. The air electrode uses corrosion resistant carbon black as a high area support for a highly dispersed spinel oxide electrocatalyst. The battery design employs flowing electrolyte, 12

P. N. Ross

1995-01-01

188

Affordable Flight Demonstration of the GTX Air-Breathing SSTO Vehicle Concept  

NASA Technical Reports Server (NTRS)

The rocket based combined cycle (RBCC) powered single-stage-to-orbit (SSTO) reusable launch vehicle has the potential to significantly reduce the total cost per pound for orbital payload missions. To validate overall system performance, a flight demonstration must be performed. This paper presents an overview of the first phase of a flight demonstration program for the GTX SSTO vehicle concept. Phase 1 will validate the propulsion performance of the vehicle configuration over the supersonic and hypersonic air- breathing portions of the trajectory. The focus and goal of Phase 1 is to demonstrate the integration and performance of the propulsion system flowpath with the vehicle aerodynamics over the air-breathing trajectory. This demonstrator vehicle will have dual mode ramjetkcramjets, which include the inlet, combustor, and nozzle with geometrically scaled aerodynamic surface outer mold lines (OML) defining the forebody, boundary layer diverter, wings, and tail. The primary objective of this study is to demon- strate propulsion system performance and operability including the ram to scram transition, as well as to validate vehicle aerodynamics and propulsion airframe integration. To minimize overall risk and develop ment cost the effort will incorporate proven materials, use existing turbomachinery in the propellant delivery systems, launch from an existing unmanned remote launch facility, and use basic vehicle recovery techniques to minimize control and landing requirements. A second phase would demonstrate propulsion performance across all critical portions of a space launch trajectory (lift off through transition to all-rocket) integrated with flight-like vehicle systems.

Krivanek, Thomas M.; Roche, Joseph M.; Riehl, John P.; Kosareo, Daniel N.

2003-01-01

189

Study of long term options for electric vehicle air conditioning  

Microsoft Academic Search

There are strong incentives in terms of national energy and environmental policy to encourage the commercialization of electrically powered vehicles in the U.S. Among these incentives are reduced petroleum consumption, improved electric generation capacity utilization, reduced IC engine emissions, and, depending on the primary fuel used for electric power generation, reduced emissions of carbon dioxide. A basic requirement for successfully

J. Dieckmann; D. Mallory

1991-01-01

190

Prospects for future hypersonic air-breathing vehicles  

NASA Technical Reports Server (NTRS)

An overview of the technical progress achieved in key areas of hypersonic airbreathing vehicle development is presented. The context for hypersonic applications is discussed with emphasis placed on technology issues and requirements, particularly for propulsion and technology integration. Attention is given to CFD technology which allows the consideration of configurations and extrapolations to flight conditions that cannot be simulated on the ground.

Beach, H. L., Jr.; Blankson, Isaiah M.

1991-01-01

191

Flight Dynamics and Modeling of a Morphing Air Vehicle  

Microsoft Academic Search

A basic model of a system employing morphing wing actuators is developed and simulated. The modeling process begins with considering Eulerian and Newtonian kinematics and dynamics as applied to the vehicle body. Several examples illustrate the importance of each fundamental principle in analytical description of moving bodies. The mass specifications are incorporated into a dynamic system in which the equations

Ali Moussawi; Manoranjan Majji; John L. Junkins

2007-01-01

192

Air System Management for Fuel Cell Vehicle Applications  

Microsoft Academic Search

Master's Thesis Research and development of fuel cell systems for multiple applications has dramatically increased in the past few years. The vehicular application of the fuel cell system as the powertrain leads to a number of unique challenges, namely physical packaging within the vehicle, durability and operation under extreme environmental conditions, and demanding duty cycles that include high peak power

JOSHUA MICHAEL CUNNINGHAM

2001-01-01

193

The C.G.E. circulating zinc\\/air battery - A practical vehicle power source  

Microsoft Academic Search

The currently proposed electric vehicle power sources are briefly summarized, and compared with the circulating zinc\\/air system. Based on current laboratory test data, this system should be capable of 110 Wh\\/kg, 80 W\\/kg in a 1 ton urban vehicle and up to 125 Wh\\/kg in heavy duty applications, with lifetimes up to twice those for lead-acid systems. Despite its comparatively

A. J. Appleby; M. Jacquier

1976-01-01

194

Intelligent energy management control of vehicle air conditioning via look-ahead system  

Microsoft Academic Search

Air conditioning systems (A\\/C) significantly increase the energy consumption of a vehicle and negatively influence its performance. A\\/C can be considered the main auxiliary load on a vehicle engine when it is operating. Thus, there are significant savings to be made by operating an A\\/C system smartly, both in terms of running costs and the effect on the environment. This

Hamid Khayyam; Saeid Nahavandi; Eric Hu; Abbas Kouzani; Ashley Chonka; Jemal Abawajy; Vincenzo Marano; Sam Davis

2011-01-01

195

Complete endocardial cushion defects in pregnancy: a case report  

PubMed Central

Introduction Complete endocardial cushion defect is a congenital heart disease characterized by a variable deficiency of the atrioventricular area in the developing heart. The mortality rate for an unrepaired endocardial cushion defect in pregnancy and the postpartum period is high. Case presentation We present a rare case of a pregnant woman with complete endocardial cushion defect. A 20-year-old Chinese woman with unrepaired complete endocardial cushion defect delivered a premature male baby at 33 weeks and six days of pregnancy in our hospital. The baby had a normal human karyotype and a birth defect of hypospadias deformity. Our patient died from heart failure 10 minutes after delivery. She had severe pulmonary hypertension and suspected trisomy 21. Conclusion Our experience further emphasizes the necessity of prenatal screening for congenital heart defects and of prompt surgical correction for endocardial cushion defects during infancy. Mortality for endocardial cushion defect during pregnancy and the postpartum period is high and women with complete endocardial cushion defect should avoid pregnancy, especially those women who cannot intellectually judge their risks.

2014-01-01

196

Distributed pheromone-based swarming control of unmanned air and ground vehicles for RSTA  

NASA Astrophysics Data System (ADS)

The use of unmanned vehicles in Reconnaissance, Surveillance, and Target Acquisition (RSTA) applications has received considerable attention recently. Cooperating land and air vehicles can support multiple sensor modalities providing pervasive and ubiquitous broad area sensor coverage. However coordination of multiple air and land vehicles serving different mission objectives in a dynamic and complex environment is a challenging problem. Swarm intelligence algorithms, inspired by the mechanisms used in natural systems to coordinate the activities of many entities provide a promising alternative to traditional command and control approaches. This paper describes recent advances in a fully distributed digital pheromone algorithm that has demonstrated its effectiveness in managing the complexity of swarming unmanned systems. The results of a recent demonstration at NASA's Wallops Island of multiple Aerosonde Unmanned Air Vehicles (UAVs) and Pioneer Unmanned Ground Vehicles (UGVs) cooperating in a coordinated RSTA application are discussed. The vehicles were autonomously controlled by the onboard digital pheromone responding to the needs of the automatic target recognition algorithms. UAVs and UGVs controlled by the same pheromone algorithm self-organized to perform total area surveillance, automatic target detection, sensor cueing, and automatic target recognition with no central processing or control and minimal operator input. Complete autonomy adds several safety and fault tolerance requirements which were integrated into the basic pheromone framework. The adaptive algorithms demonstrated the ability to handle some unplanned hardware failures during the demonstration without any human intervention. The paper describes lessons learned and the next steps for this promising technology.

Sauter, John A.; Mathews, Robert S.; Yinger, Andrew; Robinson, Joshua S.; Moody, John; Riddle, Stephanie

2008-05-01

197

Comparisons of rocket and air-breathing vehicle concepts for earth-to-orbit transportarion  

NASA Astrophysics Data System (ADS)

To illustrate that there is ample room for improvement in earth-to-orbit reliability, transportation cost and environmental cleanliness, some future European launch vehicle concepts are presented. Varying assumptions of technology level and operational strategy offer a wide range of system/subsystem options for consideration. Specific examples cited include: the advanced reusable single-stage VTOL all-rocket vehicles, the all-liquid hydrogen-oxygen variants of Ariane 5, and the advanced one-and-a-half-stage horizontal take-off air-breathing vehicles.

Dorrington, G. E.

1990-07-01

198

Indoor-outdoor air quality relationships in vehicle: effect of driving environment and ventilation modes  

NASA Astrophysics Data System (ADS)

Nitrogen oxides and carbon monoxide concentration were measured inside and outside of a light-goods-vehicle at different locations and driving conditions for a 6-month period. To investigate the exposure of the vehicle passenger to the specified outdoor pollutant, the indoor-outdoor air quality (IO) relationships under various driving conditions, namely traffic density, ventilation modes and type of roadway were studied. Four main types of driving environments were selected: highway, countryside, urban street and tunnel. The vehicle was driven under the three main types of ventilation conditions: air-conditioning with air-recirculation, air-conditioning with fresh air intake and natural ventilation. It is found that the IO ratio is not specific only to the mode of ventilation but also depends on the driving environment. The IO value can vary drastically even using the same ventilation mode when the vehicle is travelling in a different environment. It is found that using fresh-air ventilation mode, the IO can change from approximately 0.5-3 as it commutes from a highway to the countryside. The results also indicate that indoor NO level increased as the traffic density increases. The fluctuation of indoor NO level of naturally ventilated vehicle followed the variation of outdoor NO concentration with the IO value varying from 0.5 to 5. The results also show that even in an air-conditioned van, the indoor NO and CO concentration is significantly affected by that outdoor. It suggests the use of different ventilation mode when commuting in different environment.

Chan, Andy T.; Chung, Michael W.

199

Configuration Studies of Personal Air Vehicles. Personal Air Vehicle and Flying Jeep Concepts: A Commentary on Promising Approaches or What Goes Around Comes Around (About Every Twenty Years)  

NASA Technical Reports Server (NTRS)

The NASA/Langley Personal Air Vehicle (PAV) Exploration (PAVE) and the DARPA (Defense Advanced Research Projects Agency) Dual Air/Road Transportation System (DARTS) projects were established to investigate the feasibility of creating vehicles which could replace, or at the very least augment, personal ground and air transportation schemes. This overall goal implies integrating several technology areas with practical everyday transportation requirements to design a class of vehicles which will achieve the following goals: (1) Vertical, Extremely Short, or Short Takeoff and Landing (VTOL, ESTOL, STOL) capability; (2) Operation at block speeds markedly faster than current combinations of land and air transportation, particularly in critical market areas; (3) Unit cost comparable to current luxury cars and small general aviation aircraft; (4) Excellent reliability; (5) Excellent safety; (6) Ability to integrate with existing land and air transportation systems. The conclusions of these configuration studies are summarized as follows: (1) Creation of the five assigned configurations prompted added explorations, some of which were dead-ends; (2) Some components could be common to all configurations such as avionics and dual-mode suspension schemes; (3) Single-Mode PAVs can be created by removing dual-mode-specific items; (4) Aviation history provided some intriguing starting points, as in what goes around comes around; (5) CTOL (Conventional Take-off and Landing) and STOL dual-mode PAVs look feasible with single-mode PAVs being simplifications of the dual-mode approach; (6) VTOL PAVs will require development; (7) More exotic collapsing mechanisms mechanisms need development; (8) As a teaching tool, PAVs are not yet a well-enough bounded design problem.

Hall, David W.

2001-01-01

200

Affordable Flight Demonstration of the GTX Air-Breathing SSTO Vehicle Concept  

NASA Technical Reports Server (NTRS)

The rocket based combined cycle (RBCC) powered single-stage-to-orbit (SSTO) reusable launch vehicle has the potential to significantly reduce the total cost per pound for orbital payload missions. To validate overall system performance, a flight demonstration must be performed. This paper presents an overview of the first phase of a flight demonstration program for the GTX SSTO vehicle concept. Phase 1 will validate the propulsion performance of the vehicle configuration over the supersonic and hypersonic airbreathing portions of the trajectory. The focus and goal of Phase 1 is to demonstrate the integration and performance of the propulsion system flowpath with the vehicle aerodynamics over the air-breathing trajectory. This demonstrator vehicle will have dual mode ramjet/scramjets, which include the inlet, combustor, and nozzle with geometrically scaled aerodynamic surface outer mold lines (OML) defining the forebody, boundary layer diverter, wings, and tail. The primary objective of this study is to demonstrate propulsion system performance and operability including the ram to scram transition, as well as to validate vehicle aerodynamics and propulsion airframe integration. To minimize overall risk and development cost the effort will incorporate proven materials, use existing turbomachinery in the propellant delivery systems, launch from an existing unmanned remote launch facility, and use basic vehicle recovery techniques to minimize control and landing requirements. A second phase would demonstrate propulsion performance across all critical portions of a space launch trajectory (lift off through transition to all-rocket) integrated with flight-like vehicle systems.

Krivanek, Thomas M.; Roche, Joseph M.; Riehl, John P.; Kosareo, Daniel N.

2002-01-01

201

Improving the aluminum-air battery system for use in electrical vehicles  

NASA Astrophysics Data System (ADS)

The objectives of this study include improvement of the efficiency of the aluminum/air battery system and demonstration of its ability for vehicle applications. The aluminum/air battery system can generate enough energy and power for driving ranges and acceleration similar to that of gasoline powered cars. Therefore has the potential to be a power source for electrical vehicles. Aluminum/air battery vehicle life cycle analysis was conducted and compared to that of lead/acid and nickel-metal hydride vehicles. Only the aluminum/air vehicles can be projected to have a travel range comparable to that of internal combustion engine vehicles (ICE). From this analysis, an aluminum/air vehicle is a promising candidate compared to ICE vehicles in terms of travel range, purchase price, fuel cost, and life cycle cost. We have chosen two grades of Al alloys (Al alloy 1350, 99.5% and Al alloy 1199, 99.99%) in our study. Only Al 1199 was studied extensively using Na 2SnO3 as an electrolyte additive. We then varied concentration and temperature, and determined the effects on the parasitic (corrosion) current density and open circuit potential. We also determined cell performance and selectivity curves. To optimize the performance of the cell based on our experiments, the recommended operating conditions are: 3--4 N NaOH, about 55°C, and a current density of 150--300 mA/cm2. We have modeled the cell performance using the equations we developed. The model prediction of cell performance shows good agreement with experimental data. For better cell performance, our model studies suggest use of higher electrolyte flow rate, smaller cell gap, higher conductivity and lower parasitic current density. We have analyzed the secondary current density distributions in a two plane, parallel Al/air cell and a wedge-type Al/air cell. The activity of the cathode has a large effect on the local current density. With increases in the cell gap, the local current density increases, but the increase is not as significant as the increase in the current density away from the entrance. By extending the cathode below the anode, the high local current density can be reduced.

Yang, Shaohua

202

Use of cooperative unmanned air and ground vehicles for detection and disposal of mines  

NASA Astrophysics Data System (ADS)

The objective of this research is to extend the sensing capabilities of a multi-vehicle ground system by incorporating the environmental perception abilities of unmanned aerial vehicles. The aerial vehicle used in this research is a Miniature Aircraft Gas Xcell RC helicopter. It is outfitted with a sensor payload containing stereo vision cameras, GPS, and a digital compass. Geo- referenced images are gathered using the above sensors that are used in this research to create a map of the operating region. The ground vehicle used in this research is an automated Suzuki Mini-Quad ATV. It has the following onboard sensors: single-vision camera, laser range device, digital compass, GPS, and an encoder. The ground vehicle uses the above sensors and the map provided by the helicopter to traverse the region, locate, and isolate simulated land mines. The base station consists of a laptop that provides a communication link between the aerial and ground vehicle systems. It also provides the operator with system operation information and statistics. All communication between the vehicles and the base station is performed using JAUS (Joint Architecture for Unmanned Systems) messages. The JAUS architecture is employed as a means to organize inter-vehicle and intra-vehicle communication and system component hierarchy. The purpose of JAUS is to provide interoperability between various unmanned systems and subsystems for both military and commercial applications. JAUS seeks to achieve this through the development of functionally cohesive building blocks called components whose interface messages are clearly defined. The JAUS architecture allows for a layered control strategy which has specific message sets for each layer of control. Implementation of the JAUS architecture allows for ease of software development for a multi- vehicle system. This experiment demonstrates how an air-ground vehicle system can be used to cooperatively locate and dispose of simulated mines.

Zawodny MacArthur, Erica; MacArthur, Donald; Crane, Carl

2005-11-01

203

Seacoaster advanced marine vehicle. Final report  

SciTech Connect

The Seacoaster combines the high efficiencies of Surface Effect Ships (SES) with simple catamaran hull construction. It has blower pressurized air cushions that support some 80-90 percent of displacement and hence the high efficiencies. However, unlike the SES, there are no expensive and high maintenance flexible seals. Each catamaran sidehull has a simple recess molded or built into its underside. Powered blowers direct pressurized air into such recesses and thereby create lifting air cushions. There are no flexible seals of any kind and there is no air cushion between the sidehulls. Extensive towed model tests were conducted that showed the viability of the invention.

Burg, D.

1998-08-18

204

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

Microsoft Academic Search

Aluminum (Al)\\/air batteries have the potential to be used to produce power to operate cars and other vehicles. These batteries might be important on a long-term interim basis as the world passes through the transition from gasoline cars to hydrogen fuel cell cars. The Al\\/air battery system can generate enough energy and power for driving ranges and acceleration similar to

Shaohua Yang; Harold Knickle

2002-01-01

205

Parameter analysis of a practical lithium- and sodium-air electric vehicle battery  

Microsoft Academic Search

For electric vehicles (EV) having a 500km range between charges, there is a need to develop smaller and lower-cost batteries. Lithium-air has the potential to deliver a step change in the specific energy of rechargeable lithium batteries. In order to develop a practical, safe, smaller and lower-cost lithium and sodium-air rechargeable EV battery it is necessary to eliminate the formation

E. Peled; D. Golodnitsky; H. Mazor; M. Goor; S. Avshalomov

2011-01-01

206

Mission planning algorithm for autonomous control system of unmanned air vehicle  

NASA Astrophysics Data System (ADS)

Unmanned Air Vehicles (UAVs) are becoming an integral part of future military forces. This paper presents a three-layer autonomous control architecture for UAV and discusses how each layer functions to enable autonomous operation of UAV. Mission planning is the kernel of UAV autonomous control system. In this paper, PGG (Plan-Goal Graph)-based mission planning algorithm is discussed in detail and used to solve the UAV Suppress Enemy Air Defense (SEAD) mission planning problem successfully.

Yu, Zhouyi; Zhou, Rui; Chen, Zongji

2003-09-01

207

Trajectory Planning For Coordinated Rendezvous Of Unmanned Air Vehicles  

Microsoft Academic Search

A trajectory generation strategy that facilitatesthe coordination of multiple unmanned air vehiclesis developed. Of particular interest is the planning ofthreat-avoiding trajectories that result in the simultaneousarrival of multiple UAVs at their targets. Inthis approach, paths to the target are modeled usingthe physical analogy of a chain. A unique strengthof the planning approach is the ability to specify oralter the pathlength

Timothy W. Mclain; Randal W. Beard

2000-01-01

208

Development of Micro Air Reconnaissance Vehicle as a Test Bed for Advanced Sensors and Electronics  

NASA Technical Reports Server (NTRS)

This paper describes the development of a Micro/Mini Air Reconnaissance Vehicle for advanced sensors and electronics at NASA Langley Research Center over the last year. This vehicle is expected to have a total weight of less than four pounds, a design velocity of 40 mph, an endurance of 15-20 minutes, and a maximum range of 5km. The vehicle has wings that are simple to detach yet retain the correct alignment. The upper fuselage surface has a quick release hatch used to access the interior and also to mount the varying propulsion systems. The sensor suite developed for this vehicle consists of a Pitot-static measurement system for determining air speed, an absolute pressure measurement for determining altitude, magnetic direction measurement, and three orthogonal gyros to determine body angular rates. Swarming GPS-guidance and in-flight maneuvering is discussed, as well as design and installation of some other advance sensors like MEMS microphones, infrared cameras, GPS, humidity sensors, and an ultrasonic sonar sensor. Also low cost, small size, high performance control and navigation system for the Micro Air Vehicle is discussed. At the end, laboratory characterization of different sensors, motors, propellers, and batteries will be discussed.

Shams, Qamar A.; Vranas, Thomas L.; Fox, Robert L.; Kuhn, Theodore R.; Ingham, John; Logan, Michael J.; Barnes, Kevin N.; Guenther, Benjamin F.

2002-01-01

209

Development and Evaluation of Polyurethane Loose Fill Cushioning Material.  

National Technical Information Service (NTIS)

The objectives of this study were to provide a polyurethane loosefill cushioning material suitable for the protection of lightweight, fragile items and to determine if polyurethane sheet stock materials can be reused in a loosefill form. Two densities of ...

R. V. Brown

1974-01-01

210

CFD based aerodynamic modeling to study flight dynamics of a flapping wing micro air vehicle  

NASA Astrophysics Data System (ADS)

The demand for small unmanned air vehicles, commonly termed micro air vehicles or MAV's, is rapidly increasing. Driven by applications ranging from civil search-and-rescue missions to military surveillance missions, there is a rising level of interest and investment in better vehicle designs, and miniaturized components are enabling many rapid advances. The need to better understand fundamental aspects of flight for small vehicles has spawned a surge in high quality research in the area of micro air vehicles. These aircraft have a set of constraints which are, in many ways, considerably different from that of traditional aircraft and are often best addressed by a multidisciplinary approach. Fast-response non-linear controls, nano-structures, integrated propulsion and lift mechanisms, highly flexible structures, and low Reynolds aerodynamics are just a few of the important considerations which may be combined in the execution of MAV research. The main objective of this thesis is to derive a consistent nonlinear dynamic model to study the flight dynamics of micro air vehicles with a reasonably accurate representation of aerodynamic forces and moments. The research is divided into two sections. In the first section, derivation of the nonlinear dynamics of flapping wing micro air vehicles is presented. The flapping wing micro air vehicle (MAV) used in this research is modeled as a system of three rigid bodies: a body and two wings. The design is based on an insect called Drosophila Melanogaster, commonly known as fruit-fly. The mass and inertial effects of the wing on the body are neglected for the present work. The nonlinear dynamics is simulated with the aerodynamic data published in the open literature. The flapping frequency is used as the control input. Simulations are run for different cases of wing positions and the chosen parameters are studied for boundedness. Results show a qualitative inconsistency in boundedness for some cases, and demand a better aerodynamic data. The second part of research involves preliminary work required to generate new aerodynamic data for the nonlinear model. First, a computational mesh is created over a 2-D wing section of the MAV model. A finite volume based computational flow solver is used to test different flapping trajectories of the wing section. Finally, a parametric study of the results obtained from the tests is performed.

Rege, Alok Ashok

211

Towards Flight Autonomy: Vision-Based Horizon Detection for Micro Air Vehicles  

Microsoft Academic Search

Recently, substantial progress has been made towards design- ing, building and test-flying remotely piloted Micro Air Vehicles (MAVs). This progress in overcoming the aerodynamic obstacles to flight at very small scales has, unfortunately, not been matched by similar progress in autonomous MAV flight. Thus, we propose a robust, vision-based horizon detection algorithm as the first step towards autonomous MAVs. In

Scott M. Ettinger; Michael C. Nechyba; Peter G. Ifju; Martin Waszak

212

Vision-guided flight stability and control for micro air vehicles  

Microsoft Academic Search

Substantial progress has been made recently towards designing, building and test-flying remotely piloted Micro Air Vehicles (MAVs) and small UAVs. We seek to complement this progress in overcoming the aerodynamic obstacles to flight at very small scales with a vision-guided flight stability and autonomy system, based on a robust horizon detection algorithm. In this paper, we first motivate the use

S. M. Ettinger; Michael C. Nechyba; Peter G. Ifju; Martin Waszak

2002-01-01

213

Hazardous Particle Detection via Unmanned Air Vehicles: Optimal Placement of Sensors in Forward Flight.  

National Technical Information Service (NTIS)

This project explores means of enhancing the efficiency of bio/chem/nuclear hazard detection in the atmosphere by unmanned air vehicles (UAV). Specifically, the study seeks to discover if and where the placement of sensors on UAV's can maximize the volume...

J. Krispin P. S. Bernard

2010-01-01

214

Vision-based Target Geo-location using a Fixed-wing Miniature Air Vehicle  

Microsoft Academic Search

This paper presents a method for determining the GPS location of a ground-based object when imaged from a fixed-wing miniature air vehicle (MAV). Using the pixel lo- cation of the target in an image, with measurements of MAV position and attitude, and camera pose angles, the target is localized in world coordinates. The main contribution of this paper is to

D. Blake Barber; Joshua D. Redding; Timothy W. Mclain; Randal W. Beard; Clark N. Taylor

2006-01-01

215

Autonomous Robotic System for Locating Air Leakage in Manned Space Vehicles  

Microsoft Academic Search

With increased interest in manned space exploration, there is a need to develop specialized methods for the detection of air leakage from spacecraft. This paper will focus on using a free-flying robot to autonomously locate the leakage from the exterior of the vehicle. It will discuss possible options for leakage sensor selection\\/design, navigation and control of the robot, and collision

H. Inoue; K. Onda; N. Shirota; S. Sato; T. Sonoda

216

Design and Prototype Development of a Wireless Power Transmission System for a Micro Air Vehicle (MAV).  

National Technical Information Service (NTIS)

Microwave radiation at 1.0 GHz and 1.3 GHz is used to demonstrate remote powering of a micro air vehicle (MAV). Several prototype microwave rectifier systems were fabricated in microstrip using EEsof(registered) computer aided engineering (CAE) software t...

R. L. Vitale

1999-01-01

217

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

218

Tests of a full-sized mechanically rechargeable zinc-air battery in an electric vehicle  

Microsoft Academic Search

A mechanically rechargeable zinc-air battery that has high power density and fast refueling capability is described. The battery is built from modules of 32 or 44 cells connected in series, and the modules can be arranged in any combination of series and parallel connections, and in practical quantity, according to the requirements of the vehicle, motor, and controller. The results

J. R. Goldstein; B. Koretz

1993-01-01

219

Artificial insect wings of diverse morphology for flapping-wing micro air vehicles  

Microsoft Academic Search

The development of flapping-wing micro air vehicles (MAVs) demands a systematic exploration of the available design space to identify ways in which the unsteady mechanisms governing flapping-wing flight can best be utilized for producing optimal thrust or maneuverability. Mimicking the wing kinematics of biological flight requires examining the potential effects of wing morphology on flight performance, as wings may be

J K Shang; S A Combes; B M Finio; R J Wood

2009-01-01

220

Image Multiresolution Discriminant Analysis for Vision-Guided Stability of Micro Air Vehicles  

Microsoft Academic Search

Recently, we have successfully implemented and tested a vision based horizon-tracking algorithm for flight stability and autonomy in Micro Air Vehicles (MAVs). Occa- sionally, this algorithm fails in scenarios where the underlying Gaussian assumption for the sky and ground appearances is not appropriate. To improve its performance, especially in the presence of video noise, we consider a novel image analy-

Sinisa Todorovic; Michael C. Nechyba; Antonio A. Arroyo

221

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

222

A hardware in the loop simulation platform for vision-based control of unmanned air vehicles  

Microsoft Academic Search

Design and testing of control algorithms for unmanned air vehicles (UAV’s) is difficult due to the delicate and expensive nature of UAV systems, the risk of damage to property during testing, and government regulations. This necessitates extensive simulation of controllers to ensure stability and performance. However, simulations cannot capture all aspects of a flight control, such as sensor noise and

N. R. Gans; W. E. Dixon; R. Lind; A. Kurdila

2009-01-01

223

Follow-up Study on Wireless Power Transmission for Unmanned Air Vehicles.  

National Technical Information Service (NTIS)

This thesis was a continuation in part of a NPS project relating to microwave wireless power transmission for micro air vehicles (MAVs). The concept of using microwaves for transferring power in free space has existed since the beginning of the 20th centu...

L. H. Toh

2007-01-01

224

Development of Micro Air Vehicle Based on Aerodynamic Modeling Analysis in Tunnel Tests  

Microsoft Academic Search

This paper presents development of an electrically powered Micro Air Vehicle (MAV) prototype based on aerodynamic analysis in wind tunnel and water tunnel tests. Two airframe models in triangle and square wing planforms, each with a wingspan of 100mm, are analyzed with a small-scale low speed wind tunnel to examine the practical characteristics at the low Reynolds number. The test

Dong Sun; Huai-yu Wu; Rong Zhu; Ling Che Hung

2005-01-01

225

Computational Investigation of Flapping-Wing Propulsion for a Micro-Air Vehicle.  

National Technical Information Service (NTIS)

The low Reynolds number aerodynamics of the flapping-wing Micro-Air Vehicle (MAV) developed at NPS by Max Platzer and Kevin Jones was studied numerically. The dynamic mesh simulation model of the full multi-wing configuration, which consists of a fixed wi...

S. C. Lim

2006-01-01

226

Vision-guided flight stability and control for micro air vehicles  

Microsoft Academic Search

Substantial progress has been made recently towards design- ing, building and test-flying remotely piloted Micro Air Vehicles (MAVs) and small UAVs. We seek to complement this progress in overcoming the aerodynamic obstacles to flight at very small scales with a vision-guided flight stability and autonomy system , based on a robust horizon detection algorithm. In this paper, we first motivate

Scott M. Ettinger; Michael C. Nechyba; Peter G. Ifju; Martin Waszak

2003-01-01

227

Propane-Air Peakshaving Impact on Natural Gas Vehicles. Topical Report, August 1993-January 1997.  

National Technical Information Service (NTIS)

Propane-air peakshaving activities can lead to higher-than-normal propane levels in natural gas. Natural gas vehicle (NGV) fueling station operation and NGV performance can be affected by the presence of excess propane in natural gas. To assess the impact...

M. E. Richards Y. Shikari C. F. Blazek

1997-01-01

228

Rehabilitation of the Rocket Vehicle Integration Test Stand at Edwards Air Force Base  

NASA Technical Reports Server (NTRS)

Since initial use in 1958 for the X-15 rocket-powered research airplane, the Rocket Engine Test Facility has proven essential for testing and servicing rocket-powered vehicles at Edwards Air Force Base. For almost two decades, several successful flight-test programs utilized the capability of this facility. The Department of Defense has recently demonstrated a renewed interest in propulsion technology development with the establishment of the National Aerospace Initiative. More recently, the National Aeronautics and Space Administration is undergoing a transformation to realign the organization, focusing on the Vision for Space Exploration. These initiatives provide a clear indication that a very capable ground-test stand at Edwards Air Force Base will be beneficial to support the testing of future access-to-space vehicles. To meet the demand of full integration testing of rocket-powered vehicles, the NASA Dryden Flight Research Center, the Air Force Flight Test Center, and the Air Force Research Laboratory have combined their resources in an effort to restore and upgrade the original X-15 Rocket Engine Test Facility to become the new Rocket Vehicle Integration Test Stand. This report describes the history of the X-15 Rocket Engine Test Facility, discusses the current status of the facility, and summarizes recent efforts to rehabilitate the facility to support potential access-to-space flight-test programs. A summary of the capabilities of the facility is presented and other important issues are discussed.

Jones, Daniel S.; Ray, Ronald J.; Phillips, Paul

2005-01-01

229

Design of an air sampler for a small unmanned aerial vehicle.  

PubMed

In the aftermath of a nuclear accident or malevolent act, it is of paramount importance to have the capability to monitor airborne radioactive substances by collecting air samples. For potentially dangerous missions, the Radiation and Nuclear Safety Authority of Finland (STUK) has developed an air sampler to be used on a small unmanned aerial vehicle. When a Petrianov or Fluoropore filter is used in the sampler and the air velocity is 71 km h(-1), the air flow rate through the filter is 0.73 m(3) h(-1) or 0.23 m(3) h(-1), respectively. The present article introduces the developed air sampler using fluid dynamic simulations and wind tunnel data. The operation of the system was validated by collecting airborne radioactive aerosols from air. PMID:19091809

Peräjärvi, K; Lehtinen, J; Pöllänen, R; Toivonen, H

2008-01-01

230

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

231

Retention of supportive properties by eggcrate and foam wheelchair cushions.  

PubMed

This study investigated the reported lack of ability of the eggcrate cushion (EC) to provide wheelchair users with adequate support necessary for comfort and tolerably low-peak sitting pressures over time. The primary parameter used to quantify the ability of the cushion to distribute load was the indention force deflection (IFD) metric. The EC was compared to a high-density planar foam cushion (HD). The IFD was measured for both cushions after successive periods of compression to simulate use. Study results failed to support the common perception that the soft EC would lose its supportive properties more rapidly than the much firmer HD cushion. Although the initial IFD of the EC was much lower than that of the HD, a smaller percentage of its IFD was lost after compression. This difference between the two cushions likely was due to differences in packaging. The EC was rolled into a cylinder, compressing it to 60% of its original thickness; the HD was packaged without compression. PMID:10220217

Shaw, C G

1998-10-01

232

Thermal performance of aircraft polyurethane seat cushions  

NASA Technical Reports Server (NTRS)

Measurements were conducted on 7.6 x 7.6 cm samples of polyurethane seat cushion material in a modified National Bureau of Standards smoke density chamber to simulate real life conditions for an onboard aircraft fire or post-crash fire. In this study, a non-flaming heat radiation condition was simulated. Two aluminized polymeric fabrics (Norfab 11HT-26-A and Preox 1100-4) and one neoprene type material in two thicknesses (Vonar 2 and 3) were tested as heat blocking layers to protect the urethane foam from rapid heat degradation. Thermogravimetric analysis and differential scanning calorimetry were performed to characterize thermally the materials tested. It was found that Vonar 2 or 3 provided approximately equal thermal protection to F.R. urethane as the aluminized fabrics, but at a significant weight penalty. The efficiency of the foams to absorb heat per unit mass loss when protected with the heat blocking layer decreases in the heating range of 2.5-5.0 W/sq cm, but remains unchanged or slightly increases in the range of 5.0-7.5 W/sq cm. The results show that at all heat flux ranges tested the usage of a heat blocking layer in aircraft seats significantly improves their thermal performance.

Kourtides, D. A.; Parker, J. A.

1982-01-01

233

Performance Validation Approach for the GTX Air-Breathing Launch Vehicle  

NASA Technical Reports Server (NTRS)

The primary objective of the GTX effort is to determine whether or not air-breathing propulsion can enable a launch vehicle to achieve orbit in a single stage. Structural weight, vehicle aerodynamics, and propulsion performance must be accurately known over the entire flight trajectory in order to make a credible assessment. Structural, aerodynamic, and propulsion parameters are strongly interdependent, which necessitates a system approach to design, evaluation, and optimization of a single-stage-to-orbit concept. The GTX reference vehicle serves this purpose, by allowing design, development, and validation of components and subsystems in a system context. The reference vehicle configuration (including propulsion) was carefully chosen so as to provide high potential for structural and volumetric efficiency, and to allow the high specific impulse of air-breathing propulsion cycles to be exploited. Minor evolution of the configuration has occurred as analytical and experimental results have become available. With this development process comes increasing validation of the weight and performance levels used in system performance determination. This paper presents an overview of the GTX reference vehicle and the approach to its performance validation. Subscale test rigs and numerical studies used to develop and validate component performance levels and unit structural weights are outlined. The sensitivity of the equivalent, effective specific impulse to key propulsion component efficiencies is presented. The role of flight demonstration in development and validation is discussed.

Trefny, Charles J.; Roche, Joseph M.

2002-01-01

234

Impact of aeroelasticity on propulsion and longitudinal flight dynamics of an air-breathing hypersonic vehicle  

NASA Technical Reports Server (NTRS)

Many air-breathing hypersonic aerospacecraft design concepts incorporate an elongated fuselage forebody acting as the aerodynamic compression surface for a hypersonic combustion module, or scram jet. This highly integrated design approach creates the potential for an unprecedented form of aero-propulsive-elastic interaction in which deflections of the vehicle fuselage give rise to propulsion transients, producing force and moment variations that may adversely impact the rigid body flight dynamics and/or further excite the fuselage bending modes. To investigate the potential for such interactions, a math model was developed which included the longitudinal flight dynamics, propulsion system, and first seven elastic modes of a hypersonic air-breathing vehicle. Perturbation time histories from a simulation incorporating this math model are presented that quantify the propulsive force and moment variations resulting from aeroelastic vehicle deflections. Root locus plots are presented to illustrate the effect of feeding the propulsive perturbations back into the aeroelastic model. A concluding section summarizes the implications of the observed effects for highly integrated hypersonic air-breathing vehicle concepts.

Raney, David L.; Mcminn, John D.; Pototzky, Anthony S.; Wooley, Christine L.

1993-01-01

235

Assessment of air quality in a commercial cattle transport vehicle in Swedish summer and winter conditions.  

PubMed

Transport by road can induce significant stress in cattle. Thermal stress is among the main stress producing factors during transport. The provision of ventilation in livestock transport vehicles is usually through openings along the sides of the vehicle. The incoming air will affect air quality inside by regulating temperature, relative humidity, gas levels and levels of other contaminants. The aim of the present investigation was to map out the air quality in a commercial cattle transport vehicle under various climatic conditions and with varying stocking densities and transport times. Distributions of air temperature, relative humidity and concentrations of ammonia, carbon dioxide, oxygen and methane have been determined during 35 experimental journeys. In average the mean temperature inside the compartment was about 3 degrees C and 6 degrees C higher than outside temperature in summer (+7.8(-)+24.0 degrees C) and winter (-24.3(-)+12.7 degrees C) conditions respectively. The temperature increment inside, as could be expected from theory, increased with reduced ventilation and increased animal density. Many stops to load new animals lowered the temperature increment and relative humidity in winter time. In summer more stops made the compartment temperature and relative humidity increase. The inside temperature distribution was less than about 3 degrees C during both summer and winter season. Average ammonia level varied between 3 and 6 ppm depending on stocking density and number of stops with a maximum value of 18 ppm. No detectable methane levels could be found inside the compartment at any time. PMID:12731108

Wikner, I; Gebresenbet, G; Nilsson, C

2003-03-01

236

Cleaning the Air and Improving Health with Hydrogen Fuel-Cell Vehicles  

NASA Astrophysics Data System (ADS)

Converting all U.S. onroad vehicles to hydrogen fuel-cell vehicles (HFCVs) may improve air quality, health, and climate significantly, whether the hydrogen is produced by steam reforming of natural gas, wind electrolysis, or coal gasification. Most benefits would result from eliminating current vehicle exhaust. Wind and natural gas HFCVs offer the greatest potential health benefits and could save 3700 to 6400 U.S. lives annually. Wind HFCVs should benefit climate most. An all-HFCV fleet would hardly affect tropospheric water vapor concentrations. Conversion to coal HFCVs may improve health but would damage climate more than fossil/electric hybrids. The real cost of hydrogen from wind electrolysis may be below that of U.S. gasoline.

Jacobson, M. Z.; Colella, W. G.; Golden, D. M.

2005-06-01

237

Orbit-on-demand vehicle propelled by air-turborocket/ramjet engines  

NASA Technical Reports Server (NTRS)

A preliminary design study has been completed for a fully reusable, single-stage-to-orbit transatmospheric vehicle. The specified mission capability was to lift a 20,000 lb payload to low earth orbit. A ground accelerator-assisted horizontal take-off was chosen to increase operational flexibility. The multi-mode propulsion system included the use of air-turborocket, ramjet, scramjet and rocket engines. Weight and performance estimates were obtained for the vehicle. A computer package was developed to perform aerothermodynamic analyses of the propulsion modes throughout the flight environment from take-off to low earth orbit. Results are presented for a semi-optimized trajectory. The analysis indicates that a vehicle of this type has great potential for providing low cost, flexible access to space.

Hartung, L.; Karkow, J.; Ordway, W.; Pickett, D.; Muras, A.

1986-01-01

238

Analysis of possible improvement of acceleration of a high-velocity air-breathing flying vehicle  

NASA Astrophysics Data System (ADS)

Results of parametric calculations of the total aeropropulsive characteristics and characteristics of acceleration of a small-scale high-velocity flying vehicle with an air-breathing engine are presented. Integral parameters of acceleration from the flight Mach number M? = 4 to M? = 7 are determined, namely, the time required fuel stock, and range. A schematic configuration of the vehicle is considered, which allows studying the basic parameters, such as the forebody shape, the angles of surfaces of compression of the stream captured by the inlet, angles of external aerodynamic surfaces of the airframe, relative planform area of the wing panels, and relative area of the nozzle cross section. A comparative estimate of the effect of these parameters shows that it is possible to improve the characteristics of acceleration of vehicles of the type considered.

Goonko, Yu. P.; Mazhul, I. I.

2008-09-01

239

Cleaning the air and improving health with hydrogen fuel-cell vehicles  

SciTech Connect

Converting all U.S. onroad vehicles to hydrogen fuel-cell vehicles (HFCVs) may improve air quality, health, and climate significantly, whether the hydrogen is produced by steam reforming of natural gas, wind electrolysis, or coal gasification. Most benefits would result from eliminating current vehicle exhaust. Wind and natural gas HFCVs offer the greatest potential health benefits and could save 3700 to 6400 U.S. lives annually. Wind HFCVs should benefit climate most. An all-HFCV fleet would hardly affect tropospheric water vapor concentrations. Conversion to coal HFCVs may improve health but would damage climate more than fossil/electric hybrids. The real cost of hydrogen from wind electrolysis may be below that of U.S. gasoline.

Jacobson, M.Z.; Colella, W.G.; Golden, D.M. [Stanford University, Stanford, CA (US). Dept. of Civil & Environmental Engineering

2005-06-24

240

Interagency Workshop on Lighter than Air Vehicles, Monterey, Calif., September 9-13, 1974, Proceedings  

NASA Technical Reports Server (NTRS)

Papers are presented which review modern lighter-than-air (LTA) airship design concepts and LTA structures and materials technology, as well as perform economic and market analyses for assessment of the viability of future LTA development programs. Potential applications of LTA vehicles are examined. Some of the topics covered include preliminary estimates of operating costs for LTA transports, an economic comparison of three heavy lift airborn systems, boundary layer control for airships, computer aided flexible envelope designs, state-of-the-art of metalclad airships, aspects of hybrid-Zeppelins, the LTA vehicle as a total cargo system, unmanned powered balloons, and a practical concept for powered or tethered weight-lifting LTA vehicles. Individual items are announced in this issue.

Vittek, J. F., Jr.

1975-01-01

241

The Digital Twin Paradigm for Future NASA and U.S. Air Force Vehicles  

NASA Technical Reports Server (NTRS)

Future generations of NASA and U.S. Air Force vehicles will require lighter mass while being subjected to higher loads and more extreme service conditions over longer time periods than the present generation. Current approaches for certification, fleet management and sustainment are largely based on statistical distributions of material properties, heuristic design philosophies, physical testing and assumed similitude between testing and operational conditions and will likely be unable to address these extreme requirements. To address the shortcomings of conventional approaches, a fundamental paradigm shift is needed. This paradigm shift, the Digital Twin, integrates ultra-high fidelity simulation with the vehicle s on-board integrated vehicle health management system, maintenance history and all available historical and fleet data to mirror the life of its flying twin and enable unprecedented levels of safety and reliability.

Glaessgen, Edward H.; Stargel, D. S.

2012-01-01

242

An Air-Breathing Launch Vehicle Concept for Single-Stage-to-Orbit  

NASA Technical Reports Server (NTRS)

The "Trailblazer" is a 300-lb payload, single-stage-to-orbit launch vehicle concept that uses air-breathing propulsion to reduce the required propellant fraction. The integration of air-breathing propulsion is done considering performance, structural and volumetric efficiency, complexity, and design risk. The resulting configuration is intended to be viable using near-term materials and structures. The aeropropulsion performance goal for the Trailblazer launch vehicle is an equivalent effective specific impulse (I*) of 500 sec. Preliminary analysis shows that this requires flight in the atmosphere to about Mach 10, and that the gross lift-off weight is 130,000 lb. The Trailblazer configuration and proposed propulsion system operating modes are described. Preliminary performance results are presented, and key technical issues are highlighted. An overview of the proposed program plan is given.

Trefny, Charles J.

1999-01-01

243

Impact of Solar Control PVB Glass on Vehicle Interior Temperatures, Air-Conditioning Capacity, Fuel Consumption, and Vehicle Range.  

National Technical Information Service (NTIS)

The objective of the study was to assess the impact of a Saflex S Series solar control PVB (polyvinyl butyral) windshield on conventional vehicle fuel economy and electric vehicle (EV) range. The approach included outdoor vehicle thermal soak testing, Rad...

J. Rugh L. Chaney L. Ramroth M. Rose T. Venson

2013-01-01

244

A Predictive Model for Vehicle Air Exchange Rates based on a Large, Representative Sample  

PubMed Central

The in-vehicle microenvironment is an important route of exposure to traffic-related pollutants, particularly ultrafine particles. However, significant particle losses can occur under conditions of low air exchange rate (AER) when windows are closed and air is recirculating. AERs are lower for newer vehicles and at lower speeds. Despite the importance of AER in affecting in-vehicle particle exposures, few studies have characterized AER and all have tested only a small number of cars. One reason for this is the difficulty in measuring AER with tracer gases such as SF6 the most common method. We developed a simplified yet accurate method for determining AER using the occupants’ own production of CO2 a convenient compound to measure. By measuring initial CO2 build-up rates and equilibrium values of CO2 at fixed speeds, AER was calculated for 59 vehicles representative of California’s fleet. AER measurements correlated and agreed well with the largest other study conducted (R2=0.83). Multi-variable models captured 70% of the variability in observed AER using only age, mileage, manufacturer and speed. These results will be useful to exposure and epidemiological studies since all model variable values are easily obtainable through questionnaire.

Fruin, Scott A.; Hudda, Neelakshi; Sioutas, Constantinos; Delfino, Ralph J.

2014-01-01

245

Emissions of halocarbons from mobile vehicle air conditioning system in Hong Kong.  

PubMed

During the implementation of Montreal Protocol, emission inventories of halocarbons in different sectors at regional scale are fundamental to the formulation of relevant management strategy and inspection of the implementation efficiency. This study investigated the emission profile of halocarbons used in the mobile vehicle air conditioning system, the leading sector of refrigeration industry in terms of the refrigerant bank, market and emission, in the Hong Kong Special Administrative Region, using a bottom-up approach developed by 2006 IPCC Good Practice Guidance. The results showed that emissions of CFC-12 peaked at 53 tons ODP (Ozone Depletion Potential) in 1992 and then gradually diminished, whereas HFC-134a presented an increasing emission trend since 1990s and the emissions of HFC-134a reached 65,000 tons CO2-equivelant (CO2-eq) by the end of 2011. Uncertainty analysis revealed relatively high levels of uncertainties for special-purpose vehicles and government vehicles. Moreover, greenhouse gas (GHG) abatements under different scenarios indicated that potential emission reduction of HFC-134a ranged from 4.1 to 8.4×10(5)tons CO2-eq. The findings in this study advance our knowledge of halocarbon emissions from mobile vehicle air conditioning system in Hong Kong. PMID:24997256

Yan, H H; Guo, H; Ou, J M

2014-08-15

246

LTA in the USA - Here's where it stands today. [lighter than air vehicles  

NASA Technical Reports Server (NTRS)

Lighter than air (LTA) vehicles were the first aircraft to fly and, until the disasters of the 1930s, were thought by many to be the primary mode of air transport. The history of LTA in the United States is briefly traced and the reasons for the current revival in interest are discussed. The focal point for this revival was the LTA Workshop hosted by M.I.T. under the joint sponsorship of the United States National Aeronautics and Space Administration, Navy, Federal Aviation Administration and Department of Transportation. The Workshop and its results are discussed in detail.

Vittek, J. F., Jr.

1974-01-01

247

Characterization of on-road vehicle emission factors and microenvironmental air quality in Beijing, China  

Microsoft Academic Search

In this paper, we report the results and analysis of a recent field campaign in August 2007 investigating the impacts of emissions from transportation on air quality and community concentrations in Beijing, China. We conducted measurements in three different environments, on-road, roadside and ambient. The carbon monoxide, black carbon and ultrafine particle number emission factors for on-road light-duty vehicles are

Dane Westerdahl; Xing Wang; Xiaochuan Pan; K. Max Zhang

2009-01-01

248

Optimal path planning for unmanned air vehicles with kinematic and tactical constraints  

Microsoft Academic Search

We consider a class of 2D optimal path-planning problems for unmanned air vehicles (UAVs) with kinematic and tactical constraints. The existence of an optimal path class satisfying the UAV kinematic constraints and vector calculus are exploited to reduce this class of optimal path-planning problems to a parameter optimization problem. Illustrative tactical constraints arising in target touring and obstacle avoidance problems

Guang Yang; Vikram Kapila

2002-01-01

249

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

250

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

251

Optimization of MANET Connectivity Via Smart Deployment\\/Movement of Unmanned Air Vehicles  

Microsoft Academic Search

Unmanned air vehicles (UAVs) can provide important communication advantages to ground-based wireless ad hoc networks. In this paper, the location and movement of UAVs are optimized to improve the connectivity of a wireless network. Four types of network connectivity are quantified: global message connectivity, worst-case connectivity, network bisection connectivity, and k-connectivity. The problems of UAV deployment and movement are formulated

Zhu Han; A. Lee Swindlehurst; K. J. Ray Liu

2009-01-01

252

A Vision System for Horizon Tracking and Object Recognition for Micro Air Vehicles  

Microsoft Academic Search

In this paper, we develop a unified vision system for small-scale aircraft, known broadly as Micro Air Vehicles (MAVs), that not only addresses basic flight stability and co ntrol, but also enables more intelligent missions, such as ground object recognition and moving-object tracking. The proposed system defines a framework for real-time image feature extraction, horizon detection and sky\\/ground segmentation, and

Sinisa Todorovic; Michael C. Nechyba

253

A video geo-location and image enhancement tool for small unmanned air vehicles (UAVs)  

Microsoft Academic Search

This paper describes recent work conducted in collaboration with DSTO Australia and Aerosonde to develop video-based geolocation (targeting) and real-time enhancement of ground features observed from a small unmanned air vehicle (UAV). Here a combination of low-cost GPS, video and attitude sensors are used to estimate the object ground position whilst a simple super-resolution technique is used to enhance images

Danny Gibbins; Philip Roberts; Leszek Swierkowski

2004-01-01

254

Lightweight, fire-retardant, crashworthy aircraft seat cushioning  

NASA Technical Reports Server (NTRS)

A two page discussion of non-aerospace seating applications and the design of NASA's safety seat cushioning (SSC) is presented. The SSC was designed for both safety and comfort in order to replace polyurethane cushioning which is flammable and produces lethal fumes upon combustion. The SSC is composed of advanced fabric reinforced composites and is lightweight, fire-retardent, and crashworthy. The seat design consists of central elliptical tubular spring supports made of fire-resistant and fatigue-durable composites surrounded by a fire-blocking sheath. The cushioning is made crashworthy by incorporating energy-absorbing, viscoelastic layers between the nested, elliptical-hoop springs. The design is intended to provide comfortable seating that meets aircraft-loading requirements without using the conventional polyurethane materials. The designs of an aircraft seat and structural components of the SSC are also presented.

Haslim, Leonard A.; Mcdonough, Paul T.

1991-01-01

255

Contribution of vehicle emissions from an attached garage to residential indoor air pollution levels.  

PubMed

The infiltration of vehicle emissions into a house from the attached garage was studied for 16 homes of differing designs using the same extensively characterized vehicle at each home. Before the in-home measurement program, the cold-start and hot-start tailpipe emissions and hot-soak evaporative emissions from a 1993 Buick Regal were measured using standard vehicle emissions measurement methods. The emissions were chemically characterized for methane, nonmethane hydrocarbons (NMHC), and carbonyl compounds. The in-home measurements occurred over two winter seasons (1997-1998 and 1998-1999) in Ottawa, Ontario, Canada. Samples of indoor air and garage atmosphere were characterized for carbon monoxide, carbon dioxide, methane, NMHC, and carbonyl compounds. During the second year, real-time measurements of carbon, carbon dioxide, and total hydrocarbons were made to determine when and for how long the emissions plume infiltrates the house. Chemical mass balance modeling results using 31 NMHC species suggest that between 9 and 71% of the concentrations measured in the house during the hot-soak test and between 13 and 85% of the concentrations measured in the house during the cold-start test could be attributed to vehicle emissions infiltrating from the garage. In contrast, increases in carbonyl compound concentrations caused by the vehicle were difficult to detect above the already significant levels found in the houses. PMID:15149044

Graham, Lisa A; Noseworthy, Lianne; Fugler, Don; O'Leary, Kevin; Karman, Deniz; Grande, Carmela

2004-05-01

256

Ambient particulate air pollution from vehicles promotes lipid peroxidation and inflammatory responses in rat lung.  

PubMed

Oxidative stress plays a major role in the pathogenesis of particle-dependent lung injury. Ambient particle levels from vehicles have not been previously shown to cause oxidative stress to the lungs. The present study was conducted to a) determine whether short-term exposure to ambient levels of particulate air pollution from vehicles elicits inflammatory responses and lipid peroxidation in rat lungs, and b) determine if intermittent short-term exposures (every 4 days) induce some degree of tolerance. Three-month-old male Wistar rats were exposed to ambient particulate matter (PM) from vehicles (N = 30) for 6 or 20 continuous hours, or for intermittent (5 h) periods during 20 h for 4 consecutive days or to filtered air (PM <10 microm; N = 30). Rats continuously breathing polluted air for 20 h (P-20) showed a significant increase in the total number of leukocytes in bronchoalveolar lavage compared to control (C-20: 2.61 x 105 +/- 0.51;P-20: 5.01 x 105 +/- 0.81; P < 0.05) and in lipid peroxidation ([MDA] nmol/mg protein: C-20: 0.148 +/- 0.01; P-20: 0.226 +/- 0.02; P < 0.05). Shorter exposure (6 h) and intermittent 5-h exposures over a period of 4 days did not cause significant changes in leukocytes. Lipid damage resulting from 20-h exposure to particulate air pollution did not cause a significant increase in lung water content. These data suggest oxidative stress as one of the mechanisms responsible for the acute adverse respiratory effects of particles, and suggest that short-term inhalation of ambient particulate air pollution from street with high automobile traffic represents a biological hazard. PMID:17713644

Pereira, C E L; Heck, T G; Saldiva, P H N; Rhoden, C R

2007-10-01

257

Detail and experimental results of ferromagnetic levitation system of Japan air lines HSST-01\\/-02 vehicles  

Microsoft Academic Search

HSST is an acronym for high-speed surface transport and is the trade name of the vehicle levitated by the attractive electromagnets and propelled by the linear induction motor (LIM) developed by Japan Air Lines. Two test vehicles have been designed, manufactured, and flight-tested. The first test vehicle, HSST-01, marked a maximum speed of 307.8 km\\/h on a 1300-m long test

Y. Hikasa; Y. Takeuchi

1980-01-01

258

System 411L. Airborne Warning and Control System. System Study. Volume VII. System Substantiation - Air Vehicle Subsystems.  

National Technical Information Service (NTIS)

Contents: Air Vehicle Subsystem--Introduction, Secondary power (Secondary power subsystem selection, electrical power subsystem, hydraulic subsystem and auxiliary power unit), Airframe (Radome structural design, rotodome and support structural configurati...

1967-01-01

259

Environmental Assessment for Routine and Recurring Unmanned Aerial Vehicle Flight Operations at Edwards Air Force Base, California.  

National Technical Information Service (NTIS)

This Environmental Assessment evaluates the potential environmental impacts associated with the flight operations for test and evaluation of Unmanned Aerial Vehicles by the Air Force Flight Test Center within the R-2508 Complex of special use airspace and...

2006-01-01

260

Development of Optimized Piezoelectric Bending Actuators for Use in an Insect Sized Flapping Wing Micro Air Vehicle.  

National Technical Information Service (NTIS)

Piezoelectric bimorph actuators, as opposed to rotary electric motors, have been suggested as an actuation mechanism for flapping wing micro air vehicles (FWMAVs) because they exhibit favorable characteristics such as low weight, rapidly adaptable frequen...

R. K. Lenzen

2013-01-01

261

Potential benefits of oxygen-enriched intake air in a vehicle powered by a spark-ignition engine.  

National Technical Information Service (NTIS)

A production vehicle powered by a spark-ignition engine (3.1-L Chevrolet Lumina, model year 1990) was tested. The test used oxygen-enriched intake air containing 25 and 28% oxygen by volume to determine (1) if the vehicle would run without difficulties an...

H. K. Ng R. R. Sekar

1994-01-01

262

70 FR 72917 - Control of Air Pollution From New Motor Vehicles and New Motor Vehicle Engines: Technical...  

Federal Register 2010, 2011, 2012, 2013

...Vehicle Labeling requirements (40 CFR 86.098-35, 40 CFR 86.1807-01). Today's...vehicles which are chassis certified. 86.098- 35 previously applied to vehicle and...which are chassis certified. 40 CFR 86.098-35 previously applied to vehicle and...

2005-12-08

263

High Altitude Long Endurance Air Vehicle Analysis of Alternatives and Technology Requirements Development  

NASA Technical Reports Server (NTRS)

The objective of this study was to develop a variety of High Altitude Long Endurance (HALE) Unmanned Aerial Vehicle (UAV) conceptual designs for two operationally useful missions (hurricane science and communications relay) and compare their performance and cost characteristics. Sixteen potential HALE UAV configurations were initially developed, including heavier-than-air (HTA) and lighter-than-air (LTA) concepts with both consumable fuel and solar regenerative (SR) propulsion systems. Through an Analysis of Alternatives (AoA) down select process, the two leading consumable fuel configurations (one each from the HTA and LTA alternatives) and an HTA SR configuration were selected for further analysis. Cost effectiveness analysis of the consumable fuel configurations revealed that simply maximizing vehicle endurance can lead to a sub-optimum system solution. An LTA concept with a hybrid propulsion system (solar arrays and a hydrogen-air proton exchange membrane fuel cell) was found to have the best mission performance; however, an HTA diesel-fueled wing-body-tail configuration emerged as the preferred consumable fuel concept because of the large size and technical risk of the LTA concept. The baseline missions could not be performed by even the best HTA SR concept. Mission and SR technology trade studies were conducted to enhance understanding of the potential capabilities of such a vehicle. With near-term technology SR-powered HTA vehicles are limited to operation in favorable solar conditions, such as the long days and short nights of summer at higher latitudes. Energy storage system specific energy and solar cell efficiency were found to be the key technology areas for enhancing HTA SR performance.

Nickol, Craig L.; Guynn, Mark D.; Kohout, Lisa L.; Ozoroski, Thomas A.

2007-01-01

264

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

265

Suppression of the Variation of Cushion Pressure for SES Using Vertically Moving Nozzles  

Microsoft Academic Search

In this paper the variation of cushion pressure is investigated theoretically to achieve comfortable riding of SES. A simpler and practical control method is proposed to control cushion pressure changes arising from pumping phenomenon that appears in SES cruising over the waves. Cushion pressure is controlled by varying the discharge height of the vertical nozzle. In this method the nozzle

Koji Kanazawa; Kensuke Matsuo; Hideo Matsuo

2009-01-01

266

Suppression of Variation in Cushion Pressure for SES Using Vertically Moving Nozzles  

Microsoft Academic Search

In this paper, variation in cushion pressure is investigated theoretically to achieve SES ride comfort. A simple and practical control method is proposed to control cushion pressure changes caused by pumping that appears in SES cruising over waves. Cushion pressure is controlled by varying the discharge height of the vertical nozzle. In this method, the nozzle height (hover height) is

Koji Kanazawa; Kensuke Matsuo; Hideo Matsuo

2010-01-01

267

Heave Instabilities of Amphibious Air Cushion Suspension Systems.  

National Technical Information Service (NTIS)

Attempts to ascertain the accuracy with which analytical models can be used to predict the onset of heave instabilities are described with emphasis on relatively simple configurations in which important effects are uncoupled. For the basic element of mult...

M. J. Hinchey

1980-01-01

268

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

269

OCTAVE: a bioinspired visuo-motor control system for the guidance of micro-air-vehicles  

NASA Astrophysics Data System (ADS)

We have developed a visually based autopilot for Micro Air Vehicles (MAV), which we have called OCTAVE (Optical altitude Control sysTem for Autonomous VEhicles). First we built a miniature MAV and an indoor test-bed. The mini-helicopter is tethered to a whirling arm and rotates around a central pole equipped with ground-truth positioning sensors for experimental evaluation. The 100-gram rotorcraft lifts itself by means of a single rotor that can also be tilted forward (pitch) to give the craft a horizontal thrust component (propulsive force). The helicopter"s eye is automatically oriented downwards over an environment composed of contrasting features randomly arranged on the floor. Here we show the feasibility of a ground avoiding system based on a low complexity opto-electronic system. The latter relies on an Elementary Motion Detector (EMD) that estimates the optic flow in the downward direction. The EMD functional structure is directly inspired by that of the fly"s EMDs, the functional scheme of which has been elucidated at our Laboratory by performing electrophysiological recordings while applying optical microstimuli to the retina. The OCTAVE autopilot makes the aircraft capable of effective terrain following at various speeds: the MAV performs reproducible manoeuvers such as smooth cruise flight over a planar ground and hill climbing. The overall processing electronics is very light-weight, which makes it highly suitable for mounting on-board micro air vehicles with an avionic payload in the order of only a few grams.

Ruffier, Franck; Franceschini, Nicolas

2003-04-01

270

Interactions between Flight Dynamics and Propulsion Systems of Air-Breathing Hypersonic Vehicles  

NASA Astrophysics Data System (ADS)

The development and application of a first-principles-derived reduced-order model called MASIV (Michigan/AFRL Scramjet In Vehicle) for an air-breathing hypersonic vehicle is discussed. Several significant and previously unreported aspects of hypersonic flight are investigated. A fortunate coupling between increasing Mach number and decreasing angle of attack is shown to extend the range of operating conditions for a class of supersonic inlets. Detailed maps of isolator unstart and ram-to-scram transition are shown on the flight corridor map for the first time. In scram mode the airflow remains supersonic throughout the engine, while in ram mode there is a region of subsonic flow. Accurately predicting the transition between these two modes requires models for complex shock interactions, finite-rate chemistry, fuel-air mixing, pre-combustion shock trains, and thermal choking, which are incorporated into a unified framework here. Isolator unstart occurs when the pre-combustion shock train is longer than the isolator, which blocks airflow from entering the engine. Finally, cooptimization of the vehicle design and trajectory is discussed. An optimal control technique is introduced that greatly reduces the number of computations required to optimize the simulated trajectory.

Dalle, Derek J.

271

Health effects associated with passenger vehicles: monetary values of air pollution.  

PubMed

Air pollution is regarded as one of the highest priorities in environmental protection in both developed and developing countries. High levels of air pollution have adverse effects on human health that might cause premature death. This study presents the monetary value estimates for the adverse human health effects resulted from ambient air pollution. It aids decision makers to set priorities in the public health relevance of pollution abatement. The main driver of policymaker is the need to reduce the avoidable cardiopulmonary morbidity and mortality from pollutant exposures. The monetary valuation involves 2 steps: (i) relate levels of pollutants to mortality and morbidity (concentration-response relationships) and (ii) apply unit economic values. Cost of air pollution associated with passenger vehicles running over a major traffic bridge (6th of October Elevated Highway) is presented as a case study to demonstrate the use of monetary value of air pollution. The study proves that the cost of air pollution is extremely high and should not be overlooked. PMID:22845727

Marzouk, Mohamed; Madany, Magdy

2012-01-01

272

Mid-Air Retrieval technology for returning of reusable launch vehicles' boosters  

NASA Astrophysics Data System (ADS)

The multilateral analysis of reusable launch vehicles (RLV) has been carried out by the authors' team within 8 years. The studies are based on the world experience and also on the large practical experience of Khrunichev Space Center in designing, production, and operation of aerospacecraft (incuding reentry one). The analysis results are monosemantic and are the following: The only one feasible principle for the nearest future is a mid-air retrieval (MAR), which will permit potentially the creation of the effective RLV. For practical realization of the results obtained, the authors in cooperation with M. L. Mil's Moscow Helicopter Plant (MHP) and "Parachute Design" Scientific Institute have developed the launch vehicles' booster MAR technology (including the structure and principles of main elements formation). The general conclusions of the mar technology are the following: (i) it can be realized with a minimal technical risk at the earliest time (2-3 years); (ii) it can be applied to the existing expendable launch vehicles (ELV) and can be easily adapted to different launch vehicles; (iii) it can be demonstrated at minimal costs and time; and (i?) it permits the creation of the most economically effective RLV (budget savings will be up to 30% and in case of using a special operation technology, the savings can attain 41.5%).

Antonenko, S. V.; Belavskiy, S. A.

2009-09-01

273

Gait analysis of the hemophilic ankle with silicone heel cushion.  

PubMed

Shock absorption becomes very important in damaged joints with destroyed cartilage and progressive muscular imbalance as occurs in hemarthropathy. The effects of silicone heel cushioning on the ankle motion of hemophilic patients in different stages of hemarthropathy of the ankle joints was measured using an ultrasound motion analysis system. It is concluded that silicone heel cushioning has no influence on ankles in the late stage of hemarthropathy. Silicone heel cushioning will lead to uncontrolled changes of the ankle joint in the early hemarthropathic ankle, involving the tibiotalar and the subtalar joints. The angular velocity of the ankle is increased producing higher acceleration at the ankle joint. The higher angle acceleration is related to higher joint loading uncontrolled by the muscles. The resulting uncoordinated motion can cause ligamentous overloading, strains, and a higher probability of joint bleeding. Therefore, silicone heel cushioning or other shock absorbing devices that return the energy immediately to the foot are not useful for prevention and treatment of chronic hemophilic synovitis and may cause additional deterioration of the joint. PMID:9345210

Seuser, A; Wallny, T; Klein, H; Ribbans, W J; Schumpe, G; Brackmann, H H

1997-10-01

274

Cushioning bite plate adapter for x-ray film holder  

SciTech Connect

A cushioning bite plate adapter is described for use with a dental x-ray film holder, the adapter comprising: an elastically compressible member having a single attachment surface; and releasable attaching means disposed on the single attachment surface for engaging a single surface of a bite plate of the x-ray film holder.

Waldo, P.J.

1989-03-21

275

Aerodynamic modelling of insect-like flapping flight for micro air vehicles  

NASA Astrophysics Data System (ADS)

Insect-like flapping flight offers a power-efficient and highly manoeuvrable basis for a micro air vehicle capable of indoor flight. The development of such a vehicle requires a careful wing aerodynamic design. This is particularly true since the flapping wings will be responsible for lift, propulsion and manoeuvres, all at the same time. It sets the requirement for an aerodynamic tool that will enable study of the parametric design space and converge on one (or more) preferred configurations. In this respect, aerodynamic modelling approaches are the most attractive, principally due to their ability to iterate rapidly through various design configurations. In this article, we review the main approaches found in the literature, categorising them into steady-state, quasi-steady, semi-empirical and fully unsteady methods. The unsteady aerodynamic model of Ansari et al. seems to be the most satisfactory to date and is considered in some detail. Finally, avenues for further research in this field are suggested.

Ansari, S. A.; ?bikowski, R.; Knowles, K.

2006-02-01

276

Structural Sizing of a 25,000-lb Payload, Air-Breathing Launch Vehicle For Single-Stage-To-Orbit  

NASA Technical Reports Server (NTRS)

In support of NASA's Air-Breathing Launch Vehicle (ABLV) study, a 25,000-lb payload version of the GTX (formerly Trailblazer) reference vehicle concept was developed. The GTX is a vertical lift-off, reusable, single-stage-to-orbit launch vehicle concept that uses hypersonic air-breathing propulsion in a rocket-based combined-cycle (RBCC) propulsion system to reduce the required propellant fraction. To achieve this goal the vehicle and propulsion system must be well integrated both aerodynamically and structurally to reduce weight. This study demonstrates the volumetric and structural efficiency of a vertical takeoff, horizontal landing, hypersonic vehicle with a circular cross section. A departure from the lifting body concepts, this design philosophy is even extended to the engines, which have semicircular nacelles symmetrically mounted on the vehicle. Material candidates with a potential for lightweight and simplicity have been selected from a set of near term technologies (5 to 10 years). To achieve the mission trajectory, preliminary weight estimates show the vehicle's gross lift-off weight is 1.26 x 10(exp 6) lb. The structural configuration of the GTX vehicle and its propulsion system are described. The vehicle design benefits are presented, and key technical issues are highlighted.

Roche, Joseph M.; Kosareo, Daniel N.; Palac, Don (Technical Monitor)

2000-01-01

277

Structural Sizing of a 25,000-lb Payload, Air-Breathing Launch Vehicle for Single-Stage-to-Orbit  

NASA Technical Reports Server (NTRS)

In support of NASA's Air-Breathing Launch Vehicle (ABLV) study, a 25,000-lb payload version of the GTX (formerly Trailblazer) reference vehicle concept was developed. The GTX is a vertical lift-off, reusable, single-stage-to-orbit launch vehicle concept that uses hypersonic air-breathing propulsion in a rocket-based combined-cycle (RBCC) propulsion system to reduce the required propellant fraction. To achieve this goal the vehicle and propulsion system must be well integrated both aerodynamically and structurally to reduce weight. This study demonstrates the volumetric and structural efficiency of a vertical takeoff, horizontal landing, hypersonic vehicle with a circular cross section. A departure from the lifting body concepts, this design philosophy is even extended to the engines, which have semicircular nacelles symmetrically mounted on the vehicle. Material candidates with a potential for lightweight and simplicity have been selected from a set of near term technologies (five to ten years). To achieve the mission trajectory, preliminary weight estimates show the vehicle's gross lift-off weight is 1.26 x 10(exp 6) lb. The structural configuration of the GTX vehicle and its propulsion system are described. The vehicle design benefits are presented, and key technical issues are highlighted.

Roche, Joseph M.; Kosareo, Daniel N.

2001-01-01

278

Spatially- and Temporally-Resolved Measurements of Roadway Air Pollution Using a Zero-Emission Electric Vehicle  

EPA Science Inventory

Vehicle-related air pollution has an intrinsically dynamic nature. Recent field measurements and modeling work have demonstrated that near-road topography may modify levels of air pollutants reaching populations residing and working in close proximity to roadways. However, the ma...

279

Electric vehicles  

Microsoft Academic Search

The renewed interest in electric vehicles (EVs) in the wake of the California Air Resources Board mandate that 2% of the vehicles lighter than 3750 lb (1700 kg) sold by each manufacturer in that state in 1998 be zero-emission vehicles is examined. The reasons why replacing an internal combustion vehicle (ICV) with an electrically powered equivalent greatly reduces air pollution,

M. J. Riezenman

1992-01-01

280

Survey of Aerothermodynamics Facilities Useful for the Design of Hypersonic Vehicles Using Air-Breathing Propulsion  

NASA Technical Reports Server (NTRS)

This paper surveys the use of aerothermodynamic facilities which have been useful in the study of external flows and propulsion aspects of hypersonic, air-breathing vehicles. While the paper is not a survey of all facilities, it covers the utility of shock tunnels and conventional hypersonic blow-down facilities which have been used for hypersonic air-breather studies. The problems confronting researchers in the field of aerothermodynamics are outlined. Results from the T5 GALCIT tunnel for the shock-on lip problem are outlined. Experiments on combustors and short expansion nozzles using the semi-free jet method have been conducted in large shock tunnels. An example which employed the NASA Ames 16-Inch shock tunnel is outlined, and the philosophy of the test technique is described. Conventional blow-down hypersonic wind tunnels are quite useful in hypersonic air-breathing studies. Results from an expansion ramp experiment, simulating the nozzle on a hypersonic air-breather from the NASA Ames 3.5 Foot Hypersonic wind tunnel are summarized. Similar work on expansion nozzles conducted in the NASA Langley hypersonic wind tunnel complex is cited. Free-jet air-frame propulsion integration and configuration stability experiments conducted at Langley in the hypersonic wind tunnel complex on a small generic model are also summarized.

Arnold, James O.; Deiwert, George S.

1997-01-01

281

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

282

Model Update of a Micro Air Vehicle (MAV) Flexible Wing Frame with Uncertainty Quantification  

NASA Technical Reports Server (NTRS)

This paper describes a procedure to update parameters in the finite element model of a Micro Air Vehicle (MAV) to improve displacement predictions under aerodynamics loads. Because of fabrication, materials, and geometric uncertainties, a statistical approach combined with Multidisciplinary Design Optimization (MDO) is used to modify key model parameters. Static test data collected using photogrammetry are used to correlate with model predictions. Results show significant improvements in model predictions after parameters are updated; however, computed probabilities values indicate low confidence in updated values and/or model structure errors. Lessons learned in the areas of wing design, test procedures, modeling approaches with geometric nonlinearities, and uncertainties quantification are all documented.

Reaves, Mercedes C.; Horta, Lucas G.; Waszak, Martin R.; Morgan, Benjamin G.

2004-01-01

283

Flexible Wing Base Micro Aerial Vehicles: Vision-Guided Flight Stability and Autonomy for Micro Air Vehicles  

NASA Technical Reports Server (NTRS)

Substantial progress has been made recently towards design building and test-flying remotely piloted Micro Air Vehicle's (MAVs). We seek to complement this progress in overcoming the aerodynamic obstacles to.flight at very small scales with a vision stability and autonomy system. The developed system based on a robust horizon detection algorithm which we discuss in greater detail in a companion paper. In this paper, we first motivate the use of computer vision for MAV autonomy arguing that given current sensor technology, vision may he the only practical approach to the problem. We then briefly review our statistical vision-based horizon detection algorithm, which has been demonstrated at 30Hz with over 99.9% correct horizon identification. Next we develop robust schemes for the detection of extreme MAV attitudes, where no horizon is visible, and for the detection of horizon estimation errors, due to external factors such as video transmission noise. Finally, we discuss our feed-back controller for self-stabilized flight, and report results on vision autonomous flights of duration exceeding ten minutes.

Ettinger, Scott M.; Nechyba, Michael C.; Ifju, Peter G.; Wazak, Martin

2002-01-01

284

78 FR 34911 - Approval and Promulgation of Air Quality Implementation Plans; Maryland; Low Emission Vehicle...  

Federal Register 2010, 2011, 2012, 2013

...vehicle (ZEV) standards, which are the most stringent standards set. In between these fall: Ultra-Low Emission Vehicles (ULEV), Super-Ultra Low Emission Vehicles (SULEV), Partial Zero Emission Vehicles (PZEV), and Advanced...

2013-06-11

285

Graphical techniques for constraining estimates of aerosol emissions from motor vehicles using air monitoring network data  

NASA Astrophysics Data System (ADS)

For a source that emits several pollutants, the concentration ratios of the pollutants have characteristic values that are unaffected by dilution when mixing in clean air. Starting from this simple principle, and taking into account how physical and chemical processes affect observed concentrations during transport from source to receptor, two simple and general techniques for analysing hourly data to detect emissions representative of nearby source emissions, are described. These techniques are applied to air quality monitoring data to provide independent real-world constraints upon emissions inventories of primary aerosol from motor vehicles. Applying one technique to Californian data indicates that the 1995 Los Angeles inventory may overestimate such emissions. The other technique is used to derive an estimate of total yearly vehicular emissions of primary aerosol for Hong Kong, given the corresponding total emissions of oxides of nitrogen.

Bentley, S. T.

286

Formation of photochemical air pollution in central California 1. Development of a revised motor vehicle emission inventory  

NASA Astrophysics Data System (ADS)

Photochemical air pollution problems have proved difficult to understand and control in central California. A major source of uncertainty is the rate of precursor volatile organic compounds and NOx emissions, especially from motor vehicles. We develop alternative emissions estimates for on-road motor vehicles in 1990, using fuel sales data, emission factors measured in on-road studies, and ambient pollutant ratios, for a region that includes the San Francisco Bay and San Joaquin Valley air basins and Sacramento County. Fuel-based emissions estimates are compared with predictions of California's most recent motor vehicle emission factor model (EMFAC) and with an inventory that has been used in previous regional-scale photochemical modeling studies. The fuel-based inventory contains 10-50% less CO, 40-100% more nonmethane organic compounds, and 10-20% less NOx than estimated both by EMFAC and the photochemical modeling inventory. We also describe new temporal distributions of vehicle emissions by hour and day of week. Diesel trucks, a major source of NOx, have a broad midday peak in emissions on weekdays, in contrast to passenger vehicles, which show morning and afternoon commuter peaks. While passenger vehicle travel is similar on weekdays and weekends, diesel truck activity and emissions decrease by 70-80% on weekends. Vehicle emission rates and their temporal patterns are linked to a regional photochemical air pollution episode that spans a weekend in August 1990.

Marr, Linsey C.; Black, Douglas R.; Harley, Robert A.

2002-03-01

287

Survey of Aerothermodynamics Facilities Useful for the Design of Hypersonic Vehicles Using Air-Breathing Propulsion  

NASA Technical Reports Server (NTRS)

The dream of producing an air-breathing, hydrogen fueled, hypervelocity aircraft has been before the aerospace community for decades. However, such a craft has not yet been realized, even in an experimental form. Despite the simplicity and beauty of the concept, many formidable problems must be overcome to make this dream a reality. This paper summarizes the aero/aerothermodynamic issues that must be addressed to make the dream a reality and discusses how aerothermodynamics facilities and their modem companion, real-gas computational fluid dynamics (CFD), can help solve the problems blocking the way to realizing the dream. The approach of the paper is first to outline the concept of an air-breathing hypersonic vehicle and then discuss the nose-to-tail aerothermodynamics issues and special aerodynamic problems that arise with such a craft. Then the utility of aerothermodynamic facilities and companion CFD analysis is illustrated by reviewing results from recent United States publications wherein these problems have been addressed. Papers selected for the discussion have k e n chosen such that the review will serve to survey important U.S. aero/aerothermodynamic real gas and conventional wind tunnel facilities that are useful in the study of hypersonic, hydrogen propelled hypervelocity vehicles.

Arnold, James O.; Deiwert, G. S.

1997-01-01

288

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.

289

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

290

Neighborhood-scale air quality impacts of emissions from motor vehicles and aircraft  

NASA Astrophysics Data System (ADS)

A mobile monitoring platform (MMP) was used to measure real-time air pollutant concentrations in different built environments of Boyle Heights (BH, a lower-income community enclosed by several freeways); Downtown Los Angeles (DTLA, adjacent to BH with taller buildings and surrounded by several freeways); and West Los Angeles (WLA, an affluent community traversed by two freeways) in summer afternoons of 2008 and 2011 (only for WLA). Significant inter-community and less significant but observable intra-community differences in traffic-related pollutant concentrations were observed both in the residential neighborhoods studied and on their arterial roadways between BH, DTLA, and WLA, particularly for ultrafine particles (UFP). HEV, defined as vehicles creating plumes with concentrations more than three standard deviations from the adjusted local baseline, were encountered during 6-13% of sampling time, during which they accounted for 17-55% of total UFP concentrations both on arterial roadways and in residential neighborhoods. If instead a single threshold value is used to define HEVs in all areas, HEV's were calculated to make larger contributions to UFP concentrations in BH than other communities by factors of 2-10 or more. Santa Monica Airport located in WLA appears to be a significant source for elevated UFP concentrations in nearby residential neighborhoods 80-400 m downwind. In the WLA area, we also showed, on a neighborhood scale, striking and immediate reductions in particulate pollution (˜70% reductions in both UFP and, somewhat surprisingly, PM2.5), corresponding to dramatic decreases in traffic densities during an I-405 closure event ("Carmageddon") compared to non-closure Saturday levels. Although pollution reduction due to decreased traffic is not unexpected, this dramatic improvement in particulate pollution provides clear evidence air quality can be improved through strategies such as heavy-duty-diesel vehicle retrofits, earlier retirement of HEV, and transition to electric vehicles and alternative fuels, with corresponding benefits for public health.

Choi, Wonsik; Hu, Shishan; He, Meilu; Kozawa, Kathleen; Mara, Steve; Winer, Arthur M.; Paulson, Suzanne E.

2013-12-01

291

The design of passively athermalized narrow- and wide-field-of-view infrared objectives for the OBSERVER unmanned air vehicle  

Microsoft Academic Search

Some years ago QinetiQ introduced a short-range reconnaissance unmanned air vehicle (UAV), known as OBSERVER, which carried a visible three-camera sensor. To increase its versatility, a compatible infrared (IR) thermal imaging (TI) sensor was developed for the vehicle for operation in the 8-12mm waveband with a dual field of view function. The sensor incorporates a specially designed camera board, employing

Richard C. Simmons; Paul A. Manning; Trevor V. Chamberlain

2004-01-01

292

Optimal Programming of Multipoint Cushion Systems for Sheet Metal Forming  

Microsoft Academic Search

Numerical optimization technique coupled with finite element analysis of the stamping\\/sheet hydroforming process was developed to predict four possible modes for application of blank holder force (BHF) in multiple-point cushion systems, namely a) BHF constant in space\\/location and time\\/stroke, b) BHF variable in time\\/stroke and constant in space\\/location, c) BHF variable in space\\/location and constant in time\\/stroke and d) BHF

H. Palaniswamy; M. Braedel; A. Thandapani; T. Altan

2006-01-01

293

Cushioning and lateral stability functions of cloth sport shoes  

Microsoft Academic Search

In this study, we evaluated the protective functions of cloth sport shoes, including cushioning and lateral stability. Twelve male students participated in the study (mean ± s: age 12.7 ± 0.4 years, mass 40.7 ± 5.9 kg, height 1.50 ± 0.04 m). Cloth sport shoes, running shoes, basketball shoes, cross-training shoes, and barefoot conditions were investigated in random sequence. Human pendulum and cutting movement tests were used to assess

Daniel Tik-Pui Fong; Youlian Hong; Jing Xian Li

2007-01-01

294

Early Myocardial Function Affects Endocardial Cushion Development in Zebrafish  

PubMed Central

Function of the heart begins long before its formation is complete. Analyses in mouse and zebrafish have shown that myocardial function is not required for early steps of organogenesis, such as formation of the heart tube or chamber specification. However, whether myocardial function is required for later steps of cardiac development, such as endocardial cushion (EC) formation, has not been established. Recent technical advances and approaches have provided novel inroads toward the study of organogenesis, allowing us to examine the effects of both genetic and pharmacological perturbations of myocardial function on EC formation in zebrafish. To address whether myocardial function is required for EC formation, we examined silent heart (sih?/?) embryos, which lack a heartbeat due to mutation of cardiac troponin T (tnnt2), and observed that atrioventricular (AV) ECs do not form. Likewise, we determined that cushion formation is blocked in cardiofunk (cfk?/?) embryos, which exhibit cardiac dilation and no early blood flow. In order to further analyze the heart defects in cfk?/? embryos, we positionally cloned cfk and show that it encodes a novel sarcomeric actin expressed in the embryonic myocardium. The Cfks11 variant exhibits a change in a universally conserved residue (R177H). We show that in yeast this mutation negatively affects actin polymerization. Because the lack of cushion formation in sih- and cfk-mutant embryos could be due to reduced myocardial function and/or lack of blood flow, we approached this question pharmacologically and provide evidence that reduction in myocardial function is primarily responsible for the defect in cushion development. Our data demonstrate that early myocardial function is required for later steps of organogenesis and suggest that myocardial function, not endothelial shear stress, is the major epigenetic factor controlling late heart development. Based on these observations, we postulate that defects in cardiac morphogenesis may be secondary to mutations affecting early myocardial function, and that, in humans, mutations affecting embryonic myocardial function may be responsible for structural congenital heart disease.

2004-01-01

295

60 FR 52734 - Control of Air Pollution From New Motor Vehicles and New Motor Vehicle Engines: Voluntary...  

Federal Register 2010, 2011, 2012, 2013

...86.001-9, 86.004-9, and 86.098-8. ORVR-equipped vehicles must...standards and provisions specified in Sec. 86.098-8(d) and the light-duty truck refueling...light-duty vehicles specified in Sec. 86.098-8(e), and the Supplemental...

1995-10-10

296

Experimental Investigation of a Shrouded Rotor Micro Air Vehicle in Hover and in Edgewise Gusts  

NASA Astrophysics Data System (ADS)

Due to the hover capability of rotary wing Micro Air Vehicles (MAVs), it is of interest to improve their aerodynamic performance, and hence hover endurance (or payload capability). In this research, a shrouded rotor configuration is studied and implemented, that has the potential to offer two key operational benefits: enhanced system thrust for a given input power, and improved structural rigidity and crashworthiness of an MAV platform. The main challenges involved in realising such a system for a lightweight craft are: design of a lightweight and stiff shroud, and increased sensitivity to external flow disturbances that can affect flight stability. These key aspects are addressed and studied in order to assess the capability of the shrouded rotor as a platform of choice for MAV applications. A fully functional shrouded rotor vehicle (disk loading 60 N/ m2) was designed and constructed with key shroud design variables derived from previous studies on micro shrouded rotors. The vehicle weighed about 280 g (244 mm rotor diameter). The shrouded rotor had a 30% increase in power loading in hover compared to an unshrouded rotor. Due to the stiff, lightweight shroud construction, a net payload benefit of 20-30 g was achieved. The different components such as the rotor, stabilizer bar, yaw control vanes and the shroud were systematically studied for system efficiency and overall aerodynamic improvements. Analysis of the data showed that the chosen shroud dimensions was close to optimum for a design payload of 250 g. Risk reduction prototypes were built to sequentially arrive at the final configuration. In order to prevent periodic oscillations in ight, a hingeless rotor was incorporated in the shroud. The vehicle was successfully ight tested in hover with a proportional-integralderivative feedback controller. A flybarless rotor was incorporated for efficiency and control moment improvements. Time domain system identification of the attitude dynamics of the flybar and flybarless rotor vehicle was conducted about hover. Controllability metrics were extracted based on controllability gramian treatment for the flybar and flybarless rotor. In edgewise gusts, the shrouded rotor generated up to 3 times greater pitching moment and 80% greater drag than an equivalent unshrouded rotor. In order to improve gust tolerance and control moments, rotor design optimizations were made by varying solidity, collective, operating RPM and planform. A rectangular planform rotor at a collective of 18 deg was seen to offer the highest control authority. The shrouded rotor produced 100% higher control moments due to pressure asymmetry arising from cyclic control of the rotor. It was seen that the control margin of the shrouded rotor increased as the disk loading increased, which is however deleterious in terms of hover performance. This is an important trade-off that needs to be considered. The flight performance of the vehicle in terms of edgewise gust disturbance rejection was tested in a series of bench top and free ight tests. A standard table fan and an open jet wind tunnel setup was used for bench top setup. The shrouded rotor had an edgewise gust tolerance of about 3 m/s while the unshrouded rotor could tolerate edgewise gusts greater than 5 m/s. Free flight tests on the vehicle, using VICON for position feedback control, indicated the capability of the vehicle to recover from gust impulse inputs from a pedestal fan at low gust values (up to 3 m/s).

Hrishikeshavan, Vikram

297

In-flight oxygen collection for a two-stage air-launch vehicle: integration of vehicle and separation cycle design  

NASA Astrophysics Data System (ADS)

In-flight oxygen collection is a very promising technique to reduce the launch costs and improve the payload capabilities of two-stage-to-orbit semireusable launchers. Using liquid hydrogen the incoming air is deeply cooled and enriched in oxygen during the cruise phase of the first stage. The liquified enriched air is stored in the second stage which is then launched into orbit. This paper gives the result of a conceptual design of a two-stage-to-orbit air launched space vehicle. The mass, aerodynamic, and propulsive characteristics of the first stage are determined and an assessment of the influence of the collection plant performance on the subsonic first stage is made. The results for a centrifugally enhanced destillation unit are given together with the plant cycle arrangement. Integration options for the plant into the first stage are proposed and a short description of the air separation test unit and its test bench is also given.

Verstraete, D.; Bizzarri, D.; Hendrick, P.

2009-09-01

298

NASA Innovation Fund 2010 Project Elastically Shaped Future Air Vehicle Concept  

NASA Technical Reports Server (NTRS)

This report describes a study conducted in 2010 under the NASA Innovation Fund Award to develop innovative future air vehicle concepts. Aerodynamic optimization was performed to produce three different aircraft configuration concepts for low drag, namely drooped wing, inflected wing, and squashed fuselage. A novel wing shaping control concept is introduced. This concept describes a new capability of actively controlling wing shape in-flight to minimize drag. In addition, a novel flight control effector concept is developed to enable wing shaping control. This concept is called a variable camber continuous trailing edge flap that can reduce drag by as much as 50% over a conventional flap. In totality, the potential benefits of fuel savings offered by these concepts can be significant.

Nguyen, Nhan

2010-01-01

299

Improved Adaptive-Reinforcement Learning Control for morphing unmanned air vehicles.  

PubMed

This paper presents an improved Adaptive-Reinforcement Learning Control methodology for the problem of unmanned air vehicle morphing control. The reinforcement learning morphing control function that learns the optimal shape change policy is integrated with an adaptive dynamic inversion control trajectory tracking function. An episodic unsupervised learning simulation using the Q-learning method is developed to replace an earlier and less accurate Actor-Critic algorithm. Sequential Function Approximation, a Galerkin-based scattered data approximation scheme, replaces a K-Nearest Neighbors (KNN) method and is used to generalize the learning from previously experienced quantized states and actions to the continuous state-action space, all of which may not have been experienced before. The improved method showed smaller errors and improved learning of the optimal shape compared to the KNN. PMID:18632393

Valasek, John; Doebbler, James; Tandale, Monish D; Meade, Andrew J

2008-08-01

300

Experimental Study on the Wing Lift Characteristics of Biplane Micro Air Vehicle  

NASA Astrophysics Data System (ADS)

This paper investigates wing aerodynamic characteristics used for bi-plane micro-air vehicles. Surface pressure distributions of two-dimensional biplane airfoils (4% cambered-plate airfoil) were measured at a chord Reynolds number of 6.4 × 104. Lift characteristics of three-dimensional biplane rectangular wings (aspect ratio of 3) were also measured at the same Reynolds number. It was indicated that the behaviors of laminar separation bubble formed both on the upper and lower airfoils/wings affects their lift characteristics. Bi-plane wings with positive stagger, i.e. protruded upper wing indicated higher maximum lift coefficient. This is caused by different behaviors of laminar separation bubble formed on the wing.

Akiyama, Kohei; Tezuka, Asei; Sunada, Yasuto; Rinoie, Kenichi

301

A refuelable zinc/air battery for fleet electric vehicle propulsion  

SciTech Connect

We report the development and on-vehicle testing of an engineering prototype zinc/air battery. The battery is refueled by periodic exchange of spent electrolyte for zinc particles entrained in fresh electrolyte. The technology is intended to provide a capability for nearly continuous vehicle operation, using the fleet s home base for 10 minute refuelings and zinc recycling instead of commercial infrastructure. In the battery, the zinc fuel particles are stored in hoppers, from which they are gravity fed into individual cells and completely consumed during discharge. A six-celled (7V) engineering prototype battery was combined with a 6 V lead/acid battery to form a parallel hybrid unit, which was tested in series with the 216 V battery of an electric shuttle bus over a 75 mile circuit. The battery has an energy density of 140 Wh/kg and a mass density of 1.5 kg/L. Cost, energy efficiency, and alternative hybrid configurations are discussed.

Cooper, J.F.; Fleming, D.; Hargrove, D.; Koopman, R.; Peterman, K.

1995-04-20

302

A refuelable zinc/air battery for fleet electric vehicle propulsion  

NASA Astrophysics Data System (ADS)

We report the development and on-vehicle testing of an engineering prototype zinc/air battery. The battery is refueled by periodic exchange of spent electrolyte for zinc particles entrained in fresh electrolyte. The technology is intended to provide a capability for nearly continuous vehicle operation, using the fleet's home base for 10 minute refuelings and zinc recycling instead of commercial infrastructure. In the battery, the zinc fuel particles are stored in hoppers, from which they are gravity fed into individual cells and completely consumed during discharge. A six-celled (7V) engineering prototype battery was combined with a 6 V lead/acid battery to form a parallel hybrid unit, which was tested in series with the 216 V battery of an electric shuttle bus over a 75 mile circuit. The battery has an energy density of 140 Wh/kg and a mass density of 1.5 kg/L. Cost, energy efficiency, and alternative hybrid configurations are discussed.

Cooper, John F.; Fleming, Dennis; Hargrove, Douglas; Koopman, Ronald; Peterman, Keith

1995-04-01

303

The development of an experimental facility and investigation of rapidly maneuvering Micro-Air-Vehicle wings  

NASA Astrophysics Data System (ADS)

Vertical Takeoff-and-Landing (VTOL) Micro Air Vehicles (MAVs) provide a versatile operational platform which combines the capabilities of fixed wing and rotary wing MAVs. In order to improve performance of these vehicles, a better understanding of the rapid transition between horizontal and vertical flight is required. This study examines the flow structures around the Mini-Vertigo VTOL MAV using flow visualization techniques. This will gives an understanding of the flow structures which dominate the flight dynamics of rapid pitching maneuvers. This study consists of three objectives: develop an experimental facility, use flow visualization to investigate the flow around the experimental subject during pitching, and analyze the results. The flow around the Mini-Vertigo VTOL MAV is dominated by the slipstream from its propellers. The slipstream delays LE separation and causes drastic deflection in the flow. While the frequency of the vortices shed from the LE and TE varies with flow speed, the non-dimensional frequency does not. It does, however, vary slightly with the pitching rate. These results are applicable across a wide range of flight conditions. The results correlate to previous research done to examine the aerodynamic forces on the MAV.

Wilson, Lee Alexander

304

Aerodynamics of a bio-inspired flexible flapping-wing micro air vehicle.  

PubMed

MAVs (micro air vehicles) with a maximal dimension of 15 cm and nominal flight speeds of around 10 m s?¹, operate in a Reynolds number regime of 10? or lower, in which most natural flyers including insects, bats and birds fly. Furthermore, due to their light weight and low flight speed, the MAVs' flight characteristics are substantially affected by environmental factors such as wind gust. Like natural flyers, the wing structures of MAVs are often flexible and tend to deform during flight. Consequently, the aero/fluid and structural dynamics of these flyers are closely linked to each other, making the entire flight vehicle difficult to analyze. We have recently developed a hummingbird-inspired, flapping flexible wing MAV with a weight of 2.4-3.0 g and a wingspan of 10-12 cm. In this study, we carry out an integrated study of the flexible wing aerodynamics of this flapping MAV by combining an in-house computational fluid dynamic (CFD) method and wind tunnel experiments. A CFD model that has a realistic wing planform and can mimic realistic flexible wing kinematics is established, which provides a quantitative prediction of unsteady aerodynamics of the four-winged MAV in terms of vortex and wake structures and their relationship with aerodynamic force generation. Wind tunnel experiments further confirm the effectiveness of the clap and fling mechanism employed in this bio-inspired MAV as well as the importance of the wing flexibility in designing small flapping-wing MAVs. PMID:22126793

Nakata, T; Liu, H; Tanaka, Y; Nishihashi, N; Wang, X; Sato, A

2011-12-01

305

Uncertainty analysis and robust trajectory linearization control of a flexible air-breathing hypersonic vehicle  

NASA Astrophysics Data System (ADS)

Flexible air-breathing hypersonic vehicles feature significant uncertainties which pose huge challenges to robust controller designs. In this paper, four major categories of uncertainties are analyzed, that is, uncertainties associated with flexible effects, aerodynamic parameter variations, external environmental disturbances, and control-oriented modeling errors. A uniform nonlinear uncertainty model is explored for the first three uncertainties which lumps all uncertainties together and consequently is beneficial for controller synthesis. The fourth uncertainty is additionally considered in stability analysis. Based on these analyses, the starting point of the control design is to decompose the vehicle dynamics into five functional subsystems. Then a robust trajectory linearization control (TLC) scheme consisting of five robust subsystem controllers is proposed. In each subsystem controller, TLC is combined with the extended state observer (ESO) technique for uncertainty compensation. The stability of the overall closed-loop system with the four aforementioned uncertainties and additional singular perturbations is analyzed. Particularly, the stability of nonlinear ESO is also discussed from a Liénard system perspective. At last, simulations demonstrate the great control performance and the uncertainty rejection ability of the robust scheme.

Pu, Zhiqiang; Tan, Xiangmin; Fan, Guoliang; Yi, Jianqiang

2014-08-01

306

The impact of cushioned centrifugation protocols on semen quality of stallions  

Microsoft Academic Search

The objective was to determine if decreased cushion-fluid volume and increased sperm number during centrifugation, or if sperm concentration of extended semen following centrifugation, affected stallion sperm quality. Three ejaculates from each of three stallions were subjected to cushioned centrifugation (1000 x g for 20 min). Cushion-fluid volume was set at 1 or 3.5 mL, and sperm number per centrifuge

S. B. Bliss; J. L. Voge; S. S. Hayden; S. R. Teague; S. P. Brinsko; C. C. Love; T. L. Blanchard; D. D. Varner

307

Roles of TGF? and BMP during valvulo–septal endocardial cushion formation  

Microsoft Academic Search

The primordia of valves and the atrioventricular septum arise from endocardial cushion tissue that is formed in the outflow\\u000a tract (OFT) and in the atrioventricular (AV) regions during cardiogenesis. Abnormal development of the endocardial cushion\\u000a results in various congenital heart diseases. Endocardial epithelial–mesenchymal transformation (EMT) is a critical process\\u000a in cushion tissue formation and is regulated by many factors, such

Toshiyuki Yamagishi; Katsumi Ando; Hiroaki Nakamura

2009-01-01

308

Interfacing ACT-R 5.0 to an Uninhabited Air Vehicle (UAV) Synthetic Task Environment (STE)  

Microsoft Academic Search

With what external system have you attached ACT-R? We have attached ACT-R to the Air Force Research Laboratory's (AFRL's) Uninhabited Air Vehicle (UAV) Synthetic Task Environment (STE). The UAV STE is a high fidelity simulation of the Predator RQ1A UAV with built in basic maneuvering, landing, and reconnaissance tasks and data collection capabilities. The UAV STE's design and capabilities are

Jerry T. Ball; Kevin A. Gluck

309

75 FR 12123 - Federal Motor Vehicle Safety Standards; Side Impact Protection; Fuel System Integrity; Electric...  

Federal Register 2010, 2011, 2012, 2013

...Motor Vehicle Safety Standards; Side Impact Protection; Fuel System Integrity; Electric-Powered...Standard (FMVSS) No. 214, ``Side impact protection.'' The final rule incorporated...Dummies B. Location of Seat on the Non-Impact Side C. Seat Cushion Reference...

2010-03-15

310

Networking Multiple Autonomous Air and Ocean Vehicles for Oceanographic Research and Monitoring  

NASA Astrophysics Data System (ADS)

Autonomous underwater and surface vessels (AUVs and ASVs) are coming into wider use as components of oceanographic research, including ocean observing systems. Unmanned airborne vehicles (UAVs) are now available at modest cost, allowing multiple UAVs to be deployed with multiple AUVs and ASVs. For optimal use good communication and coordination among vehicles is essential. We report on the use of multiple AUVs networked in communication with multiple UAVs. The UAVs are augmented by inferential reasoning software developed at MBARI that allows UAVs to recognize oceanographic fronts and change their navigation and control. This in turn allows UAVs to automatically to map frontal features, as well as to direct AUVs and ASVs to proceed to such features and conduct sampling via onboard sensors to provide validation for airborne mapping. ASVs can also act as data nodes for communication between UAVs and AUVs, as well as collecting data from onboard sensors, while AUVs can sample the water column vertically. This allows more accurate estimation of phytoplankton biomass and productivity, and can be used in conjunction with UAV sampling to determine air-sea flux of gases (e.g. CO2, CH4, DMS) affecting carbon budgets and atmospheric composition. In particular we describe tests in July 2013 conducted off Sesimbra, Portugal in conjunction with the Portuguese Navy by the University of Porto and MBARI with the goal of tracking large fish in the upper water column with coordinated air/surface/underwater measurements. A thermal gradient was observed in the infrared by a low flying UAV, which was used to dispatch an AUV to obtain ground truth to demonstrate the event-response capabilities using such autonomous platforms. Additional field studies in the future will facilitate integration of multiple unmanned systems into research vessel operations. The strength of hardware and software tools described in this study is to permit fundamental oceanographic measurements of both ocean and atmosphere over temporal and spatial scales that have previously been problematic. The methods demonstrated are particularly suited to the study of oceanographic fronts and for tracking and mapping oil spills or plankton blooms. With the networked coordination of multiple autonomous systems, individual components may be changed out while ocean observations continue, allowing coarse to fine spatial studies of hydrographic features over temporal dimensions that would otherwise be difficult, including diurnal and tidal periods. Constraints on these methods currently involve coordination of data archiving systems into shipboard operating systems, familiarization of oceanographers with these methods, and existing nearshore airspace use constraints on UAVs. An important outcome of these efforts is to understand the methodology for using multiple heterogeneous autonomous vehicles for targeted science exploration.

McGillivary, P. A.; Borges de Sousa, J.; Rajan, K.

2013-12-01

311

An adsorption air conditioning system to integrate with the recent development of emission control for heavy-duty vehicles  

Microsoft Academic Search

The recent development to control the emissions of large diesel engines has provided opportunities for heat-driven cooling methods in vehicles. An adsorption air conditioning system is therefore proposed in this work for heavy-duty truck application. This system is powered by engine waste heat when the engine of a truck is running. When the engine is off, it can be operated

Yongfang Zhong; Tiegang Fang; Kevin L. Wert

2011-01-01

312

Research Leading to the Development of a Hydrogen-Air Fire and Explosion Detection System for Aerospace Vehicles.  

National Technical Information Service (NTIS)

Previous work demonstrated that timely detection of hydrogen-air deflagrations in aerospace vehicle environments is best based upon detection of OH band radiation (UV) from the reaction zone. The main goal of the present work was to determine to what exte...

B. Hornstein K. Hill T. Michaelis

1965-01-01

313

Australian Air Breathing Propulsion Research for Hypersonic, Beamed Energy-Propelled Vehicles  

NASA Astrophysics Data System (ADS)

A three year laser-propelled vehicle analysis and design investigation has been begun in June, 2009 by Faculty and graduate students at the University of Adelaide under a Grant/Cooperative Agreement Award to the University of Adelaide by the Asian Office of Aerospace Research and Development (AOARD). The major objectives of thsis investigation are: (a) development of hypersonic, air breathing ``lightcraft'' with innovative air inlets that enable acceptable airflow capture and combustion, and acceptable cowl-lip heating rates during hot, high-speed, high angle-of-attack hypersonic flight; (b) yest of the most promising lightcraft and inlet design in the high power laser beam that is part of the shock tunnel facility at CTO Instituto in Brazil; and (c) plan a series of laser guided and propelled flights that achieve supersonic or higher speed at the Woomera Test Facility (WTF) in South Australia-using the existing WTF launching and tracking facilities and sponsor-provided laser pointing and tracking and illumination systems.

Froning, David

2010-05-01

314

Methods for measuring performance of vehicle cab air cleaning systems against aerosols and vapours.  

PubMed

Vehicle cabs equipped with an effective air cleaning and pressurization system, fitted to agricultural and off-road machineries, isolate drivers from the polluted environment, in which they are likely to work. These cabs provide protection against particulate and gaseous pollutants generated by these types of work activities. Two laboratory methods have been applied to determining the performance characteristics of two cabs of different design, namely, optical counting-based measurement of a potassium chloride (KCl) aerosol and fluorescein aerosol-based tracing. Results of cab confinement efficiency measurements agreed closely for these two methods implemented in the study. Measurements showed that high confinement efficiencies can be achieved with cabs, which are properly designed in ventilation/cleaning/airtightness terms. We also noted the importance of filter mounting airtightness, in which the smallest defect is reflected by significant degradation in cab performance. Determination of clean airflow rate by monitoring the decrease in test aerosol concentration in the test chamber gave excellent results. This method could represent an attractive alternative to methods involving gas tracing or air velocity measurement at blowing inlets. PMID:19406910

Bémer, D; Subra, I; Régnier, R

2009-06-01

315

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

316

Reduction of discomfort during mammography utilizing a radiolucent cushioning pad.  

PubMed

The purpose of this study was to evaluate the use of a radiolucent cushioning pad during routine screening mammography to determine the degree of reduction in discomfort, any correlation of that reduction with various clinical factors, and the pad's impact on image quality, compression force, and radiation dose. A total of 512 patients presenting for routine screening mammography were evaluated. The radiolucent cushioning pads (MammoPad, Biolucent Inc., Aliso Viejo, CA) were placed on the bucky and compression paddle of the mammographic equipment (M-IV, Lorad Corp., Danbury, CT). For each patient, the radiolucent pads were used for imaging one breast while the opposite breast, which served as a control, was imaged without the pads. In all patients, the breast was positioned and compressed in standard fashion, using routine craniocaudal (CC) and mediolateral oblique (MLO) views. Patients completed a questionnaire before and after the mammogram. A visual analog scale (VAS) was used to record anticipated discomfort as well as the discomfort experienced during compression with and without the pads. Age, hormone replacement status, prior experience with mammography, compression force, and breast composition were recorded, as were dose parameters (mAs and kVp), from which midglandular dose values were calculated. On the side where the pads were used to cushion the breast, 73.5% (371/505) of women experienced a significant decrease in discomfort. Of those who benefited, there was a 47% decrease in discomfort. On the pad side, compression force was increased an average of 14%, and there was a 4% decrease in dose for the CC view and no increase in dose for the MLO view. When comparing benefit versus nonbenefit groups, a significant reduction in discomfort did not correlate with any of the clinical factors evaluated, with the exception of experienced discomfort reported after the mammogram. Use of the MammoPad radiolucent cushion on the bucky and compression paddle was an effective means of reducing discomfort during compression for a majority (73.5%) of our patients undergoing screening mammography. Image quality and the ability to detect all pertinent anatomy were maintained. PMID:15239794

Markle, Lauralyn; Roux, Susan; Sayre, James W

2004-01-01

317

Integration of Advanced Concepts and Vehicles Into the Next Generation Air Transportation System. Volume 1; Introduction, Key Messages, and Vehicle Attributes  

NASA Technical Reports Server (NTRS)

Raytheon, in partnership with NASA, is leading the way in ensuring that the future air transportation continues to be a key driver of economic growth and stability and that this system provides an environmentally friendly, safe, and effective means of moving people and goods. A Raytheon-led team of industry and academic experts, under NASA contract NNA08BA47C, looked at the potential issues and impact of introducing four new classes of advanced aircraft into the next generation air transportation system -- known as NextGen. The study will help determine where NASA should further invest in research to support the safe introduction of these new air vehicles. Small uncrewed or unmanned aerial systems (SUAS), super heavy transports (SHT) including hybrid wing body versions (HWB), very light jets (VLJ), and supersonic business jets (SSBJ) are the four classes of aircraft that we studied. Understanding each vehicle's business purpose and strategy is critical to assessing the feasibility of new aircraft operations and their impact on NextGen's architecture. The Raytheon team used scenarios created by aviation experts that depict vehicles in year 2025 operations along with scripts or use cases to understand the issues presented by these new types of vehicles. The information was then mapped into the Joint Planning and Development Office's (JPDO s) Enterprise Architecture to show how the vehicles will fit into NextGen's Concept of Operations. The team also identified significant changes to the JPDO's Integrated Work Plan (IWP) to optimize the NextGen vision for these vehicles. Using a proven enterprise architecture approach and the JPDO s Joint Planning Environment (JPE) web site helped make the leap from architecture to planning efficient, manageable and achievable. Very Light Jets flying into busy hub airports -- Supersonic Business Jets needing to climb and descend rapidly to achieve the necessary altitude Super-heavy cargo planes requiring the shortest common flight path -- are just a few of the potential new operations in the future National Airspace System. To assess the impact of these new scenarios on overall national airspace operations, the Raytheon team used the capabilities of a suite of tools such as NASA's Airspace Concepts Evaluation System (ACES), the Flight Optimization System (FLOPS), FAA's Aviation Environmental Design Tool (AEDT), Intelligent Automations Kinematic Trajectory Generator (KTG) and the Aviation Safety Risk Model (ASRM). Detailed metroplex modeling, surface delay models for super heavy transports, prioritized routing and corridors for supersonics business jets, and VLJ demand models are some of the models developed by the Raytheon team to study the effect of operating these new vehicles in the future NAS. Using this suite of models, several trade studies were conducted to evaluate these effects in terms of delays, equity in access, safety, and the environment. Looking at the impact of each vehicle, a number of critical issues were identified. The Raytheon team concluded that strict compliance to NextGen's 4-dimensional trajectory (4DT) management will be required to accommodate these vehicles unique operations and increased number of flights in the future air space system. The next section provides a discussion of this and the other key findings from our study.

Zellweger, Andres; Resnick, Herbert; Stevens, Edward; Arkind, Kenneth; Cotton William B.

2010-01-01

318

Micro-electro-mechanical flapping wing technology for micro air vehicles  

NASA Astrophysics Data System (ADS)

Army combat operations have placed a high premium on reconnaissance missions for Unmanned Aerial Vehicles (UAVs) and Micro Air Vehicles (MAVs) (less than 15 cm in dimension and less than 20 g in mass). One approach for accomplishing this mission is to develop a biologically inspired flapping wing insect that can maneuver into confined areas and possess hovering capabilities. Analysis of insect flight indicates that in addition to the bending excitation (flapping), simultaneous excitation of the twisting degree-of-freedom (pitching) is required to manipulate the control surface adequately. Traditionally, bimorph piezoelectric PZT (Pb(Zr0.55Ti0.45)O3) actuators have been used in many applications to excite the bending degree-of-freedom. In laminated or layered structures, bend-twist coupling is governed by the existence of at least one anisotropic layer not aligned with the primary plate axes. By adding a layer of off-axis PZT segments to a PZT bimorph actuator, thereby producing a layered structure to be referred to as a functionally- modified bimorph, bend-twist coupling may be introduced to the flexural response of the layered PZT. Furthermore, by selectively charging off-axis layers in specific combinations with the bimorph, the response of the functionally-modified bimorph may be tailored yielding a biaxial actuator to actively control the flapping wing response. The present study presents an experimental investigation of both traditional bimorph and functionally-modified PZT bimorph designs intended for active bend-twist actuation of cm-scale flapping wing devices.

Hall, Asha J.; Riddick, Jaret C.

2012-03-01

319

Autonomous Landing and Ingress of Micro-Air-Vehicles in Urban Environments Based on Monocular Vision  

NASA Technical Reports Server (NTRS)

Unmanned micro air vehicles (MAVs) will play an important role in future reconnaissance and search and rescue applications. In order to conduct persistent surveillance and to conserve energy, MAVs need the ability to land, and they need the ability to enter (ingress) buildings and other structures to conduct reconnaissance. To be safe and practical under a wide range of environmental conditions, landing and ingress maneuvers must be autonomous, using real-time, onboard sensor feedback. To address these key behaviors, we present a novel method for vision-based autonomous MAV landing and ingress using a single camera for two urban scenarios: landing on an elevated surface, representative of a rooftop, and ingress through a rectangular opening, representative of a door or window. Real-world scenarios will not include special navigation markers, so we rely on tracking arbitrary scene features; however, we do currently exploit planarity of the scene. Our vision system uses a planar homography decomposition to detect navigation targets and to produce approach waypoints as inputs to the vehicle control algorithm. Scene perception, planning, and control run onboard in real-time; at present we obtain aircraft position knowledge from an external motion capture system, but we expect to replace this in the near future with a fully self-contained, onboard, vision-aided state estimation algorithm. We demonstrate autonomous vision-based landing and ingress target detection with two different quadrotor MAV platforms. To our knowledge, this is the first demonstration of onboard, vision-based autonomous landing and ingress algorithms that do not use special purpose scene markers to identify the destination.

Brockers, Roland; Bouffard, Patrick; Ma, Jeremy; Matthies, Larry; Tomlin, Claire

2011-01-01

320

Autonomous landing and ingress of micro-air-vehicles in urban environments based on monocular vision  

NASA Astrophysics Data System (ADS)

Unmanned micro air vehicles (MAVs) will play an important role in future reconnaissance and search and rescue applications. In order to conduct persistent surveillance and to conserve energy, MAVs need the ability to land, and they need the ability to enter (ingress) buildings and other structures to conduct reconnaissance. To be safe and practical under a wide range of environmental conditions, landing and ingress maneuvers must be autonomous, using real-time, onboard sensor feedback. To address these key behaviors, we present a novel method for vision-based autonomous MAV landing and ingress using a single camera for two urban scenarios: landing on an elevated surface, representative of a rooftop, and ingress through a rectangular opening, representative of a door or window. Real-world scenarios will not include special navigation markers, so we rely on tracking arbitrary scene features; however, we do currently exploit planarity of the scene. Our vision system uses a planar homography decomposition to detect navigation targets and to produce approach waypoints as inputs to the vehicle control algorithm. Scene perception, planning, and control run onboard in real-time; at present we obtain aircraft position knowledge from an external motion capture system, but we expect to replace this in the near future with a fully self-contained, onboard, vision-aided state estimation algorithm. We demonstrate autonomous vision-based landing and ingress target detection with two different quadrotor MAV platforms. To our knowledge, this is the first demonstration of onboard, vision-based autonomous landing and ingress algorithms that do not use special purpose scene markers to identify the destination.

Brockers, Roland; Bouffard, Patrick; Ma, Jeremy; Matthies, Larry; Tomlin, Claire

2011-05-01

321

Fully Self-Contained Vision-Aided Navigation and Landing of a Micro Air Vehicle Independent from External Sensor Inputs  

NASA Technical Reports Server (NTRS)

Direct-lift micro air vehicles have important applications in reconnaissance. In order to conduct persistent surveillance in urban environments, it is essential that these systems can perform autonomous landing maneuvers on elevated surfaces that provide high vantage points without the help of any external sensor and with a fully contained on-board software solution. In this paper, we present a micro air vehicle that uses vision feedback from a single down looking camera to navigate autonomously and detect an elevated landing platform as a surrogate for a roof top. Our method requires no special preparation (labels or markers) of the landing location. Rather, leveraging the planar character of urban structure, the landing platform detection system uses a planar homography decomposition to detect landing targets and produce approach waypoints for autonomous landing. The vehicle control algorithm uses a Kalman filter based approach for pose estimation to fuse visual SLAM (PTAM) position estimates with IMU data to correct for high latency SLAM inputs and to increase the position estimate update rate in order to improve control stability. Scale recovery is achieved using inputs from a sonar altimeter. In experimental runs, we demonstrate a real-time implementation running on-board a micro aerial vehicle that is fully self-contained and independent from any external sensor information. With this method, the vehicle is able to search autonomously for a landing location and perform precision landing maneuvers on the detected targets.

Brockers, Roland; Susca, Sara; Zhu, David; Matthies, Larry

2012-01-01

322

65 FR 6698 - Control of Air Pollution From New Motor Vehicles: Tier 2 Motor Vehicle Emissions Standards and...  

Federal Register 2010, 2011, 2012, 2013

...emissions standards is essential...Flexibility Analysis evaluates the financial impacts of...proposed vehicle standards and fuel...gasoline sulfur content. These...the sulfur content of those...with the standards in Sec...10) An analysis of the economic...including financial...

2000-02-10

323

Attitude estimation and maneuvering for autonomous obstacle avoidance by miniature air vehicles  

NASA Astrophysics Data System (ADS)

Utilizing the Euler-Rodrigues symmetric parameters (attitude quaternion) to describe vehicle orientation, we develop a multiplicative, nonlinear (extended) variation of the Kalman filter (MEKF) to fuse data from low-cost sensors. The sensor suite is comprised of gyroscopes, accelerometers, and a GPS receiver. In contrast to the common approach of using the complete vehicle attitude as the quantities to be estimated, our filter states consist of the three components of an attitude error vector. In parallel with the time update of the attitude error estimate, we utilize the gyroscope measurements for the time propagation of the attitude quaternion. The accelerometer and the GPS sensors are used independently for the measurement update portion of the Kalman filter. For both sensors, a vector arithmetic approach is used to determine the attitude error vector. Following each measurement update, a multiplicative reset operation moves the attitude error information from the filter state into the attitude estimate. This reset operation utilizes quaternion algebra to implicitly maintain the unity-norm constraint. We demonstrate the effectiveness of our attitude estimation algorithm through flight simulations and flight tests of aggressive maneuvers such as loops and small-radius circles. We implement an approach to acrobatic maneuvering for miniature air vehicles (MAVs) using time-parameterized attitude trajectory generation and an associated attitude tracking control law. We designed two methodologies, polynomial and trigonometric, for creating functions that specify pitch and roll angles as a function of time. For both approaches, the functions are constrained by the maneuver boundary conditions of aircraft position and velocity. We construct a trajectory tracking feedback control law to regulate aircraft orientation throughout the maneuvers. The trajectory generation algorithm was used to construct several maneuvers and trajectory tracking control law successfully executed the maneuvers in the flight simulator. In addition to the simulation results, MAV flight tests verified the performance of the maneuver generation and control. To achieve obstacle avoidance maneuvering, the time parameterized trajectories were converted to spatially parameterized paths, which allowed for inertial reference frame position error to be included in the control law feedback loop. We develop a novel method to achieve the spatial parameterization using a prediction and correction approach. Additionally, the first derivative of position of the desired path is modified using a corrective parameter scheme prior to being used in the control. Using the path position error and the corrected derivative, we utilize a unit-norm quaternion framework to implement a proportional-derivative (PD) control law. This control law was demonstrated in simulation and hardware on maneuvers designed specifically to avoid obstacles, namely the Immelmann and the Close-Q, as well as a basic loop.

Hall, James K.

324

Test methodology for evaluation of fireworthy aircraft seat cushions  

NASA Technical Reports Server (NTRS)

Aircraft seat materials were evaluated in terms of their thermal performance. The materials were evaluated using (a) thermogravimetric analysis, (b) differential scanning calorimetry, (c) a modified NBS smoke chamber to determine the rate of mass loss and (d) the NASA T-3 apparatus to determine the thermal efficiency. In this paper, the modified NBS smoke chamber will be described in detail since it provided the most conclusive results. The NBS smoke chamber was modified to measure the weight loss of materials when exposed to a radiant heat source over the range of 2.5 to 7.5 W/cm sq. This chamber has been utilized to evaluate the thermal performance of various heat blocking layers utilized to protect the polyurethane cushioning foam used in aircraft seats. Various kinds of heat blocking layers were evaluated by monitoring the weight loss of miniature seat cushions when exposed to the radiant heat. The effectiveness of aluminized heat blocking systems was demonstrated when compared to conventional heat blocking layers such as neoprene. All heat blocking systems showed good fire protection capabilities when compared to the state-of-the-art, i.e., wool-nylon over polyurethane foam.

Kourtides, D. A.; Parker, J. A.

1982-01-01

325

Suppression of Variation in Cushion Pressure for SES Using Vertically Moving Nozzles  

NASA Astrophysics Data System (ADS)

In this paper, variation in cushion pressure is investigated theoretically to achieve SES ride comfort. A simple and practical control method is proposed to control cushion pressure changes caused by pumping that appears in SES cruising over waves. Cushion pressure is controlled by varying the discharge height of the vertical nozzle. In this method, the nozzle height (hover height) is kept constant according to craft motion. As the result of investigations, cushion pressures are controlled successfully by the proposed method. In addition, we show that the pressure variation depends both on hover heights and on the rates of change in cushion volume. Therefore, it is necessary to consider phase differences between craft motion and vertical nozzle displacements.

Kanazawa, Koji; Matsuo, Kensuke; Matsuo, Hideo

326

Suppression of the Variation of Cushion Pressure for SES Using Vertically Moving Nozzles  

NASA Astrophysics Data System (ADS)

In this paper the variation of cushion pressure is investigated theoretically to achieve comfortable riding of SES. A simpler and practical control method is proposed to control cushion pressure changes arising from pumping phenomenon that appears in SES cruising over the waves. Cushion pressure is controlled by varying the discharge height of the vertical nozzle. In this method the nozzle height (hover height) is kept constant according with the motion of the craft. As the result of investigations, cushion pressures are successfully controlled by the proposed method. In addition, it is shown that the pressure variation depends not only hover height but also on rate of change of cushion volume. Therefore it is also necessary to consider phase difference between the motion of models and the vertical displacement of nozzles.

Kanazawa, Koji; Matsuo, Kensuke; Matsuo, Hideo

327

Testing of aircraft passenger seat cushion material, full scale. Data, volume 2  

NASA Technical Reports Server (NTRS)

Burn characteristics of presently used and proposed seat cushion materials and types of constructions were determined. Eight different seat cushion configurations were subjected to full scale burn tests. Each cushion configuration was tested twice for a total of 16 tests. Two different fire sources were used: Jet A-fuel for eight tests, and a radiant energy source with propane flame for eight tests. Data were recorded for smoke density, cushion temperatures, radiant heat flux, animal response to combustion products, rate of weight loss of test specimens, cabin temperature, and type and content of gas within the cabin. When compared to existing seat cushions, the test specimens incorporating a fire barrier and those fabricated from advanced materials, using improved construction methods, exhibited significantly greater fire resistance. Flammability comparison tests were conducted upon one fire blocking configuration and one polyimide configuration.

Schutter, K. J.; Gaume, J. G.; Duskin, F. E.

1980-01-01

328

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

329

77 FR 3386 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Clean Vehicles Program  

Federal Register 2010, 2011, 2012, 2013

...and made changes to the Clean Vehicle Program to reflect post-1998...earning period within which vehicle manufacturers could comply...program's fleet average non-methane organic gases (NMOG) requirements...information on the Pennsylvania Clean Vehicle program, refer to...

2012-01-24

330

Design and verification of a smart wing for an extreme-agility micro-air-vehicle  

NASA Astrophysics Data System (ADS)

A special class of fixed-wing micro-air-vehicle (MAV) is currently being designed to fly and hover to provide range superiority as well as being able to hover through a flight maneuver known as prop-hanging to accomplish a variety of surveillance missions. The hover maneuver requires roll control of the wing through differential aileron deflection but a conventional system contributes significantly to the gross weight and complexity of a MAV. Therefore, it is advantageous to use smart structure approaches with active materials to design a lightweight, robust wing for the MAV. The proposed smart wing consists of an active trailing edge flap integrated with bimorph actuators with piezoceramic fibers. Actuation is enhanced by preloading the bimorph actuators with a compressive axial load. The preload is exerted on the actuators through a passive latex or electroactive polymer (EAP) skin that wraps around the airfoil. An EAP skin would further enhance the actuation by providing an electrostatic effect of the dielectric polymer to increase the deflection. Analytical modeling as well as finite element analysis show that the proposed concept could achieve the target bi-directional deflection of 30° in typical flight conditions. Several bimorph actuators were manufactured and an experimental setup was designed to measure the static and dynamic deflections. The experimental results validated the analytical technique and finite element models, which have been further used to predict the performance of the smart wing design for a MAV.

Wickramasinghe, Viresh; Chen, Yong; Martinez, Marcias; Wong, Franklin; Kernaghan, Robert

2011-12-01

331

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

NASA Technical Reports Server (NTRS)

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

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

2002-01-01

332

Multisensor 3D tracking for counter small unmanned air vehicles (CSUAV)  

NASA Astrophysics Data System (ADS)

A variety of unmanned air vehicles (UAVs) have been developed for both military and civilian use. The typical large UAV is typically state owned, whereas small UAVs (SUAVs) may be in the form of remote controlled aircraft that are widely available. The potential threat of these SUAVs to both the military and civilian populace has led to research efforts to counter these assets via track, ID, and attack. Difficulties arise from the small size and low radar cross section when attempting to detect and track these targets with a single sensor such as radar or video cameras. In addition, clutter objects make accurate ID difficult without very high resolution data, leading to the use of an acoustic array to support this function. This paper presents a multi-sensor architecture that exploits sensor modes including EO/IR cameras, an acoustic array, and future inclusion of a radar. A sensor resource management concept is presented along with preliminary results from three of the sensors.

Vasquez, Juan R.; Tarplee, Kyle M.; Case, Ellen E.; Zelnio, Anne M.; Rigling, Brian D.

2008-04-01

333

Relationship Between Vehicle Count and Particulate Air Pollution in Amman, Jordan.  

PubMed

The main objective of this cross-sectional comparative study is to observe the relationship between traffic-related air pollutants, particularly particulate matter (PM) of total suspended particulate (TSP) and PM of size 10 µm (PM10), and vehicle traffic in Amman, Jordan. Two study areas were chosen randomly as a high-polluted area (HPA) and low-polluted area (LPA). The findings indicate that TSP and PM10 were still significantly correlated with traffic count even after controlling for confounding factors (temperature, relative humidity, and wind speed): TSP, r = 0.726, P < .001; PM10, r = 0.719, P < .001). There was a significant positive relationship between traffic count and PM level: TSP, P < .001; PM10, P < .001. Moreover, there was a significant negative relationship between temperature and PM10 level (P = .018). Traffic volume contributed greatly to high concentrations of TSP and PM10 in areas with high traffic count, in addition to the effect of temperature. PMID:22899706

Alnawaiseh, Nedal Awad; Hashim, Jamal Hisham; Md Isa, Zaleha

2012-08-16

334

Artificial insect wings of diverse morphology for flapping-wing micro air vehicles.  

PubMed

The development of flapping-wing micro air vehicles (MAVs) demands a systematic exploration of the available design space to identify ways in which the unsteady mechanisms governing flapping-wing flight can best be utilized for producing optimal thrust or maneuverability. Mimicking the wing kinematics of biological flight requires examining the potential effects of wing morphology on flight performance, as wings may be specially adapted for flapping flight. For example, insect wings passively deform during flight, leading to instantaneous and potentially unpredictable changes in aerodynamic behavior. Previous studies have postulated various explanations for insect wing complexity, but there lacks a systematic approach for experimentally examining the functional significance of components of wing morphology, and for determining whether or not natural design principles can or should be used for MAVs. In this work, a novel fabrication process to create centimeter-scale wings of great complexity is introduced; via this process, a wing can be fabricated with a large range of desired mechanical and geometric characteristics. We demonstrate the versatility of the process through the creation of planar, insect-like wings with biomimetic venation patterns that approximate the mechanical properties of their natural counterparts under static loads. This process will provide a platform for studies investigating the effects of wing morphology on flight dynamics, which may lead to the design of highly maneuverable and efficient MAVs and insight into the functional morphology of natural wings. PMID:19713572

Shang, J K; Combes, S A; Finio, B M; Wood, R J

2009-09-01

335

The novel aerodynamics of insect flight: applications to micro-air vehicles.  

PubMed

The wing motion in free flight has been described for insects ranging from 1 to 100 mm in wingspan. To support the body weight, the wings typically produce 2-3 times more lift than can be accounted for by conventional aerodynamics. Some insects use the fling mechanism: the wings are clapped together and then flung open before the start of the downstroke, creating a lift-enhancing vortex around each wing. Most insects, however, rely on a leading-edge vortex (LEV) created by dynamic stall during flapping; a strong spanwise flow is also generated by the pressure gradients on the flapping wing, causing the LEV to spiral out to the wingtip. Technical applications of the fling are limited by the mechanical damage that accompanies repeated clapping of the wings, but the spiral LEV can be used to augment the lift production of propellers, rotors and micro-air vehicles (MAVs). Design characteristics of insect-based flying machines are presented, along with estimates of the mass supported, the mechanical power requirement and maximum flight speeds over a wide range of sizes and frequencies. To support a given mass, larger machines need less power, but smaller ones operating at higher frequencies will reach faster speeds. PMID:10562527

Ellington, C P

1999-12-01

336

4D metrology of flapping-wing micro air vehicle based on fringe projection  

NASA Astrophysics Data System (ADS)

Inspired by dominant flight of the natural flyers and driven by civilian and military purposes, micro air vehicle (MAV) has been developed so far by passive wing control but still pales in aerodynamic performance. Better understanding of flapping wing flight mechanism is eager to improve MAV's flight performance. In this paper, a simple and effective 4D metrology technique to measure full-field deformation of flapping membrane wing is presented. Based on fringe projection and 3D Fourier analysis, the fast and complex dynamic deformation, including wing rotation and wing stroke, of a flapping wing during its flight can be accurately reconstructed from the deformed fringe patterns recorded by a highspeed camera. An experiment was carried on a flapping-wing MAV with 5-cm span membrane wing beating at 30 Hz, and the results show that this method is effective and will be useful to the aerodynamicist or micro aircraft designer for visualizing high-speed complex wing deformation and consequently aid the design of flapping wing mechanism to enhanced aerodynamic performance.

Zhang, Qican; Huang, Lei; Chin, Yao-Wei; Keong, Lau-Gih; Asundi, Anand

2013-06-01

337

Conservation equations and physical models for hypersonic air flows over the aeroassist flight experiment vehicle  

NASA Technical Reports Server (NTRS)

The code development and application program for the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA), with emphasis directed toward support of the Aeroassist Flight Experiment (AFE) in the near term and Aeroassisted Space Transfer Vehicle (ASTV) design in the long term is reviewed. LAURA is an upwind-biased, point-implicit relaxation algorithm for obtaining the numerical solution to the governing equations for 3-D, viscous, hypersonic flows in chemical and thermal nonequilibrium. The algorithm is derived using a finite volume formulation in which the inviscid components of flux across cell walls are described with Roe's averaging and Harten's entropy fix with second-order corrections based on Yee's Symmetric Total Variation Diminishing scheme. Because of the point-implicit relaxation strategy, the algorithm remains stable at large Courant numbers without the necessity of solving large, block tri-diagonal systems. A single relaxation step depends only on information from nearest neighbors. Predictions for pressure distributions, surface heating, and aerodynamic coefficients compare well with experimental data for Mach 10 flow over an AFE wind tunnel model. Predictions for the hypersonic flow of air in chemical and thermal nonequilibrium over the full scale AFE configuration obtained on a multi-domain grid are discussed.

Gnoffo, Peter A.

1989-01-01

338

Low Dimensional Tools for Flow-Structure Interaction Problems: Application to Micro Air Vehicles  

NASA Technical Reports Server (NTRS)

A low dimensional tool for flow-structure interaction problems based on Proper Orthogonal Decomposition (POD) and modified Linear Stochastic Estimation (mLSE) has been proposed and was applied to a Micro Air Vehicle (MAV) wing. The method utilizes the dynamic strain measurements from the wing to estimate the POD expansion coefficients from which an estimation of the velocity in the wake can be obtained. For this experiment the MAV wing was set at five different angles of attack, from 0 deg to 20 deg. The tunnel velocities varied from 44 to 58 ft/sec with corresponding Reynolds numbers of 46,000 to 70,000. A stereo Particle Image Velocimetry (PIV) system was used to measure the wake of the MAV wing simultaneously with the signals from the twelve dynamic strain gauges mounted on the wing. With 20 out of 2400 POD modes, a reasonable estimation of the flow flow was observed. By increasing the number of POD modes, a better estimation of the flow field will occur. Utilizing the simultaneously sampled strain gauges and flow field measurements in conjunction with mLSE, an estimation of the flow field with lower energy modes is reasonable. With these results, the methodology for estimating the wake flow field from just dynamic strain gauges is validated.

Schmit, Ryan F.; Glauser, Mark N.; Gorton, Susan A.

2003-01-01

339

Measurements and performance prediction of an adaptive wing micro air vehicle  

NASA Astrophysics Data System (ADS)

The mission space requirements imposed on the design of micro air vehicles (MAVs) typically consist of several distinct flight segments that generally conflict: the transit phases of flight require high speeds, while the loiter/surveillance phase requires lower flight velocities. Maximum efficiency must be sought in order to prolong battery life and aircraft endurance. The adaptive wing MAV developed at the University of Arizona features a thin, deformable flying wing with an efficient rudder-elevator control system. The wing camber is varied to accommodate different flight speeds while maintaining a constant total lift at a relatively low angle of attack. A new airfoil was developed from the Selig 5010 that features a small negative pitching moment for pitch stability. Wind tunnel tests were performed and stall angles and best lift-to-drag ratios were analyzed from the data. The wind tunnel data was used in a performance analysis in order to determine the flight speeds and throttle settings for maximum endurance at each camber, as well as the MAV"s theoretical minimum and maximum flight speeds. The effectiveness of camber change on flight speed and endurance was examined with promising results; flight speed could be reduced by 25% by increasing the camber from 3 to 9% without any increase in power consumption.

Shkarayev, Sergey V.; Jouse, Wayne C.; Null, William R.; Wagner, Matthew G.

2003-08-01

340

Dynamic stability test results on an 0.024 scale B-1 air vehicle  

NASA Technical Reports Server (NTRS)

Dynamic longitudinal and lateral-directional stability characteristics of the B-1 air vehicle were investigated in three wind tunnels at the Langley Research Center. The main rotary derivatives were obtained for an angle of attack range of -3 degrees to +16 degrees for a Mach number range of 0.2 to 2.16. Damping in roll data could not be obtained at the supersonic Mach numbers. The Langley 7 x 10 foot high speed tunnel, the 8 foot transonic pressure tunnel, and the 4 foot Unitary Plan wind tunnel were the test sites. An 0.024 scale light-weight model was used on a forced oscillation type balance. Test Reynolds number varied from 474,000/ft to 1,550,000/ft. through the Mach number range tested. The results showed that the dynamic stability characteristics of the model in pitch and roll were generally satisfactory up to an angle attack of about +6 degrees. In the wing sweep range from 15 to 25 degrees the positive damping levels in roll deteriorated rapidly above +2 degrees angle of attack. This reduction in roll damping is believed to be due to the onset of separation over the wing as stall is approached.

Beeman, R. R.

1972-01-01

341

Police officer in-vehicle discomfort: appointments carriage method and vehicle seat features.  

PubMed

Musculoskeletal pain is commonly reported by police officers. A potential cause of officer discomfort is a mismatch between vehicle seats and the method used for carrying appointments. Twenty-five police officers rated their discomfort while seated in: (1) a standard police vehicle seat, and (2) a vehicle seat custom-designed for police use. Discomfort was recorded in both seats while wearing police appointments on: (1) a traditional appointments belt, and (2) a load-bearing vest/belt combination (LBV). Sitting in the standard vehicle seat and carrying appointments on a traditional appointments belt were both associated with significantly elevated discomfort. Four vehicle seat features were most implicated as contributing to discomfort: back rest bolster prominence; lumbar region support; seat cushion width; and seat cushion bolster depth. Authorising the carriage of appointments using a LBV is a lower cost solution with potential to reduce officer discomfort. Furthermore, the introduction of custom-designed vehicle seats should be considered. PMID:24681072

Filtness, A J; Mitsopoulos-Rubens, E; Rudin-Brown, C M

2014-07-01

342

Dual rotor single- stator axial air gap PMSM motor/generator drive for high torque vehicles applications  

NASA Astrophysics Data System (ADS)

The actual e – continuously variable transmission (e-CVT) solution for the parallel Hybrid Electric Vehicle (HEV) requires two electric machines, two inverters, and a planetary gear. A distinct electric generator and a propulsion electric motor, both with full power converters, are typical for a series HEV. In an effort to simplify the planetary-geared e-CVT for the parallel HEV or the series HEV we hereby propose to replace the basically two electric machines and their two power converters by a single, axial-air-gap, electric machine central stator, fed from a single PWM converter with dual frequency voltage output and two independent PM rotors, destined for hybrid electric vehicles (HEV) and military vehicles applications. The proposed topologies and the magneto-motive force analysis are the core of the paper.

Tutelea, L. N.; Deaconu, S. I.; Boldea, I.; Popa, G. N.

2014-03-01

343

Expanded polystyrene foam design with emphasis on nonimpact cushioning applications  

NASA Astrophysics Data System (ADS)

Studies into the design of expanded polystyrene (EPS) foam packaging were conducted. The studies were directed toward the development of design parameters and criteria for vibration type loadings applied to foam packaging. The mechanics of EPS foam pertaining to packaging design were examined. Design guidelines based on vibration load input and mechanical properties of EPS foam that are applicable to cushioning applications were explored. A number of combinations of specimen size were tested to characterize the size effect on mechanical properties of EPS foam. Suites of specimens of varying thicknesses and cross sections were examined. It was observed that the modulus of elasticity and the yield strength exhibited a high degree of dependency on thickness. Loading rate dependency tests were conducted on specimens having a single lateral dimension but varying thicknesses. Loading rates ranging from 8.47 x 10-3 mm/s (0.02 in./min) to 8.47 mm/s (20 in./min) were used. All mechanical properties examined in this study exhibited an increasing trend with an increase in loading rate. However, the rate of change in these properties varies with the foam thickness. Quasi-static cyclic loading studies were conducted to investigate the energy dissipation capability inherent to EPS foams. Foam specimens were subjected to cyclic loadings varying in magnitude from 50% of the apparent yield strain up to the load that causes an initial deformation of 10%. The results provide clear evidence of hysteresis energy losses even at cyclic loads below the yield point of the material. Photographic examination of the samples subsequent to loading also showed evidence of permanent deformation occurring even for small load magnitudes. Vibration studies showed that the amount of protection afforded by EPS foam from vibration loadings is generally small. It is possible to design a foam cushioning to operate as a vibration isolator only in the higher range of frequencies that are important in the shipping environment. EPS foam is not well suited for vibration protection in packaging applications. With this in mind, a guideline for adjusting an impact cushioning design to minimize the vibration impact on a packaging design is offered.

Rusmeehatthakarn, Pichai

344

Air-breathing hypersonic vehicle guidance and control studies: An integrated trajectory/control analysis methodology, phase 2  

NASA Technical Reports Server (NTRS)

An integrated trajectory/control analysis algorithm has been used to generate trajectories and desired control strategies for two different hypersonic air-breathing vehicle models and orbit targets. Both models used cubic spline curve fit tabulated winged-cone accelerator vehicle representations. Near-fuel-optimal, horizontal takeoff trajectories, imposing a dynamic pressure limit of 1000 psf, were developed. The first model analysis case involved a polar orbit and included the dynamic effects of using elevons to maintain longitudinal trim. Analysis results indicated problems with the adequacy of the propulsion model and highlighted dynamic pressure/altitude instabilities when using vehicle angle of attack as a control variable. Also, the magnitude of computed elevon deflections to maintain trim suggested a need for alternative pitch moment management strategies. The second analysis case was reformulated to use vehicle pitch attitude relative to the local vertical as the control variable. A new, more realistic, air-breathing propulsion model was incorporated. Pitch trim calculations were dropped and an equatorial orbit was specified. Changes in flight characteristics due to the new propulsion model have been identified. Flight regimes demanding rapid attitude changes have been noted. Also, some issues that would affect design of closed-loop controllers were ascertained.

Hattis, Philip D.; Malchow, Harvey L.

1992-01-01

345

Air-breathing hypersonic vehicle guidance and control studies; An integrated trajectory/control analysis methodology: Phase 1  

NASA Technical Reports Server (NTRS)

A tool which generates optimal trajectory/control histories in an integrated manner is generically adapted to the treatment of single-stage-to-orbit air-breathing hypersonic vehicles. The methodology is implemented as a two point boundary value problem solution technique. Its use permits an assessment of an entire near-minimum-fuel trajectory and desired control strategy from takeoff to orbit while satisfying physically derived inequality constraints and while achieving efficient propulsive mode phasing. A simpler analysis strategy that partitions the trajectory into several boundary condition matched segments is also included to construct preliminary trajectory and control history representations with less computational burden than is required for the overall flight profile assessment. A demonstration was accomplished using a tabulated example (winged-cone accelerator) vehicle model that is combined with a newly developed multidimensional cubic spline data smoothing routine. A constrained near-fuel-optimal trajectory, imposing a dynamic pressure limit of 1000 psf, was developed from horizontal takeoff to 20,000 ft/sec relative air speed while aiming for a polar orbit. Previously unspecified propulsive discontinuities were located. Flight regimes demanding rapid attitude changes were identified, dictating control effector and closed-loop controller authority was ascertained after evaluating effector use for vehicle trim. Also, inadequacies in vehicle model representations and specific subsystem models with insufficient fidelity were determined based on unusual control characteristics and/or excessive sensitivity to uncertainty.

Hattis, Philip D.; Malchow, Harvey L.

1991-01-01

346

A complete passive or imaging-based sensor system for unmanned air vehicle taking off and landing operations  

Microsoft Academic Search

We have successfully developed an innovative, miniaturized, and lightweight PTZ UCAV imager called OmniBird for unmanned air vehicle taking off and landing operations. OmniBird is developed through a SBIR funding from NAVAIR. It is to fit in 8 in3. The designed zoom capability allows it to acquire focused images for targets ranging from 10 to 250 feet. The innovative panning

Steven Yi

2008-01-01

347

The use of an inertial measurement unit in the flight testing of a small, remote-piloted air vehicle  

Microsoft Academic Search

A 3 meter-span, unmanned air vehicle has been flight tested in order to find its dynamic modes of motion, in-flight Euler angles, and in-flight angles of attack and sideslip angles. Instrumentation included an inertial measurement unit, a GPS, and a 3-axis sonic anemometer. ^ Before flight, the inertial measurement unit was calibrated for rotation rate, temperature, and acceleration. Each of

Edward Hale Londner

2009-01-01

348

Experimental investigation of some aspects of insect-like flapping flight aerodynamics for application to micro air vehicles  

Microsoft Academic Search

Insect-like flapping flight offers a power-efficient and highly manoeuvrable basis for micro air vehicles for indoor applications.\\u000a Some aspects of the aerodynamics associated with the sweeping phase of insect wing kinematics are examined by making particle\\u000a image velocimetry measurements on a rotating wing immersed in a tank of seeded water. The work is motivated by the paucity\\u000a of data with

Salman A. Ansari; Nathan Phillips; Graham Stabler; Peter C. Wilkins; Rafa? ?bikowski; Kevin Knowles

2009-01-01

349

On mathematical modelling of insect flight dynamics in the context of micro air vehicles.  

PubMed

We discuss some aspects of mathematical modelling relevant to the dynamics of insect flight in the context of insect-like flapping-wing micro air vehicles (MAVs). MAVs are small flying vehicles developed to reconnoître in confined spaces. This requires power-efficient, highly-manoeuvrable, low-speed flight with stable hover. All of these attributes are present in insect flight and hence the focus on reproducing the functionality of insect flight by engineering means. Empirical research on insect flight dynamics is limited by experimental difficulties. Force and moment measurements require tethering the animal whose behaviour may then differ from free flight. The measurements are made when the insect actively tries to control its flight, so that its open-loop dynamics cannot be observed. Finally, investigation of the sensory-motor system responsible for flight is even more challenging. Despite these difficulties, much empirical progress has been made recently. Further progress, especially in the context of MAVs, can be achieved by the complementary information derived from appropriate mathematical modelling. The focus here is on a means of computing the data not easily available from experiments and also on making mathematical predictions to suggest new experiments. We consider two aspects of mathematical modelling for insect flight dynamics. The first one is theoretical (computational), as opposed to empirical, generation of the aerodynamic data required for the six-degrees-of-freedom equations of motion. For this purpose we first explain insect wing kinematics and the salient features of the corresponding flow. In this context, we show that aerodynamic modelling is a feasible option for certain flight regimes, focusing on a successful example of modelling hover. Such modelling progresses from the first principles of fluid mechanics, but relies on simplifications justified by the known flow phenomenology and/or geometric and kinematic symmetries. This is relevant to six types of fundamental manoeuvres, which we define as those flight conditions for which only one component of the translational and rotational body velocities is nonzero and constant. The second aspect of mathematical modelling for insect flight dynamics addressed here deals with the periodic character of the aerodynamic force and moment production. This leads to consideration of the types of solutions of nonlinear equations forced by nonlinear oscillations. In particular, the mechanism of synchronization seems relevant and should be investigated further. PMID:17671303

Zbikowski, Rafa?; Ansari, Salman A; Knowles, Kevin

2006-06-01

350

Pair plasma cushions in the hole-boring scenario  

NASA Astrophysics Data System (ADS)

Pulses from a 10 PW laser are predicted to produce large numbers of gamma-rays and electron-positron pairs on hitting a solid target. However, a pair plasma, if it accumulates in front of the target, may partially shield it from the pulse. Using stationary, one-dimensional solutions of the two-fluid (electron-positron) and Maxwell equations, including a classical radiation reaction term, we examine this effect in the hole-boring scenario. We find the collective effects of a pair plasma ‘cushion’ substantially reduce the reflectivity, converting the absorbed flux into high-energy gamma-rays. There is also a modest increase in the laser intensity needed to achieve threshold for a non-linear pair cascade.

Kirk, J. G.; Bell, A. R.; Ridgers, C. P.

2013-09-01

351

66 FR 5002 - Control of Air Pollution from New Motor Vehicles: Heavy-Duty Engine and Vehicle Standards and...  

Federal Register 2010, 2011, 2012, 2013

The pollution emitted by diesel engines contributes greatly to our nation's continuing air quality problems. Even with more stringent heavy-duty highway engine standards set to take effect in 2004, these engines will continue to emit large amounts of nitrogen oxides and particulate matter, both of which contribute to serious public health problems in the United States. These problems include......

2001-01-18

352

9 CFR 3.62 - Primary conveyances (motor vehicle, rail, air, and marine).  

...does not have a supply of air sufficient for normal breathing...rabbit has access to sufficient air for normal breathing. ...primary conveyances used to transport rabbits shall be mechanically sound and provide fresh air by means of windows,...

2014-01-01

353

Combating urban air pollution through Natural Gas Vehicle (NGV) analysis, testing, and demonstration.  

National Technical Information Service (NTIS)

Deteriorating urban air quality ranks as a top concern worldwide, since air pollution adversely affects both public health and the environment. The outlook for improving air quality in the world's megacities need not be bleak, however, The use of natural ...

1995-01-01

354

Evaluation of some significant issues affecting trajectory and control management for air-breathing hypersonic vehicles  

NASA Technical Reports Server (NTRS)

Horizontal takeoff airbreathing-propulsion launch vehicles require near-optimal guidance and control which takes into account performance sensitivities to atmospheric characteristics while satisfying physically-derived operational constraints. A generic trajectory/control analysis tool that deepens insight into these considerations has been applied to two versions of a winged-cone vehicle model. Information that is critical to the design and trajectory of these vehicles is derived, and several unusual characteristics of the airbreathing propulsion model are shown to have potentially substantial effects on vehicle dynamics.

Hattis, Philip D.; Malchow, Harvey L.

1992-01-01

355

Characterization of Material Properties and Structural Dynamics of the Manduca Sexta Forewing for Application to Flapping Wing Micro Air Vehicle Design.  

National Technical Information Service (NTIS)

The Manduca Sexta species of moth serves as a source of biological inspiration for the future of micro air vehicle flapping flight. The ability of this species to hover in flapping flight has warranted investigation into the critical material, structural,...

R. P. O'Hara

2012-01-01

356

Next Generation Natural Gas Vehicle Program Phase I: Clean Air Partners 0.5 g/hp-h NOx Engine Concept; Final Report  

SciTech Connect

Subcontractor report details work done by Clean Air Partners to develop 0.5 g/hp-h NOx natural gas engine exhaust gas recirculation (EGR) technology for the Next Generation Natural Gas Vehicle Program.

Wong, H. C.

2003-07-01

357

Bio-inspired multi-mode optic flow sensors for micro air vehicles  

NASA Astrophysics Data System (ADS)

Monitoring wide-field surrounding information is essential for vision-based autonomous navigation in micro-air-vehicles (MAV). Our image-cube (iCube) module, which consists of multiple sensors that are facing different angles in 3-D space, can be applied to the wide-field of view optic flows estimation (?-Compound eyes) and to attitude control (?- Ocelli) in the Micro Autonomous Systems and Technology (MAST) platforms. In this paper, we report an analog/digital (A/D) mixed-mode optic-flow sensor, which generates both optic flows and normal images in different modes for ?- Compound eyes and ?-Ocelli applications. The sensor employs a time-stamp based optic flow algorithm which is modified from the conventional EMD (Elementary Motion Detector) algorithm to give an optimum partitioning of hardware blocks in analog and digital domains as well as adequate allocation of pixel-level, column-parallel, and chip-level signal processing. Temporal filtering, which may require huge hardware resources if implemented in digital domain, is remained in a pixel-level analog processing unit. The rest of the blocks, including feature detection and timestamp latching, are implemented using digital circuits in a column-parallel processing unit. Finally, time-stamp information is decoded into velocity from look-up tables, multiplications, and simple subtraction circuits in a chip-level processing unit, thus significantly reducing core digital processing power consumption. In the normal image mode, the sensor generates 8-b digital images using single slope ADCs in the column unit. In the optic flow mode, the sensor estimates 8-b 1-D optic flows from the integrated mixed-mode algorithm core and 2-D optic flows with an external timestamp processing, respectively.

Park, Seokjun; Choi, Jaehyuk; Cho, Jihyun; Yoon, Euisik

2013-06-01

358

Emerging Fuel Cell Technology Being Developed: Offers Many Benefits to Air Vehicles  

NASA Technical Reports Server (NTRS)

Fuel cells, which have recently received considerable attention for terrestrial applications ranging from automobiles to stationary power generation, may enable new aerospace missions as well as offer fuel savings, quiet operations, and reduced emissions for current and future aircraft. NASA has extensive experience with fuel cells, having used them on manned space flight systems over four decades. Consequently, the NASA Glenn Research Center has initiated an effort to investigate and develop fuel cell technologies for multiple aerospace applications. Two promising fuel cell types are the proton exchange membrane (PEM) and solid oxide fuel cell (SOFC). PEM technology, first used on the Gemini spacecraft in the sixties, remained unutilized thereafter until the automotive industry recently recognized the potential. PEM fuel cells are low-temperature devices offering quick startup time but requiring relatively pure hydrogen fuel. In contrast, SOFCs operate at high temperatures and tolerate higher levels of impurities. This flexibility allows SOFCs to use hydrocarbon fuels, which is an important factor considering our current liquid petroleum infrastructure. However, depending on the specific application, either PEM or SOFC can be attractive. As only NASA can, the Agency is pursuing fuel cell technology for civil uninhabited aerial vehicles (UAVs) because it offers enhanced scientific capabilities, including enabling highaltitude, long-endurance missions. The NASA Helios aircraft demonstrated altitudes approaching 100,000 ft using solar power in 2001, and future plans include the development of a regenerative PEM fuel cell to provide nighttime power. Unique to NASA's mission, the high-altitude aircraft application requires the PEM fuel cell to operate on pure oxygen, instead of the air typical of terrestrial applications.

Walker, James F.; Civinskas, Kestutis C.

2004-01-01

359

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

NASA Technical Reports Server (NTRS)

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

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

2003-01-01

360

Reusable Space Vehicle Baseline Conceptual Vehicle.  

National Technical Information Service (NTIS)

Modeling efforts for future space operation vehicles at the United States Air Force Research Labs Air Vehicles Directorate have been focused towards the in flight mission. To better serve the research and development effort, a simulation of the ground ope...

D. R. Maynard P. Pettit

2004-01-01

361

An efficient fluid-structure interaction method for conceptual design of flexible micro air vehicle wings: Development, comparison, and application  

NASA Astrophysics Data System (ADS)

This thesis summarizes the development, comparison, and applications of an efficient fluid-structure interaction method capable of simulating the effects that wing flexibility has on micro air vehicle (MAV) performance. Micro air vehicles wing designs often incorporate flexible wing structures that mimic the skeleton / membrane designs found in natural flyers such as bats and insects. However, accurate performance prediction for these wings requires the coupling of the simulation of the fluid physics around the wing and the simulation of the structural deformation. These fluid-structure interaction (FSI) simulations are often accomplished using high fidelity, computationally expensive techniques such as computational fluid dynamics (CFD) for the fluid physics and nonlinear finite element analysis (FEA) for the structural simulation. The main drawback of these methods, especially for use simulating vehicles that are able to be manufactured relatively quickly, is that the computational cost required to perform relevant trade studies on the design is prohibitively large and time-consuming. The main goal of this research is the development of a coupled fluid-structure interaction method computationally efficient and accurate enough to be used for conceptual design of micro air vehicles. An advanced potential flow model is used to calculate aerodynamic performance and loading, while a simplified finite element structural model using frame and shell elements calculates the wing deflection due to aerodynamic loading. The contents of this thesis include a literature survey of current approaches, an introduction to the efficient FSI formulation, comparison of the presented FSI method with higher-fidelity simulation methods, demonstrations of the method's capability for tradeoff and optimization studies, and an overview of contributions to a nonlinear dynamic algorithm for the simulation of flapping flight.

Combes, Thomas P.

362

Role of Individual and Team Cognition in Uninhabited Air Vehicle Command-and-Control.  

National Technical Information Service (NTIS)

This report documents a three-year AFOSR-funded research effort designed to study individual and team cognition in Unmanned Aerial Vehicle command-and-control. Three experiments were conducted in the CERTT lab's UAV-STE (Unmanned Aerial Vehicle - Syntheti...

H. K. Pedersen J. A. DeJoode J. C. Gorman N. J. Cooke O. O. Connor

2004-01-01

363

Reliable autonomous control technologies (ReACT) for uninhabited air vehicles  

Microsoft Academic Search

Reliable Autonomous Control Technologies (REACT) is a NASA sponsored flight research effort under the Revolutionary Concepts (RevCon) initiative. REACT seeks to develop and demonstrate an innovative software system to perform total vehicle and mission management for uninhabited aerial vehicles (UAVs). The REACT system will enable the development of safe, robust, and capable UAVs that are suitable for use in safety-

Pete Schaefer; Richard D. Colgren; Richard J. Abbott; Han Park; Amir Fijany; F. Fisher; M. L. James; S. Chien; R. Mackey; M. Zak; T. L. Johnson; S. F. Bush

2001-01-01

364

Attitude estimation and maneuvering for autonomous obstacle avoidance by miniature air vehicles  

Microsoft Academic Search

Utilizing the Euler-Rodrigues symmetric parameters (attitude quaternion) to describe vehicle orientation, we develop a multiplicative, nonlinear (extended) variation of the Kalman filter (MEKF) to fuse data from low-cost sensors. The sensor suite is comprised of gyroscopes, accelerometers, and a GPS receiver. In contrast to the common approach of using the complete vehicle attitude as the quantities to be estimated, our

James K. Hall

2009-01-01

365

78 FR 68378 - Approval and Promulgation of Air Quality Implementation Plans; Illinois; Amendments to Vehicle...  

Federal Register 2010, 2011, 2012, 2013

...February 1, 2007. The replacement of the computer-matching enforcement mechanism with...Illinois I/M program changed from a computer-matching system to a vehicle registration...using the EPA's motor vehicle emissions simulator model, MOVES2010a.\\2\\ The...

2013-11-14

366

77 FR 75388 - Approval and Promulgation of Air Quality Implementation Plans; State of Colorado; Motor Vehicle...  

Federal Register 2010, 2011, 2012, 2013

...Rebecca Russo, Air Program, Mailcode...Wynkoop Street, Denver, Colorado 80202-1129...refer to the Clean Air Act, unless the...national ambient air quality standard. (iv...monitored ambient air quality data from 2008...that the metro-Denver/NFR area...

2012-12-20

367

Testing of aircraft passenger seat cushion materials. Full scale, test description and results, volume 1  

NASA Technical Reports Server (NTRS)

Eight different seat cushion configurations were subjected to full-scale burn tests. Each cushion configuration was tested twice for a total of sixteen tests. Two different fire sources were used. They consisted of one liter of Jet A fuel for eight tests and a radiant energy source with propane flame for eight tests. Both fire sources were ignited by a propane flame. During each test, data were recorded for smoke density, cushion temperatures, radiant heat flux, animal response to combustion products, rate of weight loss of test specimens, cabin temperature, and for the type and content of gas within the cabin atmosphere. When compared to existing passenger aircraft seat cushions, the test specimens incorporating a fire barrier and those fabricated from advanced materials, using improved construction methods, exhibited significantly greater fire resistance.

Schutter, K. J.; Gaume, J. G.; Duskin, F. E.

1981-01-01

368

Multi-AXIS Vibration Mitigation Properties of Seat Cushions During Military Propeller Aircraft Operational Exposures.  

National Technical Information Service (NTIS)

There have been increasing complaints of annoyance, fatigue, and musculoskeletal pain during prolonged exposures to propulsion-generated vibration in military propeller aircraft. The objective of this study was to evaluate the effects of seat cushions on ...

S. D. Smith J. A. Smith

2005-01-01

369

National Fuel Cell Vehicle Learning Demonstration: Gen 2 Progress. California Air Resources Board 2009 ZEV Symposium. Session 2: Automotive Fuel Cell Vehicle Technologies.  

National Technical Information Service (NTIS)

Partial Contents: Fuel Cell Vehicle Learning Demonstration Project Objectives and Targets; Industry Partners: Four Automaker/Energy-Supplier Teams; Vehicle Deployment Complete at 140 FCVs, Some Early Vehicles Retired; DOE Learning Demo Fleet Has Surpassed...

J. Garbak J. Kurtz K. Wipke S. Sprik T. Ramsden

2009-01-01

370

Istra - An air-breathing ballistic space transport vehicle for Europe  

NASA Astrophysics Data System (ADS)

A new concept for Istra, a reusable space transport vehicle to succeed Ariane, is discussed. The concept involves a hydrogen ramjet combined with a reusable one-and-one-half stage, ballistic space transport vehicle which takes off and lands vertically and utilizes liquid hydrogen and liquid oxygen as fuel. The results for Istra include: a 15.4 Mg working load in low circular orbit at 155 Mg starting mass, with about a 10 percent working load ratio; a 56 percent fuel saving and a 44 percent saving in dry mass compared to two-stage rocket concepts. These results are compared to those for recent European space transport vehicle concepts.

Kramer, P. A.; Buehler, R. D.

1982-10-01

371

Misuse of Booster Cushions - An Observation Study of Children's Performance during Buckling Up  

PubMed Central

Booster cushions are effective tools to protect children from injuries in car crashes, but there remains a large amount of misuse. The aim of this study was to assess potential misuse of booster cushions in an observational laboratory study, and to identify whether booster cushion design, age or clothing had any effect. 130 Swedish children from the ages of 4–12 years participated. Each child buckled up on an integrated and on an aftermarket booster cushion in the rear seat. The older children also buckled up with seat belt only. Interviews, observations and body measurements were performed. Time to buckle up and amount of belt slack were registered. Photographs were taken to document misuse. Results showed that 77% failed to perform correct belt routing on the aftermarket cushion, independent of age, although they were familiar with this system. The misuse rate for the integrated cushion was only 4%. No misuse was found for seat belt only. Few children tightened the belt. The belt slack increased when wearing winter jackets. This indicates the importance of adding pretensioners to the rear seat. Sled tests with HIII&TNO 6y dummies were also performed for the most frequent misuse situations found. The main conclusion is that an integrated booster cushion has many advantages compared to an aftermarket cushion regarding both safety and comfort. It is easy and quick to handle, has few possibilities for misuse, has an intuitive design, the buckling up sequence is equal to buckling up with an ordinary seat belt, and younger children can buckle up correctly.

Osvalder, Anna-Lisa; Bohman, Katarina

2008-01-01

372

Efficacy of Cement-stabilized Fly Ash Cushion in Arresting Heave of Expansive Soils  

Microsoft Academic Search

Expansive clays swell and shrink seasonally when subjected to changes in the moisture regime causing substantial distress\\u000a to the structures built in them. Techniques like sand cushion and cohesive non-swelling soil (CNS) layer have been tried to\\u000a arrest heave and consequent damages to structures. Sand cushion has been proved to be counter-productive. Studies have indicated\\u000a that even though CNS layer

M. Rama Rao; A. Sreerama Rao; R. Dayakara Babu

2008-01-01

373

Light-Duty Vehicle Greenhouse Gas Emissions Inventory for Air Quality Modeling Technical Support Document.  

National Technical Information Service (NTIS)

This document provides the details of emissions data processing done in support of the Environmental Protection Agency (EPA) and National Highway Traffic Safety Administration (NHTSA) joint rulemaking effort to establish Light Duty Vehicle Greenhouse Gas ...

2010-01-01

374

78 FR 24373 - Approval and Promulgation of Air Quality Implementation Plans; Wisconsin; Amendments to Vehicle...  

Federal Register 2010, 2011, 2012, 2013

...Certain other material, such as copyrighted material, will be publicly...available docket materials are available either...1996 and later cars and light trucks have been inspected...utility vehicles, lightweight utility...

2013-04-25

375

9 CFR 3.114 - Primary conveyances (motor vehicle, rail, air and marine).  

Code of Federal Regulations, 2012 CFR

...cargo spaces that have a supply of air sufficient for each live animal contained within. Primary transport enclosures must be positioned...will have access to sufficient air. (d) Primary transport enclosures must be...

2012-01-01

376

9 CFR 3.114 - Primary conveyances (motor vehicle, rail, air and marine).  

Code of Federal Regulations, 2010 CFR

...cargo spaces that have a supply of air sufficient for each live animal contained within. Primary transport enclosures must be positioned...will have access to sufficient air. (d) Primary transport enclosures must be...

2010-01-01

377

9 CFR 3.114 - Primary conveyances (motor vehicle, rail, air and marine).  

Code of Federal Regulations, 2011 CFR

...cargo spaces that have a supply of air sufficient for each live animal contained within. Primary transport enclosures must be positioned...will have access to sufficient air. (d) Primary transport enclosures must be...

2011-01-01

378

9 CFR 3.114 - Primary conveyances (motor vehicle, rail, air and marine).  

...cargo spaces that have a supply of air sufficient for each live animal contained within. Primary transport enclosures must be positioned...will have access to sufficient air. (d) Primary transport enclosures must be...

2014-01-01

379

77 FR 1892 - Approval and Promulgation of Air Quality Implementation Plans; State of Colorado; Motor Vehicle...  

Federal Register 2010, 2011, 2012, 2013

...comments. Email: russo.rebecca@epa.gov. Mail: Carl Daly, Director, Air Program, Environmental Protection Agency...CONTACT if you are faxing comments). Hand Delivery: Carl Daly, Director, Air Program, Environmental Protection...

2012-01-12

380

Long-term trends in nitrogen oxide emissions from motor vehicles at national, state, and air basin scales  

NASA Astrophysics Data System (ADS)

A fuel-based approach is used to estimate nitrogen oxides (NOx = NO + NO2) emissions from gasoline- and diesel-powered motor vehicles. Estimates are made at the national level for the period 1990-2010. Vehicle emissions are also estimated at the state level for California, and for the South Coast (Los Angeles) and San Joaquin Valley air basins. Fuel-based emission estimates are compared with predictions from widely used emission inventory models. Changes in diesel NOxemissions vary over time: increasing between 1990 and 1997, stable between 1997 and 2007, and decreasing since 2007. In contrast, gasoline engine-related NOxemissions have decreased steadily, by ˜65% overall between 1990 and 2010, except in the San Joaquin Valley, where reductions were not as large due to faster population growth. In the San Joaquin Valley, diesel engines were the dominant on-road NOxsource in all years considered (reaching ˜70% in 2010). In the urbanized South Coast air basin, gasoline engine emissions dominated in the past and have been comparable to on-road diesel sources since 2007 (down from ˜75% in 1990). Other major anthropogenic sources of NOxare added to compare emission trends with trends in surface pollutant observations and satellite-derived data. When all major anthropogenic NOx sources are included, the overall emission trend is downward in all cases (-45% to -60%). Future reductions in motor vehicle NOxwill depend on the effectiveness of new exhaust after-treatment controls on heavy-duty trucks, as well as further improvements todurabilityof emission control systems on light-duty vehicles.

McDonald, Brian C.; Dallmann, Timothy R.; Martin, Elliot W.; Harley, Robert A.

2012-09-01

381

Long-term trends in nitrogen oxide emissions from motor vehicles at national, state, and air basin scales  

NASA Astrophysics Data System (ADS)

A fuel-based approach is used to estimate nitrogen oxides (NOx = NO + NO2) emissions from gasoline- and diesel-powered motor vehicles. Estimates are made at the national level for the period 1990-2010. Vehicle emissions are also estimated at the state level for California, and for the South Coast (Los Angeles) and San Joaquin Valley air basins. Fuel-based emission estimates are compared with predictions from widely used emission inventory models. Changes in diesel NOxemissions vary over time: increasing between 1990 and 1997, stable between 1997 and 2007, and decreasing since 2007. In contrast, gasoline engine-related NOxemissions have decreased steadily, by ˜65% overall between 1990 and 2010, except in the San Joaquin Valley, where reductions were not as large due to faster population growth. In the San Joaquin Valley, diesel engines were the dominant on-road NOxsource in all years considered (reaching ˜70% in 2010). In the urbanized South Coast air basin, gasoline engine emissions dominated in the past and have been comparable to on-road diesel sources since 2007 (down from ˜75% in 1990). Other major anthropogenic sources of NOxare added to compare emission trends with trends in surface pollutant observations and satellite-derived data. When all major anthropogenic NOx sources are included, the overall emission trend is downward in all cases (-45% to -60%). Future reductions in motor vehicle NOxwill depend on the effectiveness of new exhaust after-treatment controls on heavy-duty trucks, as well as further improvements todurabilityof emission control systems on light-duty vehicles.

McDonald, Brian C.; Dallmann, Timothy R.; Martin, Elliot W.; Harley, Robert A.

2011-11-01

382

Integrated Air\\/Ground Vehicle System for SemiAutonomous Off-Road Navigation  

Microsoft Academic Search

1.Abstract Current unmanned vehicle systems enable exploration of and travel through remote areas, but demand significant ,communications resources and constant human operation. DARPA and the US Army have,recognized these limitations and are now,pursuing semi-autonomous vehicle systems in the Future Combat Systems (FCS) program. FCS places high demands on robotic systems, which must assess mobility hazards under all weather conditions, day

Tony Stentz; Alonzo Kelly; Robert Mandelbaum; Peter Rander

2002-01-01

383

Health Effects Associated With Passenger Vehicles: Monetary Values of Air Pollution  

Microsoft Academic Search

Air pollution is regarded as one of the highest priorities in environmental protection in both developed and developing countries. High levels of air pollution have adverse effects on human health that might cause premature death. This study presents the monetary value estimates for the adverse human health effects resulted from ambient air pollution. It aids decision makers to set priorities

Mohamed Marzouk; Magdy Madany

2012-01-01

384

Ascent performance of an air-breathing horizontal-takeoff launch vehicle  

NASA Technical Reports Server (NTRS)

Simulations are conducted to investigate a proposed NASA launch vehicle that is fully reusable, takes off horizontally, and uses airbreathing propulsion in a single stage. The propulsion model is based on a cycle analysis method, and the vehicle is assumed to be a rigid structure with distributed fuel, operating under a range of atmospheric conditions. The program to optimize simulated trajectories (POST) is modified to include a predictor-corrector guidance capability and then used to generate the trajectories. Significant errors are encountered during the unpowered coast phase due to uncertainty in the atmospheric density profile. The amount of ascent propellant needed is shown to be directly related to the thrust-vector angle and the location of the center of gravity of the vehicle because of the importance of aim-drag losses to total ideal velocity.

Powell, Richard W.; Shaughnessy, John D.; Cruz, Christopher I.; Naftel, J. C.

1991-01-01

385

Numerical modeling of aerodynamics of airfoils of micro air vehicles in gusty environment  

NASA Astrophysics Data System (ADS)

The superior flight characteristics exhibited by birds and insects can be taken as a prototype of the most perfect form of flying machine ever created. The design of Micro Air Vehicles (MAV) which tries mimic the flight of birds and insects has generated a great deal of interest as the MAVs can be utilized for a number of commercial and military operations which is usually not easily accessible by manned motion. The size and speed of operation of a MAV results in low Reynolds number flight, way below the flying conditions of a conventional aircraft. The insensitivity to wind shear and gust is one of the required factors to be considered in the design of airfoil for MAVs. The stability of flight under wind shear is successfully accomplished in the flight of birds and insects, through the flapping motion of their wings. Numerous studies which attempt to model the flapping motion of the birds and insects have neglected the effect of wind gust on the stability of the motion. Also sudden change in flight conditions makes it important to have the ability to have an instantaneous change of the lift force without disturbing the stability of the MAV. In the current study, two dimensional rigid airfoil, undergoing flapping motion is studied numerically using a compressible Navier-Stokes solver discretized using high-order finite difference schemes. The high-order schemes in space and in time are needed to keep the numerical solution economic in terms of computer resources and to prevent vortices from smearing. The numerical grid required for the computations are generated using an inverse panel method for the streamfunction and potential function. This grid generating algorithm allows the creation of single-block orthogonal H-grids with ease of clustering anywhere in the domain and the easy resolution of boundary layers. The developed numerical algorithm has been validated successfully against benchmark problems in computational aeroacoustics (CAA), and unsteady viscous flows. The numerical results for pure-plunge and pure-pitching motion of SD 7003 airfoil are compared with the particle image velocimetry data of Michael Ol by plotting the contours of streamwise velocity and vorticity and also by observing the wake profile of the streamwise velocity. A very good agreement in the location of the vortices was observed between the numerical and experimental results. Also the numerical tracking of streaklines was compared with the dye injection experiments and excellent agreement in the horizontal and vertical locations of the vortex cores was observed. The importance of using the angle of attack to match the wake structures and lift forces of airfoils in pure-pitch and pure-plunge was investigated and it was found that matching the plunging amplitude with the maximum displacement of the leading edge provides a closer match in the observed wake structures and coefficient of lift. Next, the average coefficient of list of an airfoil in pure-pitch was studied and it was found that the pitching about the leading edge produced the maximum value. Two difference methods of enhancements were considered: (i) axis of rotation, and (ii) moving airfoil, as possible ways to enhance the average coefficient of lift for an airfoil pitching about its leading edge. The first case produced two times increase and the second case produced almost four times increase in the average coefficient of lift respectively. Hence these two kinds of motion can be used for lift enhancement to overcome sudden changes in the flight conditions. Finally the effect of a sinusoidal gust on an airfoil in pure-pitch and pure-plunge motion was examined. The pitching motion showed a much lesser drop in the average coefficient of lift compared to the plunging motion, suggesting its effectiveness to overcome disturbances in the freestream. The plunging motion on the other hand can be employed for cases that require the suppression of the oscillation in the lift coefficient.

Gopalan, Harish

386

On aerodynamic modelling of an insect-like flapping wing in hover for micro air vehicles.  

PubMed

This theoretical paper discusses recent advances in the fluid dynamics of insect and micro air vehicle (MAV) flight and considers theoretical analyses necessary for their future development. The main purpose is to propose a new conceptual framework and, within this framework, two analytic approaches to aerodynamic modelling of an insect-like flapping wing in hover in the context of MAVs. The motion involved is periodic and is composed of two half-cycles (downstroke and upstroke) which, in hover, are mirror images of each other. The downstroke begins with the wing in the uppermost and rearmost position and then sweeps forward while pitching up and plunging down. At the end of the half-cycle, the wing flips, so that the leading edge points backwards and the wing's lower surface becomes its upper side. The upstroke then follows by mirroring the downstroke kinematics and executing them in the opposite direction. Phenomenologically, the interpretation of the flow dynamics involved, and adopted here, is based on recent experimental evidence obtained by biologists from insect flight and related mechanical models. It is assumed that the flow is incompressible, has low Reynolds number and is laminar, and that two factors dominate: (i) forces generated by the bound leading-edge vortex, which models flow separation; and (ii) forces due to the attached part of the flow generated by the periodic pitching, plunging and sweeping. The first of these resembles the analogous phenomenon observed on sharp-edged delta wings and is treated as such. The second contribution is similar to the unsteady aerodynamics of attached flow on helicopter rotor blades and is interpreted accordingly. Theoretically, the fluid dynamic description is based on: (i) the superposition of the unsteady contributions of wing pitching, plunging and sweeping; and (ii) adding corrections due to the bound leading-edge vortex and wake distortion. Viscosity is accounted for indirectly by imposing the Kutta condition on the trailing edge and including the influence of the vortical structure on the leading edge. Mathematically, two analytic approaches are proposed. The first derives all the quantities of interest from the notion of circulation and leads to tractable integral equations. This is an application of the von Kármán-Sears unsteady wing theory and its nonlinear extensions due to McCune and Tavares; the latter can account for the bound leading-edge vortex and wake distortion. The second approach uses the velocity potential as the central concept and leads to relatively simple ordinary differential equations. It is a combination of two techniques: (i) unsteady aerodynamic modelling of attached flow on helicopter rotor blades; and (ii) Polhamus's leading-edge suction analogy. The first of these involves both frequency-domain (Theodorsen style) and time-domain (indicial) methods, including the effects of wing sweeping and returning wake. The second is a nonlinear correction accounting for the bound leading-edge vortex. Connections of the proposed framework with control engineering and aeroelasticity are pointed out. PMID:16210181

Zbikowski, Rafa?

2002-02-15

387

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

NASA Astrophysics Data System (ADS)

The shrouded-rotor configuration has emerged as the most popular choice for rotary-wing Micro Air Vehicles (MAVs), because of the inherent safety of the design and the potential for significant performance improvements. However, traditional design philosophies based on experience with large-scale ducted propellers may not apply to the low-Reynolds-number (˜20,000) regime in which MAVs operate. An experimental investigation of the effects of varying the shroud profile shape on the performance of MAV-scale shrouded rotors has therefore been conducted. Hover tests were performed on seventeen models with a nominal rotor diameter of 16 cm (6.3 in) and various values of diffuser expansion angle, diffuser length, inlet lip radius and blade tip clearance, at various rotor collective angles. Compared to the baseline open rotor, the shrouded rotors showed increases in thrust by up to 94%, at the same power consumption, or reductions in power by up to 62% at the same thrust. These improvements surpass those predicted by momentum theory, due to the additional effect of the shrouds in reducing the non-ideal power losses of the rotor. Increasing the lip radius and decreasing the blade tip clearance caused performance to improve, while optimal values of diffuser angle and length were found to be 10 and 50% of the shroud throat diameter, respectively. With the exception of the lip radius, the effects of changing any of the shrouded-rotor parameters on performance became more pronounced as the values of the other parameters were changed to degrade performance. Measurements were also made of the wake velocity profiles and the shroud surface pressure distributions. The uniformity of the wake was improved by the presence of the shrouds and by decreasing the blade tip clearance, resulting in lower induced power losses. For high net shroud thrust, a favorable pressure distribution over the inlet was seen to be more important than in the diffuser. Strong suction pressures were observed above the blade-passage region on the inlet surface; taking advantage of this phenomenon could enable further increases in thrust. However, trade studies showed that, for a given overall aircraft size limitation, and ignoring considerations of the safety benefits of a shroud, a larger-diameter open rotor is more likely to give better performance than a smaller-diameter shrouded rotor. The open rotor and a single shrouded-rotor model were subsequently tested at a single collective in translational flight, at angles of attack from 0° (axial flow) to 90° (edgewise flow), and at various advance ratios. In axial flow, the net thrust and the power consumption of the shrouded rotor were lower than those of the open rotor. In edgewise flow, the shrouded rotor produced greater thrust than the open rotor, while consuming less power. Measurements of the shroud surface pressure distributions illustrated the extreme longitudinal asymmetry of the flow around the shroud, with consequent pitch moments much greater than those exerted on the open rotor. Except at low airspeeds and high angles of attack, the static pressure in the wake did not reach ambient atmospheric values at the diffuser exit plane; this challenges the validity of the fundamental assumption of the simple-momentum-theory flow model for short-chord shrouds in translational flight.

Pereira, Jason L.

388

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

NASA Astrophysics Data System (ADS)

Rotary-wing Micro air vehicles (MAVs) due to their unique hovering and low-speed flight capabilities are specially suited for missions that require operation in constrained spaces. Size restrictions force MAVs to operate in a low Reynolds number aerodynamic regime where viscous effects are dominant. This results in poor aerodynamic performance of conventional airfoils and rotor configurations. This dissertation explores the design issues that affect the hover performance of small-scale rotors and the implementation of a working coaxial MAV prototype. A computerized hover test stand was used for the systematic testing of single and coaxial small-scale rotors. Thin circular arcs were chosen for blade manufacturing because of their good aerodynamic characteristics at low Reynolds numbers, and simplified parameterization. Influence of airfoil geometry on single rotor hover performance was studied on untwisted rectangular blades. Non rectangular blades were used to study coupled airfoil and blade parameters. Tip tapered geometries were manufactured by removing material from baseline rectangular blades producing a coupling between blade planform, twist distribution, and spanwise airfoil shape. Performance gains were obtained by introducing large negative twist angles over short radial distances at the blade tips. A parametric study of the blade geometries resulted in maximum figures of merit of 0.65. Coaxial rotor performance at torque equilibrium was explored for different trims and operating conditions. It was found that the upper rotor was marginally affected by the lower one at spacings larger than 35% of the rotor radius, and that it produced about 60% of the total thrust. Experiments showed that power loading was maximized when higher collectives were used at the lower rotor, resulting in sizable differences in rotational speed between rotors. The CFD solver INS2d was used for a two-dimensional parametric aerodynamic study of circular arc airfoils. Lift, drag, and moment coefficients were explored over a range of Reynolds numbers. Validation with wind-tunnel data showed that lift predictions were satisfactory; however, drag was under-predicted at low angles of attack. The CFD database was integrated to a BEMT rotor model through a parameterization that coupled blade planform with twist distribution and airfoil shape. Thrust and maximum FM predictions were satisfactory for rectangular and non-rectangular blades with maximum cambers of 6% and below. The BEMT model was extended to the coaxial rotor case, producing good thrust and power predictions with errors within 5% of the experimental measurements. The approach validated the use of analytical and numerical tools commonly used in full-scale analysis, and proved to be a versatile system design tool. A fully functional coaxial MAV was developed based on the aerodynamic studies performed. Transmission, rotors, and swashplate were designed from scratch. Batteries, motors, and electronics were carefully selected off-the-shelf components. The prototype has been used as a testing platform for control systems and algorithms.

Bohorquez, Felipe

389

Variable Speed CMG Control of a Dual-Spin Stabilized Unconventional VTOL Air Vehicle  

NASA Technical Reports Server (NTRS)

This paper describes an approach based on using both bias momentum and multiple control moment gyros for controlling the attitude of statically unstable thrust-levitated vehicles in hover or slow translation. The stabilization approach described in this paper uses these internal angular momentum transfer devices for stability, augmented by thrust vectoring for trim and other outer loop control functions, including CMG stabilization/ desaturation under persistent external disturbances. Simulation results show the feasibility of (1) improved vehicle performance beyond bias momentum assisted vector thrusting control, and (2) using control moment gyros to significantly reduce the external torque required from the vector thrusting machinery.

Lim, Kyong B.; Moerder, Daniel D.; Shin, J-Y.

2004-01-01

390

Maglev vehicles and superconductor technology: Integration of high-speed ground transportation into the air travel system  

SciTech Connect

This study was undertaken to (1) evaluate the potential contribution of high-temperature superconductors (HTSCs) to the technical and economic feasibility of magnetically levitated (maglev) vehicles, (2) determine the status of maglev transportation research in the United States and abroad, (3) identify the likelihood of a significant transportation market for high-speed maglev vehicles, and (4) provide a preliminary assessment of the potential energy and economic benefits of maglev systems. HTSCs should be considered as an enhancing, rather than an enabling, development for maglev transportation because they should improve reliability and reduce energy and maintenance costs. Superconducting maglev transportation technologies were developed in the United States in the late 1960s and early 1970s. Federal support was withdrawn in 1975, but major maglev transportation programs were continued in Japan and West Germany, where full-scale prototypes now carry passengers at speeds of 250 mi/h in demonstration runs. Maglev systems are generally viewed as very-high-speed train systems, but this study shows that the potential market for maglev technology as a train system, e.g., from one downtown to another, is limited. Rather, aircraft and maglev vehicles should be seen as complementing rather than competing transportation systems. If maglev systems were integrated into major hub airport operations, they could become economical in many relatively high-density US corridors. Air traffic congestion and associated noise and pollutant emissions around airports would also be reduced. 68 refs., 26 figs., 16 tabs.

Johnson, L.R.; Rote, D.M.; Hull, J.R.; Coffey, H.T.; Daley, J.G.; Giese, R.F.

1989-04-01

391

The design of passively athermalized narrow- and wide-field-of-view infrared objectives for the OBSERVER unmanned air vehicle  

NASA Astrophysics Data System (ADS)

Some years ago QinetiQ introduced a short-range reconnaissance unmanned air vehicle (UAV), known as OBSERVER, which carried a visible three-camera sensor. To increase its versatility, a compatible infrared (IR) thermal imaging (TI) sensor was developed for the vehicle for operation in the 8-12mm waveband with a dual field of view function. The sensor incorporates a specially designed camera board, employing two IR lead scandium tantalate (PST) detectors based on UK un-cooled TI technology. Since no cooling engine is required for the detectors, the sensor module is very lightweight and hence well suited to its UAV application. So as to achieve the minimum possible payload for the vehicle, in addition to the lightweight detectors and electronics board, compact low mass optical solutions were devised for the camera objectives. These functioned at a relative aperture of f/1.0 and were designed to provide stable focus and imaging performance over a comparatively large temperature span (-10°C to + 50°C) to enable all weather operation. In order to achieve an athermalisation scheme devoid of elaborate electro-mechanical drives, thermally passive solutions were developed for the objectives in which the differing thermal characteristics of the components were designed to self-cancel optically. In this paper, the design and performance limitations of the optics are discussed and the procedure employed for establishing a thin lens pre-design for one of the objectives is described.

Simmons, Richard C.; Manning, Paul A.; Chamberlain, Trevor V.

2004-12-01

392

Experimental investigation of some aspects of insect-like flapping flight aerodynamics for application to micro air vehicles  

NASA Astrophysics Data System (ADS)

Insect-like flapping flight offers a power-efficient and highly manoeuvrable basis for micro air vehicles for indoor applications. Some aspects of the aerodynamics associated with the sweeping phase of insect wing kinematics are examined by making particle image velocimetry measurements on a rotating wing immersed in a tank of seeded water. The work is motivated by the paucity of data with quantified error on insect-like flapping flight, and aims to fill this gap by providing a detailed description of the experimental setup, quantifying the uncertainties in the measurements and explaining the results. The experiments are carried out at two Reynolds numbers—500 and 15,000—accounting for scales pertaining to many insects and future flapping-wing micro air vehicles, respectively. The results from the experiments are used to describe prominent flow features, and Reynolds number-related differences are highlighted. In particular, the behaviour of the leading-edge vortex at these Reynolds numbers is studied and the presence of Kelvin-Helmholtz instability observed at the higher Reynolds number in computational fluid dynamics calculations is also verified.

Ansari, Salman A.; Phillips, Nathan; Stabler, Graham; Wilkins, Peter C.; ?bikowski, Rafa?; Knowles, Kevin

393

Experimental investigation of some aspects of insect-like flapping flight aerodynamics for application to micro air vehicles  

NASA Astrophysics Data System (ADS)

Insect-like flapping flight offers a power-efficient and highly manoeuvrable basis for micro air vehicles for indoor applications. Some aspects of the aerodynamics associated with the sweeping phase of insect wing kinematics are examined by making particle image velocimetry measurements on a rotating wing immersed in a tank of seeded water. The work is motivated by the paucity of data with quantified error on insect-like flapping flight, and aims to fill this gap by providing a detailed description of the experimental setup, quantifying the uncertainties in the measurements and explaining the results. The experiments are carried out at two Reynolds numbers—500 and 15,000—accounting for scales pertaining to many insects and future flapping-wing micro air vehicles, respectively. The results from the experiments are used to describe prominent flow features, and Reynolds number-related differences are highlighted. In particular, the behaviour of the leading-edge vortex at these Reynolds numbers is studied and the presence of Kelvin-Helmholtz instability observed at the higher Reynolds number in computational fluid dynamics calculations is also verified.

Ansari, Salman A.; Phillips, Nathan; Stabler, Graham; Wilkins, Peter C.; ?bikowski, Rafa?; Knowles, Kevin

2009-05-01

394

Acute effects of motor vehicle traffic-related air pollution exposures on measures of oxidative stress in human airways  

PubMed Central

Epidemiological studies have linked exposure to traffic-related air pollutants to increased respiratory and cardiovascular morbidity and mortality. Evidence from human, animal, and in vitro studies supports an important role for oxidative stress in the pathophysiological pathways underlying the adverse health effects of air pollutants. In controlled-exposure studies of animals and humans, emissions from diesel engines, a major source of traffic-related air pollutants, cause pulmonary and systemic inflammation that is mediated by redox-sensitive signaling pathways. Assessment of human responses to traffic-related air pollution under realistic conditions is challenging due to the complex, dynamic nature of near-roadway exposure. Noninvasive measurement of biomarkers in breath and breath condensate may be particularly useful for evaluating the role of oxidative stress in acute responses to exposures that occur in vehicles or during near-roadway activities. Promising biomarkers include nitric oxide in exhaled breath, and nitrite/nitrate, malondialdehyde, and F2-isoprostanes in exhaled breath condensate.

Laumbach, Robert J.; Kipen, Howard M.

2014-01-01

395

77 FR 33315 - Protection of Stratospheric Ozone: Alternative for the Motor Vehicle Air Conditioning Sector...  

Federal Register 2010, 2011, 2012, 2013

...4% or 40,000 ppm in the passenger breathing zone. 2. Vehicle manufacturers (i...and the ceiling limit of 4% in the breathing zone. 3. The use of CO 2 in MVAC...locating the driver's and passengers' breathing zone consistent with the head and...

2012-06-06

396

Quaternion attitude estimation for miniature air vehicles using a multiplicative extended Kalman filter  

Microsoft Academic Search

Utilizing the Euler-Rodrigues symmetric parameters (attitude quaternion) to describe vehicle orientation, we develop a multiplicative, nonlinear variation of the Kalman filter to fuse data from low-cost sensors. The sensor suite is comprised of gyroscopes, accelerometers, and a GPS receiver. Our filter states consist of the three components of an Euler attitude error vector. In parallel with the state time update,

James K. Hall; Nathan B. Knoebel; Timothy W. McLain

2008-01-01

397

Intelligent Autonomy and Vision Based Obstacle Avoidance for Unmanned Air Vehicles  

Microsoft Academic Search

ó The paper describes the development and imple- mentation of the Visual Threat Awareness (VISTA) system, its integration with the Multi-layer Architecture for Trajectory Replanning and Intelligent plan eXecution (MATRIX) for autonomous intelligent control of Unmanned Aerial Vehicles (UAV), and performance evaluation of the integrated system through ight tests. The VISTA system generates information on the threats and obstacles in

Raman Mehra; Jeffrey Byrne

398

The cost of crop damage caused by ozone air pollution from motor vehicles  

Microsoft Academic Search

The effects of ozone air pollution on the agricultural sector are an important environmental challenge facing policy makers. Most studies of the economic impact of air pollution on agriculture have found that a 25% reduction in ambient ozone would provide benefits of at least $1–2 billion annually in the United States. This paper extends existing research by estimating the benefits

James Murphy; Mark Delucchi; Donald McCubbin; H. J. Kim

1999-01-01

399

Biomechanical response to systematic changes in impact interface cushioning properties while performing a tennis-specific movement.  

PubMed

It is currently not known whether human responses across typical sports surfaces are dependent on cushioning or frictional properties of the interface. The present study assessed systematic changes in surface cushioning (baseline acrylic, rubber, thin foam, and thick foam) as participants performed tennis running forehand foot plants wearing a basic neutral shoe (plimsolls). It was hypothesized that systematic decreases in peak rates of loading, heel pressures, and perceived hardness would be yielded as surface cushioning increased (impact test device). A common acrylic top surface provided consistent frictional properties across surfaces. Kinetics (AMTI, 960 Hz and Footscan Pressure Insoles, 500 Hz), kinematics (Peak MOTUS, 120 Hz), and cushioning perception were assessed. Peak and mean loading rates of vertical ground reaction force, peak horizontal force, peak heel pressure, and rates of loading demonstrated significant correlations (P < 0.05) with the participants' perceived levels of cushioning and matched mechanical rankings of surface cushioning. In contrast, peak impact force was lowest on the least cushioned surface. Kinematic responses were not significantly different between surfaces. Present evidence supports ''peak rate of loading'' as a more suitable indicator of surface cushioning than peak impact force. Although cautionary, biomechanical support is also provided for mechanical methods of surface cushioning assessment. PMID:17654235

Stiles, Victoria; Dixon, Sharon

2007-09-01

400

Air  

MedlinePLUS

... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

401

Distinctive features of the flow past high-speed flight vehicles with air-breathing engines on subsonic, transonic, and low supersonic velocity ranges  

Microsoft Academic Search

The aerodynamic characteristics and distinctive features of the flow past hypersonic integral-layout flight vehicles with\\u000a air-breathing engines intended for cruise flight in the atmosphere are experimentally investigated. The experiments were conducted\\u000a on a simplified model designed with regard for the general principles of integration of vehicles of the class considered.\\u000a The tests were performed in a wind tunnel over the

N. A. Blagoveshchenskii; V. N. Gusev; S. M. Zadonskii

2007-01-01

402

Inflorescences of alpine cushion plants freeze autonomously and may survive subzero temperatures by supercooling  

PubMed Central

Freezing patterns in the high alpine cushion plants Saxifraga bryoides, Saxifraga caesia, Saxifraga moschata and Silene acaulis were studied by infrared thermography at three reproductive stages (bud, anthesis, fruit development). The single reproductive shoots of a cushion froze independently in all four species at every reproductive stage. Ice formation caused lethal damage to the respective inflorescence. After ice nucleation, which occurred mainly in the stalk or the base of the reproductive shoot, ice propagated throughout that entire shoot, but not into neighboring shoots. However, anatomical ice barriers within cushions were not detected. The naturally occurring temperature gradient within the cushion appeared to interrupt ice propagation thermally. Consequently, every reproductive shoot needed an autonomous ice nucleation event to initiate freezing. Ice nucleation was not only influenced by minimum temperatures but also by the duration of exposure. At moderate subzero exposure temperatures (?4.3 to ?7.7 °C) the number of frozen inflorescences increased exponentially. Due to efficient supercooling, single reproductive shoots remained unfrozen down to ?17.4 °C (cooling rate 6 K h?1). Hence, the observed freezing pattern may be advantageous for frost survival of individual inflorescences and reproductive success of high alpine cushion plants, when during episodic summer frosts damage can be avoided by supercooling.

Hacker, Jurgen; Ladinig, Ursula; Wagner, Johanna; Neuner, Gilbert

2011-01-01

403

Reduced flexibility in processing Titan 4 space launch vehicles at Cape Canaveral Air Force Station  

NASA Astrophysics Data System (ADS)

In the recent past DOD has made decisions which reduced the flexibility in processing Titan expendable launch vehicles. This study explores the history of those decisions and their effects. It identifies the throughput capacities of Titan 4 Processing facilities. It evaluates the Cape's ability to meet the Titan 4 Mission Model. The study concludes that the mission model can not be achieved by doing business as usual. Changes must be made to the work schedules (double shifts, extended work weeks, etc.) and more technicians are required. The study recommends several facility modifications which can reestablish the flexibility in processing Titan 4 vehicles for launch. It also suggests further studies which may be useful in this area.

Woolley, Michael G.

1988-04-01

404

Analysis of Aluminum-Air Battery Propulsion Systems for Passenger Vehicles.  

National Technical Information Service (NTIS)

The performance characteristics of three electric-propulsion systems based on the Al-air battery were analyzed and compared to the internal combustion engine (ICE). Battery characteristics projected from late 1979 and early 1980 experimental results were ...

J. D. Salisbury E. Behrin

1980-01-01

405

MOVES2010 Highway Vehicle Temperature, Humidity, Air Conditioning, and Inspection and Maintenance Adjustments.  

National Technical Information Service (NTIS)

The emission rates in the MOVES model database represent a single (base) scenario of conditions for temperature, humidity, air conditioning load and fuel properties. MOVES is designed to adjust these base emission rates to reflect the conditions for the l...

2010-01-01

406

A Small SemiAutonomous Rotary-Wing Unmanned Air Vehicle (UAV)  

Microsoft Academic Search

Small radio controlled (R\\/C) rotary-wing UAVs have many potential military and civilian applications, but can be very difficult to fly. Small and lightweight sensors and computers can be used to implement a control system to make these vehicles easier to fly. To develop a control system for a small UAV, an 8-bit microcontroller has been interfaced with MEMS (Micro-Electro-Mechanical Systems)

Scott D. Hanford; Lyle N. Long; Joseph F. Horn

2005-01-01

407

System modeling of an air-independent solid oxide fuel cell system for unmanned undersea vehicles  

Microsoft Academic Search

To examine the feasibility of a solid oxide fuel cell (SOFC)-powered unmanned undersea vehicle (UUV), a system level analysis is presented that projects a possible integration of the SOFC stack, fuel steam reformer, fuel\\/oxidant storage and balance of plant components into a 21-in. diameter UUV platform. Heavy hydrocarbon fuel (dodecane) and liquid oxygen (LOX) are chosen as the preferred reactants.

A. Alan Burke; Louis G. Carreiro

2006-01-01

408

Development of an iron-air battery system for electric vehicles  

Microsoft Academic Search

The development program on secondary iron-air cells continued to advance both electrodes, as well as establish state-of-the-art characteristics for 100 sq cm cells. Investigations on the air electrodes studied alternate electrode compositions fabricated by either the dry powder method or the wet pasting technique. Work on the iron electrode concluded some of the studies which were in progress, initiated some

E. S. Buzzelli

1977-01-01

409

DIFFERENCES IN AIR BAG PERFORMANCE WITH CHILDREN IN VARIOUS RESTRAINT CONFIGURATIONS AND VEHICLE TYPES  

Microsoft Academic Search

Previous studies have identified a fatality risk for children exposed to air bags, particularly in the presence of non-restraint or inadequate restraint of the child and pre-impact braking, conditions that place the child out-of-position. Consequently, many manufacturers are opting to suppress the air bag when an out-of-position child, particularly one who is unrestrained, is detected. This study provides current estimates

Rajiv A. Menon; Kristy B. Arbogast; John Cooper; Stephen A. Ridella; Mohannad Murad; Richard Barnes; Michael J. Kallan; Flaura K. Winston

410

Assessment of the capacity of vehicle cabin air inlet filters to reduce diesel exhaust-induced symptoms in human volunteers  

PubMed Central

Background Exposure to particulate matter (PM) air pollution especially derived from traffic is associated with increases in cardiorespiratory morbidity and mortality. In this study, we evaluated the ability of novel vehicle cabin air inlet filters to reduce diesel exhaust (DE)-induced symptoms and markers of inflammation in human subjects. Methods Thirty healthy subjects participated in a randomized double-blind controlled crossover study where they were exposed to filtered air, unfiltered DE and DE filtered through two selected particle filters, one with and one without active charcoal. Exposures lasted for one hour. Symptoms were assessed before and during exposures and lung function was measured before and after each exposure, with inflammation assessed in peripheral blood five hours after exposures. In parallel, PM were collected from unfiltered and filtered DE and assessed for their capacity to drive damaging oxidation reactions in a cell-free model, or promote inflammation in A549 cells. Results The standard particle filter employed in this study reduced PM10 mass concentrations within the exposure chamber by 46%, further reduced to 74% by the inclusion of an active charcoal component. In addition use of the active charcoal filter was associated by a 75% and 50% reduction in NO2 and hydrocarbon concentrations, respectively. As expected, subjects reported more subjective symptoms after exposure to unfiltered DE compared to filtered air, which was significantly reduced by the filter with an active charcoal component. There were no significant changes in lung function after exposures. Similarly diesel exhaust did not elicit significant increases in any of the inflammatory markers examined in the peripheral blood samples 5 hour post-exposure. Whilst the filters reduced chamber particle concentrations, the oxidative activity of the particles themselves, did not change following filtration with either filter. In contrast, diesel exhaust PM passed through the active charcoal combination filter appeared less inflammatory to A549 cells. Conclusions A cabin air inlet particle filter including an active charcoal component was highly effective in reducing both DE particulate and gaseous components, with reduced exhaust-induced symptoms in healthy volunteers. These data demonstrate the effectiveness of cabin filters to protect subjects travelling in vehicles from diesel exhaust emissions.

2014-01-01

411

Real-time approaches to the estimation of local wind velocity for a fixed-wing unmanned air vehicle  

NASA Astrophysics Data System (ADS)

Three real-time approaches to estimating local wind velocity for a fixed-wing unmanned air vehicle are presented in this study. All three methods work around the navigation equations with added wind components. The first approach calculates the local wind speed by substituting the ground speed and ascent rate data given by the Global Positioning System (GPS) into the navigation equations. The second and third approaches utilize the extended Kalman filter (EKF) and the unscented Kalman filter (UKF), respectively. The results show that, despite the nonlinearity of the navigation equations, the EKF performance is proven to be on a par with the UKF. A time-varying noise estimation method based on the Wiener filter is also discussed. Results are compared with the average wind speed measured on the ground. All three approaches are proven to be reliable with stated advantages and disadvantages.

Chan, W. L.; Lee, C. S.; Hsiao, F. B.

2011-10-01

412

Polymer packaging for arrayed ionic polymer-metal composites and its application to micro air vehicle control surface  

NASA Astrophysics Data System (ADS)

In this study, ionic polymer-metal composite (IPMC) actuators arrayed in horizontal as well as vertical directions were investigated for more effective actuation performance. A very thin polymer packaging structure named 'glove' was designed and fabricated, and the IPMC package, composed of the glove and the arrayed IPMCs, was applied to the multifunctional control surface of a micro air vehicle (MAV). The IPMC package is light and space-saving, and therefore appropriate for the application of a MAV which has a limitation in weight and size. A wind tunnel test was performed to demonstrate the capability of the IPMC package for the control surface of a MAV and it was confirmed that the package generates enough force to maneuver a MAV.

Kim, Seong Jun; Cho, Chahngmin; Hyup Kim, Yong

2009-11-01

413

Safety flier--a parachute-glider air-vehicle with vertical take-off and landing capability  

US Patent & Trademark Office Database

One embodiment of a Vertical Take-off and Landing (VToL) air-vehicle (FIG. 1.) having a horizontal rotor, a. providing lift and propulsion, and communicating at or near its centre to structural elements, or fuselage, b. Upon or within the fuselage structure is attached a platform, to which a payload, or occupant or pilot, d. is secured in such a manner as to permit a movement, or range-of-motion, of the payload, as a means of weight-shifting, or mass-balancing, of the vehicle for stability and control in flight. At least two planar elements, or descent-vanes, c.i & c.ii are connected to a structural element of the fuselage at a location which provides vertical and horizontal separation between the rotor and the descent-vanes, thus creating a tandem, biplane arrangement of two aerodynamically active elements which are aerodynamically balanced to provide stability and controllability in hovering flight, in forward flight, and in un-powered gliding and vertical descents. Other embodiments are described and shown.

2013-04-02

414

Modeling the effect of weekday-weekend differences in motor vehicle emissions on photochemical air pollution in central California.  

PubMed

Ambient ozone concentrations vary by day of week in some locations, often with higher concentrations observed on weekends in urban and downwind areas. Emissions of ozone precursors appear to be lower on weekends, so the behavior of ozone concentrations on weekends may indicate the outcome of particular ozone control strategies. To examine the influence of day-of-week differences in motor vehicle emissions on ambient ozone concentrations, we combine a fuel-based motor vehicle emission inventory containing weekend-specific activity with an Eulerian photochemical airshed model applied to central California. Emissions of NOx on weekends are approximately 30% lower than on weekdays due to a large drop in heavy-duty diesel truck activity, and emissions of VOC are only slightly lower on weekends. In rural areas, passenger car traffic and the associated emissions are highest on Fridays and Sundays. The combination of VOC sensitivity and reduced emissions of NOx on weekends results in higher ozone concentrations on weekends. Changes in the timing of emissions also contribute to the weekend ozone effect, but sensitivity tests show that changes in emissions timing have a minor effect compared to changes in total mass of emissions on weekends. Even in situations where reductions in NOx emissions lead to higher ozone concentrations, NOx reductions may still be necessary for control of other air pollutants such as nitrogen dioxide, nitric acid, and aerosol nitrate. PMID:12380081

Marr, Linsey C; Harley, Robert A

2002-10-01

415

Micro air vehicle-motivated computational biomechanics in bio-flights: aerodynamics, flight dynamics and maneuvering stability  

NASA Astrophysics Data System (ADS)

Aiming at developing an effective tool to unveil key mechanisms in bio-flight as well as to provide guidelines for bio-inspired micro air vehicles (MAVs) design, we propose a comprehensive computational framework, which integrates aerodynamics, flight dynamics, vehicle stability and maneuverability. This framework consists of (1) a Navier-Stokes unsteady aerodynamic model; (2) a linear finite element model for structural dynamics; (3) a fluid-structure interaction (FSI) model for coupled flexible wing aerodynamics aeroelasticity; (4) a free-flying rigid body dynamic (RBD) model utilizing the Newtonian-Euler equations of 6DoF motion; and (5) flight simulator accounting for realistic wing-body morphology, flapping-wing and body kinematics, and a coupling model accounting for the nonlinear 6DoF flight dynamics and stability of insect flapping flight. Results are presented based on hovering aerodynamics with rigid and flexible wings of hawkmoth and fruitfly. The present approach can support systematic analyses of bio- and bio-inspired flight.

Liu, Hao; Nakata, Toshiyuki; Gao, Na; Maeda, Masateru; Aono, Hikaru; Shyy, Wei

2010-12-01

416

Association of digital cushion thickness with sole temperature measured with the use of infrared thermography.  

PubMed

The main objective of this study was to investigate the association between digital cushion thickness and sole temperature measured by infrared thermography. Data were collected from 216 lactating Holstein cows at 4 to 10d in milk (DIM). Cows were locomotion scored and sole temperature was measured after claw trimming (a minimum delay of 3min was allowed for the hoof to cool) using an infrared thermography camera. Temperature was measured at the typical ulcer site of the lateral digit of the left hind foot. Immediately after the thermographic image was obtained, the thickness of the digital cushion was measured by ultrasonography. Rumen fluid samples were collected with a stomach tube and sample pH was measured immediately after collection. Additionally, a blood sample was obtained and used for measurements of serum concentrations of ?-hydroxybutyrate (BHBA), nonesterified fatty acids (NEFA), and haptoglobin. To evaluate the associations of digital cushion thickness with sole temperature, a linear regression model was built using the GLIMMIX procedure in SAS software (SAS Institute Inc., Cary, NC). Sole temperature was the response variable, and digital cushion thickness quartiles, locomotion score group, rumen fluid pH, rumen fluid sample volume, environmental temperature, age in days, and serum levels of NEFA, BHBA, and haptoglobin were fitted in the model. Only significant variables were retained in the final model. Simple linear regression scatter plots were used to illustrate associations between sole temperature (measured by infrared thermography at the typical ulcer site) and environmental temperature and between NEFA and BHBA serum levels and haptoglobin. One-way ANOVA was used to compare rumen fluid pH for different locomotion score groups and for different digital cushion quartiles. Results from the multivariable linear regression model showed that sole temperature increased as locomotion scores increased and decreased as digital cushion thickness increased. These results were adjusted for environmental temperature, which was significantly associated with sole temperature. Serum levels of NEFA, BHBA, and haptoglobin were not associated with sole temperature. However, significant correlations existed between serum levels of NEFA and haptoglobin and between serum levels of BHBA and haptoglobin. Rumen fluid pH was not associated with either locomotion score or digital cushion thickness. In conclusion, we show here that digital cushion thickness was associated with sole temperature in cows at 4 to 10 DIM. PMID:24835964

Oikonomou, G; Trojacanec, P; Ganda, E K; Bicalho, M L S; Bicalho, R C

2014-07-01

417

Kinematics of pediatric crash dummies seated on vehicle seats with realistic belt geometry.  

PubMed

Objective: A series of sled tests was performed using vehicle seats and Hybrid-III 6-year-old (6YO) and 10YO anthropomorphic test devices (ATDs) to explore possibilities for improving occupant protection for children who are not using belt-positioning booster seats. Methods: Cushion length was varied from production length of 450 mm to a shorter length of 350 mm. Lap belt geometry was set to rear, mid, and forward anchorage locations that span the range of lap belt angles found in vehicles. Six tests each were performed with the 6YO and 10YO Hybrid III ATDs. One additional test was performed using a booster seat with the 6YO. The ATDs were positioned using an updated version of the University of Michigan Transportation Research Institute (UMTRI) seating procedure that positions the ATD hips further forward with longer seat cushions to reflect the effect of cushion length on posture that has been measured with child volunteers. ATD kinematics were evaluated using peak head excursion, peak knee excursion, the difference between peak head and peak knee excursion, and the maximum torso angle. Results: Shortening the seat cushion improved kinematic outcomes, particularly for the 10YO. Lap belt geometry had a greater effect on kinematics with the longer cushion length, with mid or forward belt geometries producing better kinematics than the rearward belt geometry. The worst kinematics for both ATDs occurred with the long cushion length and rearward lap belt geometry. The improvements in kinematics from shorter cushion length or more forward belt geometry are smaller than those provided by a booster seat. Conclusions: The results show potential benefits in occupant protection from shortening cushion length and increasing lap belt angles, particularly for children the size of the 10YO ATD. PMID:24884476

Klinich, Kathleen D; Reed, Matthew P; Ebert, Sheila M; Rupp, Jonathan D

2014-11-17

418

A Common Communications, Navigation and Surveillance Infrastructure for Accommodating Space Vehicles in the Next Generation Air Transportation System  

NASA Technical Reports Server (NTRS)

Suborbital space flight and space tourism are new potential markets that could significantly impact the National Airspace System (NAS). Numerous private companies are developing space flight capabilities to capture a piece of an emerging commercial space transportation market. These entrepreneurs share a common vision that sees commercial space flight as a profitable venture. Additionally, U.S. space exploration policy and national defense will impose significant additional demands on the NAS. Air traffic service providers must allow all users fair access to limited airspace, while ensuring that the highest levels of safety, security, and efficiency are maintained. The FAA's Next Generation Air Transportation System (NextGen) will need to accommodate spacecraft transitioning to and from space through the NAS. To accomplish this, space and air traffic operations will need to be seamlessly integrated under some common communications, navigation and surveillance (CNS) infrastructure. As part of NextGen, the FAA has been developing the Automatic Dependent Surveillance Broadcast (ADS-B) which utilizes the Global Positioning System (GPS) to track and separate aircraft. Another key component of NextGen, System-Wide Information Management/ Network Enabled Operations (SWIM/NEO), is an open architecture network that will provide NAS data to various customers, system tools and applications. NASA and DoD are currently developing a space-based range (SBR) concept that also utilizes GPS, communications satellites and other CNS assets. The future SBR will have very similar utility for space operations as ADS-B and SWIM has for air traffic. Perhaps the FAA, NASA, and DoD should consider developing a common space-based CNS infrastructure to support both aviation and space transportation operations. This paper suggests specific areas of research for developing a CNS infrastructure that can accommodate spacecraft and other new types of vehicles as an integrated part of NextGen.

VanSuetendael, RIchard; Hayes, Alan; Birr, Richard

2008-01-01

419

Autonomous Soaring for Improved Endurance of a Small Uninhabited Air Vehicle.  

National Technical Information Service (NTIS)

A relatively unexplored method to improve the endurance of an autonomous aircraft is to use buoyant plumes of air found in the lower atmosphere called thermals or updrafts. Glider pilots and birds commonly use updrafts to improve range, endurance, or cros...

M. J. Allen

2005-01-01

420

Development of responsive space systems at the US Air Force Research Laboratory, Space Vehicles Directorate  

Microsoft Academic Search

The United States Air Force Research Laboratory (AFRL) is seeking to develop a new class of space systems that can be rapidly employed to meet changing conditions around the world. These systems are being developed with a strong focus on keeping the life-cycle cost very low, on getting the response time down to a matter of days, and on getting

P. M. Wegner; D. A. Hardy; D. R. Hite; G. duBro

2005-01-01

421

Field Evaluation of Built-In Test Equipment (BITE) for Vehicle Oil and Air Contamination.  

National Technical Information Service (NTIS)

A two-phase, three-year project has been completed to select and evaluate candidate commercially available Built-In Test Equipment (BITE) for monitoring diesel engine crankcase lubricant quality (Oil-BITE) and engine induction system are quality (Air-BITE...

R. A. Alvarez J. D. Tosh J. A. Russell F. M. Newman

1981-01-01

422

The Design of an Uninhabited Air Vehicle for Use in Polar Research Utilizing an Efficient and Effective Multi-Disciplinary Design Process  

Microsoft Academic Search

This paper describes the development of an uninhabited air vehicle that will primarily be used to measure changes in glacial conditions in Antarctica and Greenland. This includes documentation of the requirements definition, preliminary configuration design, structural layout, systems integration, as well as a cost analysis. The primary goal of this effort is to design an aircraft capable of autonomous operation

W. R. Donovan; R. D. Hale

423

Air Braked Vehicle Performance: FMVSS No. 121 Braking Systems Versus Pre-FMVSS No. 121 Braking Systems and Stability Augmentation Devices.  

National Technical Information Service (NTIS)

Road tests were conducted on 3 truck tractors and 4 semitrailers to evaluate the effects of Federal Motor Vehicle Safety Standard (FMVSS) No. 121, Air Brake Systems--Trucks, Buses and Trailers, on braking system performance. Tests were run in accordance w...

R. W. Radlinski

1976-01-01

424

Visual Servoing of Quadrotor Micro-Air Vehicle Using Color-Based Tracking Algorithm  

NASA Astrophysics Data System (ADS)

This paper describes a vision-based tracking system using an autonomous Quadrotor Unmanned Micro-Aerial Vehicle (MAV). The vision-based control system relies on color target detection and tracking algorithm using integral image, Kalman filters for relative pose estimation, and a nonlinear controller for the MAV stabilization and guidance. The vision algorithm relies on information from a single onboard camera. An arbitrary target can be selected in real-time from the ground control station, thereby outperforming template and learning-based approaches. Experimental results obtained from outdoor flight tests, showed that the vision-control system enabled the MAV to track and hover above the target as long as the battery is available. The target does not need to be pre-learned, or a template for detection. The results from image processing are sent to navigate a non-linear controller designed for the MAV by the researchers in our group.

Azrad, Syaril; Kendoul, Farid; Nonami, Kenzo

425

An open-source pose estimation system for micro-air vehicles  

Microsoft Academic Search

This paper presents the implementation of an open-source 6-DoF pose estimation system for micro-air ve- hicles and considers the future implications and benefits of open-source robotics. The system is designed to provide high frequency pose estimates in unknown, GPS-denied indoor environments. It requires a minimal set of sensors including a planar laser range-finder and an IMU sensor. The code is

Ivan Dryanovski; William Morris; Jizhong Xiao

2011-01-01

426

Lithium requirements for electric vehicles using lithium-water-air batteries  

Microsoft Academic Search

In the electrochemical reaction involved in the lithium-water-air battery lithium, oxygen, and CO2 are combined; Li2CO3 is left as a by product to be removed from the battery and recycled. A subcompact car weighing 910 kg would transform 7.2 kg of lithium in traveling 320 km at 97 km\\/hr. At least an equal amount of lithium per car would be

J. F. Cooper; I. Y. Borg; L. G. Oconnell; E. Behrin; B. Rubin; H. Wiesner

1975-01-01

427

Lithium requirements for electric vehicles using lithium-water-air batteries. [Mechanically rechargeable  

Microsoft Academic Search

The lithium--water--air battery is a new primary battery of such exceptional power and energy that it is a candidate to provide propulsion for electric automobiles of the future. In the electrochemical reaction involved, lithium, oxygen, and CO are combined; LiCO is left as a by-product to be removed from the battery and recycled. A subcompact car weighing 910 kg would

J. F. Cooper; I. Y. Borg; OConnell; E. L. G. Behrin; B. Rubin; H. Wiesner

1975-01-01

428

Implementation of the Rauch-Tung-Striebel smoother for sensor compatibility correction of a fixed-wing unmanned air vehicle.  

PubMed

This paper presents a complete procedure for sensor compatibility correction of a fixed-wing Unmanned Air Vehicle (UAV). The sensors consist of a differential air pressure transducer for airspeed measurement, two airdata vanes installed on an airdata probe for angle of attack (AoA) and angle of sideslip (AoS) measurement, and an Attitude and Heading Reference System (AHRS) that provides attitude angles, angular rates, and acceleration. The procedure is mainly based on a two pass algorithm called the Rauch-Tung-Striebel (RTS) smoother, which consists of a forward pass Extended Kalman Filter (EKF) and a backward recursion smoother. On top of that, this paper proposes the implementation of the Wiener Type Filter prior to the RTS in order to avoid the complicated process noise covariance matrix estimation. Furthermore, an easy to implement airdata measurement noise variance estimation method is introduced. The method estimates the airdata and subsequently the noise variances using the ground speed and ascent rate provided by the Global Positioning System (GPS). It incorporates the idea of data regionality by assuming that some sort of statistical relation exists between nearby data points. Root mean square deviation (RMSD) is being employed to justify the sensor compatibility. The result shows that the presented procedure is easy to implement and it improves the UAV sensor data compatibility significantly. PMID:22163819

Chan, Woei-Leong; Hsiao, Fei-Bin

2011-01-01

429

Criteria and air-toxic emissions from in-use automobiles in the National Low-Emission Vehicle program.  

PubMed

The U.S. Environmental Protection Agency (EPA) implemented a program to identify tailpipe emissions of criteria and air-toxic contaminants from in-use, light-duty low-emission vehicles (LEVs). EPA recruited 25 LEVs in 2002 and measured emissions on a chassis dynamometer using the cold-start urban dynamometer driving schedule of the Federal Test Procedure. The emissions measured included regulated pollutants, particulate matter, speciated hydrocarbon compounds, and carbonyl compounds. The results provided a comparison of emissions from real-world LEVs with emission standards for criteria and air-toxic compounds. Emission measurements indicated that a portion of the in-use fleet tested exceeded standards for the criteria gases. Real-time regulated and speciated hydrocarbon measurements demonstrated that the majority of emissions occurred during the initial phases of the cold-start portion of the urban dynamometer driving schedule. Overall, the study provided updated emission factor data for real-world, in-use operation of LEVs for improved emissions modeling and mobile source inventory development. PMID:16259421

Baldauf, Rich W; Gabele, Pete; Crews, William; Snow, Richard; Cook, J Rich

2005-09-01

430

Whole-body vibration during manual wheelchair propulsion with selected seat cushions and back supports  

Microsoft Academic Search

Although the exposure to whole-body vibrations (WBV) has been shown to be detrimental to seated humans, the effects of wheelchairs and seating systems on the transmission of vibration to an individual have not been thoroughly examined. The purpose of this study was to determine if the selected wheelchair seat cushions and back supports minimize the transmission of vibrations. Thirty-two wheelchair

Carmen P. DiGiovine; Rory A. Cooper; Shirley G. Fitzgerald; Michael L. Boninger; Erik J. Wolf; Songfeng Guo

2003-01-01

431

Container Cushioning Design Engineer Users Manual. (HP-9810A Version) Volume II.  

National Technical Information Service (NTIS)

A cushioning system is an interface device which isolates a protected item from the shock loads which develop in its external environment. Such a system is required when the protected item cannot survive the shock loads imposed by the external environment...

R. M. Wyskida J. D. Johannes M. R. Wilhelm

1976-01-01

432

[Current status of air pollution in Sao Paulo, Brazil: effects and problems associated with the introduction of ethanol-fueled motor vehicles].  

PubMed

Recently suggestions have been advanced that alternative fuels including ethanol, methanol or methane instead of so called "fossil fuels" may help improve the current conditions of air pollution. According to results of general survey in Sao Paulo, since their introduction in 1978, ethanol-fueled cars have increased their share to almost 50% of all light vehicles in 1983. The current status of air pollution in Sao Paulo metropolitan area (SPMA) is described in relation to the use of such alternative fuel. The average concentrations in air of SO2 and lead have been decreasing drastically during the period of 1982-88, whereas non-methane hydrocarbon, NO2 and O3 levels have been increasing to attain the worst levels in the world as indicated in Fig. 2. The use of ethanol-fuel, which contains less sulphate and lead, is thought to have contributed more or less to the above reductions of SO2 and lead in the air. However, the pollutants that have increased may derive mainly from diesel and gasoline exhausts of heavy vehicles. The general state of air pollutions appears not to have been improved, suggesting the difficulty in resolving air pollution issues. On the other hand, a current problem specific to ethanol-fuel is the aldehydes or other carcinogenic components in exhaust. Peak formaldehyde concentration, for example, have been reported to have reached 159 ppb in SPMA, which may be one of the highest levels shown in ambient air.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1720061

Kabuto, M; Tsugane, S; Hamada, G S

1990-05-01

433

Unmanned air vehicle flow separation control using dielectric barrier discharge plasma at high wind speed  

NASA Astrophysics Data System (ADS)

The present paper described an experimental investigation of separation control of an Unmanned Aerial Vehicle (UAV) at high wind speeds. The plasma actuator was based on Dielectric Barrier Discharge (DBD) and operated in a steady manner. The flow over a wing of UAV was performed with smoke flow visualization in the ?0.75 m low speed wind tunnel to reveal the flow structure over the wing so that the locations of plasma actuators could be optimized. A full model of the UAV was experimentally investigated in the ?3.2 m low speed wind tunnel using a six-component internal strain gauge balance. The effects of the key parameters, including the locations of the plasma actuators, the applied voltage amplitude and the operating frequency, were obtained. The whole test model was made of aluminium and acted as a cathode of the actuator. The results showed that the plasma acting on the surface of UAV could obviously suppress the boundary layer separation and reduce the model vibration at the high wind speeds. It was found that the maximum lift coefficient of the UAV was increased by 2.5% and the lift/drag ratio was increased by about 80% at the wind speed of 100 m/s. The control mechanism of the plasma actuator at the test configuration was also analyzed.

Zhang, Xin; Huang, Yong; Wang, WanBo; Wang, XunNian; Li, HuaXing

2014-06-01

434

Water cooling system for an air-breathing hypersonic test vehicle  

NASA Technical Reports Server (NTRS)

This study provides concepts for hypersonic experimental scramjet test vehicles which have low cost and low risk. Cryogenic hydrogen is used as the fuel and coolant. Secondary water cooling systems were designed. Three concepts are shown: an all hydrogen cooling system, a secondary open loop water cooled system, and a secondary closed loop water cooled system. The open loop concept uses high pressure helium (15,000 psi) to drive water through the cooling system while maintaining the pressure in the water tank. The water flows through the turbine side of the turbopump to pump hydrogen fuel. The water is then allowed to vent. In the closed loop concept high pressure, room temperature, compressed liquid water is circulated. In flight water pressure is limited to 6000 psi by venting some of the water. Water is circulated through cooling channels via an ejector which uses high pressure gas to drive a water jet. The cooling systems are presented along with finite difference steady-state and transient analysis results. The results from this study indicate that water used as a secondary coolant can be designed to increase experimental test time, produce minimum venting of fluid and reduce overall development cost.

Petley, Dennis H.; Dziedzic, William M.

1993-01-01

435

Verification and Tuning of an Adaptive Controller for an Unmanned Air Vehicle  

NASA Technical Reports Server (NTRS)

This paper focuses on the analysis and tuning of a controller based on the Adaptive Control Technology for Safe Flight (ACTS) architecture. The ACTS architecture consists of a nominal, non-adaptive controller that provides satisfactory performance under nominal flying conditions, and an adaptive controller that provides robustness under off-nominal ones. A framework unifying control verification and gain tuning is used to make the controller s ability to satisfy the closed-loop requirements more robust to uncertainty. In this paper we tune the gains of both controllers using this approach. Some advantages and drawbacks of adaptation are identified by performing a global robustness assessment of both the adaptive controller and its non-adaptive counterpart. The analyses used to determine these characteristics are based on evaluating the degradation in closed-loop performance resulting from uncertainties having increasing levels of severity. The specific adverse conditions considered can be grouped into three categories: aerodynamic uncertainties, structural damage, and actuator failures. These failures include partial and total loss of control effectiveness, locked-in-place control surface deflections, and engine out conditions. The requirements considered are the peak structural loading, the ability of the controller to track pilot commands, the ability of the controller to keep the aircraft s state within the reliable flight envelope, and the handling/riding qualities of the aircraft. The nominal controller resulting from these tuning strategies was successfully validated using the NASA GTM Flight Test Vehicle.

Crespo, Luis G.; Matsutani, Megumi; Annaswamy, Anuradha M.

2010-01-01

436

Inertial attitude control of a bat-like morphing-wing air vehicle.  

PubMed

This paper presents a novel bat-like unmanned aerial vehicle inspired by the morphing-wing mechanism of bats. The goal of this paper is twofold. Firstly, a modelling framework is introduced for analysing how the robot should manoeuvre by means of changing wing morphology. This allows the definition of requirements for achieving forward and turning flight according to the kinematics of the wing modulation. Secondly, an attitude controller named backstepping+DAF is proposed. Motivated by biological evidence about the influence of wing inertia on the production of body accelerations, the attitude control law incorporates wing inertia information to produce desired roll (?) and pitch (?) acceleration commands (desired angular acceleration function (DAF)). This novel control approach is aimed at incrementing net body forces (F(net)) that generate propulsion. Simulations and wind-tunnel experimental results have shown an increase of about 23% in net body force production during the wingbeat cycle when the wings are modulated using the DAF as a part of the backstepping control law. Results also confirm accurate attitude tracking in spite of high external disturbances generated by aerodynamic loads at airspeeds up to 5 ms?¹. PMID:23211685

Colorado, J; Barrientos, A; Rossi, C; Parra, C

2013-03-01

437

Unmanned air vehicle flow separation control using dielectric barrier discharge plasma at high wind speed  

NASA Astrophysics Data System (ADS)

The present paper described an experimental investigation of separation control of an Unmanned Aerial Vehicle (UAV) at high wind speeds. The plasma actuator was based on Dielectric Barrier Discharge (DBD) and operated in a steady manner. The flow over a wing of UAV was performed with smoke flow visualization in the ?0.75 m low speed wind tunnel to reveal the flow structure over the wing so that the locations of plasma actuators could be optimized. A full model of the UAV was experimentally investigated in the ?3.2 m low speed wind tunnel using a six-component internal strain gauge balance. The effects of the key parameters, including the locations of the plasma actuators, the applied voltage amplitude and the operating frequency, were obtained. The whole test model was made of aluminium and acted as a cathode of the actuator. The results showed that the plasma acting on the surface of UAV could obviously suppress the boundary layer separation and reduce the model vibration at the high wind speeds. It was found that the maximum lift coefficient of the UAV was increased by 2.5% and the lift/drag ratio was increased by about 80% at the wind speed of 100 m/s. The control mechanism of the plasma actuator at the test configuration was also analyzed.

Zhang, Xin; Huang, Yong; Wang, WanBo; Wang, XunNian; Li, HuaXing

2014-03-01

438

Aerodynamic Characteristics of the Ventilated Design for Flapping Wing Micro Air Vehicle  

PubMed Central

Inspired by superior flight performance of natural flight masters like birds and insects and based on the ventilating flaps that can be opened and closed by the changing air pressure around the wing, a new flapping wing type has been proposed. It is known that the net lift force generated by a solid wing in a flapping cycle is nearly zero. However, for the case of the ventilated wing, results for the net lift force are positive which is due to the effect created by the “ventilation” in reducing negative lift force during the upstroke. The presence of moving flaps can serve as the variable in which, through careful control of the areas, a correlation with the decrease in negative lift can be generated. The corresponding aerodynamic characteristics have been investigated numerically by using different flapping frequencies and forward flight speeds.

Zhang, G. Q.; Yu, S. C. M.

2014-01-01

439

Aerodynamic characteristics of the ventilated design for flapping wing micro air vehicle.  

PubMed

Inspired by superior flight performance of natural flight masters like birds and insects and based on the ventilating flaps that can be opened and closed by the changing air pressure around the wing, a new flapping wing type has been proposed. It is known that the net lift force generated by a solid wing in a flapping cycle is nearly zero. However, for the case of the ventilated wing, results for the net lift force are positive which is due to the effect created by the "ventilation" in reducing negative lift force during the upstroke. The presence of moving flaps can serve as the variable in which, through careful control of the areas, a correlation with the decrease in negative lift can be generated. The corresponding aerodynamic characteristics have been investigated numerically by using different flapping frequencies and forward flight speeds. PMID:24683339

Zhang, G Q; Yu, S C M

2014-01-01

440

Collaboration for Land, Air, Sea, and Space Vehicles: Developing the Common Ground in Vehicle Dynamics, System Identification, Control, and Handling Qualities  

NASA Astrophysics Data System (ADS)

This technical report is the culmination of the SCI-053 Task Group - Vehicle Dynamics, System Identification, Control and Handling Qualities. It summarizes the discussions of tank, truck, aircraft, helicopter, ship, submarine and satellite experts held over a three-year period. It addresses the various technical areas identified in the name of the task group, exploring the similarities and differences between the vehicle types and identifying areas where collaboration between experts would be the most valuable. Twenty-three specific technical issues are identified as initial areas with high potential for valuable collaboration. Overall, the report provides the vehicle expert of one environment a sufficient background on the other vehicle environments, so that meaningful discussions towards these technical collaborations can be initiated.

2002-11-01

441

Probabilistic Evaluation of Mobile Source Air Pollution: Volume 1. Probabilistic Modeling of Exhaust Emissions from Light Duty Gasoline Vehicles.  

National Technical Information Service (NTIS)

Emission factors for light duty gasoline vehicles (LDGV) are typically developed based upon laboratory testing of vehicles for prescribed driving cycles. In this project, selected LDGV data sets and modeling assumptions used to develop Mobile5a were revis...

H. C. Frey M. D. Kini

1997-01-01

442

Development of Cushioning Data for Fast Pack Program.  

National Technical Information Service (NTIS)

The Star pack design of Fast Pack containers currently being used in the Air Force Fast Pack program will provide the packaging requirements for numerous items requiring protection from shock and vibration. To insure the effective use of these Star pack c...

R. S. Larsen

1973-01-01

443

Effects on Air Pollution and Regional Climate of Producing and Using Hydrogen in Fuel Cells in all U.S. OnroadVehicles  

NASA Astrophysics Data System (ADS)

The purpose of this study was to examine the potential effects on U.S. air pollution and regional climate of switching the current U.S. fleet of onroad motor vehicles to hydrogen fuel-cell vehicles, where hydrogen was produced by (1) steam-reforming of methane, (2) wind energy, or (3) coal gasification. An additional scenario in which the U.S. fleet was switched to gasoline-electric hybrid vehicles was also examined. The model used was GATOR-GCMOM, a global-through-urban-scale nested and parallelized gas, aerosol, transport, radiation, general-circulation, mesoscale, and ocean model. U.S. emission data for the baseline case were obtained from the U.S. National Emission Inventory, which considers 370,000 stack and fugitive sources, 250,000 area sources, and 1700 categories of onroad and nonroad vehicular sources (including motorcycles, passenger vehicles, trucks, recreational vehicles, construction vehicles, farm vehicles, industrial vehicles, etc.). Emission inventories for each of the three hydrogen scenarios were prepared following a process chain analysis that accounted for energy inputs and pollution outputs during all stages of hydrogen and fossil-fuel production, distribution, storage, and end-use. Emitted pollutants accounted for included CO, CO2, H2, H2O, CH4, speciated ROGs, NOx, NH3, SOx, and speciated particulate matter. Results from the first scenario suggest that switching vehicles in the U.S. to hydrogen produced by steam-reforming of methane may reduce emission of NOx, reactive hydrocarbons, CO, CO2, BC, NO3-, and NH4+, but increase CH4, H2, and SO2 (slightly).The switch may also decrease O3 over most of the U.S. but short-term near-surfaces increases may occur over low-vegetated cities (e.g., in Los Angeles and along the Boston-Washington corridor) due to loss of NOx that otherwise titrates O3. The switch is also estimated to decrease PAN, HCHO, and several other pollutants formed in the atmosphere. Isoprene may increase since fewer oxidants (OH, O3) will be available to destroy it. Results for the scenarios involving hydrogen from wind and coal gasification, and from the hybrid scenario will also be discussed, as will regional climate effects (including effects of H2O). Findings to date suggest that, even under a worst-case scenario of 10% hydrogen leakage, the conversion of the current fleet to hydrogen-fuel cell vehicles, where hydrogen is generated by steam-reforming of methane, may result in a measurable improvement in U.S. air quality.

Jacobson, M. Z.; Colella, W. G.; Golden, D. M.

2004-12-01

444

Multi-layer metal/shape memory polymer roll-up wing structures for fitment-constrained air vehicles  

US Patent & Trademark Office Database

A laminated wing structure includes at least one layer of metal material and at least one layer of a shape memory polymer (SMP) material. The SMP is heated to a temperature in its glass transition band Tg to roll the wing around the air vehicle into a stored position. The metal layer(s) must be thin enough to remain below its yield point when rolled up. In preparation for launch, the SMP material is thermally activated allowing the strain energy stored in the layer of metal material to return the wing to its deployed position at launch. Once deployed, the SMP cools to its glassy state. The SMP material may be reinforced with fiber to form a polymer matrix composite (PMC). SMP may be used to provide shear strain relief for multiple metal layers. By offloading the motive force required to return the wing to its original deployed position from the SMP to the metal, the polymer does not acquire a permanent set and the wing may be deployed accurately.

2013-09-10

445

Ethanol and air quality: influence of fuel ethanol content on emissions and fuel economy of flexible fuel vehicles.  

PubMed

Engine-out and tailpipe emissions of NOx, CO, nonmethane hydrocarbons (NMHC), nonmethane organic gases (NMOG), total hydrocarbons (THC), methane, ethene, acetaldehyde, formaldehyde, ethanol, N2O, and NH3 from a 2006 model year Mercury Grand Marquis flexible fuel vehicle (FFV) operating on E0, E10, E20, E30, E40, E55, and E80 on a chassis dynamometer are reported. With increasing ethanol content in the fuel, the tailpipe emissions of ethanol, acetaldehyde, formaldehyde, methane, and ammonia increased; NOx and NMHC decreased; while CO, ethene, and N2O emissions were not discernibly affected. NMOG and THC emissions displayed a pronounced minimum with midlevel (E20-E40) ethanol blends; 25-35% lower than for E0 or E80. Emissions of NOx decreased by approximately 50% as the ethanol content increased from E0 to E30-E40, with no further decrease seen with E55 or E80. We demonstrate that emission trends from FFVs are explained by fuel chemistry and engine calibration effects. Fuel chemistry effects are fundamental in nature; the same trend of increased ethanol, acetaldehyde, formaldehyde, and CH4 emissions and decreased NMHC and benzene emissions are expected for all FFVs. Engine calibration effects are manufacturer and model specific; emission trends for NOx, THC, and NMOG will not be the same for all FFVs. Implications for air quality are discussed. PMID:24328061

Hubbard, Carolyn P; Anderson, James E; Wallington, Timothy J

2014-01-01

446

Sensitivity of urban airshed model results for test fuels to uncertainties in light-duty vehicle and biogenic emissions and alternative chemical mechanisms—Auto\\/oil air quality improvement research program  

Microsoft Academic Search

Three sources of uncertainty in the air quality modeling performed for the Auto\\/Oil Air Quality Improvement: Research Program, Phase I, were investigated to assess their impact on predicted ozone for test fuels in Los Angeles in year 2010. First, quadrupling the estimated total organic gas (TOG) and tripling the CO emissions from light-duty gasoline vehicles in the air quality model

Charles H. Schleyer

1995-01-01

447

A Javat universal vehicle router for routing unmanned aerial vehicles  

Microsoft Academic Search

We consider vehicle routing problems in the context of the Air Force operational problem of routing unmanned aerial vehicles from base locations to various reconnaissance sites. The unmanned aerial vehicle routing problem requires consideration of heterogeneous vehicles, vehicle endurance limits, time windows, and time walls for some of the sites requiring coverage, site priorities, and asymmetric travel distances. We propose

R. W. Hardera

448

An adaptive dual-optimal path-planning technique for unmanned air vehicles with application to solar-regenerative high altitude long endurance flight  

Microsoft Academic Search

A multi-objective technique for Unmanned Air Vehicle (UAV) path and trajectory autonomy generation, through task allocation and sensor fusion has been developed. The Dual-Optimal Path-Planning (D-O.P-P.) Technique generates on-line adaptive flight paths for UAVs based on available flight windows and environmental influenced objectives. The environmental influenced optimal condition, known as the driver' determines the condition, within a downstream virtual window

Clifford A. Whitfield

2009-01-01

449

Design of a High-Altitude Long-Endurance Solar-Powered Unmanned Air Vehicle for Multi-Payload and Operations  

Microsoft Academic Search

Several researches are being carried out at the Politecnico di Torino with the aim of designing a high altitude very-long endurance\\/unmanned air vehicle (HAVE\\/UAV). Being able to fly in the stratosphere (15-20 km) and with an endurance of about 4 months offers an advan- tage and possibility that is presently not available with conventional aircraft or satellites. A computer program

G Romeo; G Frulla; E Cestino

2007-01-01

450

Federal certification test results for 1992 model year. Control of air pollution from new motor vehicles and new motor vehicle engines  

SciTech Connect

Each manufacturer of a passenger car, (light-duty-vehicle), light-duty truck, motorcycle, heavy-duty gasoline engine, and heavy-duty diesel engine is required to demonstrate compliance with the applicable exhaust emission standard. This report contains all of the individual tests that were required by the certification-procedures found in Title 40 of the Code of Federal Regulations in Part 86. These data were submitted to the Environmental Protection Agency's Certification Division at the National Vehicle and Fuel Emissions Laboratory.

Not Available

1992-01-01

451

The Alpine Cushion Plant Silene acaulis as Foundation Species: A Bug's-Eye View to Facilitation and Microclimate  

PubMed Central

Alpine ecosystems are important globally with high levels of endemic and rare species. Given that they will be highly impacted by climate change, understanding biotic factors that maintain diversity is critical. Silene acaulis is a common alpine nurse plant shown to positively influence the diversity and abundance of organisms–predominantly other plant species. The hypothesis that cushion or nurse plants in general are important to multiple trophic levels has been proposed but rarely tested. Alpine arthropod diversity is also largely understudied worldwide, and the plant-arthropod interactions reported are mostly negative, that is,. herbivory. Plant and arthropod diversity and abundance were sampled on S. acaulis and at paired adjacent microsites with other non-cushion forming vegetation present on Whistler Mountain, B.C., Canada to examine the relative trophic effects of cushion plants. Plant species richness and abundance but not Simpson’s diversity index was higher on cushion microsites relative to other vegetation. Arthropod richness, abundance, and diversity were all higher on cushion microsites relative to other vegetated sites. On a microclimatic scale, S. acaulis ameliorated stressful conditions for plants and invertebrates living inside it, but the highest levels of arthropod diversity were observed on cushions with tall plant growth. Hence, alpine cushion plants can be foundation species not only for other plant species but other trophic levels, and these impacts are expressed through both direct and indirect effects associated with altered environmental conditions and localized productivity. Whilst this case study tests a limited subset of the membership of alpine animal communities, it clearly demonstrates that cushion-forming plant species are an important consideration in understanding resilience to global changes for many organisms in addition to other plants.

Molenda, Olivia; Reid, Anya; Lortie, Christopher J.

2012-01-01

452

Volatile organic chemical emissions from carpet cushions: Screening measurements. Final report  

SciTech Connect

The US Consumer Product Safety Commission (CPSC) has received complaints from consumers regarding the