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At least 865 records · Page 48
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NASA NTRS2018

Human Automation Teaming: Lessons Learned and Future Directions

Full autonomy seems to be the goal for system developers in almost every area of the economy. However, as we move from automated systems to autonomous systems, designers have needed to insert humans to oversee automation that has traditionally been brittle or incomplete. This creates its own problems as the operator is usually out of the loop when the automation hands over problems that it cannot handle. To better handle these situations, it has been proposed that we develop human automation teams that have shared goals and objectives to support task performance. This paper will describe an initial model of Human Automation Teaming (HAT) which has three elements: transparency, bi-directional communications, and human-directed execution. Transparency in our model is a method for giving insight into the reasoning behind automated recommendations and actions, bi-directional communication allows the operator to communicate directly with the automation, and finally the automation defers execution to the human. The model was implemented through a number of features on an electronic flight bag (EFB) which are described in the paper. The EFB was installed in a mid-fidelity flight simulator and used by 12 airline pilots to support diversion decisions during off-nominal flight scenarios. Pilots reported that working with the HAT automation made diversion decisions easier and reduced their workload. They also reported that the information provided about diversion airports was similar to what they would receive from ground dispatch, thus making coordination with dispatch easier and less time consuming. These HAT features engender more trust in the automation when appropriate, and less when not, allowing improved supervision of automated functions by flight crews.

Human-Autonomy Teaming↗
NASA NTRS1983

Rotating-fluid experiments with an atmospheric general circulation model

In order to determine features of rotating fluid flow that are dependent on the geometry, rotating annulus-type experiments are carried out with a numerical model in spherical coordinates. Rather than constructing and testing a model expressly for this purpose, it is found expedient to modify an existing general circulation model of the atmosphere by removing the model physics and replacing the lower boundary with a uniform surface. A regime diagram derived from these model experiments is presented; its major features are interpreted and contrasted with the major features of rotating annulus regime diagrams. Within the wave regime, a narrow region is found where one or two zonal wave numbers are dominant. The results reveal no upper symmetric regime; wave activity at low rotation rates is thought to be maintained by barotropic rather than baroclinic processes.

Geisler, J. E.↗
NASA NTRS1988

Numerical simulation of unsteady incompressible viscous flows in generalized coordinate systems

Several numerical solutions of the three dimensional unsteady incompressible Navier-Stokes equations in generalized coordinate systems are presented. The governing equations are discretized by finite volumes with special care to the accurate approximation of the geometric quantities. The unknowns are the pressure and the volume fluxes over the computational cell faces. This formulation results in a robust fractional step solution method for solving discrete equations. Although this method is formulated for the three dimensional case, only two dimensional unsteady results are given. Results are presented for a lid driven two dimensional cavity flow at Reynolds number of 10,000, and for the flow over a circular cylinder with vortex shedding for several Reynolds numbers in the range 100 less than Re less than 1000.

Rosenfeld, Moshe↗
NASA NTRS2005

Experimental Stage Separation Tool Development in NASA Langley's Aerothermodynamics Laboratory

As part of the research effort at NASA in support of the stage separation and ascent aerothermodynamics research program, proximity testing of a generic bimese wing-body configuration was conducted in NASA Langley's Aerothermodynamics Laboratory in the 20-Inch Mach 6 Air Tunnel. The objective of this work is the development of experimental tools and testing methodologies to apply to hypersonic stage separation problems for future multi-stage launch vehicle systems. Aerodynamic force and moment proximity data were generated at a nominal Mach number of 6 over a small range of angles of attack. The generic bimese configuration was tested in a belly-to-belly and back-to-belly orientation at 86 relative proximity locations. Over 800 aerodynamic proximity data points were taken to serve as a database for code validation. Longitudinal aerodynamic data generated in this test program show very good agreement with viscous computational predictions. Thus a framework has been established to study separation problems in the hypersonic regime using coordinated experimental and computational tools.

Murphy, Kelly J.↗
NASA NTRS1979

Numerical method for predicting flow characteristics and performance of nonaxisymmetric nozzles, theory

The theoretical foundation and formulation of a numerical method for predicting the viscous flowfield in and about isolated three dimensional nozzles of geometrically complex configuration are presented. High Reynolds number turbulent flows are of primary interest for any combination of subsonic, transonic, and supersonic flow conditions inside or outside the nozzle. An alternating-direction implicit (ADI) numerical technique is employed to integrate the unsteady Navier-Stokes equations until an asymptotic steady-state solution is reached. Boundary conditions are computed with an implicit technique compatible with the ADI technique employed at interior points of the flow region. The equations are formulated and solved in a boundary-conforming curvilinear coordinate system. The curvilinear coordinate system and computational grid is generated numerically as the solution to an elliptic boundary value problem. A method is developed that automatically adjusts the elliptic system so that the interior grid spacing is controlled directly by the a priori selection of the grid spacing on the boundaries of the flow region.

Thomas, P. D.↗
NASA NTRS1992

Mg II absorption in the spectra of 103 QSOs - Implications for the evolution of gas in high-redshift galaxies

Spectra of 103 low- and intermediate-redshift QSOs with a resolution of 4-6 A were obtained in order to investigate the statistics of the M II 2796, 2803 absorption systems over the redshift range of 0.2-2.2. New emission-line redshifts, based mostly on Mg II 2800 and semiforbidden 1909, were determined for the QSOs. The mean number density of Mg II absorbers per unit redshift range decreased from 0.97 +/-0.10 for a rest equivalent width threshold of 0.3 A to 0.27 +/-0.05 for a threshold of 1.0 A. The results are in agreement with comparable previous work. The observed equivalent width distribution could be fitted with either exponential or power-law analytic distributions, with parameters in line with those found in earlier studies. Statistical tests show that the Mg II absorbers are uniformly distributed in both comoving coordinates and velocity relative to the QSO.

Steidel, Charles C.↗
NASA NTRS1998

Aeronautics Learning Laboratory for Science, Technology, and Research (ALLSTAR)

We finished the material development of Level 1, Level 2 and most of Level 3. We created three new galleries, one of streaming videos enabling the user to select his/her appropriate speed of Internet connectivity for better performance. The second gallery on NASA's X-series aircraft and the third is on F-series aircraft. We also completed the placement and activation of all thirteen kiosks. We added one more kiosk over the number suggested in the proposal at Baker Aviation High School - a Dade County Public School for special aviation programs. We felt that the goals of this school matched ALLSTAR's goals and that the placement of the kiosk would better help the local students become interested in the Aviation and Aeronautics field. We continue to work on the development of our "Teacher Resource Guide to ALLSTAR material" in which we tied our material into the national and Florida State standards. We finished the Florida Sunshine State standards, getting positive feedback from local and other educators who use the material on a regular basis. We had another successful workshop on October 29 th, 1997. We introduced the ALLSTAR website and kiosk to about twenty science and history teachers from Dade County Public Schools (DCPS). Most teachers were from middle schools, although we had some from elementary schools also. We provided several demonstrations of the ALLSTAR material to local schools in the Dade County Public Schools (DCPS) system. We used the ALLSTAR material with FIU's summer immersion program for FLAME students. This program includes a high number of minority students interested in science and engineering. We also presented the material at National Science Teachers Association (NSTA) and National Congress on Aviation and Space Education (NCASE) conferences and will be presenting the material at the Southeast Florida Aviation Consortium (SEFAC). We provided two on-site workshops in the NSTA conference with total attended of about 70 teachers. The BBS was converted to an on-line discussion forum with a unique section on Blacks in Aviation, Prime Technologies coordinated with NASA LaRC and the Teacher Resource Centers (TRCs) for scale-up of ALLSTAR and performed live demonstrations of the software in schools and at conventions.

Levy, Cesar↗
NASA NTRS1998

NASA ALLSTAR Project

We finished the material development of Level 1, Level 2 and most of Level 3. We created three new galleries, one of streaming videos enabling the user to select his/her appropriate speed of Internet connectivity for better performance. The second gallery on NASA's X-series aircraft and the third is on F-series aircraft, We also completed the placement and activation of all thirteen kiosks. We added one more kiosk over the number suggested in the proposal at Baker Aviation High School - a Dade County Public School for special aviation programs. We felt that the goals of this school matched ALLSTAR's goals and that the placement of the kiosk would better help the local students become interested in the Aviation and Aeronautics field. We continue to work on the development of our "Teacher Resource Guide to ALLSTAR material" in which we tied our material into the national and Florida State standards. We finished the Florida Sunshine State standards, getting positive feedback from local and other educators who use the material on a regular basis. We had another successful workshop on October 29th, 1997. We introduced the ALLSTAR website and kiosk to about twenty science and history teachers from Dade County Public Schools (DCPS). Most teachers were from middle schools, although we had some from elementary schools also. We provided several demonstrations of the ALLSTAR material to local schools in the Dade County Public Schools (DCPS) system. We used the ALLSTAR material with FIU's summer immersion program for FLAME students. This program includes a high number of minority students interested in science and engineering. We also presented the material at National Science Teachers Association (NSTA) and National Congress on Aviation and Space Education (NCASE) conferences and will be presenting the material at the Southeast Florida Aviation Consortium (SEFAC). We provided two on-site workshops in the NSTA conference with total attended of about 70 teachers. The BBS was converted to an on-line discussion forum with a unique section on Blacks in Aviation, Prime Technologies coordinated with NASA LaRC and the Teacher Resource Centers (TRCS) for scale-up of ALLSTAR and performed live demonstrations of the software in schools and at conventions.

Levy, Cesar↗
NASA NTRS1998

NASA Allstar Project Aeronautics Learning Laboratory for Science,Technology, and Research (Allstar)

We finished the material development of Level 1, Level 2 and most of Level 3. We created three new galleries, one of streaming videos enabling the user to select his/her appropriate speed of Internet connectivity for better performance. The second gallery on NASA's X-series aircraft and the third is on F-series aircraft. We also completed the placement and activation of all thirteen kiosks. We added one more kiosk over the number suggested in the proposal at Baker Aviation High School - a Dade County Public School for special aviation programs. We felt that the goals of this school matched ALLSTAR's goals and that the placement of the kiosk would better help the local students become interested in the Aviation and Aeronautics field. We continue to work on the development of our "Teacher Resource Guide to ALLSTAR material" in which we tied our material into the national and Florida State standards. We finished the Florida Sunshine State standards, getting positive feedback from local and other educators who use the material on a regular basis. We had another successful workshop on October 29', 1997. We introduced the ALLSTAR website and kiosk to about twenty science and history teachers from Dade County Public Schools (DCPS). Most teachers were from middle schools, although we had some from elementary schools also. We provided several demonstrations of the ALLSTAR material to local schools in the Dade County Public Schools (DCPS) system. We used the ALLSTAR material with FIU's summer immersion program for FLAME students. This program includes a high number of minority students interested in science and engineering. We also presented the material at National Science Teachers Association (NSTA) and National Congress on Aviation and Space Education (NCASE) conferences and will be presenting the material at the Southeast Florida Aviation Consortium (SEFAC). We provided two on-site workshops in the NSTA conference with total attended of about 70 teachers. The BBS was converted to an on-line discussion forum with a unique section on Blacks in Aviation. Prime Technologies coordinated with NASA LARC and the Teacher Resource Centers (TRCs) for scale-up of ALLSTAR and performed live demonstrations of the software in schools and at conventions.

Levy, Cesar↗
NASA NTRS2007

Heliophysical Modeling at the CCMC - Community Modeling Activities to Compliment the VHGO

The Community Coordinated Modeling Center (CCMC) hosts an ever growing inventory of models to support the research activities of the Heliophysics community.In this poster we detail this model inventory. We describe the manner in which the CCMC provides access to these models to the community. This support includes model runs driven with archived data and 'realtime' runs which update as the latest data is ingested by the models. It includes runs for individual researchers and in support of observational planning and analysis for a number of flight missions. Our need to integrate the data streams into and out of numerous models and graphics packages has led to the development of a number of infra-structure component that are also highly relevant to the design of the VHGO. We discuss this issue and the natural and vital link that must develop between the VHGO and modeling centers such as the CCMC, if the usefulness of the VHGO is to be maximized.

MacNeice, P.↗
NASA NTRS1982

Finite analytic numerical solution of axisymmetric Navier-Stokes and energy equations

Convective heat transfer for steady state laminar flow in axisymmetric coordinates is considered. Numerical solutions for flow pattern and temperature distribution are obtained by the finite analytic numerical method applied to the Navier-Stokes equations expressed in terms of vorticity and stream function, and the energy equation. The finite analytic numerical method differs from other numerical methods in that it utilizes a local analytic solution in an element of the problem to construct the total numerical solution. Finite analytic solutions of vorticity, stream function, temperature and heat transfer coefficients for flow with Reynolds number of 5.0, 100.0, 1000.0, and 2000.0, and Prandtl number of 0.1, 1.0, and 10.0 with uniform grid sizes are reported for axisymmetric pipe with sudden expansion and contraction. The wall temperature is considered to be isothermal and differs from the inlet temperature. It is shown that the finite analytic solution is stable, converges rapidly, and simulates the convection of fluid flow accurately since the local analytic solution is capable of simulating automatically the influence of skewed convection through the element boundary on the interior nodal values thereby minimizing the false numerical diffusion.

Chen, C.-J.↗
NASA NTRS1989

Numerical simulation of unsteady incompressible viscous flows in generalized coordinate systems

Several numerical solutions of the three-dimensional unsteady incompressible Navier-Stokes equations in generalized coordinate systems are presented. The governing equations are discretized by finite volumes with special care to the accurate approximation of the geometric quantities. The unknowns are the pressure and the volume fluxes over the computational cell faces. This formulation results in a robust fractional step solution method for solving discrete equations. Although this method is formulated for the three-dimensional case, only two-dimensional unsteady results are given. Results are presented for a lid driven two-dimensional cavity flow at Reynolds number of 10,000 and for the flow over a circular cylinder with vortex shedding for several Reynolds numbers in the range 100 less than Re less than 1000.

Rossenfeld, Moshe↗
NASA NTRS2008

The Photogrammetry Cube

We can determine distances between objects and points of interest in 3-D space to a useful degree of accuracy from a set of camera images by using multiple camera views and reference targets in the camera s field of view (FOV). The core of the software processing is based on the previously developed foreign-object debris vision trajectory software (see KSC Research and Technology 2004 Annual Report, pp. 2 5). The current version of this photogrammetry software includes the ability to calculate distances between any specified point pairs, the ability to process any number of reference targets and any number of camera images, user-friendly editing features, including zoom in/out, translate, and load/unload, routines to help mark reference points with a Find function, while comparing them with the reference point database file, and a comprehensive output report in HTML format. In this system, scene reference targets are replaced by a photogrammetry cube whose exterior surface contains multiple predetermined precision 2-D targets. Precise measurement of the cube s 2-D targets during the fabrication phase eliminates the need for measuring 3-D coordinates of reference target positions in the camera's FOV, using for example a survey theodolite or a Faroarm. Placing the 2-D targets on the cube s surface required the development of precise machining methods. In response, 2-D targets were embedded into the surface of the cube and then painted black for high contrast. A 12-inch collapsible cube was developed for room-size scenes. A 3-inch, solid, stainless-steel photogrammetry cube was also fabricated for photogrammetry analysis of small objects.

Source record↗
NASA NTRS2012

Highlights of Space Weather Services/Capabilities at NASA/GSFC Space Weather Center

The importance of space weather has been recognized world-wide. Our society depends increasingly on technological infrastructure, including the power grid as well as satellites used for communication and navigation. Such technologies, however, are vulnerable to space weather effects caused by the Sun's variability. NASA GSFC's Space Weather Center (SWC) (http://science.gsfc.nasa.gov//674/swx services/swx services.html) has developed space weather products/capabilities/services that not only respond to NASA's needs but also address broader interests by leveraging the latest scientific research results and state-of-the-art models hosted at the Community Coordinated Modeling Center (CCMC: http://ccmc.gsfc.nasa.gov). By combining forefront space weather science and models, employing an innovative and configurable dissemination system (iSWA.gsfc.nasa.gov), taking advantage of scientific expertise both in-house and from the broader community as well as fostering and actively participating in multilateral collaborations both nationally and internationally, NASA/GSFC space weather Center, as a sibling organization to CCMC, is poised to address NASA's space weather needs (and needs of various partners) and to help enhancing space weather forecasting capabilities collaboratively. With a large number of state-of-the-art physics-based models running in real-time covering the whole space weather domain, it offers predictive capabilities and a comprehensive view of space weather events throughout the solar system. In this paper, we will provide some highlights of our service products/capabilities. In particular, we will take the 23 January and the 27 January space weather events as examples to illustrate how we can use the iSWA system to track them in the interplanetary space and forecast their impacts.

Fok, Mei-Ching↗
NASA NTRS2015

Assessing Resilience of Scheduled Performance-Based Navigation Arrival Operations

This paper assesses the resilience of scheduled Performance-Based Navigation (PBN) arrival operations. Resilience is defined as an ability to return to nominal operations following a schedule perturbation. Results from a Human-in-the- Loop (HITL) experiment that included off-nominal events to perturb the schedule are described. The schedule comes from a precision trajectory-based arrival manager. The experiment collected data regarding the response to perturbed schedules in three conditions, where: 1) a disturbance rejection algorithm made schedule adjustments automatically, 2) a Traffic Management Coordinator (TMC) participant made schedule adjustments manually, or 3) no schedule adjustments were made. Analyses showed that the simulation’s scheduled PBN operations have inherent resilience, recovering from more than half of the perturbed schedules even with no schedule adjustments. Resilience to the same off-nominal events improved with schedule adjustments; an increased proportion of perturbed schedules recovered within the length of operation run, and the average duration of the schedule’s perturbed state decreased. Compared to the manual schedule adjustments condition, a greater number of schedule adjustments occurred for the same off-nominal events in the automated condition. However, perturbed schedules were recovered more frequently and perturbations were less severe in the automated condition. Subjective and objective workload in the manual and the automated schedule adjustment conditions were similar to the no schedule adjustment condition.

Resilience↗
NASA NTRS1983

Theoretical investigations of high lift aerodynamics

A program which generates a coordinate system for a two element airfoil with the mesh points concentrated in areas of significant vorticity, i.e., boundary layer and wake is operational. The 'imbedded' grid method developed allows a transition from the scale of the main airfoil to the scale of the flap. This requirement is essential for the modeling of viscous flows over the flap and slat of a multielement airfoil. An airfoil mounted in a 2-D wind tunnel was formulated. The program is ready for a fine grid and a large number of planes to explore the characteristics of a Navier-Stokes solver in a quasi-3D case. The program was converted to a form suitable for the STAR computer. Runs were made to map a three dimensional flow field for a wall airfoil intersection with and without lift.

Bennett, G.↗
NASA NTRS1995

Geometric modeling for computer aided design

The primary goal of this grant has been the design and implementation of software to be used in the conceptual design of aerospace vehicles particularly focused on the elements of geometric design, graphical user interfaces, and the interaction of the multitude of software typically used in this engineering environment. This has resulted in the development of several analysis packages and design studies. These include two major software systems currently used in the conceptual level design of aerospace vehicles. These tools are SMART, the Solid Modeling Aerospace Research Tool, and EASIE, the Environment for Software Integration and Execution. Additional software tools were designed and implemented to address the needs of the engineer working in the conceptual design environment. SMART provides conceptual designers with a rapid prototyping capability and several engineering analysis capabilities. In addition, SMART has a carefully engineered user interface that makes it easy to learn and use. Finally, a number of specialty characteristics have been built into SMART which allow it to be used efficiently as a front end geometry processor for other analysis packages. EASIE provides a set of interactive utilities that simplify the task of building and executing computer aided design systems consisting of diverse, stand-alone, analysis codes. Resulting in a streamlining of the exchange of data between programs reducing errors and improving the efficiency. EASIE provides both a methodology and a collection of software tools to ease the task of coordinating engineering design and analysis codes.

Schwing, James L.↗
NASA NTRS1996

Structural Dynamic/CFD Interaction for Computation of Vertical Tail Buffet

The multi-disciplinary problem of tail buffeting is solved using three sets of equations. The first set is the unsteady, compressible, full Navier Stokes equations which are used for obtaining the flow-field vector and the aerodynamic loads. The second set is the coupled aeroelastic equations which are used for obtaining the bending and torsional deflections of the tail. The third set is the grid-displacement equations which are used for updating the grid coordinates due to the tail deflections. For the computational applications a sharp-edged delta wing of aspect ratio one and a rectangular vertical tail of aspect ratio one placed in the plane of geometric symmetry behind the wing are considered. The configuration is pitched at a critical angle of attack (alpha = 38 deg.) which produces asymmetric, vortex-breakdown flow of the delta wing primary vortices. The results show the effects of coupled and uncoupled bending-torsional responses and the effects of the Reynolds number.

Kandil, Osama A.↗