SEARCH · Engineering Papers

Results for “aircraft movement”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4

All sources NASA NTRS DOE OSTI

NASA NTRS1975

Verification by Remote Sensing of an Oil Slick Movement Prediction Model

The author has identified the following significant results. LANDSAT, aircraft, ships, and air-dropped current drogues were deployed to determine current circulation and to track oil slick movement on four different dates in Delaware Bay. Results were used to verify a predictive model for oil slick movement and dispersion. The model predicts the behavior of oil slicks given their size, location, tidal stage (current), weather (wind), and nature of crude. Both LANDSAT satellites provided valuable data on gross circulation patterns and convergent coastal fronts which by capturing oil slicks significantly influence their movement and dispersion.

Klemas, V.↗

NASA NTRS1976

Verification by remote sensing of an oil slick movement prediction model

The author has identified the following significant results. LANDSAT, aircraft, ships, and air-dropped current drogues were deployed to determine current circulation and to track oil slick movement on four different dates in Delaware Bay. The results were used to verify a predictive model for oil slicks given their size, location, tidal stage (current), weather (wind), and nature of crude. Both LANDSAT satellites provided valuable data on gross circulation patterns and convergent coastal fronts which by capturing oil slicks significantly influence their movement and dispersion.

Klemas, V.↗

NASA NTRS1975

Quantitative suspended sediment mapping using aircraft remotely sensed multispectral data

Suspended sediment is an important environmental parameter for monitoring water quality, water movement, and land use. Quantitative suspended sediment determinations were made from analysis of aircraft remotely sensed multispectral digital data. A statistical analysis and derived regression equation were used to determine and plot quantitative suspended sediment concentration contours in the tidal James River, Virginia, on May 28, 1974. From the analysis, a single band, Band 8 (0.70-0.74 microns), was adequate for determining suspended sediment concentrations. A correlation coefficient of 0.89 was obtained with a mean inaccuracy of 23.5 percent for suspended sediment concentrations up to about 50 mg/l. Other water quality parameters - secchi disc depth and chlorophyll - also had high correlations with the remotely sensed data. Particle size distribution had only a fair correlation with the remotely sensed data.

Johnson, R. W.↗

NASA NTRS1997

Surface Movement Incidents Reported to the NASA Aviation Safety Reporting System

Increasing numbers of aircraft are operating on the surface of airports throughout the world. Airport operations are forecast to grow by more that 50%, by the year 2005. Airport surface movement traffic would therefore be expected to become increasingly congested. Safety of these surface operations will become a focus as airport capacity planning efforts proceed toward the future. Several past events highlight the prevailing risks experienced while moving aircraft during ground operations on runways, taxiways, and other areas at terminal, gates, and ramps. The 1994 St. Louis accident between a taxiing Cessna crossing an active runway and colliding with a landing MD-80 emphasizes the importance of a fail-safe system for airport operations. The following study explores reports of incidents occurring on an airport surface that did not escalate to an accident event. The Aviation Safety Reporting System has collected data on surface movement incidents since 1976. This study sampled the reporting data from June, 1993 through June, 1994. The coding of the data was accomplished in several categories. The categories include location of airport, phase of ground operation, weather /lighting conditions, ground conflicts, flight crew characteristics, human factor considerations, and airport environment. These comparisons and distributions of variables contributing to surface movement incidents can be invaluable to future airport planning, accident prevention efforts, and system-wide improvements.

Connell, Linda J.↗

NASA NTRS1973

Human eye movements during various forms of linear acceleration and weightlessness

Eye movements of human subjects were recorded electronystagmographically in complete darkness during rectilinear horizontal accelerations as achieved in cars on the ground and also during aircraft parabolic flight. The results were compared to the movements of blinded goldfish subjected to similar changes of gravitoinertial forces. The results indicate that there is a human correlation with the gravity reference response of fish. During horizontal forward accelerations on the ground the human eyes turn downward and during horizontal backward acceleration the eyes turn upward. The human eye response to g-loads below 1 g and to weightlessness is the reverse of the tilt of the fish. While fish dive down during low g, or loop forward during weightlessness, the eyes of subjects sitting upright in an aircraft which flies at 0 g move upward.

Vonbaumgarten, R. J.↗

NASA NTRS1980

Instrument scanning and controlling: Using eye movement data to understand pilot behavior and strategies

Eye movement data and other parameters including instrument readings, aircraft state and position variables, and control maneuvers were recorded while pilots flew ILS simulations in a B 737. The experiment itself employed seven airline pilots, each of whom flew approximately 40 approach/landing sequences. The simulator was equipped with a night visual scene but the scene was fogged out down to approximately 60 meters (200 ft). The instrument scanning appeared to follow aircraft parameters not physical position of instruments. One important implication of the results is: pilots look for categories or packets of information. Control inputs were tabulated according to throttle, wheel position, column, and pitch trim changes. Three seconds of eye movements before and after the control input were then obtained. Analysis of the eye movement data for the controlling periods showed clear patterns. The results suggest a set of miniscan patterns which are used according to the specific details of the situation. A model is developed which integrates scanning and controlling. Differentiations are made between monitoring and controlling scans.

Dick, A. O.↗

NASA NTRS1992

Dynamics of the G-excess illusion

The G-excess illusion is increasingly recognized as a cause of aviation mishaps especially when pilots perform high-speed, steeply banked turns at low altitudes. Centrifuge studies of this illusion have examined the perception of subject orientation and/or target displacement during maintained hypergravity with the subject's head held stationary. The transient illusory perceptions produced by moving the head in hypergravity are difficult to study onboard centrifuges because the high angular velocity ensures the presence of strong Coriolis cross-coupled semicircular canal effects that mask immediate transient otolith-organ effects. The present study reports perceptions following head movements in hypergravity produced by high-speed aircraft maintaining a banked attitude with low angular velocity to minimize cross-coupled effects. Methods: Fourteen subjects flew on the NASA KC-135 and were exposed to resultant gravity forces of 1.3, 1.5, and 1.8 G for 3 minute periods. On command, seated subjects made controlled head movements in roll, pitch, and yaw at 30 second intervals both in the dark and with faint targets at a distance of 5 feet. Results: head movement produced transient perception of target displacement and velocity at levels as low as 1.3 G. Reports of target velocity without appropriate corresponding displacement were common. At 1.8 G when yaw head movements were made from a face down position, 4 subjects reported oscillatory rotational target displacement with fast and slow alternating components suggestive of torsional nystagmus. Head movements evoked symptoms of nausea in most subjects, with 2 subjects and 1 observer vomiting. Conclusions: The transient percepts present conflicting signals, which introduced confusion in target and subject orientation. Repeated head movements in hypergravity generate nausea by mechanisms distinct from cross-coupled Coriolis effects.

Baylor, K. A.↗

NASA NTRS1976

Powered wheels for aircraft

Engineering details, project status, system design and specifications, and test results are presented on a powered-wheel drive system based on the Dynavector rotary actuator. The design and operation of the Dynavector system (with positive displacement very-low-inertia nonrotating vane motor) are reviewed. Feasibility studies, contract data, and findings of braking tests are described. Exploded diagrams of Dynavector details are displayed. Success in using powered wheels in lieu of aircraft main engines for on-ground movements should bring benefits in energy conservation, noise abatement, reduced pollution, and alleviated congestion in the terminal area.

Long, M. J.↗

NASA NTRS1984

Pilot differences and motion cuing effects on simulated helicopter hover

The effects that cues of aircraft motion, delays in visual scene, and movement of a ship model have on pilots' ability to hover a simulated helicopter near a destroyer-class ship were examined. Twelve pilots were tested in a within-subject factorial combination of fixed-base, moving-base, and G-seat conditions in which delays of 66 or 128 ms existed in the simulator's visual display and the pilots had to hover near a moving or stationary ship. Best control performance was seen under the moving-base conditions, whereas poorest control was associated with the fixed-base simulation. An intermediate level of performance was produced by the G-seat. In addition, visual delay affected control of the roll axis of the simulation, and interactions between pilots and motion cuing and visual delay were seen. Movement of the ship model had little effect.

Ricard, G. L.↗

NASA NTRS1998

Overview of NASA Advanced Transportation Technologies Program

A General Overview of NASA Advanced Transportation Technologies Program is presented. The contents include: 1) Center-TRACON Automation System (CTAS) which provides automation tools to assist air traffic controllers in planning and controlling air traffic arriving into major airports; 2) Surface Movement Advisor (SMA) for expediting and optimizing aircraft operations on the airport surface; and 3) Terminal Area Productivity Program (TAP), which is aimed at improving airport throughput in instrument meteorological conditions to match that attainable in clear weather.

Ashford, Rose↗

NASA NTRSDate not supplied

Vision-Based Distributed Sensing at Vertiports for Advanced Air Mobility and Urban Air Mobility Approach and Landing

Advanced Air Mobility (AAM) encompasses a broad vision for air transportation, including Urban Air Mobility (UAM) as a subset. AAM aims to create a more connected and efficient transportation network across various geographical settings. However, navigating AAM aircraft in GPS-denied or degraded environments during approach and landing is challenging. Traditional vision aids like glideslopes and localizers are limited in vertiport environments due to narrow beam constraints and reduced landing angle options. This paper addresses the need for accurate navigation solutions at vertiports by proposing a vision-based distributed sensing (VIDIS) system utilizing cameras with bundle adjustment to assist incoming AAM aircraft during approach and landing while monitoring surface movements to enhance safety and efficiency. Key focus areas for current and future vertiport developers include identifying suitable sensor types and infrastructure standards to support AAM operations and including vertiport markings as vision-based navigation aids. The proposed system offers a novel approach to overcoming navigation challenges in AAM operations, particularly in urban settings where traditional aids may be insufficient. Preliminary simulation results with distributed cameras demonstrate promising outcomes for implementing bundle adjustment techniques to enhance vision-based navigation solutions at vertiports. Generating waypoint-based trajectories via waypoint integration using explicit guidance synthesis (WINGS) creates smooth AAM trajectories for landing at vertiports by using the current waypoint's terminal conditions as the initial conditions for the next waypoint. Combining bundle adjustment's ground-based solution of vertiport features with WINGS, Coplanar Pose from Orthography and Scaling with Iterations (COPOSIT), and an extended Kalman filter (EKF) estimates the state of an incoming aircraft during approach and landing at vertiports. Future work includes testing VIDIS in a high-fidelity simulation and with real-world data.

Distributed sensing↗

NASA NTRSDate not supplied

Vision-Based Distributed Sensing at Vertiports for Advanced Air Mobility and Urban Air Mobility Approach and Landing

Distributed sensing↗

NASA NTRS2000

Bioelectric Control of a 757 Class High Fidelity Aircraft Simulation

This paper presents results of a recent experiment in fine grain Electromyographic (EMG) signal recognition, We demonstrate bioelectric flight control of 757 class simulation aircraft landing at San Francisco International Airport. The physical instrumentality of a pilot control stick is not used. A pilot closes a fist in empty air and performs control movements which are captured by a dry electrode array on the arm, analyzed and routed through a flight director permitting full pilot outer loop control of the simulation. A Vision Dome immersive display is used to create a VR world for the aircraft body mechanics and flight changes to pilot movements. Inner loop surfaces and differential aircraft thrust is controlled using a hybrid neural network architecture that combines a damage adaptive controller (Jorgensen 1998, Totah 1998) with a propulsion only based control system (Bull & Kaneshige 1997). Thus the 757 aircraft is not only being flown bioelectrically at the pilot level but also demonstrates damage adaptive neural network control permitting adaptation to severe changes in the physical flight characteristics of the aircraft at the inner loop level. To compensate for accident scenarios, the aircraft uses remaining control surface authority and differential thrust from the engines. To the best of our knowledge this is the first time real time bioelectric fine-grained control, differential thrust based control, and neural network damage adaptive control have been integrated into a single flight demonstration. The paper describes the EMG pattern recognition system and the bioelectric pattern recognition methodology.

Jorgensen, Charles↗

NASA NTRS1989

Application of unstructured grid methods to steady and unsteady aerodynamic problems

The purpose is to describe the development of unstructured grid methods which have several advantages when compared to methods which make use of structured grids. Unstructured grids, for example, easily allow the treatment of complex geometries, allow for general mesh movement for realistic motions and structural deformations of complete aircraft configurations which is important for aeroelastic analysis, and enable adaptive mesh refinement to more accurately resolve the physics of the flow. Steady Euler calculations for a supersonic fighter configuration to demonstrate the complex geometry capability; unsteady Euler calculations for the supersonic fighter undergoing harmonic oscillations in a complete-vehicle bending mode to demonstrate the general mesh movement capability; and vortex-dominated conical-flow calculations for highly-swept delta wings to demonstrate the adaptive mesh refinement capability are discussed. The basic solution algorithm is a multi-stage Runge-Kutta time-stepping scheme with a finite-volume spatial discretization based on an unstructured grid of triangles in 2D or tetrahedra in 3D. The moving mesh capability is a general procedure which models each edge of each triangle (2D) or tetrahedra (3D) with a spring. The resulting static equilibrium equations which result from a summation of forces are then used to move the mesh to allow it to continuously conform to the instantaneous position or shape of the aircraft. The adaptive mesh refinement procedure enriches the unstructured mesh locally to more accurately resolve the vortical flow features. These capabilities are described in detail along with representative results which demonstrate several advantages of unstructured grid methods. The applicability of the unstructured grid methodology to steady and unsteady aerodynamic problems and directions for future work are discussed.

Batina, John T.↗

NASA NTRS1980

Physiological response to hyper- and hypogravity during rollercoaster flight

Twenty-six healthy male subjects were flown in a Lear jet aircraft through rollercoaster and parabolic weightlessness flight. Eye movements, respiration, and blood volume pulse were recorded on magnetic tape. The same subjects underwent a battery of five vestibular tests in the laboratory on the ground. One subject in each flight was flown in an upright position, the other in a 90 deg forward tilted head position. The forward tilted subjects always reported motion sickness earlier and after fewer rollercoaster maneuvers than the upright-sitting subjects. It is concluded that the susceptibility to changes of X-axis acceleration is higher than to changes of Z-axis acceleration. Correlation was found between the ability to estimate the subjective vertical (modified Mueller-Aubert-test), optokinetic nystagmus asymmetries, and susceptibility to rollercoaster flight sickness.

Von Baumgarten, R. J.↗

DOE OSTI2022

Optimizing aircraft flows at airports using data driven predicted capabilities

A method for safe and efficient use of airport runway capacity includes receiving, at an air traffic control system at an airport, airport data related to movement areas of the airport, time data related to a time period, aircraft data related to a plurality of aircraft expected to operate into and out of the airport during the time period, and environmental data related to environmental conditions predicted for the airport during the time period. The method further includes computing a probability distribution for inter-aircraft spacing by applying the airport data, the time data, the aircraft data, and the environmental data to a trained Bayesian network, producing the probability distribution for the inter-aircraft spacing as an output observation of the trained Bayesian network, and, using the probability distribution and a confidence value, identifying an inter-aircraft spacing value for the plurality of aircraft expected to operate into and out of the airport during the time period.

Sweet, Douglas↗

NASA NTRSDate not supplied

From the Knowledge-based Digital Platform (KbDP) Concept for Advanced Air Mobility Research to a Preliminary Prototype

Advanced Air Mobility (AAM) encompasses a range of innovative operational and technological changes to aviation (electric aircraft, increasingly automated aircraft, increasingly automated airspace operations, etc.) that are transforming aviation’s role in everyday movement of people and goods. There are multiple associated concepts and use cases for AAM, all interrelated, including small Unmanned Aircraft System (UAS) Traffic Management (UTM), Upper-Class E Traffic Management (ETM), Extensible Traffic Management (xTM), Regional Air Mobility (RAM), and Urban Air Mobility (UAM). These AAM operations must integrate with traditional Air Traffic Management (ATM) operations, as well as non-aviation modes of transportation and logistics. National Aeronautics and Space Administration (NASA) is spearheading an innovative digital engineering approach to integrate, communicate, and facilitate the research of multi-modal transportation systems. The Knowledge-based Digital Platform (KbDP) is a concept being developed that ties the workflows of Project Managers (PM), Principal Investigators (PI), and System Engineers together across organizational boundaries. It does so through the management of an information database defined by mathematical, data science, and system engineering principles. Machine Learning (ML) algorithms play a key role in this concept by extracting meaningful knowledge from the information database, which the human user leverages to greatly improve the efficiency and effectiveness of their research. Expected benefits of this concept include improved technology transfers from research to production, improved research portfolio investments, and research outcomes that are more integrated with all aspects of the multi-modal transportation problem. The preliminary KbDP prototype has been realized using UAM as a pathfinder use case and developed by a team of system engineer, software developer, data scientist, and interns.

Systems Engineering↗

NASA NTRS1976

Aircraft digital control design methods

Variations in design methods for aircraft digital flight control are evaluated and compared. The methods fall into two categories; those where the design is done in the continuous domain (or s plane) and those where the design is done in the discrete domain (or z plane). Design method fidelity is evaluated by examining closed loop root movement and the frequency response of the discretely controlled continuous aircraft. It was found that all methods provided acceptable performance for sample rates greater than 10 cps except the uncompensated s plane design method which was acceptable above 20 cps. A design procedure based on optimal control methods was proposed that provided the best fidelity at very slow sample rates and required no design iterations for changing sample rates.

Powell, J. D.↗