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At least 73 records · Page 4

Enhanced Vision Flight Deck Technology for Commercial Aircraft Low-Visibility Surface Operations

NASA Langley Research Center and the FAA collaborated in an effort to evaluate the effect of Enhanced Vision (EV) technology display in a commercial flight deck during low visibility surface operations. Surface operations were simulated at the Memphis, TN (FAA identifier: KMEM) air field during nighttime with 500 Runway Visual Range (RVR) in a high-fidelity, full-motion simulator. Ten commercial airline flight crews evaluated the efficacy of various EV display locations and parallax and mini cation effects. The research paper discusses qualitative and quantitative results of the simulation experiment, including the effect of EV display placement on visual attention, as measured by the use of non-obtrusive oculometry and pilot mental workload. The results demonstrated the potential of EV technology to enhance situation awareness which is dependent on the ease of access and location of the displays. Implications and future directions are discussed.

Arthur, Jarvis J., III↗

Fidelity assessment of a UH-60A simulation on the NASA Ames vertical motion simulator

Helicopter handling qualities research requires that a ground-based simulation be a high-fidelity representation of the actual helicopter, especially over the frequency range of the investigation. This experiment was performed to assess the current capability to simulate the UH-60A Black Hawk helicopter on the Vertical Motion Simulator (VMS) at NASA Ames, to develop a methodology for assessing the fidelity of a simulation, and to find the causes for lack of fidelity. The approach used was to compare the simulation to the flight vehicle for a series of tasks performed in flight and in the simulator. The results show that subjective handling qualities ratings from flight to simulator overlap, and the mathematical model matches the UH-60A helicopter very well over the range of frequencies critical to handling qualities evaluation. Pilot comments, however, indicate a need for improvement in the perceptual fidelity of the simulation in the areas of motion and visual cuing. The methodology used to make the fidelity assessment proved useful in showing differences in pilot work load and strategy, but additional work is needed to refine objective methods for determining causes of lack of fidelity.

Atencio, Adolph, Jr.↗

Simulation Technology at NASA

NASA Ames Research Center is home to several high-fidelity research flight and air-traffic control simulation facilities which, together with an experienced workforce, produce high-quality research data and findings that have proven to be applicable in the real world. These assets include the Vertical Motion Simulator (VMS), Crew Vehicle Systems Research Facility (CVSRF), Future Flight Central (FFC) air traffic control tower simulator, and several air-traffic control (ATC) simulators. The VMS combines a high-fidelity simulation capability with an adaptable simulation environment, enabling customization for numerous human-in-the-loop research applications. The distinctive feature of the VMS is its unparalleled large amplitude, high-fidelity motion capability. In over 30 years of continuous operation, the VMS has contributed significantly to the body of knowledge in a range of disciplines directly benefiting several aerospace programs and flight safety, including the design and development of flight control systems for the Joint Strike Fighter, Space Shuttle Orbiter, and rotorcraft. It continues to be used for researching new vehicle configurations, vehicle control and safety, transfer-of-training, etc., by NASA, other government agencies, and Industry.The CVSRF includes two motion-based flight simulators: a Boeing 747-400 full flight simulator and the reconfigurable Advanced Concepts Flight Simulator (ACFS). These simulators are primarily used to research air-traffic management concepts and procedures, advanced navigation and avionics concepts, and cockpit human factors. FFC is a full-sized control tower simulator with a 360-degree external field-of-view display system and reconfigurable system architecture. FFC and the ATC simulators are used for testing air-traffic management automation and decision support tools and demonstrate their feasibility in a realistic environment prior to technology transfer for implementation in the National Airspace System (NAS).To support integrated simulations and flight-tests for NASA's Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) Project, NASA developed a distributed test environment incorporating Live, Virtual, Constructive, (LVC) concepts. Development of the software enabling the LVC is conducted primarily at the Distributed Simulation Research Lab (DSRL) at NASA Ames. The LVC components provide the core infrastructure supporting simulation of UAS operations by integrating live and virtual aircraft in a realistic air traffic environment. This provides the ability to conduct tests more efficiently by promoting the use of existing distributed assets. The LVC infrastructure was used in several human-in-the-loop simulations to evaluate acceptance of Detect and Avoid (DAA) advisories used by UAS pilots to maintain well clear of other virtual traffic and to negotiate maneuvers with air traffic control. It is currently being used to support testing of self-separation algorithms between unmanned and manned aircraft in live flight. Further simulations with more comprehensive air traffic scenarios mixing live and virtual aircraft is planned.In the current fiscal environment, maintaining and upgrading these high-fidelity simulation assets and retaining the skilled workforce necessary to meet future research needs is the primary non-technical challenge.

CVSRF↗

Helicopter simulation technology: An Ames Research Center perspective

The total experience for evidence regarding the levels of motion and visual cueing fidelity required for handling-qualities research in ground-based simulators is reviewed. Positive contributions of cockpit motion were identified, but much remains to be learned regarding the sensitivities of individual control modes to cueing attenuation. A firmer understanding of the pilot's utilization of visual and motion cues is the key to more efficient use of simulation in helicopter control-systems research.

Bray, R. S.↗

Visual information processing; Proceedings of the Meeting, Orlando, FL, Apr. 20-22, 1992

Topics discussed in these proceedings include nonlinear processing and communications; feature extraction and recognition; image gathering, interpolation, and restoration; image coding; and wavelet transform. Papers are presented on noise reduction for signals from nonlinear systems; driving nonlinear systems with chaotic signals; edge detection and image segmentation of space scenes using fractal analyses; a vision system for telerobotic operation; a fidelity analysis of image gathering, interpolation, and restoration; restoration of images degraded by motion; and information, entropy, and fidelity in visual communication. Attention is also given to image coding methods and their assessment, hybrid JPEG/recursive block coding of images, modified wavelets that accommodate causality, modified wavelet transform for unbiased frequency representation, and continuous wavelet transform of one-dimensional signals by Fourier filtering.

Huck, Friedrich O.↗

Spacesuit and Space Vehicle Comparative Ergonomic Evaluation

With the advent of the latest manned spaceflight objectives, a series of prototype launch and reentry spacesuit architectures were evaluated for eventual down selection by NASA based on the performance of a set of designated tasks. A consolidated approach was taken to testing, concurrently collecting suit mobility data, seat-suit-vehicle interface clearances and movement strategies within the volume of a Multi-Purpose Crew Vehicle mockup. To achieve the objectives of the test, a requirement was set forth to maintain high mockup fidelity while using advanced motion capture technologies. These seemingly mutually exclusive goals were accommodated with the construction of an optically transparent and fully adjustable frame mockup. The mockup was constructed such that it could be dimensionally validated rapidly with the motion capture system. This paper will describe the method used to create a motion capture compatible space vehicle mockup, the consolidated approach for evaluating spacesuits in action, as well as the various methods for generating hardware requirements for an entire population from the resulting complex data set using a limited number of test subjects. Kinematics, hardware clearance, suited anthropometry, and subjective feedback data were recorded on fifteen unsuited and five suited subjects. Unsuited subjects were selected chiefly by anthropometry, in an attempt to find subjects who fell within predefined criteria for medium male, large male and small female subjects. The suited subjects were selected as a subset of the unsuited subjects and tested in both unpressurized and pressurized conditions. Since the prototype spacesuits were fabricated in a single size to accommodate an approximately average sized male, the findings from the suit testing were systematically extrapolated to the extremes of the population to anticipate likely problem areas. This extrapolation was achieved by first performing population analysis through a comparison of suited subjects performance to their unsuited performance and then applying the results to the entire range of population. The use of a transparent space vehicle mockup enabled the collection of large amounts of data during human-in-the-loop testing. Mobility data revealed that most of the tested spacesuits had sufficient ranges of motion for tasks to be performed successfully. A failed tasked by a suited subject most often stemmed from a combination of poor field of view while seated and poor dexterity of the gloves when pressurized or from suit/vehicle interface issues. Seat ingress/egress testing showed that problems with anthropometric accommodation does not exclusively occur with the largest or smallest subjects, but rather specific combinations of measurements that lead to narrower seat ingress/egress clearance.

England, Scott↗

High Fidelity Modeling of SRP and Its Effect on the Relative Motion of Starshade and WFIRST

In this paper we perform a detailed analysis of how Solar Radiation Pressure (SRP) affects the relative motion of two spacecrafts, the Wide-Field Infrared Survey Telescope (WFIRST) and Starshade, orbiting in the vicinity of the Sun-Earth L2. While WFIRST orbits about its own Libration Point Orbit (LPO), Starshade will fly a specific trajectory to align with WFIRST and observe a Design Reference Mission of pre-determined target stars. In this analysis, we focus on the transfer orbit for Starshade from one observation to the other. We will describe how SRP affects the dynamics of the Starshade relative to WFIRSTand how relevant this effect is in order to get an accurate estimate of the total difference in velocity (delta v).

WFIRST↗

Methodology development for evaluation of selective-fidelity rotorcraft simulation

This paper addressed the initial step toward the goal of establishing performance and handling qualities acceptance criteria for realtime rotorcraft simulators through a planned research effort to quantify the system capabilities of 'selective fidelity' simulators. Within this framework the simulator is then classified based on the required task. The simulator is evaluated by separating the various subsystems (visual, motion, etc.) and applying corresponding fidelity constants based on the specific task. This methodology not only provides an assessment technique, but also provides a technique to determine the required levels of subsystem fidelity for a specific task.

Lewis, William D.↗

Pilot/vehicle model analysis of visual and motion cue requirements in flight simulation

The optimal control model for pilot/vehicle analysis is used to explore the effects of a CGI visual system and motion system dynamics on helicopter hover simulation fidelity. This is accomplished by expanding the perceptual aspects of the model to include motion sensing and by relating CGI parameters to information processing parameters of the model. Simulator fidelity is examined by comparing predicted performance and workload for flight with that predicted for various simulator configuration. The results of the analysis suggest that simulator deficiencies or a reasonable nature (by current standards) can result in substantial performance and/or workload infidelity. Both CGI and motion system effects are significant for this task. There is also a distinct interaction between the two sources of pilot cues. In particular, the presence of motion reduces the sensitivity to CGI limitations.

Lancraft, R.↗

Improvements to the adaptive maneuvering logic program

The Adaptive Maneuvering Logic (AML) computer program simulates close-in, one-on-one air-to-air combat between two fighter aircraft. Three important improvements are described. First, the previously available versions of AML were examined for their suitability as a baseline program. The selected program was then revised to eliminate some programming bugs which were uncovered over the years. A listing of this baseline program is included. Second, the equations governing the motion of the aircraft were completely revised. This resulted in a model with substantially higher fidelity than the original equations of motion provided. It also completely eliminated the over-the-top problem, which occurred in the older versions when the AML-driven aircraft attempted a vertical or near vertical loop. Third, the requirements for a versatile generic, yet realistic, aircraft model were studied and implemented in the program. The report contains detailed tables which make the generic aircraft to be either a modern, high performance aircraft, an older high performance aircraft, or a previous generation jet fighter.

Burgin, George H.↗

Assessment of simulation fidelity using measurements of piloting technique in flight. II

Two components of the Vertical Motion Simulator (presently being used to assess the fidelity of UH-60A simulation) are evaluated: (1) the dash/quickstop Nap-of-the-earth (NOE) piloting task, and (2) the bop-up task. Data from these two flight test experiments are presented which provide information on the effect of reduced visual field of view, variation in scene content and texture, and the affect of pure time delay in the closed-loop pilot response. In comparison with task performance results obtained in flight tests, the results from the simulation indicate that the pilot's NOE task performance in the simulator is significantly degraded.

Ferguson, S. W.↗

Effect of motion cues during complex curved approach and landing tasks: A piloted simulation study

A piloted simulation study was conducted to examine the effect of motion cues using a high fidelity simulation of commercial aircraft during the performance of complex approach and landing tasks in the Microwave Landing System (MLS) signal environment. The data from these tests indicate that in a high complexity MLS approach task with moderate turbulence and wind, the pilot uses motion cues to improve path tracking performance. No significant differences in tracking accuracy were noted for the low and medium complexity tasks, regardless of the presence of motion cues. Higher control input rates were measured for all tasks when motion was used. Pilot eye scan, as measured by instrument dwell time, was faster when motion cues were used regardless of the complexity of the approach tasks. Pilot comments indicated a preference for motion. With motion cues, pilots appeared to work harder in all levels of task complexity and to improve tracking performance in the most complex approach task.

Scanlon, Charles H.↗

Vertical motion requirements for landing simulation

Tests were conducted to determine the significance of vertical acceleration cues in the simulation of the visual approach and landing maneuver. Landing performance measures were obtained for four subject pilots operating a visual landing simulation device which provides up to plus or minus 40 feet of vertical motion. Test results indicate that vertical motion cues are utilized in the landing task, and that they are particularly important in the simulation of aircraft with marginal longitudinal handling qualities. To assure vertical motion cues of the desired fidelity in the landing tasks, it appears that a simulator must have excursion capabilities of at least plus or minus 20 feet.

Bray, R. S.↗

A study of vertical motion requirements for landing simulation

Tests were conducted to determine the significance of vertical acceleration cues in the simulation of the visual approach and landing maneuver. Landing performance measures were obtained for four subject pilots operating a visual landing simulation mechanized in the Ames Height Control Test Apparatus, a device that provides up to plus or minus 40 ft of vertical motion. Test results indicate that vertical motion cues are utilized in the landing task, and that they are particularly important in the simulation of aircraft with marginal longitudinal-handling qualities. To assure vertical motion cues of the desired fidelity in the landing task, it appears, that a simulator must have excursion capabilities of at least 20 ft in either direction.

Bray, R. S.↗

Evaluation of Drogue Parachute Damping Effects Utilizing the Apollo Legacy Parachute Model

Drogue parachute damping is required to dampen the Orion Multi Purpose Crew Vehicle (MPCV) crew module (CM) oscillations prior to deployment of the main parachutes. During the Apollo program, drogue parachute damping was modeled on the premise that the drogue parachute force vector aligns with the resultant velocity of the parachute attach point on the CM. Equivalent Cm(sub q) and Cm(sub alpha) equations for drogue parachute damping resulting from the Apollo legacy parachute damping model premise have recently been developed. The MPCV computer simulations ANTARES and Osiris have implemented high fidelity two-body parachute damping models. However, high-fidelity model-based damping motion predictions do not match the damping observed during wind tunnel and full-scale free-flight oscillatory motion. This paper will present the methodology for comparing and contrasting the Apollo legacy parachute damping model with full-scale free-flight oscillatory motion. The analysis shows an agreement between the Apollo legacy parachute damping model and full-scale free-flight oscillatory motion.

Currin, Kelly M.↗

Man-systems evaluation of moving base vehicle simulation motion cues

A motion cue investigation program is reported that deals with human factor aspects of high fidelity vehicle simulation. General data on non-visual motion thresholds and specific threshold values are established for use as washout parameters in vehicle simulation. A general purpose similator is used to test the contradictory cue hypothesis that acceleration sensitivity is reduced during a vehicle control task involving visual feedback. The simulator provides varying acceleration levels. The method of forced choice is based on the theory of signal detect ability.

Kirkpatrick, M.↗

Vertical Motion Simulator Experiment on Stall Recovery Guidance

A stall recovery guidance system was designed to help pilots improve their stall recovery performance when the current aircraft state may be unrecognized under various complicating operational factors. Candidate guidance algorithms were connected to the split-cue pitch and roll flight directors that are standard on large transport commercial aircraft. A new thrust guidance algorithm and cue was also developed to help pilots prevent the combination of excessive thrust and nose-up stabilizer trim. The overall system was designed to reinforce the current FAA recommended stall recovery procedure. A general transport aircraft model, similar to a Boeing 757, with an extended aerodynamic database for improved stall dynamics simulation fidelity was integrated into the Vertical Motion Simulator at NASA Ames Research Center. A detailed study of the guidance system was then conducted across four stall scenarios with 30 commercial and 10 research test pilots, and the results are reported.

Schuet, Stefan↗

A high fidelity video delivery system for real-time flight simulation research

The Flight Systems and Simulation Research Laboratory (Simlab) at the NASA Ames Research Center, utilizes an extensive network of video image generation, delivery, processing, and display systems coupled with a large amplitude Vertical Motion Simulator (VMS) to provide a high fidelity visual environment for flight simulation research. This paper will explore the capabilities of the current Simlab video distribution system architecture with a view toward technical solutions implemented to resolve a variety of video interface, switching, and distribution issues common to many simulation facilities. Technical discussions include a modular approach to a video switching and distribution system capable of supporting both coax and fiber optic video signal transmission, video scan conversion and processing techniques for lab observation and recording, adaptation of image generation and display system video interfaces to industry standards, an all raster solution for 'glass cockpit' configurations encompassing Head up, Head-down, and Out-the-Window display systems.

Wilkins, Daniel A.↗