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At least 181 records · Page 10

Description of path-in-the-sky contact analog piloting display

A contact analog display called Path-In-The-Sky (PITS) integrates information on airplane attitude, airplane kinematic performance, navigation situation, and path prediction into one instrument. The pictorial format utilized in the PITS display concept was designed to reduce the required instrument scan and to simplify interpretation of informtion with the objective of reducing pilot work load. Described are the symbology of the PITS display, the coordinate systems used to generate the display, and the magnitudes of pertinent geometric characteristics selected during the display development. Also included are examples of the PITS display generated on a stand-alone graphics computer.

Knox, C. E.↗

Use of sensitivity analysis to predict pilot performance as a function of different displays

A technique for objectively evaluating different displays by sensitivity analysis is described. First, the mathematical model used to analyze static displays is developed. The technique is based on formulating functional relationships between the state variables and the variables observable in the display. The matrix of the partial derivatives of the display variables with respect to the state variables, together with the observer's acuity function, is used to calculate expected errors in the state vector estimation. The technique is expanded by the use of Kalman filtering to process a time series of observation vectors. This provides a tool for analyzing displays of dynamic processes by means of a dynamic display evaluation computer program. Results are reported using this program to simulate an Instrument Landing System approach.

Mout, M. L.↗

Recent flight test results using an electronic display format on the NASA B-737

This paper presents results of a flight evaluation of two electronic display formats for the approach-to-landing under instrument conditions. The evaluation was conducted for a baseline electronic display format and for the same format with runway symbology and track information added; its evaluation was conducted during 3-deg manual straight-in approaches with and without initial localizer offsets. Flight-path tracking performance data and pilot subjective comments were examined with regard to pilot's ability to capture and maintain the localizer and glide slope using both display fomats. The results of the flight tests agree with earlier simulation results and show that the addition of a perspective runway symbol with an extended centerline and relative track information to a baseline electronic display format improved both lateral and vertical flight-path tracking. Pilot comments indicated that the mental workload required to assess the approach situation was reduced as a result of integrating the perspective runway with extended centerline along with relative track information into the vertical situation display. The limited flight-test results also show that the flight-path performance with the integrated situation display format meets Category II Flight-Director performance criteria.

Morello, S. A.↗

Event-driven displays for manipulator control

The problem of constructing event-related information displays from multidimensional data generated by proximity, force-torque and tactile sensors integrated with the terminal device of a remotely controlled manipulator is considered. Event-driven displays are constructed by using appropriate algorithms acting on sensory data in real time. Event-driven information displays lessen the operator's workload and improve control performance. The paper describes and discusses several event-driven display examples that were implemented in the JPL teleoperator project, including a brief outline of the data handling system which drives the graphics display in real time. The paper concludes with a discussion of future plans to integrate event-driven displays with visual (TV) information.

Bejczy, A. K.↗

Cockpit displays of traffic information: Airline pilots opinions about content, symbology, and format

A number of candidate computer-generated cockpit displays of traffic information (CDTI) displays and display options were simulated statically and were shown to 23 airline pilots who were asked to respond to more than 250 questions about them. The pilots indicated that the amount and complexity of navigation information displayed should increase with altitude and map scale. Terrain information should appear automatically if a pilot's own aircraft descends below the minimum safe altitude and should include only those obstruction within 2,000 ft or less. Few pilots that weather information should be displayed on a CDTI, but if it was, it should be at pilot request only. A chevron-shaped symbol, located so that the majority of the map area was ahead was preferred. The position, altitude, ground speed, ground track, weight class, and flightpath history of other aircraft should be presented graphically by coding the shape of the symbol for other aircraft or presented digitally in data tags displayed at pilot request. All pilots thought that color coding was necessary to recognize different categories of information quickly and accurately. The majority of pilots felt that a CDTI would provide useful information even though its presence might increase their workload somewhat particularly during its introductory stages.

Hart, S. G.↗

Secondary visual workload capability with primary visual and kinesthetic-tactual displays

Subjects performed a cross-adaptive tracking task with a visual secondary display and either a visual or a quickened kinesthetic-tactual (K-T) primary display. The quickened K-T display resulted in superior secondary task performance. Comparisons of secondary workload capability with integrated and separated visual displays indicated that the superiority of the quickened K-T display was not simply due to the elimination of visual scanning. When subjects did not have to perform a secondary task, there was no significant difference between visual and quickened K-T displays in performing a critical tracking task.

Gilson, R. D.↗

Effects of magnification and visual accommodation on aimpoint estimation in simulated landings with real and virtual image displays

Twenty professional pilots observed a computer-generated airport scene during simulated autopilot-coupled night landing approaches and at two points (20 sec and 10 sec before touchdown) judged whether the airplane would undershoot or overshoot the aimpoint. Visual accommodation was continuously measured using an automatic infrared optometer. Experimental variables included approach slope angle, display magnification, visual focus demand (using ophthalmic lenses), and presentation of the display as either a real (direct view) or a virtual (collimated) image. Aimpoint judgments shifted predictably with actual approach slope and display magnification. Both pilot judgments and measured accommodation interacted with focus demand with real-image displays but not with virtual-image displays. With either type of display, measured accommodation lagged far behind focus demand and was reliably less responsive to the virtual images. Pilot judgments shifted dramatically from an overwhelming perceived-overshoot bias 20 sec before touchdown to a reliable undershoot bias 10 sec later.

Randle, R. J.↗

A tactual display aid for primary flight training

A means of flight instruction is discussed. In addition to verbal assistance, control feedback was continously presented via a nonvisual means utilizing touch. A kinesthetic-tactile (KT) display was used as a readout and tracking device for a computer generated signal of desired angle of attack during the approach and landing. Airspeed and glide path information was presented via KT or visual heads up display techniques. Performance with the heads up display of pitch information was shown to be significantly better than performance with the KT pitch display. Testing without the displays showed that novice pilots who had received tactile pitch error information performed both pitch and throttle control tasks significantly better than those who had received the same information from the visual heads up display of pitch during the test series of approaches to landing.

Gilson, R. D.↗

Performance evaluation of a kinesthetic-tactual display

Simulator studies demonstrated the feasibility of using kinesthetic-tactual (KT) displays for providing collective and cyclic command information, and suggested that KT displays may increase pilot workload capability. A dual-axis laboratory tracking task suggested that beyond reduction in visual scanning, there may be additional sensory or cognitive benefits to the use of multiple sensory modalities. Single-axis laboratory tracking tasks revealed performance with a quickened KT display to be equivalent to performance with a quickened visual display for a low frequency sum-of-sinewaves input. In contrast, an unquickened KT display was inferior to an unquickened visual display. Full scale simulator studies and/or inflight testing are recommended to determine the generality of these results.

Jagacinski, R. J.↗

Improving the MLS through enhanced cockpit displays

A simulator investigation of various prediction and quickening algorithms in computer-generated forward-looking displays is presented; the algorithms are used to improve manual aircraft control on curved microwave landing system approaches. The experimental facility consisted of a Link GAT-2 simulator, a PDP 11/40 minicomputer, a high-speed graphic display, a TV camera, and a CRT monitor. Results indicate that second- and third-order predictor displays provide the best lateral performance and that intermediate levels of prediction and quickening provide the best vertical control. Prediction/quickening algorithms of increasing computational order were found to significantly reduce aileron, rudder, and elevator control responses. The conventional crosspointer displays yielded an average 2-sigma lateral error of + or - 200 over all wind conditions at 500 m from touchdown, and was therefore unable to meet FAA requirements (+ or - 22.9 m); the pictorial-preview display yielded much better results: an average 2-sigma lateral error of + or - 27 m. Neither display was able to approach the FAA specified accuracy requirement in the vertical dimension (+ or - 3.7 m).

Jensen, R. S.↗

Frequency encoded auditory display of the critical tracking task

The use of auditory displays for selected cockpit instruments was examined. In auditory, visual, and combined auditory-visual compensatory displays of a vertical axis, critical tracking task were studied. The visual display encoded vertical error as the position of a dot on a 17.78 cm, center marked CRT. The auditory display encoded vertical error as log frequency with a six octave range; the center point at 1 kHz was marked by a 20-dB amplitude notch, one-third octave wide. Asymptotic performance on the critical tracking task was significantly better when using combined displays rather than the visual only mode. At asymptote, the combined display was slightly, but significantly, better than the visual only mode. The maximum controllable bandwidth using the auditory mode was only 60% of the maximum controllable bandwidth using the visual mode. Redundant cueing increased the rate of improvement of tracking performance, and the asymptotic performance level. This enhancement increases with the amount of redundant cueing used. This effect appears most prominent when the bandwidth of the forcing function is substantially less than the upper limit of controllability frequency.

Stevenson, J.↗

Automation of crew procedures using multifunction display and control systems

A multifunction display and control system (MFDCS) design concept has been developed for the Orbiter spacecraft. The system provides for automation of crew procedures, fault prioritization, incorporation of checklists and procedures into the display and control system and system flexibility in response to mission variation, increased experience and advancing display and control technology. Hardware included in the system includes a multifunction keyboard using programmable legend switches, a medium size flat panel display for presentation of alphanumeric information and a color CRT for the display of schematic diagrams. The access schema for the multifunction display and control system preserves the single function capability of the present set of dedicated switches while also providing for automation of many of the checklists and procedures. A basic design feature of the system is the ability to change the relative level of automation and crew interaction without modifying the system hardware or basic software operating system.

Spiger, R. J.↗

Optimal cooperative control synthesis of active displays

The utility of augmenting displays to aid the human operator in controlling high order complex systems is well known. Analytical evaluations of various display designs for a simple k/s-squared plant in a compensatory tracking task using an Optimal Control Model (OCM) of human behavior is carried out. This analysis reveals that significant improvement in performance should be obtained by skillful integration of key information into the display dynamics. The cooperative control synthesis technique previously developed to design pilot-optimal control augmentation is extended to incorporate the simultaneous design of performance enhancing augmented displays. The application of the cooperative control synthesis technique to the design of augmented displays is discussed for the simple k/s-squared plant. This technique is intended to provide a systematic approach to design optimally augmented displays tailored for specific tasks.

Garg, S.↗

Force/torque display for space teleoperation control experiments and evaluation

Experiments were performed at the Johnson Space Center (JSC), Manipulator Development Facility using the full scale Shuttle Remote Manipulator System (SRMS) to evaluate the effect of visual presentation through perspective display of the orthogonal forces and torques sensed at the manipulator end effector. The experiments investigated the effect of the display information on the management of forces and torques generated during payload berthing and deployment, as well as simulated satellite module change-out operations. The evaluation also addressed (1) issues of display format, including: force/torque scaling, point of resolution, and display mixing with video generated imagery, and (20) task related variables of payload size, alternative sources of guidance information, and control mode. The results are presented of a first-pass informal anlaysis of the analog, strip chart-recorded data from these evaluation tests. The results provide a relative measure of improvement in force management through the use of such a display, as well as information regarding the impact of display variables and task demands on operator performance.

Corker, K.↗

Optimal cooperative control synthesis of active displays

The utility of augmenting displays to aid the human operator in controlling high order complex systems is well known. Analytical evaluation of various display designs for a simple k/s sup 2 plant in a compensatory tracking task using an optimal Control Model (OCM) of human behavior is carried out. This analysis reveals that significant improvement in performance should be obtained by skillful integration of key information into the display dynamics. The cooperative control synthesis technique previously developed to design pilot-optimal control augmentation is extended to incorporate the simultaneous design of performance enhancing augmented displays. The application of the cooperative control synthesis technique to the design of augmented displays is discussed for the simple k/s sup 2 plant. This technique is intended to provide a systematic approach to design optimally augmented displays tailored for specific tasks.

Garg, S.↗

Raster graphics display library

The Raster Graphics Display Library (RGDL) is a high level subroutine package that give the advanced raster graphics display capabilities needed. The RGDL uses FORTRAN source code routines to build subroutines modular enough to use as stand-alone routines in a black box type of environment. Six examples are presented which will teach the use of RGDL in the fastest, most complete way possible. Routines within the display library that are used to produce raster graphics are presented in alphabetical order, each on a separate page. Each user-callable routine is described by function and calling parameters. All common blocks that are used in the display library are listed and the use of each variable within each common block is discussed. A reference on the include files that are necessary to compile the display library is contained. Each include file and its purpose are listed. The link map for MOVIE.BYU version 6, a general purpose computer graphics display system that uses RGDL software, is also contained.

Grimsrud, Anders↗

Quantitative evaluation of perspective and stereoscopic displays in three-axis manual tracking tasks

Optimal presentation of three-dimensional information on a two-dimensional display screen requires careful design of the projection to the display surface. Monoscopic perspective projection alone is usually not sufficient to represent three-dimensional spatial information. It can, however, be improved by the adjustment of perspective parameters and by geometric visual enhancements such as reference lines and a background grid. Stereoscopic display is another method of providing three-dimensional information to the human operator. Two experiments are performed with three-axis manual tracking tasks. The first experiment investigates the effects of perspective parameters on tracking performance. The second experiment investigates the effects of visual enhancements for both monoscopic and stereoscopic displays. Results indicate that, although stereoscopic displays do generally permit superior tracking performance, monoscopic displays can allow equivalent performance when they are defined with optimal perspective parameters and provided with adequate visual enhancements.

Ellis, Stephen R.↗

Preliminary results of a flight investigation of rotorcraft control and display laws for hover

A flight experiment designed to evaluate the effects of compatible versus incompatible display and control system response characteristics, and to evaluate a candidate display law design methodology, is described. The experiment was conducted on the NASA/Army CH-47B variable-stability helicopter using its model-following control system and a color, panel-mounted display. Three control response types representative of modern highly augmented rotorcraft and three corresponding sets of display dynamics were considered for three hover and low-speed tasks performed in simulated instrument conditions. Preliminary results based on pilot handling qualities ratings and comments indicate that performance and workload can be significantly affected by certain control and display combinations and that the display design methodology shows promise for improving the handling qualities of rotorcraft operating in conditions of low visibility.

Eshow, Michelle M.↗