Gaze-contingent multiresolutional displays (GCMRDs) center high-resolution information on the user's gaze position, matching the user's area of interest (AOI). Image resolution and details outside the AOI are reduced, lowering the requirements for processing resources and transmission bandwidth in demanding display and imaging applications. This review provides a general framework within which GCMRD research can be integrated, evaluated, and guided. GCMRDs (or "moving windows") are analyzed in terms of (a) the nature of their images (i.e., "multiresolution," "variable resolution," "space variant," or "level of detail"), and (b) the movement of the AOI (i.e., "gaze contingent," "foveated," or "eye slaved"). We also synthesize the known human factors research on GCMRDs and point out important questions for future research and development. Actual or potential applications of this research include flight, medical, and driving simulators; virtual reality; remote piloting and teleoperation; infrared and indirect vision; image transmission and retrieval; telemedicine; video teleconferencing; and artificial vision systems.

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Gaze-contingent multiresolutional displays: an integrative review.

The objective of this study was to evaluate differences in driving performance, visual detection performance, and eye-scanning behavior between glaucoma patients and control participants without glaucoma. Glaucoma patients (n = 23) and control participants (n = 12) completed four 5-min driving sessions in a simulator. The participants were instructed to maintain the car in the right lane of a two-lane highway while their speed was automatically maintained at 100 km/h. Additional tasks per session were: Session 1: none, Session 2: verbalization of projected letters, Session 3: avoidance of static obstacles, and Session 4: combined letter verbalization and avoidance of static obstacles. Eye-scanning behavior was recorded with an eye-tracker. Results showed no statistically significant differences between patients and control participants for lane keeping, obstacle avoidance, and eye-scanning behavior. Steering activity, number of missed letters, and letter reaction time were significantly higher for glaucoma patients than for control participants. In conclusion, glaucoma patients were able to avoid objects and maintain a nominal lane keeping performance, but applied more steering input than control participants, and were more likely than control participants to miss peripherally projected stimuli. The eye-tracking results suggest that glaucoma patients did not use extra visual search to compensate for their visual field loss. Limitations of the study, such as small sample size, are discussed.

/pdf/obstacle-avoidance-visual-detection-performance-and-eye-3mqbgtg7e9.pdf

Obstacle avoidance, visual detection performance, and eye-scanning behavior of glaucoma patients in a driving simulator: A preliminary study

Head-mounted displays

This study investigated how human locomotion through an obstacle environment is influenced by visual field limitation. Participants were asked to walk at a comfortable pace to a target location while avoiding multiple vertical objects. During this task, they wore goggles restricting their visual field to small (S: 40° × 25°), medium (M: 80° × 60°), large (L: 115° × 90°), or unlimited (U) visual field sizes. Full-body motion capture was used to extract for each trial the mean speed, pathlength, mean step width, magnitude of head rotation and head mean angular speed. The results show that compared with the U condition, the M and L conditions caused participants to select a wider path around the obstacles without slowing down or altering step width. However, the S condition did slow down the participants, and increased both their step width and path length. We conclude that only for the S condition, balancing problems were substantial enough to spend more energy associated with increased step width. In all cases, participants choose to optimize safety (collision avoidance) at the cost of spending more energy.

https://link.springer.com/content/pdf/10.1007%2Fs00221-011-2757-1.pdf

Human locomotion through a multiple obstacle environment: strategy changes as a result of visual field limitation.

Effects of field-of-view restrictions on the speed and accuracy of participants performing a real-world manoeuvring task through an obstacled environment were investigated. Although field-of-view restrictions are known to affect human behaviour and to degrade performance for a range of different tasks, the relationship between human manoeuvring performance and field-of-view size is not known This knowledge is essential to evaluate a trade-off befween human performance, cost, and ergonomic aspects of field-of-view limiting devises like head-mounted displays and night vision goggles which are frequently deployed for tasks involving human motion through environments with obstacles. In this study the speed and accutacy of movement were measured in 15 participants (8 men,7 women, 22.9+2.8 yr. of age) traversing a course formed by three wall segments for different field-of-view testricdons. Analysis showed speed decreased linearly with decreasing field-of-view extent, while accuracy was consistently reduced for all restricted field-of-view conditions. Present results may be used to evaluate cost and performance trade-offs for field-of-view resricting devices deployed to perform timelimited human-locomotion tasks in complex structured environments, such as night-vision goggles and head-mounted displays.

Effects of field-of-view restrictions on speed and accuracy of manoeuvring

The Aeroflightdynamics Directorate of the US Army's Aviation Research, Development and Engineering Center initiated a study to determine the effects of limiting a rotorcraft pilot's field-of-view (FOV) on performance and workload. Pilot FOV was restricted to simulate current and next generation helmet mounted display FOVs used in night vision systems. A helmet visor was constructed for this test to restrict the horizontal peripheral limits of the square shaped FOV to values of 100, 80, 60, 40, and 20 degrees. The vertical limits and overlap were held constant to 40 degrees (except for the 20 degree FOV). Six pilots executed a series of prescribed low altitude maneuvers with an instrumented NAH-IS (Cobra) rotorcraft at the Crows Landing Airfield located in California. The aircraft flight path was measured with a laser tracker. On board data was recorded, as well as pilot handling quality ratings and visual cue ratings. This test is not yet complete, but some preliminary observations and results are provided. It was observed that reducing FOV increased the difficulty of controlling the aircraft and altered head movement. Reducing FOV also diminished the pilots' situational awareness. The reduction in situational awareness affected the ability of the pilots to provide an accurate report of their own flying performance, and the ability to observe warning indicators inside the cockpit.

Effect of field-of-view restriction on rotocraft pilot workload and performance: preliminary results

: A great deal of interest has been shown in the literature in the development of new Non-Destructive Techniques (NDT). In particular, there is increasing interest in detecting, evaluating and locating cracks as well as the source of the impact causing these cracks. Fuzzy logic was shown to be useful in crack detection, and severity of crack in materials. In this paper Fuzzy logic has been used in NDT applications for identification of source of impact on the ceramic plates. Through the experimental techniques described in this paper we show that fuzzy logic can be used successfully for this purpose. The proposed methodology has been implemented as a Mamdani Fuzzy Inference System (FIS) using the Fuzzy Logic Toolbox in MATLAB.

/pdf/fuzzy-logic-approach-for-impact-source-identification-in-49vb7bnxs7.pdf

Fuzzy Logic Approach for Impact Source Identification in Ceramic Plates.

: A method for evaluating the stability of a metric for determining the health of armor plates is presented. The metric is based on the following basic premise: The amplitudes and locations of the major vibrational modes of an undamaged armor plate constitute a basic ?signature? of the armor plate. Damaging the armor plate should cause changes to both the amplitude and position of the significant vibrational modes. A metric has been developed to exploit these changes in order to distinguish between an undamaged and a damaged plate.

/pdf/evaluating-the-stability-of-a-metric-for-determining-the-4kanmsx5cl.pdf

Evaluating the Stability of a Metric for Determining the Health of Armor Plates

: A method for crack and damage detection in ceramic composite plate armors is presented. The method uses embedded piezoelectric Lead Zirconate Titanate (PZT) transducers to characterize the vibrational modes of composite armor plates. The amplitudes of the vibrational modes of damaged and undamaged plates are shown to be distinct. The differences in the vibration modes can be exploited to detect cracks and damage. Composite armor plates for testing are damaged by impact with a certain caliber round. Data from these tests can be used to design a vehicle based system for the nondestructive testing (NDT) and health monitoring of the armor plate structural integrity.

Damage Detection in Composite Plate Armor Using Ultrasonic Techniques

Problem of crack detection has attracted the attention of several investigators in the areas like defense, aeronautics, and
marine industries. In this paper we suggest fuzzy logic approach for detection of cracks and also deciding about the
severity of the crack. The data obtained from data acquisition system is processed and results presented by using various
software. Fuzzy rules are developed to determine the severity of the crack and a light controller used to indicate the
severity of the crack. The simplicity of the approach makes it very useful in many fields.

https://apps.dtic.mil/dtic/tr/fulltext/u2/a528479.pdf

Thomas Reynolds

Papers

Effect of field-of-view restriction on rotocraft pilot workload and performance: preliminary results

Fuzzy Logic Approach for Impact Source Identification in Ceramic Plates.

Evaluating the Stability of a Metric for Determining the Health of Armor Plates

Damage Detection in Composite Plate Armor Using Ultrasonic Techniques

Fuzzy Logic for Determination of Crack Severity in Defense Applications