Hyperstereopsis in helmet-mounted NVDs: time to contact estimation

Flanagan, Patrick; Stuart, G. W.; Gibbs, Peter

doi:10.1117/12.719115

Cited by 7 publications

(6 citation statements)

References 2 publications

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“…Recently, experiments have been carried out in order show to what degree exectly the effects influence the pilot. [1][2][3][4][5][6][7][8] Some of these studies support the thesis that a trained pilot can adapt to the situation quickly. Furthermore, the idea to combine modern image processing capabilities with hyperstereo sensors has been investigated in order to perceive terrain drop-offs.…”

Section: Introductionmentioning

confidence: 67%

Correcting hyperstereopsis in a helmet-mounted vision system

Peinecke

Schmerwitz

2010

SPIE Proceedings

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When used in conjunction with helmet mounted displays stereo camera views can provide invaluable advantages in, for example, aviation uses. One of the most common setups is to mount cameras to both sides of the pilot's helmet. However, since these cameras posses a larger disparity than the eyes distances to perceived objects are misinterpreted by the pilot. This may cause irritations, even sickness when combined with enhanced displays. Even in the best case the magnified disparity may lead to exaggerated distance estimations. In this paper simple computations are presented that can correct hyperstereopsis "on the fly". With the availability of fast computer hardware carrying out these computations in real time comes into reach. Furthermore, we sketch a series of experiments to evaluate the effectiveness of our approach.

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Section: Introductionmentioning

confidence: 67%

Correcting hyperstereopsis in a helmet-mounted vision system

Peinecke

Schmerwitz

2010

SPIE Proceedings

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“…However, height and rate of closure estimation remained problematical throughout both studies, although, once again, there seemed to be adjustment with increasing flight experience. For further discussion of these issues see Gibbs (2007a and2007b) and Stuart et al (2009).…”

Section: C2t Jul 30 2008mentioning

confidence: 98%

Flight performance using a hyperstereo helmet-mounted display: post-flight debriefing questionnaire

et al. 2009

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Helmet-mounted display (HMD) designs have faced persistent head-supported mass and center of mass (CM) problems, especially HMD designs like night vision goggles (NVG) that utilize image intensification (I 2 ) sensors mounted forward in front of the user's eyes. Relocating I 2 sensors from the front to the sides of the helmet, at or below the transverse plane through the user's head CM, can resolve most of the CM problems. However, the resulting increase in the separation between the two I 2 channels effectively increases the user's interpupillary distance (IPD). This HMD design is referred to as a hyperstero design and introduces the phenomenon of hyperstereopsis, a type of visual distortion where stereoscopic depth perception is exaggerated, particularly at distances under 200 feet (~60 meters). The presence of hyperstereopsis has been a concern regarding implementation of hyperstereo HMDs for rotary-wing aircraft. To address this concern, a flight study was conducted to assess the impact of hyperstereopsis on aircraft handling proficiency and pilot acceptance. Three rated aviators with differing levels of I 2 and hyperstereo HMD experience conducted a series of flights that concentrated on low-level maneuvers over a two-week period. Initial and final flights were flown with a standard issue I 2 device and a production hyperstereo design HMD. Interim flights were flown only with the hyperstereo HMD. Two aviators accumulated 8 hours of flight time with the hyperstereo HMD, while the third accumulated 6.9 hours. This paper presents data collected via written questionnaires completed by the aviators during the post-flight debriefings. These data are compared to questionnaire data from a previous flight investigation in which aviators in a copilot capacity, hands not on the flight controls, accumulated 8 flight hours of flight time using a hyperstereo HMD.

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“…The average human IPD is approximately 64mm whereas the separation of input sources on the TopOwl system is 286mm (effectively four times normal IPD) (2,24) . Hyperstereopsis is the result of fusing two images of an object into a single percept when each image results from a different lateral perspective separated by a distance greater than the IPD, leading to exaggerated lateral dimensionality (25,26) . The phenomenon arises due to a discrepancy in the convergence angle to an object from the horizontally-displaced inputs compared to the 'normal' IPD (10,27) (Fig.…”

Section: Hyperstereopsismentioning

confidence: 99%

Visual aspects of advanced sensors and helmet-mounted displays

Morgan-Warren

Woodcock

2014

Aeronaut. j. (1968)

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Visually coupled systems such as helmet mounted displays are designed to improve aircrew situational awareness by providing timely flight, targeting and other information overlaid on real or sensor-derived views of the external environment. Data can be presented in monocular, biocular or binocular fashion and are associated with visual conflicts and potential ophthalmic problems. Restricted sensor spectrum, limits of resolution, inherent system latency, the displaced visual input from remote sensors and restricted field of view may contribute to ophthalmic symptoms in aircrew. Disruption to binocularity and reliance on monocular cues for depth perception and hyperstereopsis from sensor-induced convergence disparity may cause distance estimation problems, whereas inappropriate accommodative stimuli and ocular dominance factors are common causes of eyestrain. Binocular rivalry from discordant imagery to each eye may compromise visual performance via several mechanisms. This article discusses the potential visual problems associated with visually coupled systems and the challenges of integrating complex systems with the aircrew interface.

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Hyperstereopsis in helmet-mounted NVDs: time to contact estimation

Cited by 7 publications

References 2 publications

Correcting hyperstereopsis in a helmet-mounted vision system

Correcting hyperstereopsis in a helmet-mounted vision system

Flight performance using a hyperstereo helmet-mounted display: post-flight debriefing questionnaire

Visual aspects of advanced sensors and helmet-mounted displays

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