Dr. Bernd Lorenz Profile

Dr. Bernd Lorenz

at DLR

SPIE Involvement:

Author

Publications (6)

Proceedings Article | 19 May 2006 Paper

Investigating the benefits of scene linking for a pathway HMD: from laboratory flight experiments to flight tests

Sven Schmerwitz, Helmut Többen, Bernd Lorenz, Tomoko Iijima, Anthea Kuritz-Kaiser

Proceedings Volume 6226, 62260Q (2006) https://doi.org/10.1117/12.674775

KEYWORDS: Head-mounted displays, Heads up displays, Visualization, Head, Optical tracking, Switching, 3D displays, Retinal scanning, Target detection, Atomic force microscopy

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Pathway-in-the-sky displays enable pilots to accurately fly difficult trajectories. However, these displays may drive pilots' attention to the aircraft guidance task at the expense of other tasks particularly when the pathway display is located head-down. A pathway HUD may be a viable solution to overcome this disadvantage. Moreover, the pathway may mitigate the perceptual segregation between the static near domain and the dynamic far domain and hence, may improve attention switching between both sources. In order to more comprehensively overcome the perceptual near-to-far domain disconnect alphanumeric symbols could be attached to the pathway leading to a HUD design concept called 'scene-linking'. Two studies are presented that investigated this concept. The first study used a simplified laboratory flight experiment. Pilots (N=14) flew a curved trajectory through mountainous terrain and had to detect display events (discrete changes in a command speed indicator to be matched with current speed) and outside scene events (hostile SAM station on ground). The speed indicators were presented in superposition to the scenery either in fixed position or scene-linked to the pathway. Outside scene event detection was found improved with scene linking, however, flight-path tracking was markedly deteriorated. In the second study a scene-linked pathway concept was implemented on a monocular retinal scanning HMD and tested in real flights on a Do228 involving 5 test pilots. The flight test mainly focused at usability issues of the display in combination with an optical head tracker. Visual and instrument departure and approach tasks were evaluated comparing HMD navigation with standard instrument or terrestrial navigation. The study revealed limitations of the HMD regarding its see-through capability, field of view, weight and wearing comfort that showed to have a strong influence on pilot acceptance rather than rebutting the approach of the display concept as such.

Proceedings Article | 25 May 2005 Paper

Design of a pathway display for a retinal scanning HMD

Helmut Tobben, Bernd Lorenz, Sven Schmerwitz

Proceedings Volume 5802, (2005) https://doi.org/10.1117/12.603701

KEYWORDS: Head-mounted displays, Heads up displays, Visualization, Head, Retinal scanning, Eye, Image quality, Switching, Collimation, Radar

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Proceedings Article | 25 May 2005 Paper

Human performance evaluation of a pathway HMD

Bernd Lorenz, Helmut Tobben, Sven Schmerwitz

Proceedings Volume 5802, (2005) https://doi.org/10.1117/12.603280

KEYWORDS: Heads up displays, Head-mounted displays, Visualization, Head, Error analysis, Image fusion, 3D displays, Information visualization, Optical tracking, Stars

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Proceedings Article | 11 August 2004 Paper

Crew coordination issues of EVS approaches

Bernd Lorenz, Bernd Korn

Proceedings Volume 5424, (2004) https://doi.org/10.1117/12.554449

KEYWORDS: Heads up displays, Radar, Visualization, Reflectors, Image segmentation, Extremely high frequency, Visibility, Visibility through fog, Switches, Sensors

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Enhanced Vision Systems (EVS) are currently developed with the goal to alleviate restrictions in airspace and airport capacity in low visibility conditions. Existing EVS-systems are based on IR-sensors although the penetration of bad weather (dense fog and light rain) by MMW-radar is remarkably better than in the infrared spectrum. But the quality of MMW radar is rather poor compared to IR images. However, the analysis of radar images can be simplified dramatically when simple passive radar retro-reflectors are used to mark the runway. This presentation is the third in a series of studies investigating the use of such simple landing aids. In the first study the feasibility of the radar PAPI concept was determined; the second one provided first promising human performance results in a low-fidelity simulation. The present study examined pilot performance, workload, situation awareness, and crew coordination issues in a high-fidelity simulation of 'Radar-PAPI' visual aids supporting a precision straight-in landing in low visibility (CAT-II). Simulation scenarios were completed in a fixed-base cockpit simulator involving six two-pilot flight-deck crews. Pilots could derive visual cues to correct lateral glide-path deviations from 13 pairs of runway-marking corner reflectors. Vertical deviations were indicated by a set of six diplane reflectors using intensity-coding to provide the PAPI categories needed for the correction of vertical deviations. The study compared three display formats and associated crew coordination issues: (1) PF views a head-down B-scope display and switches to visual landing upon PNF's call-out that runway is in sight; (2) PF views a head-down C-scope display and switches to visual landing upon PNF's call-out that runway is in sight; (3) PF views through a head-up display (HUD) that displays primary flight guidance information and receives vertical and lateral guidance from PNF who views a head-down B-scope. PNF guidance is terminated upon PF's call-out that runway is in sight.

Proceedings Article | 11 August 2004 Paper

Radar PAPIs: human factor issues of EVS landing aids

Bernd Korn, Bernd Lorenz, Helmut Toebben, Hans-Ullrich Doehler, Peter Hecker

Proceedings Volume 5424, (2004) https://doi.org/10.1117/12.547106

KEYWORDS: Radar, Visualization, Reflectors, Extremely high frequency, Enhanced vision, Optical tracking, Visibility, Heads up displays, Infrared imaging, Sensors

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Proceedings Article | 11 August 2004 Paper

Enhancing pilot situation awareness by using an onboard taxi guidance system: an empirical study

Bernd Lorenz, Markus Biella, Joern Jakobi

Proceedings Volume 5424, (2004) https://doi.org/10.1117/12.554486

KEYWORDS: Visibility, Visualization, Heads up displays, Control systems, Data communications, Navigation systems, Device simulation, Switches, Error analysis, Safety

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Showing 5 of 6 publications

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