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Human Research Program

Modeling and Mitigating Spatial Disorientation in Low g Environments

Completed Technology Project

Project Introduction

Observer was 'packaged' as a DLL (dynamically linked library) within SDAT. SDAT users can select whether they wish to use Observer algorithms for predicted perception, or SDAT's algorithms. While Observer may be more physiologically accurate, Observer requires data sets to be of a fixed rate and fairly high frequency (10-100 Hz). Unfortunately, actual vehicle flight data recordings rarely meet these requirements. In addition, Observer does not account for misperceptions due to sub-threshold motions, which are critical to many SDAT illusion models. Therefore, we give users the option to select Observer or SDAT algorithms for attitude perception predictions. We designed three new illusion models to SDAT based upon vertical landing vehicle scenarios that we observed in data sets provided by an anonymous source of helicopter data -- data sets that included confirmed SD events. The three models are: (1) "Undetected loss of lift" which occurs when the pilot unwittingly flies out of ground effect with insufficient thrust to maintain the new altitude, resulting in a sudden plunge toward the surface; (2) "Inadvertent drift during hover" that could result in the vehicle striking an obstacle; and (3) "Undetected drift during landing" that could cause the vehicle to tip-over. SDAT has also been enhanced with a pilot attention model called N-SEEV. N-SEEV elevates applied countermeasures when SDAT predicts that the pilot is suffering from SD and has not attended to a lower level of countermeasures. We created an updated version of SDAT's user manual and delivered SDAT and its user manual to NSBRI. We did not undertake an experiment to validate the newly enhanced SDAT because we could use existing data sets plus the new ones acquired from our anonymous source of helicopter data sets. We also judged that a simulator validation experiment would use resources needed to do the best possible job of integrating Observer into SDAT. FORT tool cost scores are not integrated into SDAT because it is inappropriate to do so; they could be integrated into Observer. The FORT tool remains a separate stand-alone tool. We performed additional FORT tool validation, and submitted an article to the Human Factors Journal. We received 40 usable survey responses, analyzed the data from the 71 missions in the responses, and submitted an article to Aviation, Space, and Environmental Medicine reporting our method and results. We also sent de-identified data to our customer, NASA-JSC's Dr. Jacob Bloomberg, and will make the full set of de-identified data available to anyone who wishes it. More »

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This is a historic project that was completed before the creation of TechPort on October 1, 2012. Available data has been included. This record may contain less data than currently active projects.