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Citation
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Laakmann F, Seyffert M, Herpich T, Saupp L, Ladwig S, Kugelmeier M, Vollrath M. 27th International Technical Conference on the Enhanced Safety of Vehicles (ESV); April 3-6, 2023; Abstract #: 23-0216, pp. 24p. Washington, DC USA: US National Highway Traffic Safety Administration, 2023 open access. |
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Abstract
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27th International Technical Conference on the Enhanced Safety of Vehicles (ESV): Enhanced and Equitable Vehicle Safety for All: Toward the Next 50 Years
https://www-esv.nhtsa.dot.gov/Proceedings/27/27ESV-000216.pdf
Research Question/Objective: Strengthening human ability to perform the driving task in emergency situations is a key ambition of vehicle design. This work aims to further improve driver reaction time by utilizing the tactile sensory channel in multi-modal warning concepts. A specific emphasis of the work is the evaluation of unique characteristics of tactile warning through an active seat belt system in contrast to other modalities. Methods and Data Sources: Two complementary user studies were conducted by two independent research facilities with two dynamic driving simulators. With 87 participants in total there was the aim for statistical relevance of the measurements. The setup included alternative driver warning concepts for both drivers, during manual and assisted driving, and drivers engaged in another task during conditional driving automation. The tactile warning by the active seat belt system consisted of a series of retract pulses on low force levels. The assumption is that drivers will benefit from a high exclusivity of the modality in comparison to a tactile seat, steering wheel or pedal. Results: In a first setup (manual driving, undistracted), the replacement of the acoustic/auditory warning by a tactile warning, when combined with a visual signal, resulted in an improvement of reaction time of 250 milliseconds for brake initiation. In a second setup (AD SAE Level 3) the driver took over vehicle control 1.0 second earlier with a combination of auditory, tactile and visual warning compared to a warning without vibrotactile alerting. Discussion: Until now, only a few studies existed aimed to evaluate a tactile warning provided by a seat belt system. The work may support, within the limitations of these studies, the initial assumption that a seat belt system providing vibrotactile stimuli to the torso - specifically chest and shoulder - shows some unique benefits. The exclusivity of the sensory channel and a low interference with other signals in the vehicle lead to high degrees of detectability, discriminability, and intelligibility. Limitations and outlook: Is the use of a tactile warning always positive, or what are effects of training or habituation? A differentiated semantic design of such tactile stimuli, the incorporation in escalating and multi-modal warning concepts, and the combination with a holistic occupant monitoring are seen as levers for improvement and subjects of further investigations. Conclusion: This research has found that tactile warning of the driver, through an active seat belt system, can contribute significantly to improved warning effectiveness and can help to improve the driver's ability to react in vehicles equipped with Advanced Driver Assistance Systems (ADAS) and Automated Driving Systems (ADS). Functions like take-over request (TOR) or forward collision warning (FCW) may benefit by more robust alerting of the driver as part of the emergency warning procedure.
Language: en |