Next-generation cars, secondary activities, and sitting configurations:​ in-line transmission of vertical vibration at seat cushion

D’Amore, Francesco; Qiu, Yi

Affiliations

¹Institute of Sound and Vibration Research, University of Southampton, Southampton SO17 1BJ, United Kingdom

Abstract

Next-generation cars will be electric, connected, autonomous, and shared. Aboard, primary activities such as driving or travelling will coexist with secondary activities such as (self-) entertaining, socialising, relaxing, sleeping, working, and eating. Although secondary activities have already been identified, related seating issues have only been touched. A three-factor mixed-design laboratory experimental study was conducted to test whether the concept of ‘sitting configuration’ (introduced and defined in this paper) is appropriate to characterise the seat–occupant system as a whole. Specifically, investigated were main effects and interaction effects of (biological) sex, vibration magnitude, and sitting configuration on in-line transmission of vertical vibration at seat cushion. With the Six-Axis Motion Simulator of the University of Southampton, six men and six women occupying a production reclining car seat were subjected to four vibration magnitudes in four sitting configurations corresponding to four pairs of primary and secondary activities. Transmissibility and coherence functions were calculated from acceleration measurements. An ANOVA model of first-resonance frequency of transmissibility showed an appreciable main effect of both vibration magnitude (F(2.21, 22.11) = 369.54, p < 0.001, η² = 0.28, ηP² = 0.97, ηG² = 0.54) and sitting configuration (F(1.98, 19.80) = 82.27, p < 0.001, η² = 0.48, ηP² = 0.89, ηG² = 0.67) but failed to show an appreciable main effect of sex (F(1, 10) < 0.001, p > 0.99, η² < 0.001, ηP² = 0.001, ηG² < 0.001) and any appreciable interaction effects (p > 0.99, η² ≤ 0.004, ηP² ≤ 0.12, ηG² ≤ 0.02). Results suggest that the concept of sitting configuration is appropriate to characterise the seat– occupant system as a whole. Ultimately, in design and development of seats for next-generation cars, secondary activities and corresponding sitting configurations should be taken into consideration to optimise not only functionality, but also comfort and protection (and related affective/emotional attributes).

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