This study investigates the tactile perceived seat-human interaction of four types of BMW 5-series seats with the same foam properties and contours but different seat cover and seat suspension properties; 38 healthy subjects participated in an experiment rating and ranking the tactile perceived properties of the seats while blindfolded. A discomfort test, a seat characterizing rating on a scale of word pairs, and the overall experience of the seats were examined in four different sitting positions. The results of the experiment were related with the outcome of an objective measurement method: a pressure measurement mat and the measurement tool of Wegner et al. [19]. The study showed that the perception of the surface while interacting with the seat is independent from the sitting position. In contrast, the perception of the hardness and the elasticity of the seat is position-dependent. The results of the seat characterization are in line with the results of the measurement tool of Wegner et al. [19]. Further research is needed to investigate the mutual interdependence of the various measurement points of the measurement tool and to improve the prediction accuracy of the seat characteristics.

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In this paper a measurement tool is described and tested to evaluate the characteristics of different elements of a seat. Many studies report a relationship between discomfort and pressure distribution, but it is unknown what exactly is happening in the interaction. The purpose of this study is to present a measuring device, which records the comfort relevant seat parameters pressure and elongation while loading a seat. The results of the study, including the repeatability, reproducibility and detectability show that the measurement method is appropriate for our purpose, although the reproducibility has to be improved by operator experience or by a more intuitive assembling of the measurement setup. An application example illustrates that the interaction of the seat components highly affect the resulting comfort relevant parameters. The question is whether this objectively recorded differences are also experienced by seat occupants, which is interesting to study in future research.

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The seat is the largest contact area between a human and the car. Optimizing this contact area is therefore highly relevant for long termcustomer satisfaction. The share of the total production costs for the interior can be between 20% - 30% of which almost 40% is for the seats. The current literature of seat research ismostly on the properties of foam related to comfort and discomfort. In this PhD a study is done to prove that the perception and the (dis-)comfort of an automotive seat is not only influenced by the foam properties and contour. Other seat components like the seat cover, lamination and the seat suspension might play a role as well. To study the effect of different elements a measurement tool was developed which records properties that are relevant for some sensors in the skin. These mechanoreceptors in the skin are shear forces, elongation, friction and pressure. A tool was developed, which is a stamp in the formof a half sphere. The half sphere is equipped with pressure and elongation sensors. This makes it possible to measure pressure and pressure distribution, elongation and shear forces. With the tool 648 samples of seats with different seat components were tested. Additionally 98 participants tested various seats with properties comparable to the 648 samples. The tests showed that it was able to measure differences in elongation, pressure and shear force.@en

This study investigates the tactile perceived influence of seat covers. Two identical BMW 3-Series seats are used, one with a leather cover and one with a fabric cover. Thirty healthy subjects participated in an experiment rating the tactile perceived properties of the seats while blindfolded. A discomfort test, a word pair rating and the overall experience of the seats were examined. The study has shown that not only the foam properties and the contour of the seat influences the seat characterisation but also the seat cover material. The leather and the fabric seats were characterised different, but the pressure distribution did not show so much differences. Furthermore, the perceived differentiation of the seats are distinctive for the seat pan and for the backrest. Therefore, further research is needed to investigate other characteristics of the seat like shear force related to various cover properties in combination with different seat components and contour combinations.

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