An Integrated Model of Static and Dynamic Measurement for Seat Discomfort

Title & Authors
An Integrated Model of Static and Dynamic Measurement for Seat Discomfort
Daruis, Dian Darina Indah; Deros, Baba Md; Nor, Mohd Jailani Mohd; Hosseini, Mohammad;

Abstract
A driver interacts directly with the car seat at all times. There are ergonomic characteristics that have to be followed to produce comfortable seats. However, most of previous researches focused on either static or dynamic condition only. In addition, research on car seat development is critically lacking although Malaysia herself manufactures its own car. Hence, this paper integrates objective measurements and subjective evaluation to predict seat discomfort. The objective measurements consider both static and dynamic conditions. Steven's psychophysics power law has been used in which after expansion; $\small{{\psi}\;=\;a+b{\varphi}_s^{\alpha}+c{\varphi}_v^{\beta}}$ where $\small{{\psi}}$ is discomfort sensation, $\small{{\varphi}_s^{\alpha}}$ is static modality with exponent $\small{{\alpha}}$ and $\small{{\varphi}_v^{\beta}}$ is dynamic modality with exponent $\small{{\beta}}$. The subjects in this study were local and the cars used were Malaysian made compact car. Static objective measurement was the seat pressure distribution measurement. The experiment was carried out on the driver's seat in a real car with the engine turned off. Meanwhile, the dynamic objective measurement was carried out in a moving car on real roads. During pressure distribution and vibration transmissibility experiments, subjects were requested to evaluate their discomfort levels using vehicle seat discomfort survey questionnaire together with body map diagram. From subjective evaluations, seat pressure and vibration dose values exponent for static modality $\small{{\alpha}}$ = 1.51 and exponent for dynamic modality $\small{{\beta}}$ = 1.24 were produced. The curves produced from the $\small{E_{q.s}}$ showed better $\small{R_{-sq}}$ values (99%) when both static and dynamic modalities were considered together as compared to Eq. with single modality only (static or dynamic only R-Sq = 95%). In conclusion, car seat discomfort prediction gives better result when seat development considered both static and dynamic modalities; and using ergonomic approach.
Keywords
Car Seat;Static Measurement;Dynamic Measurement;Seat Discomfort;Steven's Law;Psychophysics;
Language
English
Cited by
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적응형 유전알고리즘을 이용한 사용자 인터페이스 설계 방법 개발,정기효;

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