Abstract
It is thought that drivers and passengers can utilize vehicle cabin as a personal
space to take a rest or a nap when they felt fatigue and drowsiness during long drive. It is
reported that a nap for approximately 15 minutes is effective to recover from fatigue and
drowsiness while driving. In order to refresh with a short time, it is necessary for us to know
how a comfortable seat should be for their relaxation. The purpose of this study was to
propose the seat equipment that is effective to utilize vehicle cabin as a space for occupants´
refreshment. To this end, we took following three steps: First, a comfortable posture for
occupants to refresh by a short rest in a limited space of a car was clarified and equipment that
realizes the posture was proposed. Second, the equipment effect was verified by physiological
measurements. Final, issues for installing the equipment into a vehicle were examined. In
order to refresh with a short rest, it is important that occupants can relieve muscle tension and
mentally relax. For this purpose, the following equipment was proposed: the headrest with
adjustable bolster, the tilt-able cushion with great degree, and the ottoman. It was found
subjectively that the equipment mitigated physical burdens and improved relaxation. Then,
the effect of equipment was verified with physiological measurements.
Electroencephalograph revealed that the equipment promoted relaxation and kept it long so
that occupants obtained high effect of relaxation. For application of the equipment to a
vehicle, the following two important aspects were clarified: the equipment should serve wider
enough range of occupants´ sizes and should be easy to be used. By focusing on those aspects,
the requirements for layout and ease of use were proposed. In this study, vehicle cabin
utilization with seat equipment for occupants´ refreshment was investigated, and the effect of
the equipment within the limited space was clarified. Based on the findings, the practical
equipment was applied to a vehicle.
Keywords - vehicle cabin utilization, refreshment, seat equipment, relaxation,
physiological measurement.