Vehicles modified with a wheelchair transporting apparatus are
generally used for improving wheelchair users'' mobility.
However, in designing the apparatus, consideration for
passengers'' discomfort and fatigue is not sufficient. As a
countermeasure of this problem, both vibration characteristics of
the passenger-wheelchair system and passengers''
sensitivity need to be studied. In previous study, authors
constructed a vibration simulation model to predict vibration on
passengers'' body from floor vibration. This study aims to
clarify the relationship between vibration and comfort, and to
propose a method to support designing WTA by the findings of this
study.
First, we carried out a vibration experiment with a vibration
generator that vibrated the passenger-wheelchair system and
measured floor vibration, vibration on the human body, and
subjective evaluation.
Second, we discussed experimental results. The result of riding
comfort measurements proved that the characteristics of sensitivity
to vibration differ in two frequency ranges: from 2 Hz to 6 Hz and
from 6 Hz to 12 Hz. Therefore we divided the results into two
sections for these two frequency ranges.
Relationship between floor vibration and riding comfort was
examined. We carried out the multiple regression analysis and
deduced the formulas that express the value of riding comfort by
the acceleration and frequency of the vibration on the floor.
Next, relationship between body vibration and riding comfort was
examined. From the result of correlation analysis and multiple
regression analysis, vertical vibration on the upper torso is found
to be most closely related to the riding comfort. Regression
formulas that express the value of riding comfort by the
acceleration and frequency of the vertical vibration on the upper
torso were deduced.
Finally, we proposed a vibration evaluation model that can
predict riding comfort from the vertical vibration on the upper
torso, which will be valuable in designing the wheelchair
transporting apparatus.