Construction of human body vibration finite element model that simulates riding comfort of persons who ride a wheelchair

这项研究的目的是调查乘坐福利车辆携带的轮椅的人改善舒适度的可能性。首先，对日常使用福利车辆的轮椅使用者进行了访谈，调查了现状。并对真实福利车中的轮椅进行了登车实验。从物理和心理两个角度探讨了定量评价轮椅-人体振动系统振动特性的评价方法。其次，利用薄板激振装置进行了再现振动环境的轮椅台板实验。在实验中，对乘坐轮椅的人体的传递性、身体各部位的振动感评价和乘坐舒适性进行了评价。结果表明，虽然每个考生的振动行为倾向各不相同，但头部、胸顶和胸底的摆动对乘坐舒适性影响较大。特别是，4赫兹的头部垂直振动和5赫兹的头部垂直振动以及胸骨的垂直振动对乘坐舒适性的影响最为不利。研究结果表明，改变振动模式，减小振动幅度，可以改善乘坐舒适性。在此基础上，建立了基于有限元方法的轮椅-人体振动系统模型，考察了改善乘坐舒适性的可能性。根据振动模型进行的仿真表明，只有改变座垫的物理性质，才能再现人体振动的大小和振型的变化。

The purpose of this study was to investigate the possibility of comfort improvement of persons who ride wheelchairs carried in welfare vehicles. Firstly, an interview with wheelchair users who daily use welfare vehicles was carried out to investigate the present situation. A boarding experiment to the wheelchair in the real welfare vehicle was also carried out. From not only physical viewpoint but also psychological viewpoint, evaluation methods for quantitatively evaluating vibration characteristic of this wheelchair-human vibration system were examined. Secondly, another wheelchair board experiment by sheet excitation equipment that reproduced vibration environment was carried out. In the experiment, the transmissibility of human body who rode the wheelchair, the evaluation of sense of vibration at each body part and the riding comfort evaluation were evaluated. As a result, it was confirmed that swinging of head, thorax top and bottom greatly influence the riding comfort, though the vibration behavior tendencies of the each every examinee were different each other. In particular, it became clear that head vertical vibration at 4Hz and head at 5Hz and vertical vibration of the bust gave most adverse effect for the riding comfort. In this paper, it has been concluded that the change of the vibration mode as well as the decrease of magnitude of the vibration could improve riding comfort. Based on the knowledge got here, a wheelchair-human vibration system model according to finite element method was constructed to examine the possibility of this riding comfort improvement. The simulation according to the vibration model showed that the change in not only the magnitude of the vibration of the human body but also the vibration mode could be reproduced only by changing the physical properties of seat cushions.