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

本研究旨在探讨福利车轮椅使用者舒适度改善之可能性。首先，对日常使用福利车的轮椅使用者进行访谈，调查其现状。在真实的福利车上进行了轮椅的登车实验。从生理学和心理学的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板实验。在实验中，对乘坐轮椅的人体的传递率、身体各部位的振动感评价和乘坐舒适性评价进行了评价。结果表明，虽然每个受试者的振动行为倾向各不相同，但头、胸顶和胸底的摆动对乘坐舒适性影响很大。特别地，很明显，4 Hz的头部垂直振动和5 Hz的头部垂直振动以及胸部的垂直振动对乘坐舒适性产生了最不利的影响。本文认为，改变振动模态，降低振动幅值，可以改善乘坐舒适性。在此基础上，建立了轮椅-人体振动系统的有限元模型，以检验改善乘坐舒适性的可能性。根据振动模型进行的模拟表明，不仅人体振动幅度的变化，而且振动模式的变化可以通过改变座垫的物理特性来再现。

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.