Citation

Miyata Y, Onimoto H, Suzuki Y, Oga R, Sakurai T, Sugimachi T, Maki T. J. Jpn. Counc. Traffic Sci. 2021; 21(1): 11-25.

Copyright

(Copyright © 2021, The Japanese Council of Traffic Science)

DOI

10.24597/jcts.21.1_11

PMID

unavailable

Abstract

Electric wheelchairs are becoming popular in Japan as a means of transportation for the elderly. Due to the growing aging population, the number of traffic accidents involving electric wheelchairs is expected to increase in the future. Side collisions account for the highest percentage of traffic accidents involving electric wheelchairs. In our previous research, a physical crash test was carried out to simulate a side collision of an electric wheelchair with an automobile. It was found that head of the occupant in the electric wheelchair hit the road surface, which caused a head injury. However, the behavior in head injury mechanism at various collision speeds has not been studied sufficiently. In addition, the effectiveness of occupantʼs protection devices has not been adequately studied. The aim of this study is to understand the mechanism of head injuries caused as a result of side collisions of electric wheelchairs by using CAE （Computer Aided Engineering） analysis, and to evaluate the effectiveness of occupantʼs protection devices.

The CAE analysis showed that the electric wheelchair occupant was thrown out of the electric wheelchair after leaning on the vehicle side, and then, the occupantʼs head and upper body hit the road surface when the collision speeds were 20-40km/h. The occupantʼs fall behavior depends on the collision speed; therefore, the factors that caused the head injury were inconsistent. The head injury value of HIC36 also depended on the collision speed. The HIC36 exceeded the injury threshold in some collision speeds. Next, the occupantʼs protection devices were evaluated. When a lap belt was fastened, the HIC36 exceeded the injury threshold when the collision speeds were 15-40 km/h, because the occupant of the electric wheelchair fell with occupantʼs head toward the road surface. When the armrests of the electric wheelchair were flipped up and the occupant wore helmet, the occupant fell to the vehicle side when the collision speed was within 30km/h. In addition, the helmet reduced the impact to the occupantʼs head, therefore the HIC36 was below the injury threshold when the collision speeds were 10-40 km/h. From these results, there are effective for reducing head injury to the occupant that the occupant wears helmet without lap belt and armrests on electric wheelchairs are flipped up.

Language: ja

Keywords

CAE; collision test; Computer Aided Engineering; electric wheelchair; head injury; side collision; 側面衝突; 衝突実験; 電動車いす; 頭部傷害