DRIVING TESTS AND COMPUTER-SIMULATIONS OF ELECTRIC WHEELCHAIRS ON SNOW-COVERED ROADS

Not only handicapped people but also elderly people living in Hokkaido , the northernmost island in Japan, desire to participate in outdoor a ctivities during a winter season that is characterized by heavy snow a nd low temperatures. Most of these people venture outdoors to go shopp ing or to hospitals, even under severe conditions. A wheelchair is gen erally used for outdoor transport. There are, however, many problems w ith using a wheelchair during the winter; roads covered with snow and ice are very slippery, casters are easily buried in snow, and handrims are too cold to handle. Therefore, an appropriate wheelchair for outd oor use during the winter season is greatly desired. We are developing an electric wheelchair effective for outdoor use during the winter. I n this work, three types of electric wheelchairs with front-wheel driv e, rear-wheel drive and front free casters, and rear-wheel drive and m echanically controlled casters, were tested for drivability on icy roa ds, snow-covered roads, and indoor floors. In addition, computational methods were proposed to simulate the drivability of electric wheelcha irs under snowy conditions.