Abstract
Motorized wheelchairs are mainly utilized by the elderly with disabilities in outdoor environments. Accidents involving motorized wheelchairs in Japan have increased as the nation's population ages. To solve the problem, we constructed a new type of motorized wheelchair with many kinds of safety assistive technologies. One of our measures prevents the wheelchair from moving in unintentional direction and tipping over sideways on a laterally graded sidewalk by controlling the drive of each motor based on internal sensors when the wheelchair is moving across a sloped section of a sidewalk. Another of our measures prevents a large backward tipping angle when the wheelchair is moving up over grade height differences and slopes by controlling an electromagnetic brake on a bar that is attached to the rear underside of the wheelchair. The results of our indoor experiments on not only simulated slopes and grade height differences but also in real outdoor environments have confirmed the effectiveness of our safety assistive technologies.