Longitudinal stability control of electric wheelchairs for persons with severe disability

In a previous study, we developed a force-detecting interface to operate an electric wheelchair for persons with muscular dystrophy. However, the force input method of the interface tends to be directly influenced with respect to disturbance caused by road surface conditions. We proposed a disturbance removal method to detect users' intentions using experimental results on the roads, where shocks or vibrations are experienced. Moreover, because of the structure of the electric wheelchair, the vehicle behaviour may easily become unstable due to disturbances such as the caster behaviour and the shape of the road (bumps and slopes). When an user's intended input differs from the vehicle's behaviour (brought about by these disturbances), the user has the burden of revising the command to the wheelchair. We proposed the longitudinal stability control system for the wheelchair utilising an in-wheel-motor system to improve the vehicle stability with respect to environmental disturbance.