Step Passage Control of a Power-Assisted Wheelchair for a Caregiver

Various welfare devices have been developed by the influence of the population´s aging society. They are required to support caregivers and cared-for people these days because the burden of the nursing care is increasing. A method to realize a caregiver´s power-assist control for an electric wheelchair is proposed in this paper. This method enables power-assisted wheelchairs to adapt not only to flat roads but also to roads with steps. Instead of a force sensor, a reaction torque estimation observer is constructed to detect the human torque input into the wheelchair. An inclination sensor is used to detect the step and to determine the control method while passing over the step. Simulations and experiments were carried out to show the validity of the proposed method.