A novel power add-on unit for attendant propelled wheelchairs with Sensorless Speed Control and Power Assistance

In order to help an attendant who are pushing a conventional commercialized manual wheelchair in which a patient (an elderly or disabled person) is sitting in the wheelchair, in this study, we have been developing a novel power add-on unit (PAU) for attendant propelled wheelchair with sensorless speed control and power assistance. This development is based on the following three concept: to make our PAU (1) easy to be attached to and detached from the wheelchair; (2) able to be used to the most of the conventional commercialized wheelchairs; (3) have a low cost. To enhance its performance, a simple sensorless speed control is experimentally realized. Further, in order to make the attendant more easily and comfortably propel the wheelchair, a sensorless power assist approach is proposed and simulated. The results verified the effectiveness of the proposed two control approaches.