Abstract
There are people who can't transfer on their own and needs help for the move from a sitting posture to other sitting posture. However, many of them want to transfer without assistants. Therefore, we developed a robot that assists them to transfer on their own. In this investigation, we build the prototype of transfer unit for transfer assist robot. This prototype has the variable mechanism of ground area. This mechanism can raise stability of transfer assist due to open ground area and extend moving area due to close ground area. Based on motion experiments of the mechanism, it is shown that the proposed effective mechanism which designed as transfer unit for transfer assist robot.