Sit-to-stand assistance with a balancing mobile robot

This work presents a method for assisting people in getting out of chairs with a dynamically stable mobile robot. A user study is described in which force profiles and joint trajectories were recorded for a human-human sit-to-stand experiment. These data were used to develop an impedance-based controller designed to allow the ballbot to help people out of chairs. The control strategy is experimentally verified on the ballbot, a balancing mobile robot, exhibiting lean angles of over 15° and applying more than 120 N of assistive force. To our knowledge, this is the first mobile robot to assist people in standing.