Power assistance of an omnidirectional hybrid walker and wheelchair with admittance model and Iterative Learning Control

In this paper, at first we briefly present an overview of our developed hybrid walker and wheelchair robot. Then we focus on analysis and investigation of the movement in which the robot starts to ascend/descend a slope, and point out that the user´s walking velocity and the robot´s velocity are inevitably different. Further, in order to let the user get a smooth load feeling as the user use the robot on a horizontal plane, we propose V.C (Velocity Compensation) and ILC (Iterative Learning Control) to adaptively adjust the control parameter. The experiments verify the effectiveness of the proposed approaches.