Design and control of a wire-based rehabilitation robot

In this paper, a wire-based rehabilitation robot was developed for the upper extremity rehabilitation. Impedance control strategy was employed to performing two movements and compensate for the uncertain dynamics of upper extremity or this robot. Firstly, the mechanism and hardware design were developed, which consisted of cubic base frame, motors, force sensing system, wires and end-effector. Then, kinematic model was established with a geometric method. These distances between pulleys and wires' attachments on the end-effector could be calculated based on this model. Impedance control strategy was presented to minimize the tracking errors of the wire-based robot. Finally, the experimental evaluation was implemented on the built prototype. Results showed that the wire-based rehabilitation robot with impedance control strategy attained good position tracking performance during circle-shaped and linear movements.