Modeling of a novel cable driven robot for upper limb rehabilitation

In this paper, a novel upper limb rehabilitation robot is introduced which is based on cable-driven mechanism. The research focuses on developing a specific cable actuator that brings back-drivability characteristic for the rehabilitation robot. The main idea based on using a series of cables with single tension motor as power supply to control motion of multi-joint arm. Dynamic specification of two-joint cable mechanism has been explained and an open loop impedance control which is equipped with feed-forward PD controller considered as control strategy. Moreover, the performance of mechanism while tracking a specific path has been successfully simulated. Inherent back-drivability feature of simulated mechanism has been evaluated in comparison to human arm stiffness. Simulation results show the ability of the robot in human arm motion simulation which makes it useful in upper arm rehabilitation applications.