Design, Modeling and Optimal Position Control of a New Wrist Rehabilitation Robot Using Stewart Platform

In this paper a new application of Stewart platform is developed for rehabilitation utilities. Here the Stewart model is modified in order to be employed as a wrist rehabilitation robot and is controlled using a nonlinear position approach. To meet this goal kinematics of the robot is extracted using Jacobian matrix. Afterwards, the related dynamic model of the proposed robot is developed using virtual work method. In order to keep the wrist of patient within the desired path of rehabilitation a nonlinear position control is designed and implemented on the robot using Computed Torque Method (CTM). In order to move the patient wrist along a safe path an optimal path in extracted through which the least amount of acceleration and consequently interaction force will be implemented on the wrist and this path is controlled using the designed controller. By the aid of conducting some analytic simulations in MATLAB the applicability of the proposed robot for wrist rehabilitation is demonstrated. The verification of the model is performed by comparing the results with previous articles while the efficiency of the implemented controller is proved by comparing the actual path with the desired one in presence of disturbance. It is shown that by the aid of the proposed robot and controller, the wrist rehabilitation process of a patient can be successfully accomplished.