A 3-0 rehabilitation robot system is developed in this paper. The robot system is for the rehabilitation of upper extremities, especially the shoulder and elbow joints, and has 3-0 workspace for enabling occupational therapy to recover physical functions in activities of daily living(AOL). The rehabilitation robot system, which is driven by actuators, has 1 OOF in horizontal rotational motion and 2 OOF in vertical rotational motion, where all actuators are set on the ground. Parallelogram linkage mechanisms lower the equivalent inertia of the control elements as well as control forces. Also the mechanisms have high mechanical rigidity for the end effector and the handle. Passive motion mode experiments have been performed to evaluate the proposed robot system. The results of the experiments show and excellent performance in simulating spasticity of patients.
