Design and Development of an Exoskeleton System using a 3-UPU Spherical Parallel Manipulator for Rehabilitation in Stroke Patients

One of the important branches of medical robotics is rehabilitation robotics. A 3-UPU spherical parallel manipulator is designed and controlled to perform wrist extension, flexion, radial deviation and ulnar deviation motions in stroke-affected patients. This exoskeleton robot produces spherical motion about a fixed centre. In order to produce the rotational motion, the robot is designed based on certain geometric and structural conditions. Using the inverse kinematics solution the 3-UPU robot is controlled to perform rehabilitation task. The robot parts are manufactured using additive manufacturing technology. The manufacturing tolerance in universal joints have been identified. There is always a mystery behind the singularity of this robot, which describes the manner in which it will collapse in its home position. Thus, the robot is designed and developed in such a way that it can be effectively used at home position for hand rehabilitation.