Design and Analysis of a Human-Centric Shoulder Exoskeleton to Improve the Range of Motion

The upper limb exoskeletons available in the market are used to assist in carrying out activities of daily living (ADL) but have a limited range of motion (ROM). The limitation in ROM is due to the negligence of the complete shoulder complex joint motions while designing the wearable exoskeleton. This can affect the shoulder joint components due to interaction forces generated between the exoskeleton and the human shoulder in the presence of joint misalignment. This paper proposes a novel design of a human-centric shoulder exoskeleton mechanism. It is capable of exhibiting the same reachability of the human shoulder without a self-collision or collision with the human body throughout the ROM by introducing kinematic redundancy. The design procedure of the exoskeleton, which considers human joint motions, has been presented along with the static stress analysis. The actuator selection for the glenohumeral joint has also been specified along with the initial 3D printed prototype of the exoskeleton mechanism, which is further used to test and compare its maximum ROM.