This upper-limb exoskeleton has an internally rotated elbow joint and is based on an anthropomorphic 5-DOF upper-limb exoskeleton for power-assisted activity.
The proposed 3-DOF upper-limb exoskeleton contains a 2-DOF shoulder joint and a 1-DOF internally rotated elbow joint. The structural parameters of the 3-DOF upper-limb exoskeleton were determined, and the differences and singularities of the two exoskeletons were analyzed. The workspace, the joint torques and the power consumption of two exoskeletons were analyzed by kinematics and dynamics, and an exoskeleton prototype experiment was performed. The proposed non-anthropomorphic 3-DOF upper-limb exoskeleton can be applied to a power-assisted upper-limb exoskeleton in industrial settings.
3-DOF exoskeleton's specifications in comparison to 5-DOF exoskeleton:
- Reduced self-weight by removing two joints, and their corresponding actuators and eliminated singularity in the workspace.
- Same actual workspace as the 5-DOF upper-limb exoskeleton; compared with the 5-DOF upper-limb exoskeleton, the maximum joint torque of the 3-DOF upper-limb exoskeleton decreased by 50%, and the elbow external-flexion/internal-extension and the shoulder flexion/extension power consumption decreased by 55% and 46%.
- Same manipulability as the 5-DOF upper-limb exoskeleton for the hanging action process.