Bilateral, Misalignment-Compensating, Full-DOF Hip Exoskeleton: Design and Kinematic Validation

Area of Science:

• Robotics
• Biomechanics
• Human-Machine Interaction

Background:

• Reducing metabolic cost during locomotion is a primary goal for lower limb exoskeletons.
• Few devices achieve significant metabolic reduction, often due to failing to preserve natural human kinematics.
• Accurate alignment of exoskeleton joints with human joint axes is crucial for metabolic benefit, but perfect alignment is challenging.

Purpose of the Study:

• To present a novel misalignment compensation mechanism for a 3-DOF robotic system.
• To validate this mechanism through implementation in a bilateral hip exoskeleton.
• To assess the device's impact on user's natural hip motion during walking.

Main Methods:

• Development of a 3-DOF misalignment compensation mechanism.
• Integration of the mechanism into a compact, lightweight bilateral hip exoskeleton.
• Testing the exoskeleton prototype with users to evaluate kinematic preservation and donning ease.

Main Results:

• The developed hip exoskeleton is compact, lightweight, and can be donned autonomously with minimal user adaptation.
• The misalignment compensation mechanism successfully maintained the user's natural hip range of motion across all three degrees of freedom (DOF).
• Users maintained natural motion patterns while walking with the novel hip exoskeleton.

Conclusions:

• The presented misalignment compensation mechanism is effective in preserving natural hip kinematics in a bilateral exoskeleton.
• This approach facilitates the development of metabolically beneficial exoskeletons that do not impede natural locomotion.
• The novel hip exoskeleton offers a practical solution for enhancing user mobility without compromising natural movement.