Systematic Evaluation of a Knee Exoskeleton Misalignment Compensation Mechanism Using a Robotic Dummy Leg.

Area of Science:

• Robotics
• Biomechanics
• Human-Robot Interaction

Background:

• Objective assessment of physical human-exoskeleton interaction (pHEI) is crucial for wearable robots.
• Early-stage device development faces ethical and safety challenges with human testing.
• Existing methods for pHEI assessment lack objectivity and quantitative rigor.

Purpose of the Study:

• To propose and validate a novel methodology for objective pHEI assessment.
• To evaluate the effectiveness of a misalignment compensation mechanism in a knee exoskeleton.
• To accelerate the iterative development of wearable robotic devices.

Main Methods:

• Development of an active dummy leg, Leg Replica, capable of sensing interaction forces.
• Testing the methodology on a wearable active knee exoskeleton prototype.
• Quantifying interaction forces during passive and active exoskeleton motion with and without misalignment compensation.

Main Results:

• The Leg Replica methodology successfully quantified pHEI.
• The misalignment compensation mechanism reduced interaction forces during passive exoskeleton motion.
• The reduction in interaction forces was less pronounced during active exoskeleton motion, highlighting areas for improvement.

Conclusions:

• The proposed methodology provides an objective benchmark for pHEI.
• This approach facilitates device improvement prior to human testing, enhancing safety and efficiency.
• The study demonstrates the utility of Leg Replica in accelerating wearable robot development.