Ergonomics Design and Assistance Strategy of A-Suit

Area of Science:

• Biomechanics
• Human Augmentation
• Wearable Robotics

Background:

• Lower limb biomechanics and energy consumption are critical for mobility and endurance.
• Existing assistive devices often lack adaptability and ergonomic integration.
• Soft exoskeletons offer a promising approach for naturalistic human augmentation.

Purpose of the Study:

• To develop and evaluate a soft exoskeleton, A-Suit, for powered ankle plantar flexion.
• To assess the A-Suit's impact on walking endurance and metabolic energy consumption.
• To investigate the ergonomic design principles for lower limb assistive devices.

Main Methods:

• Ergonomic design based on lower limb biological structures.
• Construction of auxiliary force profiles mimicking the Achilles tendon.
• Application of iterative learning control to adjust drive unit displacements.
• Performance evaluation using treadmill walking at various speeds and inclines, measuring average heart rate (H_av).

Main Results:

• The A-Suit reduced average heart rate (H_av) by 7.25 ± 1.32% at 1.25 m/s compared to no-suit and power-off conditions.
• A maximum H_av increase of 7.83 ± 1.44% was observed due to the exoskeleton's additional mass.
• Overall H_av reduction with Power-ON across inclines was 6.93 ± 1.84% and 13.4 ± 1.93% compared to no-suit and power-off.

Conclusions:

• The A-Suit effectively reduces metabolic cost during walking, demonstrating potential for enhancing endurance.
• Ergonomic design and adaptive control are key to minimizing the metabolic penalty of exoskeleton mass.
• This technology shows viability for human augmentation and medical assistance applications.