Formulating and Deploying Strength Amplification Controllers for Lower-Body Walking Exoskeletons.

Area of Science:

• Robotics
• Human-Machine Systems
• Biomechanics

Background:

• Exoskeletons offer potential for augmenting human physical strength in diverse applications.
• Existing controllers often focus on repetitive tasks, limiting adaptability to unpredictable volitional movements.
• A need exists for versatile strength augmentation systems applicable to tasks like material handling and tool operation.

Purpose of the Study:

• To develop and demonstrate a task-agnostic force amplification controller for exoskeletons.
• To integrate this controller into a comprehensive whole-body control framework.
• To validate the system's ability to augment physical strength during unpredictable human movements.

Main Methods:

• A task-agnostic force amplification strategy was employed, utilizing force/torque sensors at the human-machine interface.
• An amplification controller was integrated into a whole-body control framework for exoskeletons.
• A powered lower-body exoskeleton was utilized to demonstrate the control framework's behavior in laboratory settings, including lifting an unknown payload.

Main Results:

• The developed controller successfully amplified the human operator's physical strength during volitional movements.
• The whole-body control framework effectively managed human-led foot transitions and inequality constraints.
• The exoskeleton demonstrated its capability to assist in lifting an unknown backpack payload while maintaining full backdrivability.

Conclusions:

• The task-agnostic force amplification approach provides a viable method for enhancing human physical strength with exoskeletons.
• The integrated whole-body control framework enables robust and adaptable exoskeleton control for dynamic tasks.
• This technology has significant implications for mobility augmentation, manual material handling, and tool operation assistance.