Design of a Payload Adjustment Device for an Unpowered Lower-Limb Exoskeleton

Area of Science:

• Biomechanics
• Robotics
• Human Augmentation

Background:

• Previous unpowered lower-limb exoskeletons with cam-follower hip joints had limited payload capacity.
• Performance degradation occurred when the exoskeleton's payload capacity was exceeded.

Purpose of the Study:

• To develop a payload adjustment device for unpowered lower-limb exoskeletons.
• To enable flexible and user-defined payload modification.
• To enhance exoskeleton performance across a wider range of loads.

Main Methods:

• Derived an exoskeleton dynamic equation to calculate required joint torque based on payload and posture.
• Designed a payload adjustment device integrated with the existing cam-follower structure.
• Utilized Adams simulation to validate the device's functionality and payload adjustment capability.

Main Results:

• The proposed device successfully demonstrated the ability to change the exoskeleton's payload capacity in simulations.
• The dynamic equation provided design guidelines for adjusting the allowable joint torque range.
• The device design considered user convenience and mass production.

Conclusions:

• The developed payload adjustment device offers a flexible solution for modifying exoskeleton payloads.
• This innovation can improve the adaptability and utility of unpowered lower-limb exoskeletons for diverse applications.
• The device allows wearers to quickly adjust the exoskeleton's payload to their specific needs.