A Walking Assist Control with Exoskeleton for Active Prosthetic Leg Motion and Its Evaluation Method in Passive...

Area of Science:

• Biomedical Engineering
• Robotics
• Biomechanics

Background:

• Developing effective gait assistance for active prosthetic legs is crucial for user mobility.
• Existing methods often require complex sensor setups or rely on friction coefficients.
• Force estimation without direct measurement is a key challenge in prosthetic control.

Purpose of the Study:

• To present a novel force sensorless knee flexion detection and gait assistance system for active prosthetic legs.
• To evaluate the impact of the proposed system on gait characteristics.
• To enable gait assistance using a minimal sensor configuration.

Main Methods:

• Utilized a Reaction Torque Observer (RTOB) to estimate ground reaction force without strain gauges or friction coefficients.
• Integrated an exoskeleton device into the prosthetic leg, functioning as an active prosthetic leg.
• Employed waist trajectory measurement to assess whole-body movement and gait characteristics.

Main Results:

• Successfully estimated ground reaction forces using the RTOB, eliminating the need for ground strain or friction data.
• Demonstrated the system's ability to provide gait assistance for active prosthetic legs.
• Quantified differences in gait characteristics across able-bodied individuals, passive prosthetic users, and active prosthetic users.

Conclusions:

• The proposed sensorless approach advances gait assistance for active prosthetic legs.
• This method offers a viable solution for developing control systems with fewer sensors.
• Further analysis of gait characteristics aids in improving prosthetic leg functionality and user experience.