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Force and Position Control in Humans - The Role of Augmented Feedback
Published on: June 19, 2016
Myoelectric hand prosthesis force control through servo motor current feedback
Tálita Saemi Payossim Sono1, Luciano Luporini Menegaldo
1Mechanical Engineering Department, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
Artificial Organs
|August 18, 2009
Summary
This study demonstrates closed-loop control for a mechanical finger using electromyographic (EMG) signals. This EMG-controlled prosthetic finger achieved more precise grip force modulation compared to open-loop systems.
Area of Science:
- Biomedical Engineering
- Robotics
- Neuroprosthetics
Background:
- Developing advanced prosthetic devices is crucial for restoring function.
- Electromyographic (EMG) signals offer a promising interface for controlling prosthetic limbs.
- Accurate prehension force control is essential for natural object manipulation.
Purpose of the Study:
- To design and implement a closed-loop control system for a mechanical finger using EMG signals.
- To investigate the feasibility of indirect prehension force estimation via motor current.
- To compare the performance of closed-loop EMG control with open-loop control.
Main Methods:
- A three-degrees-of-freedom mechanical finger prototype was developed.
- EMG signals from arm muscles of volunteers commanded the finger's actuator.
- Prehension force was indirectly estimated by measuring the DC servo motor's current.
- A plant model (finger, motor, object) was created and parameters identified experimentally.
- A classical feedback phase-lead compensator was designed for closed-loop control.
Main Results:
- The closed-loop control system successfully modulated prehension force.
- Indirect estimation of prehension force using motor current was validated.
- The controlled mechanical finger demonstrated significantly more accurate force modulation of a compliant object than open-loop control.
Conclusions:
- EMG-based closed-loop control is effective for mechanical finger prehension.
- Indirect force estimation via motor current is a viable method.
- This approach enhances the dexterity and functionality of prosthetic devices.
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