Gait Phases Blended Control for Enhancing Transparency on Lower-Limb Exoskeletons
| Autor: | Massimiliano Solazzi, Antonio Frisoli, Simone Marcheschi, Francesco Porcini, Alessandro Filippeschi, Cristian Camardella |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
0209 industrial biotechnology
Control and Optimization Computer science wearable robotics 0206 medical engineering Biomedical Engineering 02 engineering and technology 020901 industrial engineering & automation Gait (human) Artificial Intelligence Control theory physical human-robot interaction Prosthetics and exoskeletons transparency Torque Finite-state machine Mechanical Engineering Work (physics) 020601 biomedical engineering Computer Science Applications Exoskeleton Weighting Human-Computer Interaction Preferred walking speed Discontinuity (linguistics) Control and Systems Engineering Computer Vision and Pattern Recognition |
| Popis: | A major challenge in the design and control of exoskeletons is the preservation of the user.s natural behavior when interacting with these machines. From this point of view, one of the most important features is the transparency of the exoskeleton. An ideally transparent exoskeleton follows the user's movements without interaction forces. This is the goal of many control algorithms proposed in the literature. Traditional algorithms are based on finite state machines and are affected by assistive torque discontinuity problems in the transitions between phases. State-of-the-art methods approach this problem by imposing a smooth transition that does not account for variable walking speed. In this work, the authors propose an innovative control algorithm for a lower-limb exoskeleton. The proposed control aims at solving the torque discontinuity problem, without requiring a smooth transitions strategy. The proposed control algorithm continuously blends the output of two independent single stance dynamic models, by weighting the contribution of each stance model to the total assistance based on the gait phase. A linear regressor is used to produce the weights, and it requires a brief user-specific calibration. Results showed a significant reduction of interaction forces, and a longer stride length when compared to two finite-state-machine-based controls at two speeds on the treadmill and one self-selected-speed in an overground walk. |
| Databáze: | OpenAIRE |
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