This preprint is under consideration at Journal of NeuroEngineering and Rehabilitation. A preprint is a preliminary version of a manuscript that has not completed peer review at a journal. Research Square does not conduct peer review prior to posting preprints. The posting of a preprint on this server should not be interpreted as an endorsement of its validity or suitability for dissemination as established information or for guiding clinical practice.
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Research
Longhan Xie
Corresponding Author
ORCiD: https://orcid.org/0000-0002-5137-1413
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Background
The construction of lightweight robots poses one of the major challenges in the field of active robots since bearing the weight of an active robot significantly increases metabolic cost. However, few studies have achieved a substantial reduction in the robot weight. The primary reason is that the weight of the actuator, which comprises the main weight of the robot, is limited by the specific power, power requirements and assisting efficiency.
Methods
In this paper, we propose a new method that is utilizing the energy harvesting function of the Achilles tendon to improve the assistance efficiency of ankle robots to reduce the weight of the actuator and we design a novel ankle robot to test the validity of the method. The robot works with the ankle plantar flexor at 43%-60% of the gait cycle and has no other effects on the joints or the tendon of the lower limb. Healthy subjects were recruited to test the prototype in three conditions: free walking, power-on walking, and power-off walking. Data on the robot assisting power, metabolic cost and kinematics in different conditions were collected and analyzed.
Result
The results showed that the ankle robot can deliver forces at the controlled assistance timing. The average assisting power of 0.0650±0.0054 W/kg per leg resulted in an 8.7±8.1% and 19.0±6.4% net reduction in metabolic cost in power-on walking compared to free-walking and power-off walking, respectively.
Conclusion
Compared with the results of some of the best research, our initial result supports the validity of the method. This method can help to reduce the weight of active robots and the technical innovative method to determine the assistance timing more accurately and the novel design of the ankle robot can provide a reference for future research. To the best of our knowledge, this method is the first to use the human physiological structure to optimize the design of active robots.
Keywords
Assisting efficiency, Ankle robot, Energy harvesting, Achilles tendon, assistance timing
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Peer Review Timeline
CURRENT STATUS: Under Review
Version 1
Posted 02 Jun, 2020
No community comments so far
Editorial decision: Withdrawn by author
On 26 Jan, 2021
Review #2 received
Received 18 Sep, 2020
Reviewer #2 agreed
On 23 Aug, 2020
Reviewer #1 agreed
On 22 Jul, 2020
Reviewers invited
Invitations sent on 19 Jul, 2020
Editor assigned
On 26 May, 2020
First submitted
On 25 May, 2020
Submission checks complete
On 25 May, 2020
Editor invited
On 25 May, 2020
Metrics
Comments: 0
PDF Downloads: ...
HTML Views: ...
Subject Areas
Robotics
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This preprint is under consideration at Journal of NeuroEngineering and Rehabilitation. A preprint is a preliminary version of a manuscript that has not completed peer review at a journal. Research Square does not conduct peer review prior to posting preprints. The posting of a preprint on this server should not be interpreted as an endorsement of its validity or suitability for dissemination as established information or for guiding clinical practice.
Learn more about In Review
Research
Longhan Xie
Corresponding Author
ORCiD: https://orcid.org/0000-0002-5137-1413
Badges
Prescreen
This manuscript passed our Prescreen assessment
Complete author information
Appropriate declaration statements
Potential risks to human health
Prescreen
Peer Review Timeline
CURRENT STATUS: Under Review
Version 1
Posted 02 Jun, 2020
No community comments so far
Editorial decision: Withdrawn by author
On 26 Jan, 2021
Review #2 received
Received 18 Sep, 2020
Reviewer #2 agreed
On 23 Aug, 2020
Reviewer #1 agreed
On 22 Jul, 2020
Reviewers invited
Invitations sent on 19 Jul, 2020
Editor assigned
On 26 May, 2020
First submitted
On 25 May, 2020
Submission checks complete
On 25 May, 2020
Editor invited
On 25 May, 2020
Metrics
Comments: 0
PDF Downloads: ...
HTML Views: ...
Subject Areas
Robotics
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Background
The construction of lightweight robots poses one of the major challenges in the field of active robots since bearing the weight of an active robot significantly increases metabolic cost. However, few studies have achieved a substantial reduction in the robot weight. The primary reason is that the weight of the actuator, which comprises the main weight of the robot, is limited by the specific power, power requirements and assisting efficiency.
Methods
In this paper, we propose a new method that is utilizing the energy harvesting function of the Achilles tendon to improve the assistance efficiency of ankle robots to reduce the weight of the actuator and we design a novel ankle robot to test the validity of the method. The robot works with the ankle plantar flexor at 43%-60% of the gait cycle and has no other effects on the joints or the tendon of the lower limb. Healthy subjects were recruited to test the prototype in three conditions: free walking, power-on walking, and power-off walking. Data on the robot assisting power, metabolic cost and kinematics in different conditions were collected and analyzed.
Result
The results showed that the ankle robot can deliver forces at the controlled assistance timing. The average assisting power of 0.0650±0.0054 W/kg per leg resulted in an 8.7±8.1% and 19.0±6.4% net reduction in metabolic cost in power-on walking compared to free-walking and power-off walking, respectively.
Conclusion
Compared with the results of some of the best research, our initial result supports the validity of the method. This method can help to reduce the weight of active robots and the technical innovative method to determine the assistance timing more accurately and the novel design of the ankle robot can provide a reference for future research. To the best of our knowledge, this method is the first to use the human physiological structure to optimize the design of active robots.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
This preprint is available for download as a PDF.
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