PONE-D-24-04796Research on Control Strategy of Pneumatic Soft Bionic Robot Based on Improved CPGPLOS ONE

Dear Dr. Zhao,

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Van Thanh Tien Nguyen, Ph.D.

Academic Editor

PLOS ONE

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“This work was done in the Institute of Robotics at Shenyang University of Technology with support from the National Natural Science Foundation of China (Grant No. 52005344). We are grateful for this support. Besides, we would also like to thank the Department of Mechanical Engineering of the National University of Singapore for their support for the develop successfully of this work.”

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Additional Editor Comments:

Dear Dr. Wenchuan Zhao,

Thank you for submitting your manuscript to PLOS ONE.

The review stage has been completed, and we are pleased to inform you that we have received positive feedback from the reviewers regarding your work.

We kindly request that you revise your manuscript in accordance with the questions and comments raised by the reviewers. It is essential that you provide a clear, point-to-point response to each reviewer. Additionally, please meticulously review the English grammar and structure in your revised manuscript.

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Please do not hesitate to reach out if you have any further questions or concerns.

Thank you for your valuable contributions.

Sincerely yours,

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Partly

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: No

Reviewer #2: Yes

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: In this paper, the motion control strategy of pneumatic soft bionic robot based on improved central pattern generator (CPG) and adaptive neuro-fuzzy inference system (ANFIS) is proposed. By constructing a two-layer neural network model coupled by 22 Hopfield neuron oscillators, the motion of the robot is effectively controlled. The simulation and experimental results show that the strategy can quickly respond to the change of input parameters and output stable position signals. The strategy successfully realizes the propulsion waveform of biological rhythm movement, which shows its accuracy and anti-interference characteristics. Generally speaking, this research establishes a novel control strategy for pneumatic soft bionic robot, and contributes to the motion control in soft robot. However, before the paper is accepted, the author should consider the following questions.

1. In the first part of this paper, many researches on robot control based on cpg are introduced. Now the existing researches have realized adaptive control, which can improve the performance. What are the obvious advantages of the motion control system proposed in this paper compared with it?

2. How did the CPG control model expression (1) in Section 2.1 of the article come from? Please explain.

3. In the establishment of the topological structure in Section 2.4, there is no coupling relationship between the nodes in the first layer and the second layer. When the nodes in the first layer and the nodes in the second layer make mistakes, the signal transmission between them can't be realized, so it seems that the control system can't adjust and correct them by other nodes. Please give a reasonable explanation and a solution.

4. For the experimental test, the paper only compares the signal data of neurons with the simulation data, and whether the collected data such as motion trajectory and swimming distance mentioned in the article can be given, so as to intuitively see whether the control system can achieve the expected motion goal.

5. In the conclusion of this paper, it is mentioned that the motion control strategy realizes the accuracy and anti-interference of various motion modes controlled by the robot. What is the anti-interference here? Please introduce it in detail.

Reviewer #2: This paper proposed a CPG-ANFIS-PID motion control strategy for a pneumatic soft bionic robot, which can quickly respond to input parameter changes between different swimming modes, and stably output smooth and continuous dynamic position signals. However, the verification process for control effectiveness in the paper is relatively brief, and here are some suggestions:

1. The experimental verification section is too simple, only providing information on the output signal. It is necessary to supplement the actual control effect of the proposed control algorithm on the robot, including but not limited to swimming speed, turning radius, and the switching effect of different motions.

2. As authors state, “This article combines the complementary characteristics of neural networks and fuzzy theory to build an ANFIS, which can fully utilize the learning ability of neural networks and the ability of fuzzy systems to deal with fuzzy and qualitative knowledge.” (Page 14). The authors need to add comparisons in simulation and experiments to demonstrate the advantages of CPG-ANFIS-PID motion control strategy, such as the comparison results with general CPG control.

3. The introduction section of the paper is simply a stack of references and requires further logical enhancement.

4. References on CPG control are not comprehensive enough, here are some examples:

[1] Thandiackal, R., Melo, K., Paez, L., Herault, J., Kano, T., Akiyama, K., … & Ijspeert, A. J. (2021). Emergence of robust self-organized undulatory swimming based on local hydrodynamic force sensing. Science robotics, 6(57), eabf6354.

[2] Zhong, Y., Hong, Z., Li, Y., & Yu, J. (2023). A General Kinematic Model of Fish Locomotion Enables Robot Fish to Master Multiple Swimming Motions. IEEE Transactions on Robotics.

[3] Ijspeert A J, Crespi A, Ryczko D, et al. From swimming to walking with a salamander robot driven by a spinal cord model[J]. science, 2007, 315(5817): 1416-1420.

[4] Yu, J., Wu, Z., Wang, M., & Tan, M. (2015). CPG network optimization for a biomimetic robotic fish via PSO. IEEE transactions on neural networks and learning systems, 27(9), 1962-1968.

5. The clarity of the image should be further improved, preferably by using vector graphics.

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Reviewer #1: No

Reviewer #2: No

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PONE-D-24-04796R1Research on control strategy of pneumatic soft bionic robot based on improved CPGPLOS ONE

Dear Dr. Zhao,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please submit your revised manuscript by Jul 21 2024 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Van Thanh Tien Nguyen, Ph.D.

Academic Editor

PLOS ONE

Journal Requirements:

Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

Additional Editor Comments:

Please note that the reviewers' articles suggestion for citing in your manuscript are not encouraged if they are not related to your work. Thạnk you. 

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

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3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

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4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

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5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

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6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: It can be clearly seen that the author has put a lot of efforts into integrating the opinions and suggestions put forward in the first review. The current version of this paper is more comprehensive. The motion control strategy of pneumatic soft bionic robot based on improved central pattern generator (CPG) and adaptive neuro-fuzzy inference system (ANFIS) realizes accurate control and various tests, which provides valuable resources for the control of multi-motion modes of pneumatic flexible bionic robot with complex structure.

The references can be further expanded to highlight the significance of this study. Such and other relative references can be referred.

[1] The neuromechanics of animal locomotion: From biology to robotics and back

[2] Target tracking control of a bionic mantis shrimp robot with closed-loop central pattern generators

[3] Development and Motion Control of Biomimetic Underwater Robots: A Survey

After the above revisions, the manuscript can be accepted for publication.

Reviewer #2: This paper mainly discusses how to improve the motion control precision and anti-interference ability of soft robot, and puts forward the control strategy suitable for pneumatic soft bionic robot. The English writing is well and all figures are clear. Moreover, the authors have addressed my comments. I have no more question and I think it can be accept in current form. In the future, the authors can consider how to do a better integration without tether.

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: Yes: Gang Chen

Reviewer #2: No

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While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

Research on control strategy of pneumatic soft bionic robot based on improved CPG

PONE-D-24-04796R2

Dear Dr. Zhao,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

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Kind regards,

Van Thanh Tien Nguyen, Ph.D.

Academic Editor

PLOS ONE

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