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by
  • Chenxu Xiao 1,
  • Li Tang 2,* and
  • Zhiyuan Lu 1
  • et al.

Reviewer 1: Guangbin Cai Reviewer 2: Keigo Watanabe Reviewer 3: Anonymous

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In this paper, the author proposes an event-triggered control method for flapping-wing robot aircraft system based on high-gain observers. Simulations are presented to illustrate the effectiveness of the proposed method.

Overall, the paper has certain engineering application value, but the research motivation and challenges need further refinement, and the writing of the paper requires further standardization. Specific comments are as follows:

  1. The research motivation and challenges of this paper need to be further refined.
  2. It is recommended that the control framework diagram of the whole research content be given in the paper.
  3. Some of the formulas in the paper are vague and should be adjusted.
  4. For event-triggered control, the control consumption can be further reduced by introducing an internal dynamic variable, known as dynamic event-triggered, such as IEEE Transactions on Aerospace and Electronic Systems, 2025, Dynamic event-triggered gain-scheduled H∞ control for a polytopic LPV model of morphing aircraft, which can be referred to either in the main text or in future outlooks.
  5. The simulation is not enough. It is recommended to add comparative simulations to validate the advantages of the method presented in this paper. In addition, there is almost no triggering after 10s in Figures 6 and 7. Please analyze the cause of this phenomenon.
  6. The author should show the future research direction in conclusion.
  7. The citations in the references need further consideration, as multiple papers by the same author have been cited.
Comments on the Quality of English Language

The quality of English language needs to be improved.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

1) Why is a high-gain observer necessary in the first place? You should clearly explain why a normal observer is not sufficient. I think a high-gain observer is a kind of disturbance observer.

2) What is the Zeno phenomenon? Please add an explanation so that people outside this field can understand it.

3) You formulate the control of this flapping robot as ET Control, but have you clearly described the necessary conditions for fitting it into the framework of ET control?

In other words, are the necessary conditions for the controlled object to be considered appropriate for ET control satisfied? Especially in terms of stability.

4) Isn't this more of an idea similar to random sampling control? Or maybe it would be more appropriate to call it so-called down sampling control.

What is the difference with this random sampling control?

5) Fig. 8 and 9: Why does the observer response behave so oscillatoryly with respect to the actual response? Is the observer poorly designed? I think we should do gain design or pole placement to get a more damped response.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The reviewed article concerns the area of ​​application of movable wings in aircraft, which are observed in many living creatures with the ability to fly. The authors describe such application using the example of Flapping-wing robot aircraft systems. The assumptions regarding the purpose of the research were formulated correctly, but the assumption of the impossibility of observing mechanical quantities describing the movement of the wing is unjustified. In modeling using FEM, all quantities describing the movement can be calculated. The article does not contain any research results on a real object, so where does the assumption about the impossibility of conducting direct observation come from?

The adopted geometric model of the aircraft (Fig. 1) raises major doubts. It looks as if an attempt was made to replace the classic solution of obtaining lift in an aircraft with movable wings. In my opinion, such an approach is incorrect - the lift force is generated as a result of the flow around the air profile when a certain speed is given to the air stream. In the case of movable wings, the theory of generating lift as a result of the work of an aircraft propeller should rather be applied.

To sum up, the article requires consideration in terms of the assumptions regarding modeling and interpretation of the obtained results.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The modifications are generally satisfactory with no further comments.

Comments on the Quality of English Language

good

Author Response

Comment: The modifications are generally satisfactory with no further comments.

Response: We sincerely appreciate your positive feedback on our revisions. Thank you for your time and valuable insights throughout the review process, which have significantly improved the quality of our manuscript.

Reviewer 3 Report

Comments and Suggestions for Authors

In my first review I drew attention to several issues. I mostly agree with the Authors' answers and accept them. Unfortunately, I cannot accept the Authors' model of an aircraft with flapping wings (Figure 1). For an aircraft with flapping wings, a completely different type of construction should be used. This will have a major impact on the geometric appearance of the model of such an aircraft. I propose changing Figure 1 to one that will correspond to the assumptions described in the article (an aircraft with moving wings).

Author Response

Please see the attachment.

Author Response File: Author Response.pdf