Predictor–Corrector Guidance for a Hypersonic Morphing Vehicle

Round 1

Reviewer 1 Report

Comments for author File: Comments.pdf

Minor editing of English language required

Author Response

Please see the attachment.

The full text has been modified in English language

Author Response File: Author Response.docx

Reviewer 2 Report

Dear Authors.

I studied the paper very carefully to understand each aspect of the presented research. I think that this is a valuable manuscript.

This is original research. I did not detect plagiarism.

However, in the proposed form, the paper cannot be accepted for publication. Below please see the list of my suggestions on how to improve the quality of the paper.

General comments

*** The main problem with this paper is that the presented results might be difficult or even impossible to reproduce. I suggest including more implementation details.

*** What simulation environment or language (MATLAB, C) was used to implement the developed model?

*** In the presented formulas, you used a lot of parameters. I am of the opinion that you should clearly explain how to set these parameters.

*** The English language should be improved. Sometimes it is rather difficult to understand some issues. For example, please see line 266 “Bank angle scheme includes size and sign scheme.” Such comments are too short.

*** What about the propulsion of this aircraft? Is the vehicle equipped with an engine?

*** In the study, you reported scenarios with circular no-fly zones. Did you consider other shapes?

*** Did you consider the influence noise of the sensors on the performance of the proposed method? This issue might be crucial for the whole system.

*** Could you include more simulation scenarios? In that way, the paper will be much more interesting for the readers.

Specific comments

*** Lines 19 – 67, Introduction ***

Several times you used the phrases like “Reference [11]…”. I think it should be completely reorganized. It will be much better to write “Liu et al. in [11]…”

I think that you should include more citations. You simply listed the existing works with a brief explanation. In this part of the paper, you should rather include a discussion of the advantages and disadvantages of the existing approaches. It should be a critical literature review.

*** Line 69 ***

You mentioned that “The shape of the aircraft is a wave-rider…”. Could you include more details? I suggest including precise data about the object. Could you include a separate figure with the shape of the object and its basic dimensions? These data are very important to make the results reproducible.

*** Line 74, Figure 1 ***

Could you replace Figure 1 with a more detailed drawing?

*** Lines 78 – 79 ***

You mentioned that “…satisfies the assumption of instantaneous equilibrium”. Could you explain this assumption? This is not clear and rather difficult to understand.

*** Line 84, Equations 1 ***

Did you derive these equations by yourself or find them in the literature? Maybe it will be better to include some references here.

How did you obtain the lift and drag of the vehicle? I think that the aerodynamic characteristics should be presented. This information is very important to reproduce the results.

*** Line 85 ***

You mentioned that “r denotes the distance between the aircraft's center of gravity”. This is completely unclear. You should define precisely what is the second point. It should be something like this “r denotes the distance between the aircraft's center of gravity and XXX” where XXX is the definition of the second point.

*** Line 87 ***

Did you consider the variation of gravity acceleration g with altitude or assumed that g = 9.81 m/s2?

*** Lines 107 and 109 ***

Please replace “type” with “Type”.

*** Line 113 ***

In the formula on delta beta you used the function “nsin(phi)”. Could you explain this issue? I think that is a typographical mistake.

*** Lines 156 – 157 ***

You included the phrase “Selection algorithm parameters:…” Could you explain how to select these parameters?

*** Line 430, Figure 7 ***

The altitude of the aircraft changes significantly and oscillates. Could you explain this phenomenon?

*** Lines 431 – 432, Figure 9 ***

Did you present the commanded or actual angle of attack? The values change very rapidly. Please include additional comments.

*** Lines 434 – 438 ***

Could you include a more detailed interpretation of the results?

*** Lines 473 – 481, Figure 16, 17, 18, 19, 20, 21, 22 ***

In the legend entries, the word “tragectory” should be replaced by “trajectory”.

*** Line 480, Figure 23 ***

A separate vertical axis for "dynamic pressure" and "heating rate" should be included.

*** Line 487 ***

Please remove the phrase “Error! Reference source not found.” and update all the fields in the paper.

*** Lines 500 – 510 ***

“Conclusions” is definitely too short. Could you suggest some further possible research directions? What is the contribution of this paper to the existing knowledge? Such issues must be precisely explained once again at the end of the paper.

*** Lines 519 – 576 ***

The “References” should be formatted ideally according to MDPI requirements.

 

In the attached PDF file I highlighted the problematic issues in blue color. I hope the paper will be publishable in the future. Please carefully revise the whole paper. I wish you great success in your endeavours.

 

Kind regards,

 

Reviewer

The Quality of English Language require extensive editing. The manuscript includes a lot of mistakes.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Dear Authors.

Thank you kindly for the revised version of the manuscript. Thank you for the detailed response to all my comments.

I studied the paper again very carefully. I think that the proposed version of the paper is much better when compared with the initial submission. You solved most of the problematic issues. However, I detected a set of minor issues.

*** Line 106 ***

In line 106 you used a superscript. Please see “…are given as follows [37]:” . Please remove this superscript.

*** Lines 341 – 342 ***

The heading angle is denoted by “Psi_Los”. Something went wrong with the use of the subscript “Los”. Could you unify the notation?

*** Figure 13 ***

Can you include a small subplot with a magnified view of the curve? There are many data points, and it is rather hard to see “Fit” and “Y = T” curves.

I highlighted the problematic issues in the attached pdf file. I think that the manuscript can be accepted for publication.

Kind regards,

 

Reviewer

I think that the English Language is rather fine. Only minor editing of the text is required.

Author Response

Please see the attachment.

Author Response File: Author Response.docx