A Robust Control Algorithm of a Descent Vehicle Angular Motion in the Earth’s Atmosphere
, Alexey Lapin, Vladimir Ryabchenko, Andrey Proletarsky, Maria Selezneva * and Konstantin NeusypinRound 1
Reviewer 1 Report
The paper describes a robust earth lander algorithm and compares it with an existing methodology.
The introduction of the paper partially shows the motivation of the paper. The first paragraphs starts some examples, which should be cited. The next part of the introduction shows the similar approach, however it hasn't shows the novelty and the role of the robustness in the applied formula. The last section, which is unnecessary to understand the paper is about the half of the full introduction. This is relatively long compared to the full Introductory text. It would be more important to highlight the goals of the research and the advantages/disadvantages of the other used optimization algorithms.
The methodology section is organized well and describes in detail the used algorithms.
Some more words from the other algorithm which used for the comparison, should be mentioned.
Please, revise the English of the Title.
The text of the figures is written in Russian. Please, translate the text and improve the quality/resolution of the figures, because it's hard to read them.
Author Response
Thanks to the reviewer for a detailed study of our article. All comments have been taken into account, the corresponding changes have been made to the text of the article.
The first paragraph starts some examples, which should be cited.
Answer: The first paragraph of the introduction has been removed OR references to the literature have been added to the first paragraph of the introduction.
The next part of the introduction shows the similar approach, however it hasn't shows the novelty and the role of the robustness in the applied formula.
Answer: Introduced into the introduction paragraphs about the role of robustness (SIXTH paragraph) and the novelty of the proposed approach (SEVENTH paragraph)
The last section, which is unnecessary to understand the paper is about the half of the full introduction. This is relatively long compared to the full Introductory text. It would be more important to highlight the goals of the research and the advantages / disadvantages of the other used optimization algorithms.
Answer: The final paragraph of the introduction in the previous version of the article has been deleted. The objectives of the study and the advantages of the proposed approach are added in the introduction (SIXTH paragraph).
Some more words from the other algorithm which used for the comparison, should be mentioned.
A description of the standard algorithm has been added to the introduction (FIFTH paragraph).
Please, revise the English of the Title.
Answer: Done.
The text of the figures is written in Russian. Please, translate the text and improve the quality / resolution of the figures, because it's hard to read them.
Answer: Done.
Author Response File: 
Author Response.docx
Reviewer 2 Report
No control structure (diagram) is presented.
No algorithm (flow-diagram) for the control method (robust controller designing procedure) is presented.
More simulated results have to be presented
The conclusions must be more detailed presented and linked with the results presented in Figure 1 and 2 and Tables 3 and 4.
Author Response
Thanks to the reviewer for a detailed study of our article. All comments have been taken into account, the corresponding changes have been made to the text of the article.
No control structure (diagram) is presented. No algorithm (flow-diagram) for the control method (robust controller designing procedure) is presented.
Answer: The classical law of modal control with a feedback matrix is applied, the structural diagram of which is standard and can be found in any reference book on the theory of automatic control (see, for example, Krasovsky A.A.) The research task was not to change the classical structure of the control law, but in finding a feedback matrix with the desired characteristics and substituting the found matrix into the standard circuit as feedback.
More simulated results have to be presented
Answer: A universal feedback matrix has been obtained, which is determined only by the mass-inertial characteristics of the descent vehicle and the desired poles of the closed-loop control system. The higher the values of the mass-inertial characteristics, the more thrust the control motors must be installed. In this case, as shown by modeling, the transient processes of stabilization of the angular position of the descent vehicle are approximately the same. In addition, in the given example, statistical modeling of a series of transient processes was carried out. The foregoing makes it inexpedient to include additional examples of mathematical modeling in the article.
The conclusions must be more detailed presented and linked with the results presented in Figure 1 and 2 and Tables 3 and 4.
Answer: Additional details have been added to the conclusions, containing links to the results presented in figures and tables.
Round 2
Reviewer 1 Report
Dear Authors,
Thank you for your improvements, I can accept most of them, however, I have problems with the first one, where the previous example changed but the citation also missing from the new example.
The number of citations and the proposed overview/examples are a bit short for an impact factored paper.
Author Response
Dear reviewer, thanks for the comment
As noted by the reviewer, additional links to relevant journals have been added in the introduction
Reviewer 2 Report
I want to keep my original opinion and consider the manuscript has not
been enough improved to reconsider my initial observations.
Author Response
Dear reviewer, thanks for the comments
In accordance with the comments, the following adjustments have been added to the article
No control structure (diagram) is presented. No algorithm (flow-diagram) for the control method (robust controller designing procedure) is presented.
Answer: The structural diagram of the on-board model of the controlled angular motion of the spacecraft is shown in Figure 1. The structural diagram of the proposed robust control algorithm is shown in Figure 2.
More simulated results have to be presented
Answer: An additional simulation of the motion of other vehicles with different mass-inertial characteristics and parameters of control motors has been carried out. The ranges of characteristics are presented in Table 6, and the simulation results are shown in Table 7.
Round 3
Reviewer 2 Report
No more comments
