Review Reports

Round 1

Reviewer 1 Report

The article entitled “Robust Control System of Quadrotor Based on Linear Active Disturbance Rejection” was reviewed.

The paper is interesting but has some principal issues:

1.      The format of the paper is not good. There is not a result section, discussion and as such it is difficult to evaluate its results.

2.      After the introduction a short material and method section should include the drone used, its characteristics in a table, how the constants for the mathematical model was obtained.

3.      It is a simulation and as such the name of the article should be Simulation of a quadrotor under Linear Active Disturbance Rejection.

4.      The variables values for excessive wind for modelling should be written and explained.

Considerations:

In the abstract you should write in extense the meaning of ADRC, as well as RBF.

In page 2 remove reference….. in the following sentence: On the basis of PID control, Professor Han Jingqing improved it into an ADRC; Reference [13] proposes an adaptive sliding mode controller combined with sliding mode control, which has better stability.

What is the meaning of LADRC and LESO.

Remove the words of literature in this paragraph. For example, remove In the literature [15], A neural network observer is proposed [15], and the weights and center values of the Neural Network can be updated online, so it is suitable for approximating any nonlinear function, making the system more robust;

In equation 6 of page 4 were are the constants referred by: The rotation of the quadrotor is represented by θ、φ、ψ

In page 5 eliminate below: The robust control system is shown in Figure 3 below.

Change to 3.2.1. Design of RBFNN

Change to 3.2.2. LESO

Table 1 and Table 2 have to be fixed. Both have to be centered and the description of each table inserted at the top.

In figure 6 the square script within each figure has to be bigger.

The conclusion is not well written and should include some results.

References:

The references are not well written.

In all the references there must be a comma after the surname, before the name. After the name of the article name [J] has to be removed. The journal has the year highlighted followed by the volume and page numbers.

For example, references 1 and 9 have the surnames in capital letters, which is wrong. The comma between surname and name is missing and the name should only present the first letter.

 

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Summary: In order to address the issue that the quadrotor is susceptible to various disturbances during the takeoff process of non-horizontal planes and powerful disturbances, a control strategy based on linear active disturbance rejection is proposed in this study.

    Comments and Suggestions: + A short paragraph describing the structure of the paper needs to be included at the end of the introduction   + A related work section is missing and needs to be added in order to give the reader the ability to compare the proposed approach with similar proposed approaches    + A table summarizing the main contributions of previous related works and comparing them with the approach proposed by the authors will be of great value.   + In the related work section, the authors need to consider security aspects related to the use of quadrotors. For this purpose they are invited to include the following references: - https://ieeexplore.ieee.org/abstract/document/9842403 -  https://www.mdpi.com/2504-446X/6/11/363   + A Discussion will be helpful for emphasizing the strong points of the proposed approach and for identifying its limitations too    + The conclusion is too short and needs to be extended.   + No future work directions are presented   + Are simulations enough to evaluate the feasibility and the efficiency of the proposed approach? Why not perform some real experiments?!   + The abbreviation RBFNN corresponds to which original terms? This notion is not enough clear.   + Figure 4: Does the model contain only one hidden layer on many ones?   + The abbreviation LESSO corresponds to which original expression?    

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Manuscript ID applsci – 2069666

Title: "Robust Control System of Quadrotor Based on Linear Active Disturbance Rejection".

 

Undoubtedly, the presented manuscript is relevant from a scientific and practical point of view, especially in the context of the industry 4.0. This study opens up defined prospects in this field of knowledge. Manuscript entitled "Robust Control System of Quadrotor Based on Linear Active Disturbance Rejection" of interest for a highly ranked journal like "Applied Sciences".

 

This manuscript includes the next adequate structure:

* Introduction (p. 1 – 2);

* Mathematical model (p. 3 – 4);

* Controller Design (p. 4 – 14);

* Conclusion (p. 14).

Weakness and methodological inaccuracies are not detected. The figures and tables are appropriate; they reflect the complex results of this study. References list is adequate and includes 29 titles.

 

I hope that next suggestions can help to improve the manuscript.

1. Indicate the directions of further research or improvements.

2. Attentive text proofreading is needed.

3. Also references list proofreading is needed. I suggest you to follow the link:

https://www.mdpi.com/journal/applsci/instructions

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The article Simulation of a Quadrotor Under Linear Active Disturbance Rejection

Was reviewed again and the following comments are:

The article looks much better.

 

It is important to justify the type of drone used to obtain the characteristics of table 1. If the characteristics were taken from a small o a bigger drone they will change. If it was constructed by the authors it should be included. This is fundamental in the article although it is a simulation.

The last paragraph just before the conclusion section should be moved after the title: 4. System simulation

Although you mention the attitude as the most critical variable there is no way to prove it if there are no comparison between experiments

 

 

References

There are still errors in the references.

References 14 and 15 have still the names in capital letters.

Reference 4 puts the journal number (6) within parenthesis, that should be removed.

After a point, a space should be added in most of the references.

 

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The authors took into account all my remarks and suggestions. I think the paper is ready for publication now. Good luck.

Author Response

Thank you for your suggestions, all of which are very important and they have guided us in our thesis writing and research work. Once again, I would like to express my sincere gratitude for your help.