Speed-Gradient Adaptive Control for Parametrically Uncertain UAVs in Formation

Round 1

Reviewer 1 Report

This paper focuses on the problem of decentralized control of unmanned aerial vehicle (UAV) formation in the presence of parametric uncertainty. A revised version of the feedback linearization approach has been proposed and implemented to transform a point mass UAV model. A linear model is obtained as a consequence of this, and within this model is an undetermined value for the mass of the UAV. At the same time, I have some concerns regarding this. 

1. WHich channel model for the UAV is considered in this work?

2. How the convergence of the proposed scheme is guaranteed here?

3. How the trajectory of UAV is optimized in this work?

4. Please explain in detail the working principle of the proposed scheme.

5. A lot of work has been done in the literature. Please explain in detail how your work is different from the others. Please explain this in a tabular form. 

6. Some of the recent work for the UAV is missing e.g. 

a)  What Will the Future of UAV Cellular Communications Be? A Flight From 5G to 6G

b)  Optimizing Computational and Communication Resources for MEC Network Empowered UAV-RIS Communication

c)  Joint Optimization of Sensors Association and UAVs Placement in IoT Applications With Practical Network Constraints

d) Intelligent ubiquitous computing for future UAV-enabled MEC network systems

7. Please Proofread the paper carefully and try to remove any possible errors and grammatical typos. 

 

Author Response

Review #1
This paper focuses on the problem of decentralized control of unmanned aerial vehicle (UAV) formation in the presence of parametric uncertainty. A revised version of the feedback linearization approach has been proposed and implemented to transform a point mass UAV model. A linear model is obtained as a consequence of this, and within this model is an
undetermined value for the mass of the UAV. At the same time, I have some concerns regarding this.

Authors’ response
Thank you for the positive, in general, assessment of our paper, the valuable comments, and the suggestions. In the revised paper all your comments are taken into account. Changes in the paper text are highlighted in blue.

1. Which channel model for the UAV is considered in this work?

Authors’ response. The UAV communication channels are not considered in the present paper and it is assumed that the information exchange necessary for the implementation of the proposed algorithms is feasible in one form or another. The corresponding remark is added to the problem description of Sec. 4, below line 291 (revised manuscript).

2. How the convergence of the proposed scheme is guaranteed here?

Authors’ response. The convergence of the proposed scheme follows from Proposition 1 and its proof (lines 231–238), Proposition 2 and its proof (lines 244–253), Proposition 3 and its proof (lines 332–342), and is illustrated by simulation results of Sec. 5.

3. How the trajectory of UAV is optimized in this work?

Authors’ response. The UAV In this work the UAV trajectory is considered given by some other, mission planning, algorithm, as it is stated below line 291: Unlike [5,23,27,42,73–75], in the present paper it is assumed that the reference trajectory (15) along which the UAV group should move is preliminary given.

4. Please explain in detail the working principle of the proposed scheme.

Authors’ response. The working principle of the proposed scheme is explained in lines 173–179. It is as follows: in this work, the feedback linearization method is applied to the nonlinear aircraft model. The uncertain mass is introduced into a linearized system, in contrast to the usual approach, where the feedback-linearized plant dynamics are described
by double integrators. This makes it possible to apply adaptation methods, such as IRM adaptive control, taking into account the presence of the unknown UAV mass.

5. A lot of work has been done in the literature. Please explain in detail how your work is different from the others. Please explain this in a tabular form.

Authors’ response
Thank you for the suggestion. Discussion Sec. 6 is added. Differences of the present work with the other ones are summarized in a tabular form in Tab. 1. 

6. Some of the recent work for the UAV is missing e.g.
a) What Will the Future of UAV Cellular Communications Be? A Flight From 5G to 6G
b) Optimizing Computational and Communication Resources for MEC Network Empowered UAV-RIS Communication
c) Joint Optimization of Sensors Association and UAVs Placement in IoT Applications With Practical Network Constraints
d) Intelligent ubiquitous computing for future UAV-enabled MEC network systems 

Authors’ response
Thank you for the suggestion. The mentioned works are cited in the revised manuscript, see [11,12,13,72]. The corresponding paragraphs are highlighted in blue (lines 57-68, 285–291).

7. Please Proofread the paper carefully and try to remove any possible errors and grammatical typos.

Authors’ response
English spelling and grammar were double-checked throughout the paper for fixing errors and grammatical typos.

The Authors are grateful to the Reviewer for the valuable comments and suggestions. We hope the revised manuscript satisfies the journal’s demands for the paper’s quality and can be accepted for publication.
Very sincerely,
Boris Andrievsky,
on behalf of the Authors

Author Response File: Author Response.pdf

Reviewer 2 Report

Please see the attached file.

Comments for author File: Comments.pdf

Author Response

Review #2
This paper investigated the problem of the decentralized control of UAV formation in the case of parametric uncertainty. The authors proposed a new version of the feedback linearization approach for a point mass UAV model transformation. Generally, the authors seem have done a solid work. However, some parts are not clear, and need to be further clarified, both the motivations and contributions are missing. The reviewer has the following concerns:

Authors’ response
Thank you for the positive, in general, assessment of our paper, the valuable comments, and the suggestions. In the revised paper all your comments are taken into account. Changes in the paper text are highlighted in blue.

1. The background is not well introduced. After the first paragraph, the authors directly introduced the existing works. The development of decentralized control and unmanned aerial vehicle (UAV) formation should be added.

Authors’ response
The information on the development of decentralized control and UAV formation is extended in the revised manuscript, see lines 57–73 and Sec. 6 (lines 442–450).

2. It is suggested to use past tense to introduce the existing works, such as [20], [21], [23], [24], [27], [33] and [34].

Authors’ response
Citations in the review part of the paper were systematically converted into the past tense as per the Reviewer’s suggestion (the corresponding changes are highlighted in blue).

3. It is suggested to introduce the following recent works in UAV [R1] and robust design [R2]-[R4] fields to highlight the state-of-the-art of this paper.
[R1] “Supporting IoT with rate-splitting multiple access in satellite and aerial-integrated networks,” IEEE Internet of Things Journal, vol. 8, no. 14, pp. 11123-11134, Jul. 2021.
[R2] “SLNR-based secure energy-efficient beamforming in multibeam satellite systems,” IEEE Transactions on Aerospace and Electronic Systems, early access, Jul. 2022, doi: 10.1109/TAES.2022.3190238.
[R3] “Refracting RIS aided hybrid satellite-terrestrial relay networks: Joint beamforming design and optimization,” IEEE Transactions on Aerospace and Electronic Systems, vol. 58, no. 4, pp. 3717-3724, Aug. 2022.
[R4] “Joint beamforming and power allocation for satellite-terrestrial integrated networks with non-orthogonal multiple access,” IEEE Journal of Selected Topics in Signal Processing, vol. 13, no. 3, pp. 657-670, June 2019.

Authors’ response. Thank you for the suggestion. The mentioned relevant works are cited in the revised manuscript, see [14,69,70,71]. The paragraphs with citations are highlighted in blue, see lines 71, 275–284.

4. Both the motivations and contributions are missing, which should be much emphasized to emphasize the novelty of this paper.

Authors’ response. The novelty of this paper is emphasized in lines 173–180 of the revised manuscript (highlighted in blue).

5. There are too many symbols in this paper, it is better to add a Table to list them, which would improve the readability of this paper.

Authors’ response. As per the Reviewer’s suggestion, table Nomenclature is added to the manuscript, lines 479–482.

6. What is the relationship between Eq. (4) and (11)?
Authors’ response. Eq. (11) is the result of the substitution (10) into (4). 

7. In simulation results, it is suggested to add some comparisons with the existing decentralized control schemes of UAV formation.

Authors’ response. Thank you for the suggestion. Section 5.4 UAV Group Control under External Disturbances (lines 400–441) with comparing simulation results was added to the revised manuscript.

The Authors are grateful to the Reviewer for the valuable comments and
suggestions. We hope the revised manuscript satisfies the journal’s demands for the paper’s quality and can be accepted for publication.

Very sincerely,
Boris Andrievsky,
on behalf of the Authors

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Author Adress all the comments. 
The Paper is accepted in its current form.

Reviewer 2 Report

The authors have addressed my concerns, no further comments.