Intervehicle Security-Based Robust Neural Formation Control for Multiple USVs via APS Guidance

Round 1

Reviewer 1 Report

This paper presents an algorithm for implementing the formation switch mission on the inter-vehicle security-based robust formation control for unmanned surface vehicles. Specifically, it develops an adaptive potential ship-based guidance principle to secure the inter-vehicle collision. The authors use the artificial potential field so that the adaptive potential ship can program the real-time attitude reference for the unmanned surface vehicles with the security inter-vehicle distance while achieving the path-following task. A robust adaptive formation control algorithm is proposed to obtain the effective stabilization of the unmanned surface vehicles to the artificial potential field by fusion of a disturbance observer and the robust neural damping technique. Overall, I think the manuscript has merit. 

Some comments to improve the paper are: 

* In the introduction, add a paragraph that states the main objective of the paper and also its structure in order to improve its readability. 

* In the description of the variables, include their units. 

* Equation 3 is not linked to a sentence/paragraph. Is it linked to Assumption 1? Please explain. 

* Avoid referencing equations before they appear in the document, e.g., eqs 4 and 5. 

* Include a block diagram of the proposed robust adaptative formation control structure scheme. 

* Verify all the variables and acronyms used in the manuscript are defined in the main text even if they were already defined in the abstract, e.g., SGUUB is not defined in the manuscript's main text. 

* The theorem is very generic/open. It is necessary to define how to tune the design parameters, or on the other hand, under what conditions of the parameters the theorem holds. 

* Is there any way to compact the expressions in the theorem and proof in matrix form?

* Improve the size and quality of Figure 3. 

* The inputs in Figure 5 are very large. USV 3 needs more than -2x10^-12 Nm. Is that possible? The same observation is for the comparative example in Figure 12. Please be more realistic in the inputs. 

* The language/writing needs improvements. There are some typos in the document. There are a lot of wrong punctuation signs, or they are missing. Avoid the use of contractions.  

* The language/writing needs improvements. There are some typos in the document. There are a lot of wrong punctuation signs, or they are missing. Avoid the use of contractions.  

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear Authors;

I read the manuscript carefully, I think that the content is suitable to this journal with originality and novelty. This study shows the formation within consideration of the inter-vehicle collision avoidance. I only have several comments like as:

- The authors should describe kinematic model of USV, why it is three degrees of freedom.

- To explain the formulas (4-5), the authors should give a figure depicting the geometric relationship of GVS leader and n of GVS followers.

- In the manuscript, the authors have not explained why to use the BRF-NN model, so the content should be presented more clearly.

- In the manuscript, what are activation (transfer) functions for model BRF-NN? What is the configuration of this model?

- In equation (20) derived from equation number (1), it is showed relationship between the matrix [J] and the linear velocity of the USV, but in equation (20) is only the relationship of position, so the authors should check these equations.

- The result of numerical simulations should be presented more clearly to see the effectiveness of the proposed model.

The article has new content, but I think the authors should revise and answer some above comments to improve the quality of the manuscript.

Sincerely,

Dear Authors;

I think the authors should check the sentence structure as well as the grammar in English. 

Thanks for supporting.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

There is one more observation left. Be consistent with the use of the units, the manuscript mixes angles in degrees and in radians, please unify it. 

Minor corrections are needed.