Observer-Based Autopilot Heading Finite-Time Control Design for Intelligent Ship with Prescribed Performance

Round 1

Reviewer 1 Report

The topic of the paper is within the scope of the journal and this paper is quite interesting. The paper seems to have a contribution. However, a major revision is needed to rewrite the paper to reflect the contribution properly. Some observations are given below. These may help to revise the paper.

1/ Despite the motivating topic, the theoretical contribution of the manuscript does not seem significant and the experimental contribution does not consider. Thus, I am concerned about the application and practicability of this theory for ship system. The novelty of the approach is rather low since it seems all the methods are existing.

 

2/ In the introduction, it needs to be explored more with recently published work. The literature review in the introduction is not sufficient, the more attention of USV or ship should be added is docking or berthing, the authors can refer as: https://dx.doi.org/10.5574/JAROE.2016.2.4.192.

Moreover, the concept of sliding mode control should be discussed in terms of a deeper state of the art, some new works related to sliding mode control of second-order systems, especially the dynamic sliding mode control methods, robust sliding mode method, multiple sliding mode methods and so on, should be included. To help the authors in this direction, I suggest the following reference: https://doi.org/10.3390/s21030747, DOI: 10.1109/ACCESS.2020.3048706, https://doi.org/10.3390/math8081371

And the introduction should be added to do a better job of explaining the existing methods and why they are or are not valuable.

3/ A graph presenting the coordinate systems, state variables and control variables should be included for greater clarity.

4/ A flowchart needs to be included to explain the sequence of steps of the proposed method.

5/ Please add more the figures of membership functions of x1, x2 and output y. And explain them?

6/ The paper is simply a simulated heading model in horizontal plane motion of ship. The superiority of the proposed control algorithm is unclear. The explanations and analysis of simulation results should be enriched to show the validity of the data.

7/ Please proofread the paper thoroughly. I can find some spelling mistakes, Figure 3 needs a “legend” to separate the different used methods, please check all the captions and text of all figures in this paper. All captions now are wrong.

8/ Compared with existing results, the advantages of the paper should be further highlighted and the occurred difficulties of the conducted topic can be explained. What are the underlying factors that led to better performance of the proposed method?

9/ Conclusion needs extended elaboration on the topic, results, lessons learned and future works.

10/ Finally, from the simulations with satisfactory results, the system performance is expected in actual experiments with your proposed method. This paper now is difficult to prove the advantages of the proposed algorithm.

 

 

 

 

 

Author Response

1/ Despite the motivating topic, the theoretical contribution of the manuscript does not seem significant and the experimental contribution does not consider. Thus, I am concerned about the application and practicability of this theory for ship system. The novelty of the approach is rather low since it seems all the methods are existing.

-------Thanks for your valuable comments. According to the reviewers’ comments and suggestions, we have revised the manuscript carefully. Hopefully, the revised manuscript is satisfactory to you and reviewers. 

2/ In the introduction, it needs to be explored more with recently published work. The literature review in the introduction is not sufficient, the more attention of USV or ship should be added is docking or berthing, the authors can refer as: https://dx.doi.org/10.5574/JAROE.2016.2.4.192.Moreover, the concept of sliding mode control should be discussed in terms of a deeper state of the art, some new works related to sliding mode control of second-order systems, especially the dynamic sliding mode control methods, robust sliding mode method, multiple sliding mode methods and so on, should be included. To help the authors in this direction, I suggest the following reference: https://doi.org/10.3390/s21030747, DOI: 10.1109/ACCESS.2020.3048706,

 https://doi.org/10.3390/math8081371

And the introduction should be added to do a better job of explaining the existing methods and why they are or are not valuable.

-------Thanks for your valuable comments, we have added the following closely related references in the revised manuscript.

[35]M. T. Vu et al ., Robust Position Control of an Over-actuated Underwater Vehicle under Model Uncertainties and Ocean Current Effects Using Dynamic Sliding Mode Surface and Optimal Allocation Control, Sensors 2021, 21(3), 747.

[36]M. T. Vu et al., "Station-Keeping Control of a Hovering Over-Actuated Autonomous Underwater Vehicle Under Ocean Current Effects and Model Uncertainties in Horizontal Plane," in IEEE Access, vol. 9, pp. 6855-6867, 2021, doi: 10.1109/ACCESS.2020.3048706.

[37]Yaozhen, H.; Hairong, X.; Weigang, P.; Changshun, W. A fuzzy sliding mode controller and its application on ship course control. Proceedings of the 7th International Conference on Fuzzy Systems and Knowledge Discovery, China, 10-12 August 2010, pp. 635–638.

3/ A graph presenting the coordinate systems, state variables and control variables should be included for greater clarity.

-------Thanks for your valuable suggestions. We have added the graph in Figure 1.

 

4/ A flowchart needs to be included to explain the sequence of steps of the proposed method.

-------Thanks for your valuable suggestions. We have added the flowchart in Figure 2.

5/ Please add more the figures of membership functions of x1, x2 and output y. And explain them?

-------Thanks for your valuable suggestions. We have added the membership functions in Figure 11.

6/ The paper is simply a simulated heading model in horizontal plane motion of ship. The superiority of the proposed control algorithm is unclear. The explanations and analysis of simulation results should be enriched to show the validity of the data.

-------Thanks for your careful reading. The explanations and analysis of simulation results have been enriched.

7/ Please proofread the paper thoroughly. I can find some spelling mistakes, Figure 3 needs a “legend” to separate the different used methods, please check all the captions and text of all figures in this paper. All captions now are wrong.

-------Thanks for your careful reading. Those spelling mistakes have been corrected. A“legend”has been added in Figure. All the captions and text of all figures have been checked.

8/ Compared with existing results, the advantages of the paper should be further highlighted and the occurred difficulties of the conducted topic can be explained. What are the underlying factors that led to better performance of the proposed method?

-------Thanks for your suggestions and comments.

9/ Conclusion needs extended elaboration on the topic, results, lessons learned and future works.

-------Thanks for your suggestions and comments. Conclusions has been extended in this manuscript.

 

10/ Finally, from the simulations with satisfactory results, the system performance is expected in actual experiments with your proposed method. This paper now is difficult to prove the advantages of the proposed algorithm.

-------Thanks for your suggestions and comments.

Author Response File: Author Response.pdf

Reviewer 2 Report

I am confident that the topic of the article is interesting and essential in terms of research. In order to enhance the article quality, I suggest the following remarks be taken into account:

1. Please give the full name of the acronyms the first time they appear in the text (line 82: NN).
2. The authors should add flowchart of proposed analysis.
3. Equation 7: Vector not marked in bold and consequently further.
4. The model which was used in simulation wasn't presented.
5. Figures 1-8: Wrong figures descriptions.
6. Line 208: Why is assumed this values?
7. The References should be extended to include the publications on intelligent solutions in shipping that refer to the discussed subject, for instance:
   • Nicolau, V. Neuro-fuzzy system for intelligent course control of underactuated conventional ships, in Proceedings of the IEEE International Workshop on Soft Computing Applications, Hungary, 21-23 August 2007, pp. 95-101.
   • Borkowski P., Zwierzewicz Z. „Ship course stabilization based on a simplified computer dynamics model” Scientific Journals of the Maritime University of Szczecin no. 5(77), 2005 (97-109)
   • Yaozhen, H.; Hairong, X.; Weigang, P.; Changshun, W. A fuzzy sliding mode controller and its application on ship course control. Proceedings of the 7th International Conference on Fuzzy Systems and Knowledge Discovery, China, 10-12 August 2010, pp. 635–638.

Author Response

1/ Please give the full name of the acronyms the first time they appear in the text (line 82: NN).

-------Thanks for your careful reading. The full name has been given in this manuscript.

2/ The authors should add flowchart of proposed analysis.

-------Thanks for your suggestions and comments. The flowchart has been added in Figure 2.

3/ Equation 7: Vector not marked in bold and consequently further.

-------Thanks for your careful reading. We have revised vector by bold marked in this manuscript.

4/ The model which was used in simulation wasn't presented.

-------Thanks for your comments.

5/ Figures 1-8: Wrong figures descriptions.

-------Thanks for your careful reading. We have revised the figures descriptions.

6/ Line 208: Why is assumed this values?

-------Thanks for your comments. This values can be different, it is the initial value, the values will not influence the performance of system. But the designed parameters are given by simulation results which have good performance. Different parameter values have different performance.

 

7/ The References should be extended to include the publications on intelligent solutions in shipping that refer to the discussed subject, for instance:

-------Thanks for your suggestions and comments, we have added the following closely related references in the revised manuscript.

[38]Nhu, H. L. , et al. "Perturbation Observer-Based Robust Control Using a Multiple Sliding Surfaces for Nonlinear Systems with Influences of Matched and Unmatched Uncertainties." (2020).

[39]Nicolau, V. Neuro-fuzzy system for intelligent course control of underactuated conventional ships, in Proceedings of the IEEE International Workshop on Soft Computing Applications, Hungary, 21-23 August 2007, pp. 95-101.

[40]Borkowski P., Zwierzewicz Z. „Ship course stabilization based on a simplified computer dynamics model” Scientific Journals of the Maritime University of Szczecin no. 5(77), 2005 (97-109)

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Thank you for the revised manuscript. The new version is good now. The quality of the paper has been improved by properly addressed my previous comments. For this, the paper is much better structured and easy to understand.
+ Please check all the xlabel and ylable notations and text of all figures in this paper. I found some error font and notation in some Figures. Please check carefully.

+ Please check the caption of Figure 11. Is it membership function? It is the figure result of Heading angle and heading varying with the time. Please clarify it!

Other comments:

In ref [35]- [37], the author´s name is wrong and not enough. Please re-arrange as below:

Vu, M.T.; Le, T.-H.; Thanh, H.L.N.N.; Huynh, T.-T.; Van, M.; Hoang, Q.-D.; Do, T.D. Robust Position Control of an Over-actuated Underwater Vehicle under Model Uncertainties and Ocean Current Effects Using Dynamic Sliding Mode Surface and Optimal Allocation Control. Sensors 2021, 21, 747. https://doi.org/10.3390/s21030747

M.T. Vu, H.L.N.N. Thanh, T.T. Huynh, Q.T. Do, T.D. Do, Q.D. Hoang, T.H. Le, “Station-Keeping Control of a Hovering Over-Actuated Autonomous Underwater Vehicle Under Ocean Current Effects and Model Uncertainties in Horizontal Plane”. IEEE Access, Volume 9, pp. 6855-6867. DOI: 10.1109/ACCESS.2020.3048706

Thanh, H.L.N.N.; Vu, M.T.; Mung, N.X.; Nguyen, N.P.; Phuong, N.T. Perturbation Observer-Based Robust Control Using a Multiple Sliding Surfaces for Nonlinear Systems with Influences of Matched and Unmatched Uncertainties. Mathematics 2020, 8, 1371. https://doi.org/10.3390/math8081371

In addition, the format of references needs to be unified with the aim to satisfy the requirement of the journal, and the DOI number of some new references needs to be added in this paper. Please check carefully.

Author Response

Thank you for the revised manuscript. The new version is good now. The quality of the paper has been improved by properly addressed my previous comments. For this, the paper is much better structured and easy to understand.

+ Please check all the xlabel and ylable notations and text of all figures in this paper. I found some error font and notation in some Figures. Please check carefully.

-------Thanks for your valuable comments. The wrong xlabel and ylable notations have been rearranged in this manuscript.

 

+ Please check the caption of Figure 11. Is it membership function? It is the figure result of Heading angle and heading varying with the time. Please clarify it!

-------Thanks for your careful reading. Figure 11 is the figure result of heading and heading rate, the membership of {/hat x_2} has been shown in Figure 3. In this manuscript, we have deleted Figure 11.

 

Other comments:

 

In ref [35]- [37], the author´s name is wrong and not enough. Please re-arrange as below:

 

Vu, M.T.; Le, T.-H.; Thanh, H.L.N.N.; Huynh, T.-T.; Van, M.; Hoang, Q.-D.; Do, T.D. Robust Position Control of an Over-actuated Underwater Vehicle under Model Uncertainties and Ocean Current Effects Using Dynamic Sliding Mode Surface and Optimal Allocation Control. Sensors 2021, 21, 747. https://doi.org/10.3390/s21030747

 

M.T. Vu, H.L.N.N. Thanh, T.T. Huynh, Q.T. Do, T.D. Do, Q.D. Hoang, T.H. Le, “Station-Keeping Control of a Hovering Over-Actuated Autonomous Underwater Vehicle Under Ocean Current Effects and Model Uncertainties in Horizontal Plane”. IEEE Access, Volume 9, pp. 6855-6867. DOI: 10.1109/ACCESS.2020.3048706

 

Thanh, H.L.N.N.; Vu, M.T.; Mung, N.X.; Nguyen, N.P.; Phuong, N.T. Perturbation Observer-Based Robust Control Using a Multiple Sliding Surfaces for Nonlinear Systems with Influences of Matched and Unmatched Uncertainties. Mathematics 2020, 8, 1371. https://doi.org/10.3390/math8081371

 

In addition, the format of references needs to be unified with the aim to satisfy the requirement of the journal, and the DOI number of some new references needs to be added in this paper. Please check carefully.

-------Thanks for your careful reading. The author’s name is rearranged, and the missing DOI number have been added in this manuscript.

Author Response File: Author Response.pdf

Reviewer 2 Report

My suggestions provided in my original review have been incorporated in the manuscript. From my side the work is accepted in this new version.

Author Response

My suggestions provided in my original review have been incorporated in the manuscript. From my side the work is accepted in this new version

-------Thanks for your supportment.

Author Response File: Author Response.pdf