COLREG-Compliant Optimal Path Planning for Real-Time Guidance and Control of Autonomous Ships

Round 1

Reviewer 1 Report

This paper concerns with the issue of optimal path planning for guidance and control of autonomous ships using the RRT star algorithm. In my opinion, this manuscript is well organized and the derivations seem correct. However, the paper needs to take into account some real-time situations to perform experiments to validate the simulation study. An experimental study should be incorporated and validated against the simulation studies.
Some typos and grammatical errors should be checked carefully, and some formatting problems need to be modified.

Author Response

This paper concerns with the issue of optimal path planning for guidance and control of autonomous ships using the RRT star algorithm. In my opinion, this manuscript is well organized and the derivations seem correct. However, the paper needs to take into account some real-time situations to perform experiments to validate the simulation study. An experimental study should be incorporated and validated against the simulation studies.

Thank you for your comment. I definitely agree with your point; experimental studies will be carried out extensively in the future, once the facilities will be available. Even if it exploits a high-fidelity validated dynamic simulation model, the presented study is subject to all the limits of the numeric simulation and has to be intended as a low-budget preliminary test in the sight of the future experimental campaign.

Some typos and grammatical errors should be checked carefully, and some formatting problems need to be modified.

Thank you for your suggestions. I checked the grammar and typos and rephrased some long sentences.

Reviewer 2 Report

• The paper is very informative. The terms used in maritime field are briefly presented but still enough for a novice to understand the topic.
• The paper is well-presented: all components of the system are well introduced, the used figures are self-explanatory.
• There are a few grammatical errors, some sentences are long and hard to understand. But those are minor.
• It would be interesting to see the results e.g when more than one target ship are nearby and all of them behave unexpectedly.

Author Response

The paper is very informative. The terms used in maritime field are briefly presented but still enough for a novice to understand the topic.

The paper is well-presented: all components of the system are well introduced, the used figures are self-explanatory.

Thank you for your kind comments.

There are a few grammatical errors, some sentences are long and hard to understand. But those are minor.

Thank you for the comment. I corrected many grammar errors and typos, and rephrased some long and verbose sentences.

It would be interesting to see the results e.g when more than one target ship are nearby and all of them behave unexpectedly.

Thank you for the comment. Obviously, the simulations presented in the paper are far from being exhaustive of all the possible cases, but your suggestion is on point. In the first scenario, both targets behave unexpectedly, but indeed the own ship manages them one at the time. In the light of your suggestion, I added one more (winding yet successful) sub-case to the second scenario, trying to force the own ship close to both the targets.

Reviewer 3 Report

A list of acronyms should be made and added to the paper before the list of
references.

Author Response

A list of acronyms should be made and added to the paper before the list of references.

Thank you for your suggestion. I added the acronym list at the end as you suggested. Moreover, I checked the text explains all the acronyms.