Research on Unmanned Aerial Vehicle Path Planning
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe article focuses on analyzing and classifying path-planning algorithms for UAVs. It categorizes these algorithms into traditional, intelligent, and hybrid types, further dividing them based on different planning aspects like space, time, and task. The authors systematically evaluate each category's strengths and limitations, aiming to identify optimal solutions for various UAV applications. The paper's primary contribution lies in offering a detailed overview of the current state of UAV path-planning algorithms, highlighting their practical applications, and suggesting directions for future research.
The article could be improved by providing accurate descriptions for some qualities, for example, accurate or highly accurate trajectories could be described in mm, cm, m, or relative units. For example in "...method emphasized the crucial link between flight step size and path quality, where a smaller step length enhances path planning accuracy at the expense of increased computational effort" it does not say any limitations or examples of step size, and path quality, or computational effort or its units.
Also, I have reviewed the document, but I was unable to find the specific title of the article referred to as "Our" in Table 1. Where it should be algorithm superior to all others. If this is to be kept in the article, reference should be provided and clearly state, where authors find their algorithm in each of the classification and qualities tables. If the authors don't have an article describing the algorithm, a detailed section with a description and systematic analysis, and, an example of application should be provided.
Author Response
Thank you very much for your letter and the comments from the referees about our paper submitted to Drones. We have learned a lot from the referee's comments, which are fair, encouraging, and constructive. After studying the advice carefully, we have made corresponding changes. Our response is shown below, and we have made changes in yellow color to highlight our manuscript. If you have any questions about the paper, please do not hesitate to contact us.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsArticle title:
Research on Unmanned Aerial Vehicles Path Planning
General comments:
The paper reviews the current research on unmanned aerial vehicles path planning. The review covers many of the significant algorithms that are current in the research domain. The authours begin the review going through the notable algorithms, followed by classifying the algorithms according to their functions. The paper ends with a note on recommended future research directions. Overall, the authours were successful in identifying the credible sources for each algorithm. The discussion is clear and unbiased. However, there are a few cases where more sources should be referenced, as a single source cannot represent the features of an algorithm. There are also a few errors which are highlighted in the detailed comments.
Detailed comments:
Line 16: first keyword “u” is in a different font.
Line 20: The “a” in aerial and “v” in vehicles are in different fonts.
Line 20-21: I don’t fully agree with this definition. Technically, UAV refers to the vehicle itself, regardless of its mode of operation. Not all UAVs or drones are designed to operate autonomously; most UAVs are still manually operated.
Line 62: Table 1, the third column “main features” require some vertical spacing adjustment. It is hard to tell where the current row ends and the next row starts.
Line 93: I think “Path Planning Objectives” is a more suitable title for this subsection.
Line 159: Table 2, there is only 1 reference for the potential field method. Are the advantages and disadvantages summarised based on this reference only? For a more comprehensive review paper, more references should be included.
Line 162-164: This sentence can be rewritten. It is not clear which algorithm is worse than which two other algorithms.
Line 165: Please elaborate on what “threats” are.
Line 160-167: This paragraph seems a bit out of place. Is the signpost method another space modelling algorithm? Is there a reference that the reader can read more about the method?
Line 188: I think there is a typo “high-cost” should be “height-cost”.
Table 3: Similar to Table 1, vertical spacing adjustments or row dividers can really help with the presentation of these data.
Line 308: Typo, “Intelligent” Algorithm.
Figure 3 and Figure 4: It is a bit strange that the branches of swarm intelligence algorithm are included in a separate figure, whereas the AI algorithm branches are in figure 3, when they are all under the same intelligent algorithm title.
Figure 3: Typo, “Intelligent”.
Line 329, the “DE” abbreviation, assuming it means differential evolution, seems to be the first instance of this abbreviation appearing in this paper. Please use the full name of the algorithm. Similarly, “NSGA-II”. This will be helpful for readers who are not familiar with evolutionary algorithms.
Line 342: “Bio-Inspired” algorithm is a more common name. You actually changed to this name on line 361. It is better to keep the names consistent.
Line 642: Words such as “let’s” are informal and should be avoided.
Line 669 to 671: this is the basically the same as what Is stated in line 644-648. This can be removed for conciseness. There are also a few other instances which the authors are encouraged to review for conciseness. Such as line 700-703 is basically the same as 658-661. It is not necessary to reiterate the importance of path planning at the beginning of each section.
Line 726: Section 5 feels like a complete change in focus compared to previous sections. The section focuses on discussing the limitation of current Multi-UAV path planning methods and potential for future research, rather than the current research activities. If this is intentional then the section name should be renamed accordingly.
Line 790: “3D and 4D” will be more consistent. In addition, 4D path planning is usually referred to incorporating time as the 4th dimension. Here the authours are suggesting including multi-UAV cooperation as the 4th dimension. This should be clarified at the beginning of the section.
Comments on the Quality of English LanguageThere are a few minor mistakes. Overall, the English is fine.
Author Response
Thank you very much for your letter and the comments from the referees about our paper submitted to Drones. We have learned a lot from the referee's comments, which are fair, encouraging, and constructive. After studying the advice carefully, we have made corresponding changes. Our response is shown below, and we have made changes in yellow color to highlight our manuscript. If you have any questions about the paper, please do not hesitate to contact us.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsIn this paper, the authors provide an overview of UAV path planning algorithms. The review of path planning algorithms is quite extensive. 136 literature sources are reviewed. The authors gave examples of how to classify the algorithms.
I missed two things in the paper:
- The authors could have done more research on i4D path planning algorithms. This is now partially covered in section 6.1.
- By analysing the different algorithms, the authors could have used the criteria of efficiency or complexity of the algorithm to create a sort of "map".
All in all, I liked the work.
Author Response
Thank you very much for your letter and the comments from the referees about our paper submitted to Drones. We have learned a lot from the referee's comments, which are fair, encouraging, and constructive. After studying the advice carefully, we have made corresponding changes. Our response is shown below, and we have made changes in yellow color to highlight our manuscript. If you have any questions about the paper, please do not hesitate to contact us.
Author Response File: Author Response.pdf
