Energy Efficiency of Connected Autonomous Vehicles: A Review
Round 1
Reviewer 1 Report
The paper addresses the subject of Connected Autonomous Vehicles. As presented, it is intended to provide an overview of existing studies.
The paper is not well organized and does not provide details on particular issues.
The authors should clearly define the objective followed and subsequently provide details.
The logic of the paper should be revised. The authors should identify some issues and subsequently focus on detail.
Some technical aspects require attention:
Using only mass in translation is not accurate in evaluating the inertia effect (eq.6 / lines 118-119).
There are different notations for the rolling resistance coefficient (see eq. 3 and eq. 14).
Please review the notation used in line 277. “Engine power efficiency” is not correct.
Please explain the use of Figure 5 in Section 4.1. The plot does not refer to the generator efficiency.
Please review the title of section 5 (line 645).
Please review the text in line 332.
Please explain the method used to determine the data presented in Figure 6. It may be one of the significant contributions of the paper, but it lacks explanations.
The paper is a collection of statements that are not connected by any bonds.
The paper should be substantially revised.
Author Response
Please see the attachment
Author Response File: 
Author Response.pdf
Reviewer 2 Report
General comment:
The manuscript intends to review the state-of-the-art of energy efficiency of autonomous eCAV. The concept and objective are clear and well described. The review is valuable. The methodology is not clearly explained, and it is the main weakness of the manuscript. The structure of the work and its organisation are adequate. The references have been selected carefully and cover the range of objective of the paper. The results are not new but important.
Please take into account the following remarks:
1. Title: Consider to change "survey" with "review". Please pay attention that the key difference between "survey" and "review" is that a "survey" is a method of data collection, while a "review" is an evaluation or critique of something based on opinions and analysis. Surveys aim to collect information, while reviews provide assessments and opinions.
2. Methodology: There is a lack of clear methodology. Describe the applied methodology and justify using the review method(s). Please also select a method for comparative analysis, explain and then apply it. In the manuscript, no specific method for comparative analysis has been introduced, which in some parts caused a chaotic content and repeating of some statements.
3. Completion of the study: To improve the quality of the work you may consider to define some general "cases" and provide the comparative analysis for these defined "cases" (this is only a suggestion).
2. Writing: Please carefully read again the manuscript and correct it, adequately. There are many sentences that start with small letter, some words are repeated each after one, the punctuation is not correct, etc. Please do a proofread of your manuscript. For example, see:
Lines 181 (the-> The), 183 (proposed proposed), 197 (should be 12%-28%), 212 (two->to), 263 (By simulation -> Based on the simulation results ...), 331 (survived -> surveyed), 371 (decreasing -> Decreasing), 383 (cancellation -> Cancellation), 426 (but -> But), 430 (it -> It)., also what is the clear information given in this sentence? - please avoid unclear, bold and unspecific sentences), 466 (,However -> . However), 474 (Which -> which), 529 (, It -> . It), 585 & 607 (In another work -> correct the style), etc.
3. This review does not include the risk assessment, certainty analysis, and safety aspects of different methods used for increasing the level of energy efficiency of eCAV. At least, please provide a map of increased energy efficiency by using the introduced methods vs risk and safety criteria.
4. All figures, tables and equations should be mentioned in the text prior to their inserting in the manuscript. Additionally, they have to be put after their mentioning in the text to help a reader to catch and understand the content. These rules are completely disregarded. For example Fig.1 is given in Page 3 but mentioned in Line 126 on Page 4. The issue is visible for tables, too. Please check all figures and tables.
5. Please carefully name all symbols used in the equations where they are appeared in the text for the first time. This is not regarded, too. For example see Eq. (1).
6. Eq. (2) is wrong. The area has been included two times in the equation, first by "A" and then by integrating from 0 to "s_f" in "ds". This makes the equation incorrect and the dimensions of both sides of the equation will not be the same. Simply, cancel "A".
7. The number of methods considered under Chapter 3 is 6, not 7 as is mentioned in Line 146 ("seven common approaches").
8. Fig. 2 in unnccessary.
9. In Figs. 3 and 4 give also the values and per cents.
10 Provide the quantitative analysis for comparison of the results delivered in Tabs. 1 and 2 (it can be in a new table or can be added in Tab. 2).
11. Conclusion: please mention the main results more specifically, write them by bulleting or numbering, and provide the list of research needs and gaps.
Please see the above mentioned issues and make a proofread.
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Reviewer 3 Report
The emergence of connected and autonomous vehicles (CAVs) is a promising step towards improving transportation efficiency, yet we must also consider the potential increase in energy consumption due to their widespread use.The optimization of acceleration control and regenerative brakes in electric CAVs (e-CAVs) serves as a prime example of how cutting-edge technology can be harnessed to enhance transportation efficiency.
Some comments:
Equation 2. Is the variable s to represent time? Why is t not considered? It would be necessary to define the term Sf.
Line 126. Figure 1 must be found immediately after being referenced or mentioned.
Error in equation 9. Must be Fair instead of Eair
Line 138. It is suggested to put it as a new equation and improve the explanation.
In the subsection “3.2. Fleet timing” a comparative table of the methods reviewed in the literature is suggested.
Lines 321-322. You have several references, expand the idea.
In the subsection.
In the subsection “3.4. Car following” it is suggested to include metaheuristic methods for optimization, for example: https://doi.org/10.3390/electronics10101199
Line 499. It is suggested to include references.
Line 511. It is suggested to include references.
Line 521. It is suggested to include references.
Line 645 summery? Did you mean summary?
Comments on the Quality of English Language (will be shown to authors) Minor editing of English language required, some words and ideas should reviewed.
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The paper can be accepted for publication.
Reviewer 2 Report
Thank you for your response and the revised version of the manuscript. Most of my remarks and comments have received adequate attention, and the necessary modifications have been implemented.
A proofread can improve the quality of the manuscript.
