Shape Design Optimization of a Robot Arm Using a Surrogate-Based Evolutionary Approach

Round 1

Reviewer 1 Report

The authors present the application of an evolutionary algorithm to the optimized design of a robot arm. According to the authors, novelty lies in the optimization of geometric parameters. However, the work suffers from serious shortcomings to be accepted for publication in its current state. The Introduction is the section that is best suited with respect to the rest of the paper. Read the paper is very difficult, as the material is badly written and presented to reader:

- Section 2 can be improved by merging the subsections.
- The solution adopted for the problem (Section 2.4) can be merged with Section 3 by creating a new section called Methodology or something similar.
- There is no need to repeat so many times in the paper 'The objective of this paper [...]'. It is enough to indicate it at the beginning of the article.
- Between lines 269 and 278 the authors explain what the coefficient of determination is. This paragraph should be deleted because R^2 is something well known, or perhaps they should include a bibliographical reference to some statistics handbook.
- There are several details to be fixed as well. For example (a) python --> Python, (b) Figures 7, 8, 9 and 10 do not look right.
- Section 4 Results and Discussion should be split into two, a section for Results and another for Discussion.

In summary, the work should be rewritten in a more polished, organized, and carefully spun manner to make it easier for the reader to understand.

Author Response

Reply to reviewers’ comments

 First reviewer

 Comments and Suggestions for Authors:

(Q1) The authors present the application of an evolutionary algorithm to the optimized design of a robot arm. According to the authors, novelty lies in the optimization of geometric parameters. However, the work suffers from serious shortcomings to be accepted for publication in its current state. The Introduction is the section that is best suited with respect to the rest of the paper. Read the paper is very difficult, as the material is badly written and presented to reader:

(Q2) - Section 2 can be improved by merging the subsections. 

- The solution adopted for the problem (Section 2.4) can be merged with Section 3 by creating a new section called Methodology or something similar. 

(Q3) - There is no need to repeat so many times in the paper 'The objective of this paper [...]'. It is enough to indicate it at the beginning of the article.

(Q4) - Between lines 269 and 278 the authors explain what the coefficient of determination is. This paragraph should be deleted because R^2 is something well known, or perhaps they should include a bibliographical reference to some statistics handbook. 

(Q5) - There are several details to be fixed as well. For example (a) python --> Python, (b) Figures 7, 8, 9 and 10 do not look right. 

(Q6) - Section 4 Results and Discussion should be split into two, a section for Results and another for Discussion.

(Q7) In summary, the work should be rewritten in a more polished, organized, and carefully spun manner to make it easier for the reader to understand.

1. Authors’ responses:

Thank you for the reviewer’s suggestions and comments which are very helpful in improving the quality of the paper. The responses to the reviewer’s comments are given as follows and the modifications have been highlighted in the revised version of the manuscript.

Q1 : The authors present the application of an evolutionary algorithm to the optimized design of a robot arm. According to the authors, novelty lies in the optimization of geometric parameters. However, the work suffers from serious shortcomings to be accepted for publication in its current state. The Introduction is the section that is best suited with respect to the rest of the paper. Read the paper is very difficult, as the material is badly written and presented to reader:

 Authors’ response:

The manuscript has been rewritten to enhance the readability of the contents. All the grammatical mistakes have been corrected.  

(Q2) - Section 2 can be improved by merging the subsections. 

- The solution adopted for the problem (Section 2.4) can be merged with Section 3 by creating a new section called Methodology or something similar. 

 Authors’ response:

Section 2 and portion of Section 3 in the original manuscript have been merged to produce a new Section 2 titled “Techniques for Robot Arm Analysis and Design” in the revised version of the manuscript. In the new Section 2, the properties of the robot and techniques used for robot analysis and design have been described in detail.

 (Q3) - There is no need to repeat so many times in the paper 'The objective of this paper [...]'. It is enough to indicate it at the beginning of the article.

Authors’ response:

The objective of the paper is now only mentioned in the Introduction of the paper.

(Q4) - Between lines 269 and 278 the authors explain what the coefficient of determination is. This paragraph should be deleted because R^2 is something well known, or perhaps they should include a bibliographical reference to some statistics handbook. 

 Authors’ response:

The coefficients of R² are to be determined.

The paragraph about R² has been modified to make it concise and a reference has been added for readers to get detailed information.

(Q5) - There are several details to be fixed as well. For example (a) python --> Python, (b) Figures 7, 8, 9 and 10 do not look right. 

Authors’ response:

The manuscript has been thoroughly checked and the mistakes have been corrected. The quality of Figures 7-10 has been enhanced.

(Q6) - Section 4 Results and Discussion should be split into two, a section for Results and another for Discussion.

Authors’ response:

In the revised version of the manuscript, the simulation results have been included in Section 3 titled “Shape Design Optimization of 2^nd Robot Arm” and Section 4 is only for discussion.

(Q7) In summary, the work should be rewritten in a more polished, organized, and carefully spun manner to make it easier for the reader to understand.

Authors’ response:

The revised version of the manuscript has been modified in compliance with the reviewer’s suggestions and comments. In the revised version of the manuscript, the proposed optimization method and its applications have been presented in a systematic way. The techniques for robot arm analysis and design, which involve the target performance to be achieved and the framework of the proposed SBEO method, are described in Section 2. The procedure for performing the shape design optimization process of the 2^nd robot arm and the simulation results are given in Section 3. In Section 4, a discussion on three aspects, ie, the issues of performance improvement, computational efficiency, and sensitivity analysis, of the proposed optimization problem is presented. Section 5 is the conclusion and future works. Thus, the readability of the revised manuscript has been greatly enhanced.

The revised manuscript is following the attached file. Thanks a lot.

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper is well written and well organized. The methodology can be considered as appropriate. In my opinion, the paper is interesting and appropriated for the journal, but some minor changes should be done.

The authors should change the first letter of the title section to the caps lock.

The Introduction seems appropriate and includes relevant references.

The types of letters between different sections are different.

Figure 8 should have more quality.

The conclusion should be more detailed, based on conclusions.

There is no bibliography of this journal in the references.

Author Response

Reply to reviewers’ comments

Second Reviewer

1. Comments and Suggestions for Authors

The paper is well written and well organized. The methodology can be considered as appropriate. In my opinion, the paper is interesting and appropriated for the journal, but some minor changes should be done.

(Q1) The authors should change the first letter of the title section to the caps lock.

(Q2) The Introduction seems appropriate and includes relevant references.

(Q3) The types of letters between different sections are different.

 (Q4) Figure 8 should have more quality.

 (Q5) The conclusion should be more detailed, based on conclusions.

 (Q6) There is no bibliography of this journal in the references.

1. Authors’ responses:

Thank you for the reviewer’s suggestions and comments which are very helpful in improving the quality of the paper. The responses to the reviewer’s comments are given as follows and the modifications have been highlighted in the revised version of the manuscript.

(Q1) The authors should change the first letter of the title section to the caps lock.

Authors’ response:

The first letter of the title section has been changed to capital letter in the revised version of the manuscript.

(Q2) The Introduction seems appropriate and includes relevant references.

Authors’ response:

Thank you for the reviewer’s comment.

(Q3) The types of letters between different sections are different.

Authors’ response:

The types of letters between different sections are modified to be the same in the revised version of the manuscript.

 (Q4) Figure 8 should have more quality.

Authors’ response:

The quality of Figure 8 has been improved.

 (Q5) The conclusion should be more detailed, based on conclusions.

 Authors’ response:

The conclusion has been modified and more detailed information has been added.

(Q6) There is no bibliography of this journal in the references.

Authors’ response:

One reference has been added into reference [20].

Revised manuscript see the attached file. Thanks a lot.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors of this paper have undertaken all the changes suggested in the review, significantly improving paper presentation. However, there are still important details to be fixed before publication. With these corrections the paper would be ready for publication:

(1) Figure 7 is very small, a reader barely appreciates the axis labels. Please remove a Chinese text to the left of 'Linear (X=Y)' or write it in English.

(2) The results of an experiment have the category of a section and therefore paragraphs 3.6.2 + 3.6.3 should go to a section Results. Very important: all material in the Discussion section should go to Results. What the authors refer to as Discussion is not the discussion of the results, but more results of your work. In short, create a new Results section that is the 3.6.2+3.6.3+Discussion stuff.

(3) In the current version of the paper, the present section 5 Conclusions should be expanded to include discussion of the paper, i.e., to state advantages, limitations, comparison with other similar papers etc., as well as future work, conclusions etc., and rename this new section Discussion.

Author Response

Response to Reviewer 1 Comments

First reviewer (Round 2)

 A. Comments and Suggestions for Authors:

The authors of this paper have undertaken all the changes suggested in the review, significantly improving paper presentation. However, there are still important details to be fixed before publication. With these corrections the paper would be ready for publication:

Q1: Figure 7 is very small, a reader barely appreciates the axis labels. Please remove a Chinese text to the left of 'Linear (X=Y)' or write it in English.

Q2: The results of an experiment have the category of a section and therefore paragraphs 3.6.2 + 3.6.3 should go to a section Results. Very important: all material in the Discussion section should go to Results. What the authors refer to as Discussion is not the discussion of the results, but more results of your work. In short, create a new Results section that is the 3.6.2+3.6.3+Discussion stuff.

Q3: In the current version of the paper, the present section 5 Conclusions should be expanded to include discussion of the paper, i.e., to state advantages, limitations, comparison with other similar papers etc., as well as future work, conclusions etc., and rename this new section Discussion.

B. Authors’ responses:

Thank you for the reviewer’s suggestions and comments which are very helpful in improving the quality of the paper. The responses to the reviewer’s comments are given as follows and the modifications have been highlighted in the revised version of the manuscript.

Q1: Figure 7 is very small, a reader barely appreciates the axis labels. Please remove a Chinese text to the left of 'Linear (X=Y)' or write it in English.

Authors’ response:

The quality of Figure 7 has been enhanced and the Chinese text on it has also been removed.

Q2: The results of an experiment have the category of a section and therefore paragraphs 3.6.2 + 3.6.3 should go to a section Results. Very important: all material in the Discussion section should go to Results. What the authors refer to as Discussion is not the discussion of the results, but more results of your work. In short, create a new Results section that is the 3.6.2+3.6.3+Discussion stuff.

Authors’ response:

Paragraphs 3.6.2, 3.6.3 and Section 4 Discussions in the original manuscript have been merged to produce a new Section 4 titled “Simulation Results” in the revised version of the manuscript. The modifications from line 266 to line 382 have been highlighted with red color in the revised version of the manuscript.

Q3: In the current version of the paper, the present section 5 Conclusions should be expanded to include discussion of the paper, i.e., to state advantages, limitations, comparison with other similar papers etc., as well as future work, conclusions etc., and rename this new section Discussion.

Authors’ response:

In the revised version of the manuscript, Section 5 have been expanded to include the outcomes (advantages), conclusions, limitations and future works of the proposed method as shown from line 383 to line 418. The heading of Section 5 has been renamed as “Discussions”

Others:

1. Due to above modifications, the introduction of section has also been changed as shown from line 101 to line 105.
2. The flowchart of MOEA/D-DE algorithm for multi-objective optimization has been added to figure 8 as shown from line 285 to line 287.

Author Response File: Author Response.docx

Round 3

Reviewer 1 Report

The paper has been revised completely according to the remarks and criticisms. Therefore, as it stands, it should be published.