Research on Path Tracking for an Orchard Mowing Robot Based on Cascaded Model Predictive Control and Anti-Slip Drive Control

Round 1

Reviewer 1 Report

Article is very long and deeply analysed. But, it seems, that it does not fit to Agronomy journal. The article is directly related to mathematical modelling of automatic control of robot. 

As well, it is not clear what is Chapter 5 Simulation Experiment and Field Experiment Verification of Path Tracking Control. Is it conclusions or just chapter. Please correct it.

All other remarks are noted in the attached file.

Comments for author File: Comments.pdf

Language is good  enough, but native english speaker review is needed.

Author Response

Reviewer 1：

1. Article is very long and deeply analysed. But, it seems, that it does not fit to Agronomy journal. The article is directly related to mathematical modelling of automatic control of robot.

Response: Thank you for your comments. The topic of this paper is the path tracking and drive anti-skid control of orchard mowing robot. The design background is in the orchard scene, which can provide a technical reference for the path tracking of orchard machinery

2. As well, it is not clear what is Chapter 5 Simulation Experiment and Field Experiment Verification of Path Tracking Control. Is it conclusions or just chapter. Please correct it.

Response: Thanks for raising your concerns. We changed the wrong title, which should have been the conclusion.

3. All other remarks are noted in the attached file.

Response: Thanks for your good suggestions. In response to the comments on your attached file, we have made a complete modification as follows:

（1）Change the ‘MPC’ of the title to ‘Model Predictive Control’.

（2）References are added to the first paragraph of the introduction（Chapter 1）.

（3）The standard format of reference journals modifies the format of reference citations.

（4）We added the objectives of this study at the end of introduction（Chapter 1）.

（5）Change the ‘Technical parameters’ to ‘Qualificationl’.（Chapter 2, Section 2.1）.

（6）Change the ‘Body quality’ to ‘Mowing robot quality’.（Chapter 2, Section 2.1）.

（7）The detailed description of Figure 1 was added.

（8）Changed the font in Figure 13（Section 3.4）.

（9）The format of references is unified according to the format of journals（References）.

4. Language is good enough, but native english speaker review is needed.

Response: We thank the reviewer’s comment and suggestion. We have re-polished the whole article in English, especially in some terminology.

Author Response File: Author Response.docx

Reviewer 2 Report

This is an interesting study, but my background is not related to mowing robots or Anti-slip Drive Control. However, I send you some comments.

First, in introduction authors must introduce the objectives of this study at the end of this chapter. The goals should be well presented in a clear and concise way.

Authors have presented a short material and method chapter, but different chapters for presenting methods and results on simulation and field experiments. These chapters are difficult to be understand by a reader not familiar with this topic. I think that authors should present these chapters as subchapters of result chapter, and later a discussion chapter. The authors have not discussed their results. In scientific papers, results must be discussed with other studies related to the studied topic. Conclusions also lack in this study.

These are only general recommendations because I have not a clear knowledge about this topic.

Minor editing of English language required

Author Response

1. This is an interesting study, but my background is not related to mowing robots or Anti-slip Drive Control. However, I send you some comments.

Response: Thanks for raising your concerns. We have made modifications according to your comments.

2. First, in introduction authors must introduce the objectives of this study at the end of this chapter. The goals should be well presented in a clear and concise way.

Response: Thank you for your comments. We added the objectives of this study at the end of introduction（In summary, the path tracking algorithm based on MPC can effectively solve the problems of agricultural machinery in navigation and path tracking, but it does not solve the problem of driving wheel skidding in the orchard environment. In this paper, a cascade path tracking control method of orchard mowing robot is designed,which is based on the linear time-varying kinematic model of four-wheel mower. To solve the problem that the fixed time domain is difficult to adapt to the complex orchard environment, the adaptive time domain model prediction controller is designed. Aiming at the complex and varied road conditions of the orchard, a driving anti-skid controller was constructed by fuzzy control and PID algorithm to realize the driving anti-skid control. The proposed method improved the stability and the path tracking accuracy of the orchard mowing robot.）

3. Authors have presented a short material and method chapter, but different chapters for presenting methods and results on simulation and field experiments. These chapters are difficult to be understand by a reader not familiar with this topic. I think that authors should present these chapters as subchapters of result chapter, and later a discussion chapter. The authors have not discussed their results. In scientific papers, results must be discussed with other studies related to the studied topic. Conclusions also lack in this study.

Response: Thanks for your good suggestions. We have reorganized the chapters of the paragraph and added the results and discussion sections to make it easier for readers to understand.

4. These are only general recommendations because I have not a clear knowledge about this topic.

Response: Thank you for your comments. Your advice gave me a good idea.

5. Minor editing of English language required

Response: We thank the reviewer’s comment and suggestion. We have re-polished the whole article in English, especially in some terminology.

Author Response File: Author Response.docx

Reviewer 3 Report

1- Abstract need more improvements to cover study details. Please rephrase it  

2- English language needs more editing and improvements

3- Introduction needs to be improved to show the problem statement, previous studies related to this work and research gap. What this work will cover this gap?.  

4- Please add section about description for study area supported by figure?.  

5- You need to add section about discussion to compare the results obtained with previous works to promote the present results  

6- Figures need to be more clear, please increase the quality

7- Conclusion section needs full rephrasing to be clear for potential readers.

Extensive editing of English language required

Author Response

1. Abstract need more improvements to cover study details. Please rephrase it

Response: Thank you for your comments. We rewrote the Abstract to make this paragraph more concise.

2. English language needs more editing and improvements.

Response:Thanks for the reminder. We have re-polished the whole article in English, especially in some terminology.

3. Introduction needs to be improved to show the problem statement, previous studies related to this work and research gap. What this work will cover this gap?

Response: Thanks for your good suggestions. We have improved the problem statement and added some previous studies related to this work，The purpose of the article is specified in the introduction.（In summary, the path tracking algorithm based on MPC can effectively solve the problems of agricultural machinery in navigation and path tracking, but it does not solve the problem of driving wheel skidding in the orchard environment. In this paper, a cascade path tracking control method of orchard mowing robot is designed,which is based on the linear time-varying kinematic model of four-wheel mower. To solve the problem that the fixed time domain is difficult to adapt to the complex orchard environment, the adaptive time domain model prediction controller is designed. Aiming at the complex and varied road conditions of the orchard, a driving anti-skid controller was constructed by fuzzy control and PID algorithm to realize the driving anti-skid control. The proposed method improved the stability and the path tracking accuracy of the orchard mowing robot.）

4. Please add section about description for study area supported by figure?

Response: Thanks for raising your concerns. We added section about description for study area supported by figure.（Chapter 2, Section 2.1,Figure 1；Chapter 3, Section 3.2,Figure 4）.

5. You need to add section about discussion to compare the results obtained with previous works to promote the present results.

Response: We thank the reviewer’s comment and suggestion. We have changed the title of Chapter 4 and added a discussion of the comparison of previous work at the end of this chapter.

6. Figures need to be more clear, please increase the quality

Response: Thank you for your comments.  We reworked some pictures to make them clearer.（Figure 3, Figure 5, Figure 9, Figure 10, Figure 13, Figure 18,）

7. Conclusion section needs full rephrasing to be clear for potential readers.

Response: Thanks for reminding us. We rewrote the conclusion to make this paragraph more concise.

Author Response File: Author Response.docx

Reviewer 4 Report

The article is well-written showing an application of a mobile robot. I do not have suggestions.

The article is well-written and needs some minor English corrections.

Author Response

1. The article is well-written showing an application of a mobile robot. I do not have suggestions.

Response: Thank you for your approval. We made some changes in the abstract, introduction, and discussion to make the paper easier to understand.

2. The article is well-written and needs some minor English corrections.

Response: Thanks for your good suggestions. We have re-polished the whole article in English, especially in some terminology.

Author Response File: Author Response.docx