Lodged Sugarcane/Crop Dividers Interaction: Analysis of Robotic Sugarcane Harvester in Agriculture via a Rigid-Flexible Coupled Simulation Method

Round 1

Reviewer 1 Report

This paper introduces a novel method for crop division in agri robotics.

The paper is interesting and well written with good figures and diagrams. The methodology and evaluation is appropriate with conclusions grounded in the results.

The only recommendations I have is to include in the introduction exactly what you have done to build on the current state of the art in agri robotics. I find this a big vague, so it may be worth reiterating this towards the end of the section.

Secondly, include a future works section. Here discuss adaptations to your system that can be made to make it more robust and any other future experiments you plan to do on the project.

Overall, this is a very good paper and a firm acceptance after a few minor adjustments to the text. 

Author Response

Dear Editor:

Re: actuators-1508460 entitled “Lodged sugarcane/Crop dividers Interaction Analysis of Sugarcane Harvester in Smart Agriculture via A Rigid-Flexible Coupled Simulation Method”

We all appreciate very much the editor and reviewers’ invaluable comments on our paper. Based on the reviewers’ comments and suggestions, we have modified the paper, and our correspondences to the reviewers’ concerns are listed as follows:

The correspondence to Reviewer 1:

1. This paper introduces a novel method for crop division in agri robotics.

The paper is interesting and well written with good figures and diagrams. The methodology and evaluation is appropriate with conclusions grounded in the results.

The only recommendations I have is to include in the introduction exactly what you have done to build on the current state of the art in agri robotics. I find this a big vague, so it may be worth reiterating this towards the end of the section.

R:   We thank the reviewer for their positive comments on the manuscript. Based on the recommendations of reviewers, we have added a description of the current state of the art of agricultural robotics in the introduction, especially in the area of sugarcane harvesters, which is the focus of this paper.The revised part is marked in blue font in the re-uploaded manuscript.

“As the primary raw material for sugar production, sugarcane is mainly grown in tropical and subtropical regions [1-4], and is an essential economic pillar industry in many countries and regions [5-6]. The use of mechanized sugarcane harvesting can greatly improve efficiency, and with the rapid development of smart agriculture, the development of intelligent harvesting machinery has become a hot spot for research in recent years. For sugarcane harvesters, Kallaya et al. provide a reasonable reference method for planning the driving route of harvesters in order to reduce the loss rate of sugarcane mechanical harvesting [7]. In [8], the required power requirements and field performance of sugarcane harvester components in operation were quantified. Lucas et al. evaluated the quality of mechanically harvested sugarcane in three different cropping methods using statistical methods[9].

The planting area of sugarcane in China ranks third globally, mainly in provinces such as Guangxi, Guangdong and Hainan [10-11]. The planting of sugarcane in this area is mainly based on slopes and hills. Due to the influence of typhoons and monsoon climate every year, sugarcane will lodging to different degrees during the growth process [12-13]. It is worth noting that lodged sugarcane (LS) brings difficulties to mechanized harvesting and increases the loss rate of mechanical harvesting, bringing economic losses to farmers. In the mechanized harvesting process, if the LS cannot be raised to a certain height, this will cause the knife to cut the sugarcane multiple times and increase the root damage rate [14-15]. More importantly, this will reduce the yield and seriously affect the sugarcane's sprouting growth in the coming year [16-17]. Therefore, the design of the crop dividers of the sugarcane harvester is particularly important.”

2. Secondly, include a future works section. Here discuss adaptations to your system that can be made to make it more robust and any other future experiments you plan to do on the project.

Overall, this is a very good paper and a firm acceptance after a few minor adjustments to the text. 

R:   Thank you reviewer for their valuable comments. We have added planning for future work to the conclusion, as shown below:

“This coupled simulation approach can be applied to many applications to analyze mechanical systems to improve the efficiency and reliability of the system. Finally, as possible future work, we further optimize the design of crop dividers to explore more precise operating parameters, providing initial conditions and parameter configuration for future coordinated operation between unmanned harvesters in smart agriculture.”

Reviewer 2 Report

This manuscript conducted a simulation research on the interaction between Lodged sugarcane and Crop dividers, and verified the results with field experiments. Specific comments are as follows:

1.The title are suggested to revise to be more specific.

2.English writing should be improved thoroughly.

3.Explain the vertical height of the center (VHC) clearly.

4.In the end of introduction. The aim of this paper should be more clear and it should be written in future tense.

5.In 3.2 Simulation design. How are the factor levels determined?

6.In 4.1 Validation test. The field condition is suggested to describe.

Author Response

Dear Editor:

Re: actuators-1508460 entitled “Lodged sugarcane/Crop dividers Interaction Analysis of Sugarcane Harvester in Smart Agriculture via A Rigid-Flexible Coupled Simulation Method”

We all appreciate very much the editor and reviewers’ invaluable comments on our paper. Based on the reviewers’ comments and suggestions, we have modified the paper, and our correspondences to the reviewers’ concerns are listed as follows:

The correspondence to Reviewer 2:

1. This manuscript conducted a simulation research on the interaction between Lodged sugarcane and Crop dividers, and verified the results with field experiments. Specific comments are as follows:

The title are suggested to revise to be more specific.

R:   We thank the reviewer for their valuable comments and recognition of the work done on the manuscript, which strengthens our confidence in improving the quality of the manuscript. We have responded to the experts' questions and marked them in blue in the re-uploaded manuscript. We have revised the title of the manuscript.

“Lodged sugarcane/Crop dividers Interaction Analysis of Sugarcane Harvester in Agriculture Robotic via A Rigid-Flexible Coupled Simulation Method”

2. English writing should be improved thoroughly.

R:   Thanks to the reviewer for their valuable comments. We have thoroughly checked and carefully revised the language of the manuscript, and hope to meet the journal's requirements.

3. Explain the vertical height of the center (VHC) clearly.

R:   Thanks to the reviewer for their valuable comments. we have made the vertical height of the center (VHC) clearer in the re-uploaded manuscript and marked it with blue font.

“According to actual needs and existing research, sugarcane height variation is an important indicator to describe the lifting efficiency [23]. In order to clearly observe the height variation pattern of LS during the lifting process, the change trend and average maximum value of the VHC in the process of sugarcane lifting are selected as evaluation indicators. The VHC of the sugarcane is shown in Figure 6. The sugarcane is set to be homogeneous, and the midpoint coincides with the centroid. The calculation is as follows:”

4. In the end of introduction. The aim of this paper should be more clear and it should be written in future tense.

R:  Thanks to the reviewer for their valuable comments. We made careful corrections and marked them in blue in the re-uploaded manuscript.

“The rest of this paper is organized as follows. Section 2 will briefly analyze the kinematic characteristics of the spiral crop dividers. Section 3 will describe the establishment of the simulation model of the crop dividers and sugarcanes, and determine the experimental design plan and evaluation index. Section 4 will first verify the accuracy of the simulation model, based on which the interaction between LS/spiral crop dividers is analyzed and the experimental results are discussed. The conclusion section will be presented in section 5.”

5. In 3.2 Simulation design. How are the factor levels determined?

R:   Thanks to the reviewer for their valuable comments. The selection of these factors was determined with reference to existing studies and the real environment faced by the harvester in its operational work.

“According to the analysis of LS in Section 2, this article takes severe LS (0°≤θ＜30°) as the research object, and chooses a lodging angle of 15°. Sugarcane stalks with forward lodging and reverse lodging have no contact with the crop divider during the harvesting operation, so they are out of the scope of the study[25]. The lodging postures of sugarcane are selected as side and forward lodging, side lodging, side and inverse lodging, and the side angles are respectively 30°, 60°, 90°, 120° and 150°. Refer to the relevant studies conducted by [12], the FV of the harvester is selected as 1 km/h, 2 km/h, and 3 km/h, and the experimental analysis under different conditions is carried out .

[25]Song, C.; Ou, Y.; Liu, Q.; Xie, F. Simulation and experiments of two-stage spiral  sugarcane picking-up mechanism.Transactions of the  CSAE. 2011, 27(5): 106-110. 

[12]Xing, H.; Ma, S.; Wang, F.; Bai, J.; Ma, J. Aerodynamic Performance Evaluation of Sugarcane Harvester Extractor Based on CFD. Sugar Tech. 2021,23(3):627-633. ”

6. In 4.1 Validation test. The field condition is suggested to describe.

R:   Thanks to the reviewer for their valuable comments. We have added a detailed description of the validation test conditions.

“In order to verify the accuracy of the simulation model, a field verification experiment was carried out during the sugarcane harvest season in 2020, in Daxu Village, Laibin City, Guangxi Province, as shown in Figure 7. Ratoon sugarcane was selected for the experiment, the variety is Guiliu 136, the average height is about 2860mm, and the planting density is 8 roots/m. In the field validation test, it is difficult to obtain the position change of the sugarcane centroid at different times. Therefore, the maximum height average value of the midpoint of the sugarcane in each group of tests is selected as the evaluation index. During the test, the FV of the harvester was selected to be 2 km/h, and the sugarcane was selected to be in severe lodging, and the side angle was about 30°, 60°, 90°, 120° and 150°. The experimental results are shown in Table 2. It can be clearly seen that the maximum error rate between the simulation and experimental results is 8.84%, and the minimum error is 3.53%. Errors in the test are unavoidable, random errors caused by parameter settings, uneven ground in the field, or variable speed control of the harvester driver. After calculation, the average error rate is 5.41%. We believe that the simulation model established by the rigid-flexible coupled method is accurate.”

Reviewer 3 Report

The article is interesting, a rigid-flexible coupling simulation method with theory analysis was proposed to improve the lifting efficiency of the crop dividers on severely lodged sugarcane. The interaction law between the sugarcane stalk and the crop dividers was analyzed. Field experiments and the operational performance of the crop dividers on sugarcane in different lodging postures were investigated. The following errors or inaccuracies in the text have been noted:

For Equation 2, what’s the specific mean for ?_??

Line 206 and 207, the authors take the severe LS as 0° ≤ ?＜30°? Is that true? I think the condition of severe LS is 0° ≤ θ＜30°. Confirm it.

For Figure 8, what are the exactly numbered #1, #2 and #3 sugarcane in each picture?

Line 354 to 359, expression style of these words do not fit well with Conclusions. Verify needed.

I recommend to publish this article after realization of these improvements.

Author Response

Dear Editor:

Re: actuators-1508460 entitled “Lodged sugarcane/Crop dividers Interaction Analysis of Sugarcane Harvester in Smart Agriculture via A Rigid-Flexible Coupled Simulation Method”

We all appreciate very much the editor and reviewers’ invaluable comments on our paper. Based on the reviewers’ comments and suggestions, we have modified the paper, and our correspondences to the reviewers’ concerns are listed as follows:

The correspondence to Reviewer 3:

1. The article is interesting, a rigid-flexible coupling simulation method with theory analysis was proposed to improve the lifting efficiency of the crop dividers on severely lodged sugarcane. The interaction law between the sugarcane stalk and the crop dividers was analyzed. Field experiments and the operational performance of the crop dividers on sugarcane in different lodging postures were investigated. The following errors or inaccuracies in the text have been noted:

For Equation 2, what’s the specific mean for ?

R:   We thank the reviewers for their valuable opinions and recognition of the work done, which enhanced our confidence in the quality improvement of the manuscript.We responded to the expert questions and marked in blue in the re-uploaded manuscript.

Regarding formula 2, we explain as follows: formula 2 describes the position change of the contact point of the lodging sugarcane and the crop dividers at different times, and clearly finds the parameters that affect it. By obtaining the derivative, we can further solve the speed change of the contact point at different times, which can provide theoretical guidance for the optimization of the parameters of the crop dividers.

2. Line 206 and 207, the authors take the severe LS as 0° ≤δ＜ Is that true? I think the condition of severe LS is 0° ≤ θ＜30°. Confirm it.

R:   Thanks to the reviewer for their valuable comments. Due to our carelessness, the part was written incorrectly.The correct description should be “0° ≤ θ＜30°”.

3. For Figure 8, what are the exactly numbered #1, #2 and #3 sugarcane in each picture?

R:   Thanks to the reviewer for their valuable comments. We conducted simulations of the interaction between three sugarcanes and the crop dividers simultaneously in our experiments, and labeled the sugarcanes as #1, #2 and #3 according to the order of contact with the crop dividers.The purpose of this is to clearly describe the law of interaction between the sugarcanes and the sugarcane lifter.

4. Line 354 to 359, expression style of these words do not fit well with Conclusions. Verify needed.

I recommend to publish this article after realization of these improvements.

R:   Once again, we thank the expert for their approval of the manuscript, and we have revised the content of the conclusions.

“This paper introduces different categories of sugarcane lodge by side angles and lodging angles, establishes a simulation model of LS and spiral crop divider using the rigid-flexible coupling method, and verifies the accuracy of the model by field tests.

The test results concluded that with the increase of FV the time of sugarcane being lifted to the maximum height showed a decreasing trend. The slipping frequency is the greatest during lifting the side and forward LS, especially when the side angle is about 30°. When the side angle is about 90°and 120°, the LS lifted most smoothly and rapidly. According to the analysis of the lifting speed and passing rate of VHC, the recommended choice of LS posture during the operation of the harvester is: side and reverse lodged > side lodged > side and forward lodged.

This coupled simulation approach can be applied to many applications to analyze mechanical systems to improve the efficiency and reliability of the system. Finally, as possible future work, we further optimize the design of crop dividers to explore more precise operating parameters, providing initial conditions and parameter configuration for future coordinated operation between unmanned harvesters in smart agriculture.”

Round 2

Reviewer 1 Report

Paper is much improved in this revision, and acceptable for publication. 

Reviewer 2 Report

The manuscript has been revised carefully.

Reviewer 3 Report

None