Research on the End Effector and Optimal Motion Control Strategy for a Plug Seedling Transplanting Parallel Robot

Round 1

Reviewer 1 Report

Dear Authors,

The revised manuscript entitled: [Research on the End Effector and Optimal Motion Control Strategy for a Plug Seedling Transplanting Parallel Robot] by Xiong Zhao et al. has now been completed. Based on my review, I must inform you that mentioned paper has been revised. Hence, this paper can be recommended to be published in the Journal of Agriculture.

The paper discusses the modeling, controlling, and construction of a parallel robot for plug seedling transplanting. Overall, this paper's subject is intriguing and has some publishable information. In addition, the presentation of the results in terms of the study objectives was effective. The following enhancements, however, could be considered.

1.      The text contains a few typographical errors.

2.      Details, numbers, and results should not be given in the abstract. In the abstract, it is necessary to mention the novelty, significant and valuable goals that are considered in the article. Please rewrite the abstract.

3.      The literature review of the paper needs to be improved. The authors do talk about the literature in Section 1; however, their literature review is very short. Ideally, I would like to see a separate section dedicated to other similar robots found in the literature. If not, add at least one or two paragraphs in Section 1. Also, The authors should refer to the most recent and relevant published works (2021 & 2022) to highlight the contributions of the present work. For example,

Vafapour R, Gharib MR, Honari-Torshizi M, Ghorbani M. ON THE APPLICATIVE WORKSPACE AND THE MECHANISM OF AN AGRICULTURE 3-DOF 4-CABLE-DRIVEN ROBOT. International Journal of Robotics and Automation. 2021 Jan 1;36(2).

Tong, J., Qiu, Z., Zhou, H., Bashir, M.K., Yu, G., Wu, C. and Du, X., 2022. Optimizing the path of seedling transplanting with multi-end effectors by using an improved greedy annealing algorithm. Computers and Electronics in Agriculture, 201, p.107276.

And ….

4.      The authors are not investigating the uncertainty of the mechanism and new control methods in such robots.

5.      Some of the figures are not clear enough.

Yours Sincerely.

 Author Response

Author's Reply to the Review Report (Reviewer 1)

Thank you for taking the time to process the submission of our original paper entitled “Research on the End Effector and Optimal Motion Control Strategy for a Plug Seedling Transplanting Parallel Robot”.

1. The text contains a few typographical errors.

Response: The full text has been processed by the dedicated paper polisher AJE. The full text has been checked again and some words have been modified, such as: “analysis” (line 265), “center” (lines 293 and 409) in Section 3 and “behavior” (lines 398, 408, 413, 417 and 430) in Section 5.

2. Details, numbers, and results should not be given in the abstract. In the abstract, it is necessary to mention the novelty, significant and valuable goals that are considered in the article. Please rewrite the abstract.

Response: We have modified parts of the Abstract. Sentences involving data, details, results have been replaced. Now, parts of abstract were as follow (lines 16 and 23):

“This paper took broccoli seedlings as the research object and developed an image recognition system suitable for seedling health recognition and pose judgement, researched and designed a plug-in end effector that reduces leaf damage, and conducted orthogonal tests to obtain a substrate parameter combination containing the moisture content, the seedling age, the transplanting acceleration suitable for culling operations.”

“A single operation time was greatly reduced, and the whole machine was systematically built. the average time of single-time seedling removal was measured, and the transplanting efficiency of the whole machine was high. In the seedling damage rate gap test, the leaf damage rate was low.”

3. The literature review of the paper needs to be improved. The authors do talk about the literature in Section 1; however, their literature review is very short. Ideally, I would like to see a separate section dedicated to other similar robots found in the literature. If not, add at least one or two paragraphs in Section 1. Also, The authors should refer to the most recent and relevant published works (2021 & 2022) to highlight the contributions of the present work. For example,

 Vafapour R, Gharib MR, Honari-Torshizi M, Ghorbani M. ON THE APPLICATIVE WORKSPACE AND THE MECHANISM OF AN AGRICULTURE 3-DOF 4-CABLE-DRIVEN ROBOT. International Journal of Robotics and Automation. 2021 Jan 1;36(2).

 Tong, J., Qiu, Z., Zhou, H., Bashir, M.K., Yu, G., Wu, C. and Du, X., 2022. Optimizing the path of seedling transplanting with multi-end effectors by using an improved greedy annealing algorithm. Computers and Electronics in Agriculture, 201, p.107276.    

And ….

Response: We have modified parts of the Introduction. The descriptions of related similar robots are added in Introduction. References order is also adjusted accordingly. Now, parts of Introduction were as follow (line 66):

“ In order to solve major problems posed by utilizing cable-driven robots for agricultural or gardening purposes, Vafapour R represented an agriculture 4-cable robot for some agricultural activities[15]. He revealed the workspace limitations for the robot’s end-effector to be restricted. Focused on the adjustability of its several joints, a model is presented to achieve an ideal design for the robot’s motortopulley mechanism.

An improved greedy simulated annealing algorithm (IGSA) based on MTSP mode was proposed by Junhua T for path optimization[16]. One manipulator attached with five end effectors. When the machine starts replug operation, the manipulator moves to the source tray to grasp the entire row of healthy seedlings. The operation of grasping the seedlings is not allowed when an end effector identifies a vacant cell. Then the manipulator moves to the target tray with the healthy seedling. The end effectors in the manipulator release the healthy seedling into several vacant cells of the target trays. In the end, the manipulator with empty end effectors return to the source tray. Subsequently, the seedlings are grasped in rows from top to bottom.”

4. The authors are not investigating the uncertainty of the mechanism and new control methods in such robots.

Response: This delta robot is relatively mature. In addition to controlling the delta robot, it also controls an additional rotating cylinder to complete the replacement seedling action. This article mainly set up a closed image acquisition system, conducted a three-level and three-factor orthogonal test to obtain optimal combination of parameters, used the PSO-AFSA algorithm and 5th degree B-spline curve to search for the optimal time in one single operation, built the whole machine and carried out related experiments. We are sorry that the uncertainty of the mechanism and new control methods in such robots were not covered in this article.

5. Some of the figures are not clear enough.

Response: All pictures are checked and some are updated (lines 291 and 448), such as Figures 6 and 8.

Reviewer 2 Report

The paper ‘Research on the End Effector and Optimal Motion Control Strategy for a Plug Seedling Transplanting Parallel Robot’ developed an image recognition system suitable for broccoli seedling health recognition and pose judgment, researched and designed a plug-in end effector that reduces leaf damage, and conducted orthogonal tests to obtain a substrate parameter combination suitable for culling operations.

The theme of the paper is interesting, the manuscript is complete and suitable for the special issue. Only some comments:

-some typos are present in the text and should be corrected (i.e. line 56 a capital letter inside the sentence);

- what is the column D in Table 2? Please explain it.

- Figure 8 is not very clear, please improve it.

Author Response

Author's Reply to the Review Report (Reviewer 2)

Thank you for taking the time to process the submission of our original paper entitled “Research on the End Effector and Optimal Motion Control Strategy for a Plug Seedling Transplanting Parallel Robot”.

1. -some typos are present in the text and should be corrected (i.e. line 56 a capital letter inside the sentence)

Response: The uppercase letters of line 56 have been corrected. The remaining typos have been checked. Such as: “analysis” (line 265), “center” (lines 293 and 409) in Section 3 and “behavior” (lines 398, 408, 413, 417 and 430) in Section 5.

2. - what is the column D in Table 2? Please explain it.

Response: When using the software to analyze the experimental data, the software needs 4 columns of parameters to calculate. This experiment only needs to analyze the influence of the moisture content, the seedling age, and the transplanting acceleration three factors on the results. The software will automatically generate a blank factor for calculation. The existence of the actual D item has no effect on the experimental results. Table 2 has been modified to delete D data in the Table 2 (line 282).

3. - Figure 8 is not very clear, please improve it.

Response: Figure 8 has been updated. Increased clarity and replaced with unclear colors (line 448).

Reviewer 3 Report

On one hand, the problem presented by the authors is very interesting as it is the research on the end effector and optimal motion control strategy for a plug seedling transplanting parallel robot. After a closed image acquisition system was set up, The plug seedlings were divided into four categories according to the leaf area and the direction of seedling crossing. A three-level and three-factor orthogonal test was conducted. The optimal combination of parameters was obtained. The PSO-AFSA algorithm and 5th degree B-spline curve were used to search for the optimal time in one single operation. Finally, The whole machine was systematically built and related experiments were carried out. It is proved that the results can provide a reference for the localized development of greenhouse high-speed and low-loss seedling removal equipment.

On the other hand, the article lacks clarity and formality in describing the details of the procedures.

I would recommend to:

1. The last paragraph of the introduction should appropriately mention what method was used and what results were obtained.

2. Is the meaning of ABCD in Table 2 the same as the meaning of Parameters of the orthogonal experiment ABC in Table 1?

3. How are k1, k2, and k3 obtained in Table 2, and what do they mean?

4. In Figure 7, the angle  between the AB rod and the XY plane is missing.

5. When removing and supplementing seedlings in different positions in Section 5, is the Trajectory discrete point sequence also different? Is the calculation result of Fig. 9 、Fig. 10、Fig. 11 universal?

6. In the last paragraph and conclusion of Section 5, it is mentioned that "the robot operation in a single time does not exceed 1.36 s", does this include the end effector adjusting the orientation according to the state of the seedling?

7. There are transplanting efficiency experiments in Section 5, and there is no information on experimental seedlings here. Are the seedlings used in this experiment same as the experiment in Section 1?

Author Response

Author's Reply to the Review Report (Reviewer 3)

Thank you for taking the time to process the submission of our original paper entitled “Research on the End Effector and Optimal Motion Control Strategy for a Plug Seedling Transplanting Parallel Robot”.

1. The last paragraph of the introduction should appropriately mention what method was used and what results were obtained.

Response: Now, The last paragraph of the Introduction has been rewrite (line 138). This is shown below:

“This article mainly set up a closed image acquisition system, conducted a three-level and three-factor orthogonal test to obtain optimal combination of parameters, used the PSO-AFSA algorithm and 5th degree B-spline curve to search for the optimal time in one single operation, built the whole machine and carried out related experiments. This research provides a reference for the localized development of greenhouse high-speed and low-loss seedling removal equipment.”

2. Is the meaning of ABCD in Table 2 the same as the meaning of Parameters of the orthogonal experiment ABC in Table 1?

Response: Yes, the meaning of A,B, and C were same. In Table 2, When using the software to analyze the experimental data, the software needs 4 columns of parameters to calculate. This experiment only needs to analyze the influence of the moisture content, the seedling age, the transplanting acceleration three factors on the results. The software will automatically generate a blank factor for calculation. The existence of the actual D item has no effect on the experimental results. Table 2 has been delete D data in the table 2 (line 282).

3. How are k1, k2, and k3 obtained in Table 2, and what do they mean?

Response: k1, k2, and k3 represent the average comprehensive scores of moisture, temperature and humidity in the first, second and third levels respectively. For example, the value of k1 is equal to the average value of comprehensive score when the number is 1 in the column with experiment number A. R represents range. For example, the value of R is equal to the maximum of k1,k2 and k3 minus the minimum of k1,k2,k3.

This is added in Section 3.

4. In Figure 7, the angle q between the AB rod and the XY plane is missing.

Response: The angle q is added in Figure 7 (line 291). The figure is updated.

5. When removing and supplementing seedlings in different positions in Section 5, is the trajectory discrete point sequence also different? Is the calculation result of Fig. 9 、Fig. 10、Fig. 11 universal?

Response: When the target is different, trajectory discrete points are different. We choose the farthest distance to calculate the time required to run in one time. Although this calculation was not universal, it is representative.

6. In the last paragraph and conclusion of Section 5, it is mentioned that "the robot operation in a single time does not exceed 1.36 s", does this include the end effector adjusting the orientation according to the state of the seedling?

Response: Actually, before the end effector move, the state of the seedling is detected. When the end effector starts to move along the trajectory discrete point sequence, the orientation starts to work at same time. the average time for a single removal and supplementation operation is 3.1s.

This is added in second paragraph of section 6 (line 506).

7. There are transplanting efficiency experiments in Section 5, and there is no information on experimental seedlings here. Are the seedlings used in this experiment same as the experiment in Section 1?

Response: In these two sections, the seedlings we used were all provided by the Hangzhou Xiaomiao company. Unlike the first section of the text, the humidity of the seedlings we used was 60%-70% and the seedling age was 25 days.

“The seedlings were provided by the Hangzhou Xiaomiao company. the humidity of the seedlings we used was 60%-70% and the seedling age was 25 days.” is added in Section 6 (line 518).