Biomechanical Characterization of Bionic Mechanical Harvesting of Tea Buds

Round 1

Reviewer 1 Report

The whole section 2.1 should be under introduction.

Line  80   “Intermeshing region….”  Is this incomplete sentence a subsection because it stands alone?
Lines 91 - 94  sentences look like justification of the study. It shouldn’t be under materials and methods.
Line254 -  “before upward them”  please recast.

Author Response

Dear Reviewer,

Thanks very much for taking your time to review this manuscript. I really appreciate all your comments and suggestions! Please find my itemized responses in below .

Response to the Reviewer

1. The whole section 2.1 should be under introduction

Response: Thanks for the suggestion. We have redirected some of the content to other chapters. We introduced the object of the experimental study, the handpicking principle and the mechanical parameters in the section 2.1, which if put into the introduction below will have unclear referents. In order to make the content of the article more clearly presented. We would like to keep this section in this position. We would still like you to reconsider it.

2. Line 80 “Intermeshing region….” is this incomplete sentence a subsection because it stands alone?

Response: Yes, it is a very good suggestion. We have revised description as “After clamping the picking point in the intermeshing region, the wrist rotates to drive the finger to rotate, and the finger rotates at a certain angle to pick the shoots off.” For the detail, please see the revised version(line 83-85).

3. Lines 91 - 94  sentences look like justification of the study. It shouldn’t be under materials and methods.

Response: Yes, it is a very good suggestion. We have adapted this passage to Chapter 3.(line 163-167).

4. Line254 -  “before upward them”  please recast.

Response: Yes, thank you for the reminder. We found this phrase in line 257.We have revised description as “When picking tea buds by hand, the fingers first bend the shoots at a certain angle and then the fingers lift off the buds. ”For the detail, please see the revised version(line 271-272).

Thanks again!

Reviewer 2 Report

1. The aim and brief methodology are not clearly mentioned in the abstract.

2. In page #1, line #12, “The purpose is to develop low damage picking equipment for famous tea.” This sentence makes the reader confused about the aim of the study. Authors aim to develop the equipment or characterize the harvested tea buds. Please state clearly.

3. In Page#2, line #66, please specifically state the tea stalk mechanical properties. For example, pressure or force.

4. Please include the full definition of HD (high definition) on page#5, line 153.

5. The sample size used in the experiment is not mentioned in section 2.2.

6. Does the shear picking on every sample result in an almost similar appearance of the wound area (with burr and hollow)?

7. The methodology does not provide the force measurement method for the thumb and index finger (Fig.7).

8. The standard deviation or the error bar is not included in Fig.8.

9. The authors mentioned that the findings are consistent with previous works, so what is the uniqueness of the current findings?

10. It is to suggest that the authors compare the previous results by providing the related quantitative results of previous works. 

Author Response

Dear Reviewer,

Thanks very much for taking your time to review this manuscript. I really appreciate all your comments and suggestions! Please find my itemized responses in below .

Response to the Reviewer

1. The aim and brief methodology are not clearly mentioned in the abstract.

Response: Yes, it is a very good suggestion. We have revised description as “Therefore, in order to improve the quality of mechanically harvested tea buds, the study of bionic picking is beneficial to reduce the damage rate of mechanical picking. In this paper, the manual flexible picking process is studied and a bionic bladeless mechanical picking mechanics model is developed. The relationship between mechanical properties and structural deformation of tea stalks was obtained by microstructural observation and mechanical experimental analysis. Determination of bud bionic picking mechanics flow by combined loading tests. ”For the detail, please see the revised version (line 10-16).

2. In page #1, line #12, “The purpose is to develop low damage picking equipment for famous tea.” This sentence makes the reader confused about the aim of the study. Authors aim to develop the equipment or characterize the harvested tea buds. Please state clearly.

Response: Yes, thank you for the reminder. This paper is to investigate the mechanism of bionic harvesting mechanics of tea buds. We have revised description as “Therefore, in order to improve the quality of mechanically harvested tea buds, the study of bionic picking is beneficial to reduce the damage rate of mechanical picking. ”For the detail, please see the revised version (line 10-12).

3. In Page#2, line #66, please specifically state the tea stalk mechanical properties. For example, pressure or force.

Response: Yes, thank you for the reminder. We have revised description as “The principles of bionic low damage picking mechanics were determined by analyzing finger flexibility forces, tea stalk mechanical properties (flexible clamping force, compression force, pull-off force, bending force), and tea-bud picking paths.” For the detail, please see the revised version (line 68-71).

4. Please include the full definition of HD (high definition) on page#5, line 153.

Response: Yes, thank you for the reminder. We have revised description as “A five-megapixel high definition (HD) electronic eyepiece enabled the display of the pictures on the computer. ”For the detail, please see the revised version (line 154-155).

5. The sample size used in the experiment is not mentioned in section 2.2.

Response: Yes, thank you for the reminder. We have revised description as “In this paper, 500 test samples were prepared for analysis of the stems. ”For the detail, please see the revised version (line 119-120).

6. Does the shear picking on every sample result in an almost similar appearance of the wound area (with burr and hollow)?

Response: Yes, we conducted 20 sets of experiments. The final sheared tea wound areas were obtained with burrs and hollow. We randomly selected one set of results as experimental data to present in the paper.

7. The methodology does not provide the force measurement method for the thumb and index finger (Fig.7).

Response: The finger force is measured in the same way as in Figure 4, mode a. And we have added the related test introduction. We have revised description as “To identify the mechanical properties of the fingers at the point of engagement with the tea, the thumb and the forefinger were placed on separate fixation blocks. The respective force changes were measured according to the displacement of the different fingers. The ballast structure was designed according to the shape of the tea stalk. ”For the detail, please see the revised version (line 122-126).

8. The standard deviation or the error bar is not included in Fig.8.

Response: Yes,Thank you for the reminder. We have redrawn the picture.For the detail, please see the revised version (line 235).

9. The authors mentioned that the findings are consistent with previous works, so what is the uniqueness of the current findings?

Response: Yes, it is a very good suggestion. According to your comments, We have added related content.

“The previous work did not specify the force parameters of the thumb tip and the joint between the first and second joints of the index finger.” For the detail, please see the revised version (line 203-204).

“However, the previous research studied the shear force of the stalk and did not analyze the squeezing force between the fingers and the stalk.” For the detail, please see the revised version (line 253-255).

“ In this paper, bending force, pull-off forces and stalk structure are analyzed simultaneously. ”For the detail, please see the revised version (line307-308).

“Previous Wu's study showed decreasing values of stem stiffness from bottom to top. In this paper, the bending force of the stalk is measured at different positions. The test results show that the stiffness of the stalk decreases slowly from the bottom to the top and then decreases rapidly." For the detail, please see the revised version (line330-333).

10. It is to suggest that the authors compare the previous results by providing the related quantitative results of previous works.

Response: Yes, it is a very good suggestion. According to your comments, We have added related content.

“However, Dzidek's study was conducted for the ventral region of the finger, where the pressure was 1.2 N when the ventral deformation was 1.46 mm. ”For the detail, please see the revised version (line 201-203).

“Previous Cao's study showed a linear correlation between stalk cross-sectional area and shear force. The shear force is 0.6 N when the cross-sectional area of the tea stalk is 1.8 mm2. The results of this study showed a linear correlation between stalk cross-sectional area and squeezing pressure. The squeezing pressure was 4.4 N for a tea stalk cross-sectional area of 1.8 mm2.”For the detail, please see the revised version (line 249-253).

“Previous studies by Hang showed that the average values of shear force at BIS and OTS were 0.97N and 1.2N. The results of this study showed that the mean values of the pull-off forces at BIS and OTS were 2.2 N and 2.6 N at 0 deg.”For the detail, please see the revised version (line 305-307).

We would like to express our heartfelt thanks to you again.

For the detail, please see the revised version (line 303-314).

Thanks again!

Reviewer 3 Report

The authors of the work took up the difficult topic related to the cultivation of tea, and more precisely its collection. I agree that manual harvesting is very good for the quality of the collected plants, but it is ineffective. Hence, the subject of the automation of tea leaf harvesting is very important.

The authors of the study could describe in more detail the way in which they conducted the experiment and in their conclusions, state whether they plan to work in the experimental fields, and later on larger-scale research to verify their research.

In addition, the Authors could refer to the scale on which tea is grown in the World and Asia in the introduction.

The work is very interesting and possible to publish after slight corrections (mentioned above).

Author Response

Dear Reviewer,

Thanks very much for taking your time to review this manuscript. I really appreciate all your comments and suggestions! Please find my itemized responses in below.

Response to the Reviewer

1. The authors of the study could describe in more detail the way in which they conducted the experiment and in their conclusions, state whether they plan to work in the experimental fields, and later on larger-scale research to verify their research.

In addition, the Authors could refer to the scale on which tea is grown in the World and Asia in the introduction.

Response: Yes, it is a very good suggestion. We have revised description as “The global tea cultivation area is 4.89 million hectares[2].”For the detail, please see the revised version (line 31-32 and line 433).

2. The work is very interesting and possible to publish after slight corrections (mentioned above).

Response: We thank the reviewer for their recognition. Your encouragement gives us more motivation to create more useful results for the field of tea harvesting.

Thanks again!