Multidirectional Dynamic Response and Swing Shedding of Grapes: An Experimental and Simulation Investigation under Vibration Excitation

Round 1

Reviewer 1 Report

This work presents a dynamic model for estimating the micro-vibration stems caused by grape cutting，This is an important research direction，Because basically all related papers are on the kinematics and dynamics analysis of the robotic arm, but few people study the dynamics of the picking target in depth。This goes against the "notion of lossless" in picking，This is because the derivation of the microscopic kinetic model of fruits like grapes requires a lot of knowledge of mathematics and mechanics. On the other hand, with the emergence of technologies such as deep reinforcement learning, people try to reduce the barriers between virtual and reality, such as Domain Adaptation Theory theory, which also requires such models as the basis for PAC Learning.Therefore, this article is worthy of recognition in terms of research direction, work quality, and research practicality.

But there are some small suggestions to the author, so that this article can do better:

 (1) The verification method of the kinetic model of this article is completed by using analysis and other papers to verify, and the analysis process is completely correct, which is acceptable in the process of writing scientific research papers, but if a test bed can be built, Doing some simulation or measurement experiments will make the work more complete.

  (2) The description of the mode and harmonic response in the article can be more detailed, because the essence of the content of high-order finite element analysis is a mathematical method rather than a pure technical method. A detailed description will make it easier for readers of the paper Understand the author's thinking.

 （3）There are relatively many factors and data in the expression design of the final result, which can be listed with the help of tools such as tables (of course, this is not necessary).

（4）Pay attention to some of the descriptions of the research objectives. Grapes, grape clusters, nodes, stems, etc. have slight errors in botany and mechanical application models. It is very necessary to clearly express this.

Author Response

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Reviewer 2 Report

-          Lines 12-13: “During mechanized table grape harvesting, berries are subjected to vibration and collision, which can cause shedding and damage to the fruit “. There is still no mechanical harvesting for table grapes. Mechanical harvesting for grapes destined to produce wine are extensively commercially used and are the ones that use vibration to detach the fruits. However, no mechanical or robot system has been developed to harvest “grape fruit”.

-          The objective of the study is completely misdirected. The study of the vibration detachment of the fruits is completely unrelated to robotic picking and it is related to wine harvested (wine grape harvesting machines).

-          The literature review is confusing and not clearly related to the aim of the study.

-          It seems that the aim of the study is simulate the vibration of the fruits (it is not clear referred to a grape cluster or is referred to the individual fruit). However, there is no connection to fruit harvesting for table grapes with robotic grippers.

-          Lines 41-42: “Therefore, studying the dynamic responses of grapes during harvest is essential to achieving low-damage or non-damaging picking”. The objective of the study is not clear.

-          A literature review about fruit detachment using vibratory devices is missing from the introduction.

-          The literature review seems to be focus on robot harvesting. However, no review has been developed about different robot and grippers for table grape harvesting.

-          In M& M section the harvesting method seems to be vibratory using mechanical (not robotic) machines (vibratory wine harvester). This part should be review in the introduction. If the simulation is prepared for table grapes the vibratory systems can not be used and the main idea of the research is not useful.

-          There is no experimental design, no information about the test with real fruit has been provided (lines 263-276 is providing a general information but not a real validation, it should be placed in the introduction).  Table 2 is not enough, a real test related to the simulation should be provided.  It is crucial to design an experimental set up to test real fruit to validate the simulation proposed.

-          No statistical analysis has been developed (no numerical results have been provided).

-          The conclusions are completed unrelated to the real harvesting process.  The results showed are not providing valid information that could be used to develop table grape harvesting (or improve wine harvesters).

Author Response

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Reviewer 3 Report

Substantive assessment:
Was the analyzed group randomly selected? By definition, no two are alike. The harvester must be universal and take into account all possible combinations of cluster shape. A vision system is needed, recognizing shapes in real time, the so-called computer image analysis. Such systems are already used by, for example, orchard sprayers. Harvest losses will always be there, they just need to be minimized. Yes, the selected vibration frequencies are important, but also the way of receiving the falling bunches. Similar problems occur when harvesting currants, but in this case the dynamic damage will be smaller due to the smaller masses of individual clusters. Manual harvesting is therefore still practiced in many vineyards in Europe. Expensive and slow, but gives better quality fruit.

Editorial Rating:
- in the entire typescript we use one way of writing units in accordance with SI (see line 98 and table 2 - Density)
- Is everything in Figure 4 (and Figure 5 on the left)?

Author Response

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Round 2

Reviewer 2 Report

- A clear explanation about what the authors consider “actual harvesting of table grape stems”should be required. It is crucial to clarified if the table grape harvesting considered is the actual one “labor harvesting” or is based on a possible future develop of a prototype that should be clearly described.

- It is necessary a validation of the simulation using actual fruit.

- A statistical analysis should be included in order to validate the results.

 

 

Author Response

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Author Response File: Author Response.docx