Dynamics Simulation and Field Test Verification of Multi-Functional Beekeeping Loading Box Based on the Tracked Vehicle

Round 1

Reviewer 1 Report

In the introduction, when describing the multibody program employed for the simulations, the authors cite many works in order to justify the validity of the software. I think that it is enough with citing the work where the program is presented, or a web reference to the software's website. The rest of the citations does not contribute to this work.

In line 99, the verbs are not properly conjugated in my opinion.

The sentence of line 105 seems to miss a verb.

Equations 4 and 5 are not very useful. I suggest the authors to explain the velocity changes in text. The details of the maneuver can be referenced if the data is uploaded toguether with the article.

The rest of the work is well organized, and the virtual tests are also supported by experimental test. I suggest to accept the work.

Author Response

Dear Reviewer:

We would like to thank you for your careful reading, helpful comments, and constructive suggestions, which have significantly improved the presentation of our manuscript.

We have carefully considered all comments from the reviewers and revised our manuscript accordingly. The manuscript has also been double-checked, and the typos and grammar errors we found have been corrected. In the following section, we summarize our responses to each comment from the reviewers. We believe that our responses have well addressed all concerns from the reviewers. We hope our revised manuscript can be accepted for publication.

Dear Editors and Reviewers,

We would like to thank you for your careful reading, helpful comments, and constructive suggestions, which has significantly improved the presentation of our manuscript.

We have carefully considered all comments from the reviewers and revised our manuscript accordingly. The manuscript has also been double-checked, and the typos and grammar errors we found have been corrected. In the following section, we summarize our responses to each comment from the reviewers. We believe that our responses have well addressed all concerns from the reviewers. We hope our revised manuscript can be accepted for publication.

1. In the introduction, when describing the multibody program employed for the simulations, the authors cite many works in order to justify the validity of the software. I think that it is enough with citing the work where the program is presented, or a web reference to the software's website. The rest of the citations does not contribute to this work.

• We gratefully thank the reviewer for the precious time making constructive remarks. We have removed the research about other people from the introduction. After that, a module introduction of the software used was added, and the network reference of the software website was correctly referenced. (lines 119-120)

2. In line 99, the verbs are not properly conjugated in my opinion.

• Thank you so much for your careful check. We have followed your instructions and revised the original text. (line 99)

3. The sentence of line 105 seems to miss a verb.

• Thank you for pointing out this problem in the manuscript. We have revised the manuscript in this sentence. (line 105-106)

4. Equations 4 and 5 are not very useful. I suggest the authors to explain the velocity changes in text. The details of the maneuver can be referenced if the data is uploaded together with the article.

• Thanks for your kind advice. Considering the reviewer’s suggestion, we have added the text description and figures of the speed change to make it more intuitive. (lines 378-417)

Thank you for giving us the opportunity to improve the quality of our paper.

Sincerely yours,

Xiongzhe Han, Ph.D.

Kangwon National University

Reviewer 2 Report

The paper presents a simulation- and experiment-based analysis of a tracked vehicle for use in the apiary industry. The relevance for this research is adequately highlighted in the introduction. Field tests are performed on the tracked vehicle in real conditions. A multibody model of the vehicle is constructed and used to perform simulations under similar conditions as the field tests. The precise conditions are difficult to incorporate in an idealized simulation settings, but the model shows a good qualitative coherence with the experiments to be used for further analysis.

Overall comments:

1. I miss a direct comparison of the simulated and measured graphs. You reference the results in the text (mainly indicating that real conditions are less controllable than simulated conditions), but it would be nice to have two plots on the same graph to compare.
2. I am not a fan of the 3-dimensional style plots presented in the results section. It makes it harder to interpret the data. For instance, It is difficult to compare the influence of the road conditions in figure 15c. In the other plots a qualitative comparison is sufficient, but for instance in figure 15c, being able to compare the plots qualitatively would have added value.
3. Please improve all figure resolutions.

Punctual comments (some comments are open questions indicating that something is not fully clear to me; please clarify the confusion in the text for future readers as they may have the same interpretation as myself):

1. L217: You reference an empirical formula for a high-speed track (reference [20]), whereas this is a low-speed track (as mentioned on L206). Please explain in the text why this formula is still applicable for this use case.
2. L222: 10% of the vehicle weight is roughly 650N, which is very different from the 5000N listed here. Where does this large difference come from? If the preload value is determined in a different manner than with the empirical value, it would preferably not be mentioned. See also my previous comment.
3. L283: Please add a reference for the numbers in the table.
4. L296-301: What is meant with “not possible to directly calculate […]”? Do you mean that you needed to post-process the required dynamics from the generalized (relative or absolute) coordinates that are used to solve the equations of motion? Or is there another difficulty involved here? Please clarify in the text what you mean more precisely.
5. L300-301: Why do you only consider the translation of the frame’s COG? Its rotation also influences oscillations observable over the entire frame, including the contact points.
6. L320-324: If fixed joints are used, then the rigid model is equivalent to using an updated mass value, COG location vector, and inertia tensor. Including many bodies makes the model slower to solve, and less accurate. What is the benefit of the followed approach?
7. L341: Please have a consistent usage of bracket style and multiplication symbol (”X” is typically used for a vector cross product).
8. L341: The function is doubly defined for x=x_1
9. L341: This function does not seem to be a step function as the gradient at x=x_1 is non-zero.
10. L342-343: If the independent variable represents time, then perhaps using “t” might be more clear.
11. L349-351: Equations 4, 5, and 6 are not equations (they are missing a “=”).
12. L349-351: The step function has not yet been defined as a function. Please add the dependencies (especially their order) to equation 3.
13. L349-351: I think plotting these functions would be more valuable than listing numbers here.
14. L366-369: Figure 9a seems to be a Google maps image, in which case I am not sure you can use it, or if Google should be attributed. (https://about.google/brand-resource-center/products-and-services/geo-guidelines/#google-maps)
15. L376: The weight of a honey-loaded frame is simulated by a pack of paper, which is not really a rigid body. Could you comment on how the additional vibrations resulting from the deformation of the paper package influences the results? Perhaps the induced frequencies are much higher than the frequency range of interest (which I expect them to be), but then that should be clarified in the text.
16. L376: An empty frame weighs 0.8kg, and a honey-loaded frame weight 2.5kg. Then the additional mass added to an empty frame should be 1.7kg in order to simulate a honey-loaded frame. This was probably accounted for properly, but the figure indicates the pack of paper to be 2.5kg.
17. L381: The maximal lower limit of the operating temperature is “-40°C”, and not “+40°C”.
18. L436: When transporting bee frames, the COG is higher than when transporting beehives, which would lead me to believe that it is more prone to tipping over, resulting in a lower maximum uphill slope. But the numerical results are the other way around. As this result in counter-intuitive, could you clarify this in the text?
19. L439: Please use an “arctan” notation to avoid confusion.
20. L439: I am a bit surprised that the critical value of tipping is only kinematics-driven. I would expect the driving torque of the vehicle to have a significant influence here as well. Could you comment on the amplitude of the applied torque/track forces and their resulting tipping moment?
21. L461: From the images it seems that the bee hive is hanging from the top side and the accelerometer is positioned in the center of the frame (presumably also the location for which the simulation results are generated). It is not clear if the variation -1.579mm...0.49mm and space -2.5mm…2.5mm are both at the center of the center of the frame or at the bottom of the frame. Now it seems that the displacement at the bottom of the frame might be larger than the 2.5mm margin due to the rotation of the frame. Please clarify this in the text where this data is generated.
22. L608: The load bearing capabilities of the road conditions is presumably also causing the different pitch angles as described in L562-L563. If so, it would be beneficial to already mention it there.
23. L805-808: “operated better on soft ground” —> shouldn’t this be the other way around? On soft ground the pitch angle was larger.

Author Response

Dear Reviewer:

We would like to thank you for your careful reading, helpful comments, and constructive suggestions, which have significantly improved the presentation of our manuscript.

We have carefully considered all comments from the reviewers and revised our manuscript accordingly. The manuscript has also been double-checked, and the typos and grammar errors we found have been corrected. In the following section, we summarize our responses to each comment from the reviewers. We believe that our responses have well addressed all concerns from the reviewers. We hope our revised manuscript can be accepted for publication.

Author Response File: Author Response.pdf