Parameter Study for Establishing a Synchronizer Control Strategy in Tractor Dual-Clutch Transmission
, Seong-Jun Kim 3, Jin-Kam Park 2, Young-Jun Park 1,4,5,* and Jin-Woong Lee 2,*Round 1
Reviewer 1 Report
Comments and Suggestions for Authors
Comments
The title of this manuscript is”Parameter Study for Establishing a Synchronizer Control Strat- 1egy in Tractor Dual Clutch Transmission”. The content of the manuscript is innovative., However, the manuscript mainly studied the parameter testing of the synchronizer shifting process and did not propose a control strategy for the synchronizer. Therefore, there are issues with the content and title of the manuscript being inconsistent.
In addition, there are some doubts about the expression of the manuscript content, as stated below:
1 ) In 130 line, “…….speed is referred to as synchronizer synchronization.” The “synchronizer” should be removed here .
2) In 142 line, “Fa: axial force, N”, The “Fa” is shift force and noted, because during the shifting process, the synchronizer is subjected to axial reaction force, which can be distinguished.
3) ) In 142 line, “Ffric: friction force between components, N”, The Ffric should be indicated as axial frictional force to distinguish it from the circumferential frictional force on the conical surface.
4) In184, in Figure 4, the working principle of the hydraulic valve should be explained; The working components of hydraulic valves should be labeled in Figure 4, such as the oil ports or chambers labeled with pressure 1 and pressure 2
5) In 210 line, for the title of this manuscript, the author needs to consider whether the pressure control valve shown in Figure 6 is necessary to appear in the manuscript; If this pressure valve appears in the manuscript, then the structure and working principle of this proportional pressure control valve should be introduced.
6) In 225 line, the sub-transmission with 4 speeds is not shown in Figure 8, but its transmission ratio is shown in Table 3. Therefore, Figure 8 should provide a complete transmission schematic diagram, including the sub-transmission with 4 speeds.
7) In 234-237 line, the test bench used for testing the transmission and synchronizer is introduced, and the schematic or physical diagram of this test bench should be presented and explained, along with an introduction to how the signals in Figures 10, 11, and 12 are measured.
8) In table8, case 1 and case 2, it needs to be explained that when the current is 700mA, its shifting force is smaller than that of 600mA. Why is this?
9) All coordinate axis units in the diagram should be indicated. In Figure 19, please explain why there is fluctuation in the input torque around 33.4?
10) The conclusion section should be briefly introduced. And the analysis part of the conclusion should be placed in Part 5 Test Results.
Author Response
The title of this manuscript is”Parameter Study for Establishing a Synchronizer Control Strategy in Tractor Dual Clutch Transmission”. The content of the manuscript is innovative.,
However, the manuscript mainly studied the parameter testing of the synchronizer shifting process and did not propose a control strategy for the synchronizer.
Therefore, there are issues with the content and title of the manuscript being inconsistent.
- The purpose of this paper is to conduct a study before proposing a control strategy, analyzing the factors affecting the shifting quality during pre-selection. Therefore, it is correct to say that this is a parameter study to establish a synchronizer control strategy for a tractor dual-clutch transmission.
In addition, there are some doubts about the expression of the manuscript content, as stated below:
1) In 130 line, “…….speed is referred to as synchronizer synchronization.” The “synchronizer” should be removed here .
- In 134 line, It was revised to reflect the reviewer's opinion.
2) In 142 line, “Fa: axial force, N”, The “Fa” is shift force and noted, because during the shifting process, the synchronizer is subjected to axial reaction force, which can be distinguished.
- In 146 line, It was revised to reflect the reviewer's opinion.
3) ) In 142 line, “Ffric: friction force between components, N”, The Ffric should be indicated as axial frictional force to distinguish it from the circumferential frictional force on the conical surface.
- In 146 line, It was revised to reflect the reviewer's opinion.
4) In184, in Figure 4, the working principle of the hydraulic valve should be explained; The working components of hydraulic valves should be labeled in Figure 4, such as the oil ports or chambers labeled with pressure 1 and pressure 2
- A proportional pressure relief valve in a hydraulic system operates by maintaining a specific pressure level. When the pressure increases, the valve closes to reduce fluid inflow, and when the pressure decreases, it opens to increase fluid inflow, thereby ensuring system stability. This mechanism is utilized for precise pressure control within the system.
- In 194 line, The above information has been added and the picture has also been modified.
5) In 210 line, for the title of this manuscript, the author needs to consider whether the pressure control valve shown in Figure 6 is necessary to appear in the manuscript; If this pressure valve appears in the manuscript, then the structure and working principle of this proportional pressure control valve should be introduced.
- In 214 line, I decided to delete the photo of this proportional pressure reducing valve.
6) In 225 line, the sub-transmission with 4 speeds is not shown in Figure 8, but its transmission ratio is shown in Table 3. Therefore, Figure 8 should provide a complete transmission schematic diagram, including the sub-transmission with 4 speeds.
- In 226 line, A schematic diagram of the transmission including the sub-transmission has been provided.
7) In 234-237 line, the test bench used for testing the transmission and synchronizer is introduced, and the schematic or physical diagram of this test bench should be presented and explained, along with an introduction to how the signals in Figures 10, 11, and 12 are measured.
- In Chapter 5(274 line), testing configuration, we have added information about the layout of the test bench and which devices receive test result signals.
8) In table 8, case 1 and case 2, it needs to be explained that when the current is 700mA, its shifting force is smaller than that of 600mA. Why is this?
- In Case 1 and Case 2, we did not say that the shifting force when the current was 700mA was less than 600mA, but that there was an optimal current for each case. The reason there is an optimal current in each case is because each gear ratio is different and the relative speed is also different. In 321 line, We have added information about this.
9) All coordinate axis units in the diagram should be indicated. In Figure 19, please explain why there is fluctuation in the input torque around 33.4?
- In 438 line, The fluctuation in torque around 33.4 seconds is believed to occur during the post-synchronization phase due to the impact generated in the process of engagement. This torque variation is attributed to the excessive force applied when colliding with a rigid object, resulting in the fixation of the gear. This information has been mentioned in the conclusion, and thus, no modifications have been However, considering the suggestion from advice number 10, which recommends relocating the analysis section from the conclusion to part 5, I will incorporate this content into the results. Also, Overall, the graph coordinate axis name settings have been modified.
10) The conclusion section should be briefly introduced. And the analysis part of the conclusion should be placed in Part 5 Test Results.
- It was revised to reflect the reviewer's opinion.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for Authors
1. Although the abstract provides a brief overview of this study, it does not fully summarize the main findings of the paper. For example, the abstract does not specify the methods used in the experiment or the experimental results supported by data. I suggest that you revise the abstract to provide a clearer summary of your results.
2. There are insufficient references on tractor powertrains.
3. There are some inadequacies in the format of the article. For example, there are numerous blank spaces in the image titles and the following text. Please carefully review the format of manuscript and make necessary corrections.
4. The significance of this paper is not expound sufficiently. The author need to highlight this paper's innovative contributions.
5. The conclusion of the article only explains the conclusions obtained from the experiment and does not indicate the next research direction in the future. I suggest the author consider adding relevant content in this regard.
Comments on the Quality of English Language
Minor editing of English language required
Author Response
- Although the abstract provides a brief overview of this study, it does not fully summarize the main findings of the paper. For example, the abstract does not specify the methods used in the experiment or the experimental results supported by data. I suggest that you revise the abstract to provide a clearer summary of your results.
- In 19-28 line, It was revised to reflect the reviewer's opinion.
- There are insufficient references on tractor powertrains.
- In 58-61, It was revised to reflect the reviewer's opinion.
- There are some inadequacies in the format of the article. For example, there are numerous blank spaces in the image titles and the following text. Please carefully review the format of manuscript and make necessary corrections.
- It was revised to reflect the reviewer's opinion.
- The significance of this paper is not expound sufficiently. The author need to highlight this paper's innovative contributions.
- In 68-77 line, It was revised to reflect the reviewer's opinion.
- The conclusion of the article only explains the conclusions obtained from the experiment and does not indicate the next research direction in the future. I suggest the author consider adding relevant content in this regard.
- It was revised to reflect the reviewer's opinion. Also, This paper is a parameter study to propose a synchronizer preselection control strategy. Research to present a control strategy using the results obtained from this is currently in progress and is planned to be written as the topic of the next paper.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for Authors
1) The manuscript is very lengthy considering the findings of the study. There are total 27 figures and 27 Tables, in the manuscript which make it almost impossible to draw the attention of researchers.
2) What problems can arise if the preselection in a DCT is too slow? It needs to be answered.
3) Why the authors chose to use the results from 600 mA and above in the analysis?
4) The manuscript is very difficult to understand and should be modified and restructured focusing on reducing its length by giving only significant findings and drawing the conclusion.
Author Response
1) The manuscript is very lengthy considering the findings of the study. There are total 27 figures and 27 Tables, in the manuscript which make it almost impossible to draw the attention of researchers.
-The author is fully aware that there are many figures and tables, but this study is a basic study for developing a preselection control strategy for DCT, and the result values based on variable parameters were judged to be an important part in the control strategy development. Therefore, we decided that all results due to variable parameters should be presented, and we have presented them all.
2) What problems can arise if the preselection in a DCT is too slow? It needs to be answered.
-In 68-77 line, if the preselection of DCT is delayed, damage to the synchronizer will occur, causing problems such as rapid changes in rotational inertia and inability to synchronize relative speeds, resulting in poor shifting quality.
3) Why the authors chose to use the results from 600 mA and above in the analysis?
-The control current that we initially tried to implement was set in 100mA increments from 400mA, which is the theoretical pressure at which the actuator can push the synchronizer sleeve, to 900mA, which is the maximum current that can be applied to the actuator, but it was determined that the current was less than 500mA. We discovered a phenomenon where the synchro sleeve does not move depending on the number of stages. Therefore, to do the analysis, Testing was performed using a current of 600 mA or higher, with all units preselected.
4) The manuscript is very difficult to understand and should be modified and restructured focusing on reducing its length by giving only significant findings and drawing the conclusion.
-The respective result analysis for each control parameter variation derived through this study is considered an important measure in the development of control strategies. However, with the review committee's opinions, we removed the overlapping results and conclusions, summarized them, and restructured the paper to make it easier to understand.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for Authors
The conclusion section should include the research results where there is no need to cite references, as shown" [30]" in line 566.
Comments on the Quality of English Language
Moderate editing of English language required.
Author Response
The conclusion section should include the research results where there is no need to cite references, as shown" [30]" in line 566.
- It was revised to reflect the reviewer's opinion.
Reviewer 3 Report
Comments and Suggestions for Authors
The authors have improved upon the manuscript and answered the queries raised.
Author Response
The authors have improved upon the manuscript and answered the queries raised.
- Thank you for reading my article and giving me advice.
