Unsupervised Tool Wear Monitoring in the Corner Milling of a Titanium Alloy Based on a Cutting Condition-Independent Method
Round 1
Reviewer 1 Report
The manuscript has good information, but needs amendments for consideration:
1. The abstract needs to be rewritten. The abstract should present the research problem, goal, scientific contribution, applied methods, results, findings, main conclusions.
2. I think that the literature should be cited in a different way. In my opinion, it is much better Jun et al. [6] proposed..... Niu et al. [8] presented........ Gao et al. [11] used......
3. Figure 3 is not clear. What is shown in the figure is not visible.
4. Are all the equations shown in the manuscript original or are some of them quoted. So far, only equations 16-20 have been cited.
5. Provide information about the workpiece (composition, mechanical properties, physical properties, thermal properties).
6. Elaborate in detail the choice of machining parameter?
7. Elaborate on the choice of fixtures (locating and clamping)?
8. Estimate the measurement uncertainty (for all results).
9. A discussion of "physical" processes would significantly raise the quality of this research. Discuss your results scientifically.
10. The main results, scientific contribution, limitations and future research should be highlighted in conclusions.
11. To improve the quality of English used in this manuscript and make sure English language, grammar, punctuation, spelling, and overall style are correct, further proofreading is needed.
Author Response
Dear reviewer,
Firstly, we would like to express our sincere thanks for your valuable comments and suggestions on our paper. The main corrections in the paper and the responds are as follows.
1.The abstract needs to be rewritten. The abstract should present the research problem, goal, scientific contribution, applied methods, results, findings, main conclusions.
Reply: Thank you very much for your valuable comment. We have rewritten the abstract. Supplements and revisions were made to the research questions, objectives, scientific contributions, applied methods, results, findings, and main conclusions. All the contents above are highlighted in red.
- I think that the literature should be cited in a different way. In my opinion, it is much better Jun et al. [6] proposed..... Niu et al. [8] presented........ Gao et al. [11] used......
Reply: Thanks for your valuable comment. We have revised the related parts in section “Introduction” and marked them in red.
- Figure 3 is not clear. What is shown in the figure is not visible.
Reply: Thanks for your valuable comment. Figure 3 has been revised and the key information has been marked and explained.
- Are all the equations shown in the manuscript original or are some of them quoted. So far, only equations 17-21 have been cited.
Reply: Thanks for your valuable comment. Formulas 1, 2, and 6 are classical and commonly used mathematical expressions; formulas 3-5 are put forward in our study when extracting the inherent time-frequency features; formula 7 is the index we propose to evaluate the effectiveness of the features; formulas 8-15 are the main formulas in our proposed clustering algorithm CAGS; formula 16 is the factor in our study to characterize tool wear conditions. Thus, all the above formulas need not to be cited.
- Provide information about the workpiece (composition, mechanical properties, physical properties, thermal properties).
Reply: Thanks for your valuable comment. We supplemented the information of the workpiece in section “Experiments” and highlighted it in red.
- Elaborate in detail the choice of machining parameter?
Reply: Thanks for your valuable comment. The experiments in this study are conducted based on an actual machining process, in which the parameters were determined. Besides, the tool wear monitoring system proposed in this manuscript was a cutting condition independent method. Thus, the choice of machining parameters had little influence on system validation.
- Elaborate on the choice of fixtures (locating and clamping)?
Reply: Thanks for your valuable comment. Our cutting workpieces are fixed directly on the dynamometer, which is fixed on the machine tool through a vice. We supplemented the information of the fixtures in section “Experiments” and highlighted it in red.
- Estimate the measurement uncertainty (for all results).
Reply: Thanks for your valuable comment. We have taken measurement uncertainty into account for the data obtained in the experiments. The error bar is added to the AEs feature graphs(Figure 9-12) to find the real trends when verifying the effectiveness of optimal features. In the clustering process, the data is processed based on the statistical principle, which eliminate the influence of the measurement uncertainty. The subsequent analysis is based on the clustering results so that the problem of measurement uncertainty need not to be considered.
- A discussion of "physical" processes would significantly raise the quality of this research. Discuss your results scientifically.
Reply: Thanks for your valuable comment. In this paper, we propose a solution framework for tool wear monitoring based on signal processing and machine learning, which treats the physical mechanism of the cutting process as a black-box problem. Thus, we find the relationship between the cutting process and tool wear conditions by using the statistics method. Usually, the discussions of the physical mechanism are achieved by establishing a numerical or analytical model of the cutting process.
- The main results, scientific contribution, limitations and future research should be highlighted in conclusions.
Reply: Thanks for your valuable comment. We have revised and supplemented the main results, scientific contributions, limitations, and future research in conclusions. All the contents above are highlighted in red.
- To improve the quality of English used in this manuscript and make sure English language, grammar, punctuation, spelling, and overall style are correct, further proofreading is needed.
Reply: Thanks for your valuable comment. We have proofread and corrected the English language, grammar, punctuation, spelling and overall style of the article and highlighted it in red.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Journal: Machines (ISSN 2075-1702)
Manuscript ID: machines-1813831
The authors presented an article about “Unsupervised tool wear monitoring in corner-milling of titanium alloy based on a cutting condition independent method’. I think the paper is well organized and appropriate for “Machines” journal but the paper will be ready for publication after major revision.
· The abstract looks good. The results obtained should be added to the abstract in the form of a sentence.
· Figure 3 is too small. The magnification ratio should be increased. (Line 180)
· In the last paragraph of the introduction, it should be expressed the novelty of the study, the differences from the past in detail.
· Results and discussion and conclusion parts are inadequate according to citation and analyze in detail. There should be the importance of the study in detail, comparison results with other approaches in literature, the success of the experimental and computational results.
· Please fix the typographical and eventual language problems in paper.
· The paper is well-organized yet there is a reference problem. First, your reference list contains no paper from “Machines” journal. If your work is convenient for this journal’s context then there are many references from this journal. Secondly, cited sources should be primary ones. Namely, indexed area shows the power of a paper and directly your paper’s reliability. Please make regulations in this direction.
· The article should be rearranged by taking into account the journal writing rules and citation rules.
*** Authors must consider them properly before submitting the revised manuscript. A point-by-point reply is required when the revised files are submitted.
Author Response
Dear reviewer,
Firstly，we would like to express our sincere thanks for your valuable comments and suggestions on our paper. The main corrections in the paper and the responds are as follows.
- The results obtained should be added to the abstract in the form of a sentence.
Reply: Thanks for your constructive suggestion. We have added the obtained results to the abstract in the form of sentences, and highlighted in red.
- Figure 3 is too small. The magnification ratio should be increased. (Line 180)
Reply: Thanks a lot for your constructive suggestion. We have revised Figure 3 and key information has been annotated.
- In the last paragraph of the introduction, it should be expressed the novelty of the study, the differences from the past in detail.
Reply: Thanks a lot for your constructive suggestion. We have compared our unsupervised method with the state of art of supervised methods, and illustrate the novelty of this study. All the contents above are highlighted in red.
- Results and discussion and conclusion parts are inadequate according to citation and analyze in detail. There should be the importance of the study in detail, comparison results with other approaches in literature, the success of the experimental and computational results.
Reply: Thanks a lot for your constructive suggestion. We have supplemented the results and discussion and conclusions sections, mainly including the importance of the study, the results compared with other methods, and the success of the experiments. All of the above are highlighted in red in the results and discussion and conclusions sections.
- Please fix the typographical and eventual language problems in paper.
Reply: Thanks a lot for your constructive suggestion. We have proofread and corrected the English language, grammar, punctuation, spelling and overall style of the article and highlighted it in red.
6.Your reference list contains no paper from “Machines” journal. If your work is convenient for this journal’s context then there are many references from this journal.
Reply: Thanks a lot for your constructive suggestion. In the revised paper, three related references published in “Machines” have been added and the numbers of references have been also corrected correspondingly.
- The article should be rearranged by taking into account the journal writing rules and citation rules.
Reply: Thanks a lot for your constructive suggestion. We have rearranged our manuscript as required to fit it to the journal writing rules and citation rules.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The manuscript has been corrected.
Reviewer 2 Report
The authors made all requested revisions. I believe that the article can be published in its final form in the "Machines" journal.
