Real-Time Diagnosis and Fault-Tolerant Control of a Sensor Single Fault Based on a Data-Driven Feedforward-Feedback Control System

Round 1

Reviewer 1 Report

It seems that while the paper may be interesting, it brings no clear novelty to the field of fault diagnosis. The experiment is poorly described, Authors do not indicate what exactly the system is. There is also no comparison to any other methods. Thus, the paper is more of conference PhD candidate paper rather than a full Journal article.

Author Response

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Reviewer 2 Report

The paper's aim has been achieved systematically, and the paper is well organized. However, below are some points that need to consider:

• The abstract needs to be improved as its current form does not adequately reflect what is conducted in the paper.
• On page 2, line 67, the abbreviation of least squares (PLS), I think, is not correct. Please check.
• Some symbols in Figure 1, such as Y(s) and Q(s), need to be defined.
• Please give short definitions of the additive and the multiplicative faults.
• More details about Figures 2 and 3 are required to be presented to help the reader to follow them easily.
• Why did you choose cubic polynomial fitting equations to estimate the signal value before and after the fault arises?
• How did you deal with the ∈ in Equation 12?
• Please check the used symbols in Equation 17 as they are written differently from the equation when defined.
• Why θ(s)=0 in Equation 18?
• The conclusion section does not wrap up the paper adequately.
• The article needs more editing and proofreading as many short paragraphs need to be merged and some grammatical and punctuation errors.

Author Response

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Reviewer 3 Report

The manuscript under review is interesting and documented, including both theoretical and practical results. The bibliography shows the authors' adequate documentation. However, I consider that the paper will benefit if the authors address within the manuscript the following aspects:

General remarks regarding the paper. The authors must assume more clearly in the paper their original contribution by specifying this fact and by highlighting the fact that starting from a certain point there are presented the original and novel aspects of their research. The authors must state more clearly their original methods, their original results and conclusions, the novelty of their study.

Remark regarding the "Abstract" of the paper. I consider that the authors should structure the "Abstract" as to cover the most important points of interest: the authors should have positioned the manuscript's topic in a broad context therefore covering appropriately the topic's background; the authors should have presented succinctly the methods they have employed in order to attain the purpose of their study; the authors should have summarized the most important outcomes of their study and the conclusions that one could draw. I consider that the abstract of the manuscript under review will be improved if the authors state and explain concisely at the end of the abstract the clear contribution that their study has brought to the current state of knowledge. In the abstract, the authors must state more clearly for the reader what is the meaning, the purpose, the usefulness of the research developed within the paper, what are their methods, their original results and conclusions as well as the novelty of their study.

Remarks regarding the results of the paper. The authors should in detail present the findings and their main implications, also highlighting current limitations of their study, and briefly mention some precise directions that they intend to follow in their future research work. I consider that the paper will benefit if the authors make a step further, beyond their analysis and provide an insight at the end of this section regarding what they consider to be, based on the obtained results, the most important, appropriate and concrete actions that the decisional factors and all the involved parties should take in order to benefit from the results of the research conducted within the manuscript.

Remark regarding the "Conclusions" section. I consider that it will benefit the manuscript and at the same time it will highlight even more the authors' contribution if they provide an insight stating clearer what is the purpose and usefulness of their study. Secondly, I consider that the authors should provide more details regarding the domains in which their modeling strategy can be applied, because it is not suitable to put the reader in the situation of interpreting, analyzing, continuing or refining the study from the manuscript under review.

Author Response

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Reviewer 4 Report

The authors of this manuscript propose a real-time diagnosis and fault-tolerant control method for single sensor faults in a data-driven feedforward-feedback control system. Their ideas are based on the ultrasonic liquid level sensor as the research object. Overall, the manuscript is well-written with very few language mistakes. The introduction section introduces the reader to the topic and discusses the state-of-the art, which is recent and adequate. The proposed method is well-explained. This is aided with the related mathematics and figures. The numerical results are well-presented and discussed. Finally, the conclusions section is supported by the outcomes of the results.

My only comment is regarding a couple of typing mistakes:

1.       Line 228, the word “Figure”

2.       Line 250, the unit “Hz”

Good work!

Author Response

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Reviewer 5 Report

1. Abstract can be written in more comprehensive and focused manner. Abstract, summarize the numerical results of proposed work, and discuss how it outperforms existing works.

2. Related work should be mentioned in a separate section by highlighting the comparative analysis in tabular manner. What are the unique features of this study compared to the existing works?

3. Contributions should be highlighted in bullet points and justified literature

4. A ‘Research Gap’ section should incorporate which will states the purpose of the study.

5. Methodology of the proposed research should be discussed in clear manner. Section 2 and section 3 should be merged to develop proper Methodology section. 

6. Conclusion also required presenting in more quantitative manner.

7. A comparative analysis of proposed fault detection, fault location, fault estimation, fault isolation, and control methods with existing methods is completely missing to find the novelty and superiority of the proposed work. 

8. Test system description is also missing. 

9. More recent literature review with critical analysis is required. 

Author Response

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Round 2

Reviewer 1 Report

no further comments

Author Response

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Reviewer 5 Report

Authors incorporated most of the comments raised by the reviewer. Lastly, check the language and organization of the manuscript. 

Author Response

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