Control for a Class of Unstable High-Order Systems with Time Delay Based on Observer–Predictor Approach
Round 1
Reviewer 1 Report
Comments for author File: 
Comments.pdf
Author Response
The manuscript has been carefully reviewed and corrected with respect to grammatical. In fact, the document has been sent to Proof-Reading-Service.com for editing and proofreading, certificate is attached. Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 2 Report
The proposed technique is unique, with updated conditions. However, some suggestions, queries, and updates need to be addressed for further article clarity. I strongly suggest the authors update the methodology and results section with higher dead-time process models (If possible, please experiment on the real-time system). Please find the comments in the attached document.
Comments for author File: Comments.pdf
The article and the proposed technique are interesting. However, I strongly suggest the authors to update the results and methodology clearly before accepting the article.
Author Response
The manuscript has been carefully reviewed and corrected with respect to grammatical. In fact, the document has been sent to Proof-Reading-Service.com for editing and proofreading, certificate is attached. Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
1) A similar problem has been discussed in [R1] and [R2]. The authors need to discuss the differences between their work and that of [R1]-[R2].
[R1]. "Simple stability criteria for systems with time-varying delays", 2004. [https://doi.org/10.1016/j.automatica.2004.03.011]
[R2]. "Stability and worst-case performance analysis of sampled-data control systems with input and output jitter", 2012. [http://doi.org/10.1109/ACC.2012.6315304]
2) According to Eq. (2), this manuscript focuses on only systems with real poles. Am I right? If so, this should be clearly mentioned in the manuscript.
3) Figure 1: Make sure all variables are properly defined in the text. For instance, what are g1 and g2? Also, consider presenting R(s) in the depicted block diagram.
4) Equation (7) is weird. First, continuos-time variables (phi_1 and phi_2) and discrete-time variable (y) are mixed. Second, this equation implies that y(t+\tau)=y(t).
5) Consider comparing your method with a state-of-the-art method. This would help the readers to understand advantages and disadvantages of the proposed method.
English of the manuscript is acceptable.
Author Response
The manuscript has been carefully reviewed and corrected with respect to grammatical. In fact, the document has been sent to Proof-Reading-Service.com for editing and proofreading, certificate is attached. Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 4 Report
The goal of this paper, as exposed by the authors, is to propose an observer-predictor scheme designed to estimate an internal signal of the system.
Although the paper is interesting, and the authors have put effort into its elaboration, it has some flaws that make it impossible for me to recommend it for publication. In particular, it is not clear whether the authors' contributions to THIS publication. Section I should contain an in-depth review of state of the art, but presents after a short introduction some works.
Keyword “Stabilization” was entered only once in the introduction section, although it is specified even in the title. My opinion is that "stabilization" must also be debated in the experimental part of the article. What types of linear delay systems were considered in this implementation?
Sections 6 and 7 are very concise and does not provide the expected experimental material and data and the innovation factor brought by the authors. Figures 7-8 are not textual presented as much as it should. My main concern is the lack of comparison data to other implementations. While related work from section I (maybe it's better to write it separately) should be praised for its, in order to highlight the benefits of the observer-predictor proposed scheme.
The aspects related to the output response and stability region must be explained, presented and validated with practical data, if there are made in the laboratory on a test model. What impact does the transfer function (25) and lim (26) have on the output response in examples 1-2 (Fig 7-8)? A “discussion” section can be added.
What are the contributions of the authors and the research innovation brought with this publication? (otherwise, no citations should be inserted in the Conclusions section).
References must be updated, citing new articles recently published in prestigious journals and conferences.
Author Response
The manuscript has been carefully reviewed and corrected with respect to grammatical. In fact, the document has been sent to Proof-Reading-Service.com for editing and proofreading, certificate is attached. Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
No further comment.
Acceptable.
Reviewer 4 Report
Thank you very much for providing responses to all my previous concerns.
