Construction and Evaluation of a Control Mechanism for Fuzzy Fractional-Order PID

Round 1

Reviewer 1 Report

Dear author,

The article is related to using a fuzzy logic unit to adjust the PID controller parameters of a pneumatic system. In my opinion, the subject is interesting and suitable for the journal.

However, I have some suggestions and questions:

 

1. In your reference list (33 positions), there are no references from Applied Sciences. In my opinion, you should justify your journal selection by providing some references.
2. You have normalised values in Figure 4 a) and b) - range from minus one to one. You should provide the formula for normalisation.
3. In Figure 4c, the negative values of outputs are omitted. Why?
4. In your fuzzy linguistic rule-base (table 2), you have the NB output of DKP when e is ZE e and De is ZE. Is this correct? I think it's a common mistake since the sequence of e in the second column (when De is ZE) is: NS, NB, ZE, which does not seem correct. The stability rule is that output should be ZERO for ZERO values of inputs.
5. You declare in general that you used Matlab. Did you use any specialised units such as Fuzzy Logic Toolbox or Simulink?
6. Figures with charts (5,6,7,8,9) can have visible grid lines, which would improve the readability.
7. Your work includes simulations only. Do you plan any laboratory experiments which would validate your results?

Regards,

Author Response

Response Sheet

Reviewer 1

Comment 1:

More references have been added related to the topic.

Comment 2:

Normalization formula has been catered.

Comment 3:

Negative values are now edited in the manuscript.

Comment 4:

Table 2 of Fuzzy linguistic has been checked.

Comment 5:

Specialised units were not used.

Comment 6:

Gridlines have been added in the images 5, 6, 7, 8, 9.

Comment 7:

No laboratory experiments were used but can be implemented in the future.

 

Comment No.	Page No.	Response
1	2-3	More references has been added.
2	7	Normalization formula has been added.
3	8	Figure 4c is showing all values negative and positive.
4	8	Table 2 of Fuzzy linguistic has been checked.
5	-	Specialised units were not used.
6	9-11	Gridlines have been added in the images 5, 6, 7, 8, 9.
7	-	No laboratory experiments were conducted.

 

 

 

 

 

 

 

Reviewer 2 Report

The article under review is devoted to the study of the problem of using a fuzzy fractional-order proportional integral derivatives (FFOPID) controller in automatic pressure control systems. The authors as a result of the research have shown that the use of the FFOPID controller improves the performance, resilience and flexibility of the controller.

The studies were carried out only by the method of mathematical modeling using the MatLab software.

In the introduction and literature review, the prerequisites for conducting research are briefly outlined. In the main parts of the paper, a description of the object for the application of the FFOPID regulator (for the automatic pressure control system) is given. A mathematical description of the integer order PID controller, the fractional order PID controller, and the fuzzy fractional order PID controller are presented. The results of modeling and comparison of the quality of regulation in systems with these controllers are presented.

In general, this is an interesting work, the results of which may be useful to specialists in the field of automation and control.

During the review, I would like to ask for a few clarifications:

1. To what extent does a change in the parameters of the control object affect the quality of regulation? It would be necessary to carry out the results of such studies.
2. The problem of noise immunity of the proposed controller requires clarification.

In addition, I would like to make the following recommendations:

 

3. The introduction should be expanded. The goal and objectives of the research being carried out should be formulated more clearly. The novelty of the solutions proposed by the authors requires explanation. Otherwise, gets the impression that the authors applied well-known solutions for a new technological object.
4. The results of experimental verification of the functioning of the proposed regulator should have been added to the paper.
5. Figures 1 and 3 should be submitted in higher quality. Figure 2 was missing from my version of the paper.

 

Author Response

Reviewer 2

Comment 1:

Research Design has been reviewed and it seems fine.

Comment 2:

The problem of noise immunity is not seen mentioned anywhere in the paper. So cant clarify.

Comment 3:

Introduction has been expanded and current studies have been added.

Comment 4:

Few lines related to verification of the functioning of the proposed regulator.

Comment 5:

All images have been edited to the best resolution.

 

Comment No.	Page No.	Response
1	-	Research Design has been reviewed and it seems fine.
2	-	The problem of noise immunity is not seen mentioned anywhere in the paper.
3	3	Introduction has been edited and refered with related studies.
4	8, 11	Few lines related to verification of the functioning of the proposed regulator.
5	-	All images have been edited to the best resolution.

Reviewer 3 Report

The proposed manuscript is devoted to the actual item of high-precision control methods, combining fuzzy logic and fractional-order PID controller. As a whole, this research is adequate and contains new useful results, concerning ways of improvement of discussed control scheme for pneumo system. But in order to publish this paper in ApplSci MDPI journal, it is necessary to improve some drawbacks and the description of the proposed method.

1.             The manuscript is actually specialized on pneumo systems, but this specificity is not clearly discussed, although the potential reader is to appreciate if any other task with close structure of sensors/ actuators, delay parameters or ranges of parameter deviations will be compatible with the used scheme of data processing. Also the choice of test signals is desirable to be commented, referring, if it is universal  or typical for pneumo systems. As the author has given typical signals after Fig.1, then it preferably to comment, how their possible deviations may influence on finally modelled parameters.

2.             Please, comment briefly the procedures to obtain exps. (4), (5), (6).

3.              The description is not clearly done for fractional differ-integral techniques according to Grunwald- Letnikov , the Riemann-Liouville, and the Caputo. It is desirable to motivate briefly the reader which of them and why is actual for the discussed system.

4.              The obtained by me file did not contain Fig.2 but only its caption, this is to be checked. Also, fonts of symbols in exp. (1) and (3) seem to be distorted and are to be verified. This also refers to symbols in rows 137-138 in the manuscript.

5.              Abbreviations IAE and ISE in Table 3 are to be disclosed (i.e. after their first use).

Author Response

Comment 1:

Pneumo systems has been defined in the manuscript.

Comment 2:

The Cohen-Coon procedure has been briefly described.

Comment 3:

Some lines have been added related to the fractional differ-integral techniques according to Grunwald- Letnikov , the Riemann-Liouville, and the Caput

Comment 4:

All figures are now present in the manuscript and have been edited to the best resolution.

Comment 5:

 Abbreviations IAE and ISE have been disclosed on their first use.

Comment 6:

Language and spelling has been checked in the manuscript.

 

Comment No.	Page No.	Response
1	3	Pneumo systems are defined.
2	5	The Cohen-Coon procedure has been briefly described.
3	6	Some lines have been added related to the fractional differ-integral techniques according to Grunwald- Letnikov
4	-	All figures are now present in the manuscript and have been edited to the best resolution.
5	11	Abbreviations IAE and ISE have been disclosed on their first use.
6	1-11	Language and spelling has been checked.

Round 2

Reviewer 1 Report

Dear Authors,
In my opinion, you made all the suggested amendments and the article may be published.

Best Regards,

Author Response

Thank you for your positive feedback, much appreciated.

Reviewer 2 Report

The authors recycled the paper. However, I did not get clear answers to questions 1, 2 and 4.

Despite the fact that the Introduction has been supplemented, from my point of view, it still requires revision. It is necessary to formulate the goal and objectives of the research more clearly. It is necessary to explain the novelty of the solutions proposed by the authors. In addition, for which point 1.1. Pneumatic System is highlighted in the Introduction ? This looks strange.

I continue to recommend this paper for reconsideration after major revision.

Author Response

Comment 1: Does the introduction provide sufficient background and include all relevant references? Must be improved

Response: Introduction has been improved, some more studies have been added and the novelty of the proposed method has also been incorporated. Page no 1-3, line numbers, 21-26, 103-113.

Comment 2: Are all the cited references relevant to the research? Yes

Response: Thank you for your positive feedback, much appreciated.

Comment 3: Are the methods adequately described? Must be improved.

Response: The Methods of the study heading has been mentioned from where the design has started, page no 3, line number, 115.

Author Response File: Author Response.pdf