Distributed Model Predictive Control Applied to a Sewer System
Round 1
Reviewer 1 Report
Abstract
The abstract could be improved by a concise background on the need for paper.
Introduction
Some of the abbreviations and shortenings are confusing for the reader, in particular overflows (CSO) which has been used only two times. I suggest minimising the use of these short formats.
Page 2 Line 45 please add more references for the following sentence: “Some simulation models constitute benchmarks for the sewer [3].”
Page 2 Line 55: please rewrite or omit this sentence: “Regarding the control systems for UDS, a good review is presented in [5].” Such a statement about an article is not helping the reader.
Page 2 Lines 57-62 please provide references for each named methods, and briefly explain each method (this can be provided within a table with additional columns to highlight pros and cons of each method).
Page 2 Line 64-65 please provide examples from the literature.
Page 2, lines 66-67: please rewrite the following part as it is currently unclear: “although they offer as main disadvantage the increase of rules to be applied as the complexity of the system increases”
Page 2, lines 64-89. In this paragraph different examples from the literature are provided which are quite useful for the reader, however there is a need to more quantifiably evaluate their findings. For example rather than saying: “and to the control of UDS [20], with good results.” Please provide the accuracy or efficiency of the utilised system.
Page 3, lines 140-141 I am not sure if the location of the studies are helping your argument:” Other countries in which MPC control algorithms have been studied and / or applied to UDS are Canada [23], Colombia [41] and Germany [42].”
The introduction section is quite long and is it directing the reader appropriately, nor identifying the gap in the literature. By utilising the table mentioned above, please make the section shorter and more specific. The section should magnify the need for your paper by highlighting the gap in the literature.
Page 12 Line 348, I am not sure which figure are you referring to in: “The control system presents a hierarchical structure as shown in figure [5 25,23].” If the references are the source used for generating the figure then simply add them to the caption of the figure and drop them from the main body.
Page 16 Lines 449 to 452: Section 8 is not the right place to introduce the fuzzy method. The following seems unnecessary and should be omitted. “For example, if you consider the temperature in a boiler, you can go from a precise numerical value of temperature to its belonging degree to "high" or "low" sets, or even "dangerous", "high", "medium” of “low”, depending on the linguistic labels available.”
The results are presented by Figures 12 to 19 covering almost 8 pages of the paper, from page 20 to 27. I suggest you consider either combining the graphs, or keeping some and present the rest as an Appendix or to find another way for presenting the data as in its current format it makes the paper too long.
A very short conclusion for such a long paper. Please write an appropriate concluding discussion, if not two separated sections for each, in which the significance of your work should be highlighted together with its practicality for the future research and the industry. Please specifically mention whether and how the fuzzy approach helped as this is not very clear from the paper. Finally mention the limitations of the work and how future work can improve the research.
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
This paper discussed the different structures of MPC applied on a sewer system. For the distributed MPC structure, the system is decomposed into sub-systems with sectorization techniques. Similar results are obtained with distributed MPC and centralized MPC, with the advantages of solving simpler optimization problems in distributed MPC.
To improve the quality of this work, I suggest that authors carefully review the text (according to journal template) by checking the grammar and correcting the few errors and inaccuracies found in the document
In particular, before it can be published on Processes, I think it is necessary to evaluate the following issues:
- In figure 2, I think maybe the 5 in triangle should be 6 according to figure1.
- It is difficult to compare the difference between decentralized, centralized and distributed MPC in the figures 12-19. It would be much better if you put the responses of one tank in one figure with different MPC in figure 12, 14, 15, 16, 18, 19. And put different subfigures as one figure in 13 and 17.
- In table 4 and 5. The Tov,1 and Tov, 4 are smaller in decentralized MPC than those in centralized MPC. However, the Vov,1 and Vov,4 are bigger in decentralized MPC than those in centralized. Can you explain this in the text?
- The font of equations on page 15-16 is not correct. Please check also other parts.
Author Response
Please see the attachment
Author Response File: Author Response.docx
Reviewer 3 Report
An interesting paper, which should be published
Author Response
Please see the attachment
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
The abstract could be improved to make it more catchy.
Reviewer 2 Report
The authors revised the paper according to my comments
