Mathematical Analysis and Real-Time Control of a Novel 5-DOF Robotic System with a Parallel Kinematics Structure for Additive Manufacturing Technologies
, Kagan Koray Ayten 1, Mehran Mahboubkhah 2, Gurkan Kalınay 1, Sadrettin Golcugezli 3 and Sina Akhbari 2Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis paper presented the design of a 5-DOF robotic platform with parallel kinematics structure for additive manufacturing application. Overall, the proposed concept is interesting and the authors also presented a lot of design and experimental details. However, several issues should still be addressed to improve the quality of this manuscript. Below are some come comments for the authors to consider:
1. In line 133-136, the authors claimed that the proposed robotic platform is "more flexible, sustainable, cost-effective, more precise, and capable of achieving high work speeds compared to traditional additive manufacturing methods". However, no comparison between the proposed platform and the state-of-the-art systems was conducted in this work. In my opinion, the authors should perform some detailed comparisons to show the advantage of the proposed robotic platform.
2. The authors should provide the controller parameters used in the four experimental cases, e.g., k_p, k_i, k_d, etc.
3. What is the difference between the left and right figure in Figure 7? If they are the same, one figure is enough to illustrate the proposed prototype.
4. The authors should provide the model and manufacturer information of the motors and controller board used in the prototype in Figure 7.
5. Currently, there are many studies using additive manufacturing technologies to fabricate customizable robotic systems (see the references below). From this point of view, the authors are also recommended to mention those work in the Introduction section as important examples of the customizability advantage of additive manufacturing technologies. Below are some related work on 3D-printed robotic systems:
"LARG: A Lightweight Robotic Gripper With 3-D Topology Optimized Adaptive Fingers". https://doi.org/10.1109/TMECH.2022.3170800
"A 3D-printed robotic system for fully automated multiparameter analysis of drinkable water samples". https://doi.org/10.1016/j.aca.2021.338491
Author Response
Dear referee,
Thank you very much for your suggestions for our article. Responses to the requested revisions for the article are given in attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe proposed work is novel however some issues would improve its presentation and justify its applicability to the additive manufacturing domain that it targets.
The enumeration of lines stops at 194 and continues sporadically, so some comments in this review do not refer to a specific line.
Even though the Economist article mentioned in lines 48-49 is not scientific it should be also cited.
The DOF acronym is defined in line 78 but already used in line 20. Then it is written in full in line 108. In line 111, it is written without capitalisation. In line 115, it is used in another format. Please define it the first time it is used and use it consistently.
Section 1 mixes introductory material with a literature review. This is not always a problem, but in this case, introductory remarks and literature review are interleaved. Section 1 starts with an introduction. Then it reviews the literature and then it continues with text that suits the introduction. I think that the reader would be better served if a clear distinction was made.
In line 101, nine works are referenced at once ([22–30]). One sentence is not sufficient for reviewing these works and, therefore, their review should be elaborated. A similar occurrence is in the reference of [31–34].
When citing two works, e.g. “[35–36]” the two references should be separated by a comma, not a dash.
Line 183: in “ith” the “th” part should be in superscript. It is also sometimes written in italics and other times in plain text. Please use it consistently.
Figure 4 has 8 enumerated components (the numbers in the circles), but I can find no definition on the description of the figure on page 8 of what these numbers correspond to.
Figure and Table captions should all end with a period (‘.’).
MSE and ISE acronyms are not defined.
Figure 5 is cluttered and needs very high magnification to be inspected. Consider presenting the zoomed-in parts of the figure as subfigures to facilitate readability.
In the results section, I am unable to find a description of the method by which the errors in the results section were measured. Is it that either the sliding mode controller or the standard PID controller are considered as ground truth and, if so, why?
Figures 8 through 11 exhibit the following issues. They provide “zoom-ins” on details of the figure, but this is not explained to the reader making them hard to follow. Also, there is no commentary on what these details indicate. It is up to the authors, but I think that it would be no problem if the details were presented below the main figure as subfigures. Also, please consider using vector plots for them.
The term additive is used in the title, the introduction, and the discussion, but nowhere else in the paper. Why is it so? I think that since the proposed work targets additive mechanisms some experiment should be performed where a structure is printed and the printed structure is quantitatively compared against its 3D model, to understand the effective error. Alternatively, it should be shown or explained to the reader that the system is capable of supporting additive manufacturing (3D printing).
Temperature plays a crucial role in 3D printing, affecting the quality, strength, and accuracy of printed objects. The paper does not discuss issues related to the temperature condition of the system pertinent to (a) Bed Adhesion in preventing the first layers of the print from warping or curling up and (b) Cooling after the material is deposited, which is necessary to solidify the material and define the shape of the printed object.
Comments on the Quality of English Language
The paper would benefit from proofreading by a native speaker or a grammar checker. The most common errors are the erroneous use of the plural and single forms and the correct use of articles.
Author Response
Dear referee,
Thank you very much for your suggestions for our article. Responses to the requested revisions for the article are given in attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe authors have revised the manuscript according to my comments. Therefore, I recommend to publish this paper in this journal.
Reviewer 2 Report
Comments and Suggestions for AuthorsI find that the authors responded sufficiently to the comments of both reviewers and that the paper now merits publication.
