Real-Time 3D Mapping in Isolated Industrial Terrain with Use of Mobile Robotic Vehicle
Round 1
Reviewer 1 Report
Dear Authors,
Thanks very much for your manuscript submission to MDPI Journal of Electronics. This paper presents a conceptual framework on concurrent built-up for 3D map of the industrial environment. The authors claimed that they achieved the task of creating the 3D map of environment via adopting the planar map acquired from the 2D SLAM process, then made estimates on the local pose of the mobile robotic vehicle. They conducted a few real tests to validate the proposed hybrid 3D SLAM method, while the outcome is to confirm the solution for 3D map creation, the availability of their work in real-time or post-processing scenarios.
This is a short article, containing some set of good work, while the major defects are also transparent. It is incomplete in some points as expected by professional criteria of reviews, the set of experiments also lack quantitative analysis; besides, the conclusion section also needs major revisions. A few comments on major and minor parts for further edits are listed as follows (may not limited to these).
Major aspects suggested for further improvement:
a) Abstract: the current version only contains ~142 words, the statements are quite generic. Based on the actual load of contributions, I suggest the authors to expand the abstract to 180~200 words. Specific details of your approach (i.e., how do you propose the hybrid 3D SLAM approach, what innovations of your method is superior to other SLAM related work?) Besides, some keynote quantative results on concluding remarks, need to be supplemented in your updated version. Thanks a lot!
b) Introduction: I reviewed the four paragraphs, in my opinion, the authors can be a little bit more specific on the designs for mobile robotic vehicles. The current version in the first paragraph is too generic to be acceptable. Meanwhile, professional papers have a clear statement (in the second last paragraph) on the main summary of contributions on your research study, in 2-4 manifolds (and binded with some specific details), which is suggested for supplementation. The authors need to rewrite this section, extend the historical review, and make up the missed statements.
c) Section 2: SLAM Problem (or better be "Related work"): Two problems should be addressed. One is that the authors missed to present latest work 2D or 3D SLAM based (2020-2022) in this version, the other is that current descriptions looks unprofessional and only a couple of single mathematical models got contained. My suggestions: briefly cite any prior work (before 2018) and merge them to the Introduction section; the state-of-the art work (2019-2022) needs to be re-arranged in 2-3 paragraphs (don't keep the one paragraph per work style!) with emphasis on the SLAM related approaches based on different models. A few more specific details should be addressed on each manifold. In addition, if the authors were able to show a conceptual framework (proposed workflow or architecture of their 3D hybrid approach, or a tabulated results for the progress on recent advances on SLAM), it might be much clearer and more understandable.
d) Figures and Tables: the image resolution of some characters in Fig. 1 should be enhanced. The current version contains some blurs, and some transparent distortions should be calibrated. I think the font style should be TImes New Roman or Palatino Linotype (with proper font size). Be sure that when you are editing the draft, don't let any figure or table crossing over two pages, and apply middle-alignment. Many thanks for your updates.
e) Section 4: Environment Description and Experimental Results: I suggest that some subsections need to be adjusted. For instance, the visual results as specified in Figs. 3-6, looks a bit generic and somewhat lacks evidence. The authors also missed a subsection of quantitative analysis, which may include variation of parameters for your proposed 3D SLAM approach, and cover the related figures and tables in Sections 3-4. The suggested part can be cascaded in before Section 5 (right after sub-section 4.2). Some other sensitivity analysis or ablation study (if any), are supposed to be included.
f) Discussions: The authors missed to present this part. Discussions should not just be manatory while need to be critical. If the authors chose not to discuss anything, at least one paragraph on limitations of study can be further supplemented. Please consider a major rewrite on this section.
g) Conclusions: while the current version contains four paragraphs, the structure of this part should be adjusted, the narrations may also require a major rewrite. This section may have missed some concluding remarks on the keynote quantitative results; some specific statements must be included. Also, I suggest the authors expand the last two paragraphs with a summary of research challenges and future study orientations, etc. In a word, please consider reshaping this crucial section, which should also be different from the Abstract session.
h) References: a) Most citations are fine, each had been applied with the professional standards on citing journal and conference proceedings (by checking the most recent MDPI template) for some citations; Please check the abbreviated format for "Sensors" or "Electronics". b) Regarding those "online available" references, please check whether the citation style on volumes and numbers comply with the format MDPI template as specified; c) A few more latest publications in Years 2019-2022 which are similar / parallel to your study area on single / hybrid SLAM approaches, cloud computing and related computer engineering techniques, typically deep learning based approaches on real-time or post-processed 3D mapping, are supposed to be supplemented in your updates.
Minor problematic issues to be addressed in the revised version:
a) Please remove some of the redundant spacing or loose formating in the content and the references, i.e., those at Lines 28, 82 and 226, etc ). Your may edit MDPI online template has the options to adjust that. Thanks a lot!
b) In some sections, the literal quality of English can be improved. I would recommend the peer-reviewed authors to polish the literal aspects of this research article, including grammatical checking and careful proofreading.
c) Apply uniform font size and style on the characters of each figures, and fix the remaining formatting issues in the proofreading process.
Once again, wish you the best of luck for paper coming into acceptance. Thank you for your interests on publishing at MDPI Journal of Electronics. Stay well and take care!
With warm regards,
Yours faithfully,
Author Response
Thank you very much for taking the time to assess our manuscript and for giving us the opportunity to submit a revised draft of the manuscript. We tried to solve all the concerns and made the change the was suggested.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Well done, however, the following additions and fixes are worth considering:
· Does the ACML-EKF block in Fig. 1a correspond to that in Fig. 1b and if so, why is it not shown in one diagram
· It is unclear what 9DOF information from the IMU is used for
· Why Authors suggest that the usage of the AMCL is efficient for cases where the estimation process is disturbed by environmental errors like robot’s slippage or skidding
Author Response
Thank you very much for taking the time to assess our manuscript and for giving us the opportunity to submit a revised draft of the manuscript. We tried to solve all the concerns and made the change the was suggested.
Author Response File: Author Response.pdf
Reviewer 3 Report
In this paper, the authors present a concept of creating a 3D maps uses particle filters together with data from sensors to estimate position.
The paper should be more detailed.
The results obtained, the novelty and the advantages of using the new concept of creating 3D maps should be much better highlighted.
The paper should present more technical aspects, such as: the method of registration the point cloud, the registration mode for horizontal and sloping roads, accuracy of horizontal and vertical measurement, visualizing the results in real time, image processing, etc. The experiment should be performed using several scenarios.
It should also be presented how it influences, simple or complex shape, vehicle speed, temperature, humidity or dust, the accuracy of the registration.
Author Response
Thank you very much for taking the time to assess our manuscript and for giving us the opportunity to submit a revised draft of the manuscript. We tried to solve all the concerns and made the change the was suggested.
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
The paper has been partially improved, but has been improved over the first version.
Just a few remarks:
Acronyms must be explained the first time they are mentioned. For example, the acronym AMCL is written in lines 231 and 266. The acronym should be written in parentheses in line 12. In line 280 it should be replaced by the acronym.
In relations 4 and 5, what does T represent?
In lines 81 and 82 the sentence must be aligned.
Author Response
We appreciate the time and effort that you as reviewer dedicated to providing feedback on our manuscript and are grateful for the insightful comments on and valuable improvements to our paper. We tried to solve all the concerns and made the improvements the was suggested.
We appreciate the time and effort that you as reviewer dedicated to providing feedback on our manuscript and are grateful for the insightful comments on and valuable improvements to our paper. We tried to solve all the concerns and made the improvements the was suggested.
Acronyms must be explained the first time they are mentioned. For example, the acronym AMCL is written in lines 231 and 266. The acronym should be written in parentheses in line 12. In line 280 it should be replaced by the acronym.
Missing acronyms where first used have been supplemented. In line 280 acronym was applied.
In relations 4 and 5, what does T represent?
The T character in relations 4 and 5 represents transposition. We wanted to clearly indicate that X(2) and X(3) are vectors, not linear matrices.
In lines 81 and 82 the sentence must be aligned.
We made a fix as well as a few other editorial issues that were still found.
