Real-Time Self-Positioning with the Zero Moment Point Model and Enhanced Position Accuracy Using Fiducial Markers

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The abstract does not quite clearly explain the task. It would be desirable to explain for what purposes the pedestrian positioning inside the premises is required. Perhaps it is required for the use of virtual and augmented reality, then everything would be clear, no questions arise. Perhaps it is required to control the performance of some specific work, also clear. Perhaps it is required to help a blind or visually impaired person better navigate his apartment, or, perhaps, to improve the control of a wheelchair. Maybe it is required for all these types of work or for something else, but in order for the reader to understand the task, this should be indicated in the abstract, at least briefly. Otherwise, the reader somehow does not immediately understand and finds it difficult to agree that the positioning of people inside the premises is one of the most important and urgent tasks. An indication of the purposes of such positioning is needed. Perhaps this can also be useful and used for robotic cleaners, robotic vacuum cleaners, robotic deliverers of small goods and cargo or correspondence, and so on.

Probably instead of " Proposal method » would it be better to use "Proposed method"?

 

Barely li correctly statement V lines 72–73: “A method has been proposed to calculate the three-dimensional self-position using multiple markers [ 16][ 17]”. This statement means that no one has used or proposed using markers for positioning before these publications. However, back in 2012, the reviewer encountered the use of markers for positioning a person, as well as for positioning the instrument of a surgeon who performs an operation and for positioning the instrument of a robotic surgeon, markers with a special type of reflection or glow. And even then, this was not considered some kind of special novelty. So the aforementioned articles, written in 2020 and 2022, cannot claim to be the originality of this idea. At a minimum, the phrase should be changed in such a way that the aforementioned articles use, for example, markers for positioning, but it should not be claimed that this method was proposed in these articles, which means that the authors of these articles have copyright in this idea, which, of course, does not exist.

If we link the positioning problem to the problem of modeling human gait, then perhaps in some specific cases positioning may be more accurate, but it should be remembered that in this case we are no longer talking about solving only the positioning problem, regardless of the way a person moves, but it will depend on the compliance of human behavior with the model of movement that is embedded in solving the problem. Perhaps this will give rise to some additional difficulties when using this method. It is advisable to explain why the authors of the article limit the methods of human movement only to those that they embed in the model. The types of movement and gait can be much more diverse, unless it is some specific task. For example, children can play, jump, crawl, walk on all fours. Adults can dance or for some other reason move in some other way, for example, during gymnastics or during an interactive game using virtual reality. Adults can also move in an unconventional way when communicating or playing with children, with pets, when cleaning a room, when doing some work or flash mobs, etc. Even, for example, people can move in an unconventional way to correct the work of a robot vacuum cleaner.

The proposed markers seem too complicated, unjustifiably complicated. They are based on the idea of a specific form. Apparently, it is not assumed that the marker can be attached to clothing without being too rigid, the marker can rotate around its axis. It can be located at an angle and not be fully recognized. Traditionally, markers are made in the form of luminous dots or point reflective elements, such markers are cheaper, they can be placed quite a lot, they do not interfere with movement. Probably, the proposed markers have some advantage, but this should be explained.

It is obvious that the problem of determining the position can be solved with extremely high accuracy, for example, using interference methods using, for example, a semiconductor laser. The problem is of interest in the required accuracy (permissible error) and the permissible complexity and price of such a product, and also, for example, the question of how many people can be simultaneously covered by such a system, one, or two, or several, or an unlimited number of people? In this case, depending on the problem, the solutions can be completely different. This should be explained in the statement section of the article, where the problem is set and the requirements for the system are described. In the conclusion, it is desirable to indicate to what extent the problem has been solved, if it has been solved, and whether further research is required, if so, what kind and for what purpose.

 

 

Author Response

Comments1: The abstract does not quite clearly explain the task. 

Answer1: As written in the abstract, the task in this research is self-localization. I added the social significance of this task.

 

Comments2: Probably instead of " Proposal method » would it be better to use "Proposed method"?

Answer2: The title of Chapter 2 has been revised.

 

Comment3: This statement means that no one has used or proposed using markers for positioning before these publications.

Answer3: That was not my intention.
I cited a paper from recent research that adopted this technique. Research using markers has been around for a long time, but other reviewers pointed out to me that I should describe the latest trends, so I introduced it this way.
I hope you understand.

 

Comment4: Perhaps this will give rise to some additional difficulties when using this method. 

Answer4: As mentioned in the abstract and conclusion, this research aims to estimate self-location in large indoor environments such as warehouses and factories. In most cases, the user will be walking normally. Therefore, dancing or unconventional movements are not assumed. Also, even if the user makes some strange movements and the position calculation is deviated, it can be corrected with markers.
However, running movements are possible, so this is a future topic.

 

Comment5: Probably, the proposed markers have some advantage, but this should be explained.

Answer5: The 2D barcode used in this research can measure position and orientation using only a monocular camera. Systems that use reflective markers, such as those used in motion capture, require multiple cameras and are not suitable for mobile phones.
A concise summary of the above has been added to Chapter 4.

 

Comment6:  This should be explained in the statement section of the article, where the problem is set and the requirements for the system are described. In the conclusion, it is desirable to indicate to what extent the problem has been solved, if it has been solved, and whether further research is required, if so, what kind and for what purpose.

Answer6: The "Conclusion" has been revised to include a statement that this technology will contribute to solving a certain social issue as an example.

Reviewer 2 Report

Comments and Suggestions for Authors

This is a fascinating article.

Minor issues:

There is a lack of relative work. Please expand that chapter and use more references. The end of the chapter should show the new contribution to science in your article.

Please describe your method using a scheme - it would be more readable.

Please describe the parameters of the camera.

Figure 9 What are the differences between series? Why in the middle first is y-axis and second is also y -axis?

Fig 10 - Please expand that calculation, for example, with MSE.

Fig 13 please add the real trajectory.

 

 

Author Response

Comments1: There is a lack of relative work. Please expand that chapter and use more references. The end of the chapter should show the new contribution to science in your article.

Answer1: References have been added.

Comments2: Please describe your method using a scheme - it would be more readable.

Answer2: Flow diagram added.

Comments3: Please describe the parameters of the camera.

Answer3: Camera parameters have been added (sub section 5.1). 

Comments4: Figure 9 What are the differences between series? Why in the middle first is y-axis and second is also y -axis?

Answer4: Fig. 9 shows the x and y orbits of roots 1 to 3. It was hard to see, so I remade it.

Comments5: Fig 10 - Please expand that calculation, for example, with MSE.

Answer5: Added MSE.

Comments6: Fig 13 please add the real trajectory.

Answer6: The actual trajectory was not measured. Comparison with actual measurements was evaluated in previous experiments.
A rough trajectory (green line) has been added to Fig. 13. The wearer walked along this trajectory.

Reviewer 3 Report

Comments and Suggestions for Authors

1.     It is recommended that a description of the most critical and innovative quantitative indicators of the paper be added to the abstract.

 

2.     It is recommended to add a test for real-time in the experimental section. Add graphs to describe real-time testing.

 

3.     Algorithm flowchart is missing, it is suggested to add it in the algorithm section.

 

4.     The innovation of this paper needs to be further clarified, and the conclusion part of the paper also lacks the comparison of the same type of system, it is better to have a comparison table to show the advancement.

 

5.     There are some formatting errors in the references that need to be corrected.

Author Response

Comment1: It is recommended that a description of the most critical and innovative quantitative indicators of the paper be added to the abstract.

Answer1:This research is a self-localization method, and the relative position error is an appropriate evaluation index, so this is described here.

 

Comment2:  It is recommended to add a test for real-time in the experimental section. Add graphs to describe real-time testing.

Answer2:The final experiment is a real-time demonstration. We are also creating a video.

 

Comment3:Algorithm flowchart is missing, it is suggested to add it in the algorithm section.

Answer3:Added algorithm flow.

 

Comment4:The innovation of this paper needs to be further clarified, and the conclusion part of the paper also lacks the comparison of the same type of system, it is better to have a comparison table to show the advancement.

Answer4:The accuracy comparison using IMU has been evaluated in the experimental section.

 

Comment5:There are some formatting errors in the references that need to be corrected.

Answer5:Understood. I cannot make a decision on this, so I will ask the publisher to check it after the manuscript is accepted.

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

The reviewers' comments and suggestions have been revised, and the paper is ready for publication.