A Snake-Like Robot with Envelope Wheels and Obstacle-Aided Gaits
Round 1
Reviewer 1 Report
This paper has developed and experimented a snake-like robot with envelope wheels. First, the envelope wheel has been designed, and the kinematics of the whole robot has been modelled. Second, some kinematic gaits for the snake-like robot have been introduled. After that, the mechanical design and the system architecture have been developed. Finally, the experiments have been demonstraited.
The authors have responded for my comments. And, the manuscript has been improved a lot. However, still I have some concerns as follows:
Major coment:
- It's my understanding that the novelty of this manuscript is on new design of snake-like robot, not gaits generation, because the gaits generation have been proposed in author's previous study. However, the contents of this manuscript is the gaits generation. Thus, I suggest to change construction of the contents. Current manuscript reports kinematics analysis of the envelope wheel first. Second, two basic gaits are introduced. Third, the design of the robot including mechanical system, electrical system and communication system is proposed. After that, another gaits are introduced. Finally, the experiments are demonstrated. That is, topics of both gait generation and robot design are mixid. Thus, authors improve construction of the manuscript.
Minor comments:
- There are two Figure 9.
- Page 11, line 307, different font can be found.
- Page 11, line 313 and 315, 4^st and 5^st are 4^th and 5^th.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
I am really happy on these improvements you made.
I suggest some fig. 23 improvement, but there no demand. Pictures of real robot shows real experiment conditions, but it is not so eveident to percept movement of the robot. In this case some picture and the rest as shematic sketch will reveal more details and would be more clear to reėader.
Secondly, I think your conclusions are diminishing your results and miss some evident thing - control of friction in future research.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
The Authors propose a snake-like robot with envelope wheels and two new obstacle-aided gaits. The paper is well structured. The introduction has been properly conducted with respect to the motivation of the problem and the techniques that have been used. In general, the methodology is clearly explained. However, more detailed should be provided about the control system: do you have some kind of feedback for controlling the entire system?
In the experimental section, the Authors should also provide more quantitative results that allows evaluating the performance of the proposed solution in a more objective way.
There are also several typos throughout the manuscript. Thus, editing of English language is also recommended.
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The authors have responded broadly for my review comments and improved the manuscript to fit the conclusion of the paper. However, the detail of the mechanical design is not suitable. The authors have shown the result of mechanical design, however, have never shown its design processes such as quantitative required specifications and actual specifications including velocity, force, and/or torque. That is important for readers.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
The Authors have addressed most of my comments and suggestion. Therefore I recommend the publication of the paper.
An additional check of English language is still required in the new text added before final publication (to correct minor typos).
Author Response
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Author Response File: Author Response.pdf
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
Well written paper, very nice mechanical design and analysis.
Reviewer 2 Report
This paper has developed and experimented a snake-like robot with envelope wheels. First, the envelope wheel has been designed, and the kinematics of the whole robot has been modelled. Second, some kinematic gaits for the snake-like robot have been introduled. After that, the mechanical design and the system architecture have been developed. Finally, the experiments have been demonstraited.
Comments:
- The novelty of this paper is anable to find. Almonst of contents including key idea (envelop wheel and slider link), modeling and control sysytem have been arleady published by authors.
- The construction of the introduction part is very poor. The authors discussed in detail with respect to related researches, however, the perpose, issues and approaches of this paper is finally not mentioned. That makes contribution of this paper decrease even if excelent result was shown in the paper. Thus, I strictly suggest the author to improve Introduction part.
- The authors missed some reference regarding 3D snake-like robot. Also, analysis of a snake-like robot capabling of changing wheel position has been proofed. To add the reference helps to improve contribution of this paper. Hence, I suggest to add following references.
Rollinson, David, et al. "Design and architecture of a series elastic snake robot." 2014 IEEE/RSJ International Conference on Intelligent Robots and Systems. IEEE, 2014.
Nansai, Syunsuke, et al. "Development of snake-like robot with rotational elastic actuators." 2011 11th International Conference on Control, Automation and Systems. IEEE, 2011.
Wright, Cornell, et al. "Design of a modular snake robot." 2007 IEEE/RSJ International Conference on Intelligent Robots and Systems. IEEE, 2007.
Nansai, Shunsuke, Masami Iwase, and Hiroshi Itoh. "Generalized Singularity Analysis of Snake-Like Robot." Applied Sciences 8.10 (2018).
- There are a lot of elementaly mistakes. Generally, figure cannot straddle pages (Figure 7 and Figure 22). In addition, a lot of reference mistakes of figure and equation can be found. English in line 140-143 cannot be understood. With respect to line 261-264, there is no relation from above. Is it copy from somewhere? Trigonometric functions such as sin, cos and tan are generally written in Roman.
- Explanation about Figure 17 is hard to understand.
- In line 170 to 171, authors mention "wall", which wall does authors mean?
- Regarding to Figure 15, what differences are there between "module" and "unit"?
- Regarding to next of equation 7, "b" and "c" are not defined.
- In line 129, does "gesture" mean "posture"?
Reviewer 3 Report
Very nice research, but paper misses/lacks some important issues:
No implementing issues discussed in the introduction;
Formulation of task simply missing in the paper - you need to add it;
Symmetrically, no task - no conclusions on research, it would structure all paper;
Snake and other limbless reptiles very dependent of friction to surface (ratio of friction in orthogonal directions), here is actually the same case, but formulation should be provided;
Resulting movement with various gaits has different efficiency, which should be considered.
