A Bio-Inspired Manipulator with Claw Prototype for Winged Aerial Robots: Benchmark for Design and Control

Round 1

Reviewer 1 Report

The authors present a bio-inspired manipulator with a claw prototype and its control architecture. In particular, a manipulator contains two fully actuated and one passive joint and target to perform perching mechanism. However, the proposed system is weak in terms of overall novelty particularly bioinspiration design. The reviewer does not think the proposed work is sufficient enough for the publication. Please find comments as following, 

1) The proposed system is simply a problem of the three-link inverted pendulum with two full and one underactuated joint. The authors can find enough literature with a very advanced control architecture such as optimal control, adaptive control, etc. Also, it is loosely inspired by biology. How this work is novel and what is the main contribution?

2) The claim of lightweight is vague; what kind of new approach has been considered for making it lightweight. The proposed fabrication method is just a conventional approach using metallic links and commercial motors. 

3) It is not clear if the claw design is an active gripper, or it is always fixed on the passive link. Please elaborate in detail. 

4) Please add all captions for Figures 1, 2, and label subfigures properly in Figures 3, 4,6, and 10.

6) Please label the colors in Figure 10, 11. 

7) Why did the authors not implement control architecture with an aerial robot? It would be interesting to see. 

 

 

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The work is an interesting research project and comes in line with the rest of the works published by the members of this group.

I would suggest using other examples of tasks performed while maintaining equilibrium.

Overall, the material was presented in a coherent way, minor attention to the text is needed.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Dear Authors:

Thank you for the contribution of this work to the research community. The paper proposes a new methodology to achieve trajectory tracking with the end-effector of ornithopters and based on the nature inspired research. The work focuses on the design and control aspect of the bioinspired robots. Successful experimental results demonstrate the validity of the approach.

It would be nice to present the result for one application where the robot performs a designated task while perched.

 

Looking forward to the fully functional manipulator as your future work.

Best!

Author Response

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Author Response File: Author Response.pdf

Reviewer 4 Report

From a reviewer's point of view, this work is a novel and an interesting one.

The title of the contribution is precise, well-formulated and it fully corresponds to the treated topic.

The authors have a high level of understanding of current research, explanatory frameworks, and problems within the field of inquiry.

Appropriate research aims and objectives are delineated in this contribution.

The paper is well-structured having a well-written abstract which reflects the content of the article.

The authors clearly stated the problem under investigation in the introduction, summarized relative research.

The article identifies the procedures followed. The contribution is written with clarity. The narrative is logical and coherent. The authors used the appropriate techniques for analysis of the research objects in order to meet the aims of the study.

The accurate interpretation of outcomes, well substantiated by the results of the analysis has been achieved by them. The presentation of the results in terms of the research objectives has been successfully made.

Appropriate methods have been used in a well-founded manner. The authors have been able to draw logical conclusions from the results.

Conclusions are accurate and clearly based on outcomes. The paper presents figures and tables of high quality.

In my opinion, there is enough good data in this article; I still have the following questions about the article:

 

1- Figure 2b: please explain in more detail why the kinematic model (drawing) described with black lines in figure 2b is slightly different compared to the red one? Number of joints and links!

 

2- Experimental results, row 238: Please identify in more detail if there is a two or three active actuators that is included in the control algorithm. You have ankle joint, knee joint and hip join. Hip joint is controlled or you just add the friction?

 

3- At the final version of the manuscript, please be careful when describing the figures – row 262; Thus, in Fig. 10 top we show a new experiment…(top, bottom, left, right)

 

4- Figure 10, right: you presents a grasping force (0,015 Nm). Is this really a grasping force or grasping torque calculated based on grasping force?

 

5- Figure 11: It will be sufficient to presents the positions of the entire structure at different times (cycles). We know the angles q1, q2, and q3 during the cycles, table 4. Please consider adding more figures describing the exact kinematic structure if the system at different end effector positions.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Thank you for the clarification, static friction plays a critical role in the proposed design. The authors can emphasize it in the abstract too. The reviewer recommends it for publication.