Computational Dynamics of Multi-Rigid-Body System in Screw Coordinate

Round 1

Reviewer 1 Report

Reviewer’s Comments:

The manuscript “Newton-Euler dynamics of multi-rigid-body system in Plücker coordinate” is a very interesting work. This paper investigates the kinematics and dynamics offor multi-rigid-body systems in screw form. The Newton-Euler dynamics equations are established based on Plücker coordinates. All forces and torques of the multi-rigid-body system can be solved straightforwardly since they are explicit in the form of Plücker coordinates. The displacement and acceleration are unified in matrix form, which associate the kinematics and dynamics in the variable of velocity. Only a oOne-step numerical algorithm only is needed to solve the displacements and accelerations. As a result, all the absolute displacements, velocities and accelerations are obtained by one kinematic equation directly. The kinematics and dynamics of Gough–Stewart platform are used to validate the method. While I believe this topic is of great interest to our readers, I think it needs major revision before it is ready for publication. So, I recommend this manuscript for publication with major revisions.

1. In this manuscript, the authors did not explain the importance of multi-rigid-body system in the introduction part. The authors should explain the importance of multi-rigid-body system.

2) Title: The title of the manuscript is not impressive. It should be modified or rewritten it.

3) Correct the following statement “Although this paper only discusses the application of Gough–Stewart platform, which represents a the most complex multi-rigid-body system, it is’s also effectivefit for developing algorithms for the kinematics and dynamics analysis of other multi-rigid-body systems”.

4) Keywords: The multi-rigid-body system is missing in the keywords. So, modify the keywords.

5) Introduction part is not impressive. The references cited are very old. So, Improve it with some latest literature.

6) The authors should explain the following statement with recent references, “Euler's two laws of motion for a rigid body are grouped together into a single equation by the Newton–Euler equation”.

7) Add space between magnitude and unit. For example, in synthesis “21.96g” should be 21.96 g. Make the corrections throughout the manuscript regarding values and units.

8) The author should provide reason for this statement “Here, S represents a spherical joint, U represents a universal joint and P represents a prismatic joint”.

9. Comparison of the present results with other similar findings in the literature should be discussed in more detail. This is necessary in order to place this work together with other work in the field and to give more credibility to the present results.

10) Conclusion part is very long. Make it brief and improve by adding the results of your studies.

 

11) There are many grammatic mistakes. Improve the English grammar of the manuscript.

Minor editing of English language required

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript considers the kinematics and dynamics of multi-rigid-body systems in screw form.

The manuscript is organized with tables and diagrams. The following concerns must be considered before it can be accepted for publication.

1.     It is not clear the advantage of the proposed procedure with respect to existing methods. A comparison should be performed with selected existing model.

2.     In the proposed approach the bar must be considered rigid. Considerations on this constraint should be added.

3.     Novelties of the paper should be better pointed out.

4.     English should be checked.

English should be checked.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

-The paper language is so bad. Many typos and grammatical errors have been detected. 

- The Motivations of the presented are not obvious at all. A deep survey of the previous research should be provided with more recent references.

- The contributions of the presented paper should be mentioned in the introduction section supported with good state of the art. 

- The stability of the proposed approach should be checked using Lyapunov theory for example to ensure the validity of the proposed method

- The conducted results should be compared with other related research works to assure the efficiency of the proposed approach

- Most of the used references are old which weaken the presented work and its soundness

 

-The paper language is so bad. Many typos and grammatical errors have been detected.  Also, many sentences need to be rewritten: Examples:

   -Although this paper only discusses the application of Gough–Stewart platform, which represents the most complex multi-rigid-body system, it is also effective for developing algorithms for the kinematics and  dynamics analysis of other multi-rigid-body systems.

    Please rewrite

  - As it is well known, multi-rigid-body system has a complex system with a lot of links and joints, and extensive researches have been published on kinematics and dynamics

      Please rewrite

   - Gough–Stewart platform is a complex and typical multi-rigid-body system, it has excellent performances consisting of high loading ability, good dynamic response and precise motion

      Please rewrite

  - The displacement, velocity and acceleration of kinematics is the base of the dynamics

    Grammatically  Wrong 

  -  Both translation and rotation are required to describe the kinematics of a mechanisms with a suitable mathematical framework in a relatively general way [19,20]

     Grammatically  Wrong 

 - The kinematics can be simplified by resorting to Plücker coordinate, many researchers have applied Plücker coordinate in kinematics [24,25] in parallel mechanisms.

    Grammatically  Wrong 

  -In kinematics, the absolute displacement, velocity and acceleration of each joint and link in the absolute coordinate frame can be derived which can be applied in the dynamics directly.

   Please rewrite

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Author Response

Please read the uploaded response.

Author Response File: Author Response.pdf