Comparative Study of Physics Engines for Robot Simulation with Mechanical Interaction

Round 1

Reviewer 1 Report

In the introduction part of the paper, general mathematical equations should be given and the problems in the desired development should be explained.  The algorithms used in these robot software should be mentioned in detail and at least some equations should be given. Otherwise, the paper will have the consistency of a review paper. 

Literature review has been done in general, therefore all studies in the literature should be given in a comparative table. The capabilities and limitations of these studies should be examined.

You should look at the following studies:

i)Advanced robotics analysis toolbox for kinematic and dynamic design and analysis of high‐DOF redundant serial manipulators, H Ozakyol, C Karaman, Z Bingul, Computer Applications in Engineering Education 27 (6), 1429-1452

ii)Novel fractional hybrid impedance control of series elastic muscle-tendon actuator, MJ Fotuhi, Z Bingul, Industrial Robot: the international journal of robotics research and application

Author Response

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Reviewer 2 Report

The paper is well-written and easy to understand.

The authors compared the performance of four different physics engines which were applied in simple and complex scenarios. The performance were in terms of mean error, maximum force angle and maximum penetration depth.

The findings of the research could provide useful information about the performance of a particular physics engine performing a particular task.

Author Response

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Reviewer 3 Report

The comparison of robot modelling and analysis software is presented in this manuscript [t. The content is suitable as a software selection tool. however, there is no research content that would help researchers to get inspired and work on it. 

Author Response

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Reviewer 4 Report

Review Comment

This is a very interesting paper, the author discusses the advantages and limitations of four physical engines(ODE, Bullet, Vortex and MuJoCo) in different industrial scenarios. However, the following issues require further explanation by the author:

1.Does the conclusion of this paper have clear data indicators?The abstract and conclusion of the paper only mentioned the limitations of the four physical engines, but did not give details of the limitations.

2. Some statements are overstated.For example, it is mentioned in line 66 that the four physics engines involved in this article are the most cited. But the reference 16 didn’t state it.

3. Are the simulation scenarios designed in this paper as close to reality as possible? For example, In the third figure of Figure 1, why do the boxes in the second column tilt and the boxes in the third column do not?

4. Are there clerical errors in the words “top” and “bottom” in Figure 5 and Figure 6?                                                                                                            

5. Why the average acceleration is used to calculate the error in Section 4.1? According to the scenario designed in this paper, the friction factor is 0.3. Therefore, the acceleration of each box in the acceleration phase should be the same. From the fourth picture in Figure 1, it can be seen that the spacing of boxes in each column is different. Therefore the acceleration and deceleration phases of each box are different. It is hoped that the author can provide a more complete Force Error definition.

6.The limitations given in this paper are mainly reflected in where the four physical engines all exist. Does this not help researchers choose a more appropriate physical engine?

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Author Response

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