Optimal Kinematic Task Position Determination—Application and Experimental Verification for the UR-5 Manipulator

Round 1

Reviewer 1 Report

The authors present a method for robotic manipulator path planning. The technique focuses on minimalizing the joints' velocity during task execution. The authors implemented the simulation method and also on a real UR-5 robot. 

The authors did an excellent job presenting related works and problem background in section 1; highlighting the challenge and complexity of manipulator optimal placement problem. I appreciate that the authors provide a high-level structure of the paper in section 1 so that the reader can easily follow the rest of the article. 

The article is lengthy, but the authors present the technique in a good structure. The authors went into detail about the proposed method with a block diagram showing how the design works. However, I found that is oversimplifies the problem. For example, at line 207, the authors mention: "a Genetic Algorithm is employed to conduct the search for the optimal  location of the kinematic task" but do not provide any more context about that "Genetic Algorithm". I am curious what kind of Genetic Algorithm they are using and if using another algorithm is any different.

The rest of the article is just about discussing the application of the method and the experiments. I appreciate that the authors implemented the technique on a real robotics arm. However, the presentation in the article doesn't convince me that the result is significant. 

Overall, I found this article is poorly represented. Too lengthy and oversimplifies the detail of the algorithm. I suggest the authors rewrite the paper, focus more on the algorithm, and include a pseudo code. Reformat the figure and table, and make them more presentable. 

For example:

Resize figure 1, so it can fit in the article, and avoid leaving a huge blank in page 5

Reformat table 1 for better clarity and presentation 

Author Response

Reply to the Reviewer 1 report is in the attached file

Author Response File: Author Response.pdf

Reviewer 2 Report

In line 145, fist by first must be changed.

In line 175, am by an must be changed.

In line 234, eh by the must be changed.

In line 329, se by set must be changed.

Subsections 5.1 and 5.2 have the same name.

Author Response

Reply to the Reviewer 2 report is in the attached file

Author Response File: Author Response.pdf

Reviewer 3 Report

The authors present an article concerning a method for determining the optimal position of a robotic task within a manipulator's workspace, considering the minimum singularity-free paths in joint space to achieve high kinematic performance. One of the steps of the method is an optimization procedure, and in the results section, an optimal result is compared to one bad result.
I recommend that the authors may address the following comments for the improvement of the manuscript and the reader's clarity.
Point 1
One of the key points of the method is the optimization process. The process also depends on the number of intermediate points defined by the operator between two task points.
Consider the following remarks to improve the paper for publication:
Add diagrams or tables showing how these parameters influence the optimization process.
Point 2
The minimization of the joint velocities drives the optimization process. The result's effectiveness depends on the maximum allowable joint speed and the time used to execute the movement.
Consider the following remarks to improve the paper for publication:
Add a discussion concerning execution trajectory time and maximum allowable joint speed.
Point 3
The authors discuss only an optimal compared to a bad result. The discussion is a trivial performance comparison of the effectiveness of the method.
Consider the following remarks to improve the paper for publication:
First, discuss the steps followed by the optimization process to achieve optimal results, showing the performance improvement step by step. Then, if you need a bad reference task positioning again, add a discussion on how it is defined.
Point 4:
There are single spelling errors to be correct, e.g. line 175.

Author Response

Reply to the Reviewer 3 report is in the attached file

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors addressed all of my concerns in this version. This paper is now ready for a publication.

Author Response

We would like to thank the reviewer for the input on our paper and suggestions for its improvements prior to publication. 

Reviewer 3 Report

After the first review round, the authors introduced a few modifications to the paper. The reviewer recorded modifications in these locations: line 373, lines 340-345, lines 390-393, and lines 518-520.
From the scientific point of view, the paper is precisely the same as the first revision. Therefore, the reviewer suggests that the authors introduce in the paper the same modification already indicated in the previous revision.

Author Response

The reply to reviewer 3 is in the attached "Response to Reviewer 3.docx" file.

Author Response File: Author Response.pdf