Sensor-Based Identification of Singularities in Parallel Manipulators

Round 1

Reviewer 1 Report

This paper presents a general sensor-based method 4 to identify singularities in parallel manipulators workspace with low computational cost.

This paper contains some interesting results. Please find the following comments that may help improve the paper.

1) It is suggested to highlight the challenges of the investigated problem.

2) Is there any assumptions being made for the system model? Please discuss it.

3) More detail should be provided for Figure 4.

4) Please confirm the number in Table 1.

5) The reference section can be updated by adding some more related references to enhance the readability of this paper.

6) The conclusion section can be enhanced by discussing some future directions.

 The language of this paper can be further improved.

Author Response

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Reviewer 2 Report

The article proposes a sensor-based methodology to identify singularities of Type I and II in three non-redundant PKMs. The method is applied to several robots, both for educational and industrial purposes. The results show good accuracy of the identified singularities, demonstrating that the proposed method may be used in practical applications. It could be particularly useful in educational robots. Some remarks below.

In section 3, explain what are the fundamental movements of the PKMs, which are used in the calculations of the thresholds eth and (ith)’.

In section 4, give a pseudo-code or a flowchart of the MATLAB code used for the identification of the Type I singularities.

In section 5, give a pseudo-code or a flowchart of the MATLAB code used for the identification of the Type II singularities.

In section 6, give a pseudo-code or a flowchart of the ROS2 implementation used for the identification of the Type II singularities in the 3UPS+RPU PKM.

Add some comments about the robustness of the proposed strategy. Is the method prone to detecting false singularities? In a normal trajectory, if some peaks occur, will this affect the procedure? And so on. In this case, how to solve these problems?

Only minor misprints are detected.

Author Response

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Reviewer 3 Report

the work is very interesting. using sensors to detect singularities is not new, but the idea to detect the current change for Type I singularity is novel. 

the  reviewer has a few comments for authors consideration.

1. kinematic models are better presented. 

2. the singularity detection with sensors have to be justified with respect to kinematic measurement.

3. sensor specifications are missing, which should be included.

the paper is well written. 

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

the reviewer has no more comments

Author Response

The authors would like to thank the help of the reviewer to improve the paper’s readability