Perturbation Observer-Based Obstacle Detection and Its Avoidance Using Artificial Potential Field in the Unstructured Environment
Round 1
Reviewer 1 Report
Obstacle detection and avoidance method are proposed by using mechanics theory other than computer vision mostly current researchers applying, it is highly significant. The author can improve the article in giving more description in the aspect of theoritical bases, such as Artificial Potential Field, a more precise parameter expression just like very small and shar turned corner etc., and more key suport data for results, for example Figure 16.
Author Response
Thank you very much for your valuable comments. Your suggestions have improved the quality of the manuscript. The authors have tried to address the reviewer's concern.
The point to point response is attached in a PDF file
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This paper proposed a detection-avoidance method combining sliding perturbation observer (SPO) and artificial potential field (APF). The topic is meaningful in practical robotic applications, and the combination of SPO and APF sounds reasonable. However, there are some questions that the authors need to be answered.
(1) The English writing needs to be improved, there are many unclear descriptions.
(2) Some Symbols in the equations are not explained. For instances, τ in Eq. (1), u in Eq. (2), x^. in Eq. (5), etc.
(3) The typesetting of text and figures in the paper is chaotic and some of the figures are blurred.
(4) The article does not introduce in detail how to obtain the positional relationship between the endeffector of the manipulator and the obstacle by calculating Fc. Since this distance is an important parameter in the repulsion field, it needs to be explained (how to obtain the parameter D in Eqs. (18) & (19).
(5) The conclusion and contribution of the paper need to be strengthened.
(6) There are some figures that have been published in previously published paper and the authors should pay attention to proper citation.
M. Salman, H. Khan, S. J. Abbasi, J. H. Kim, J. W. Lee and M. C. Lee, "Sensor-less Obstacle Collision Detection for Robot Manipulator," in 19th International Conference on Ubiquitous Robots (UR), Jeju, 2022.
Author Response
Thank you very much for your valuable comments. Your suggestions have improved the quality of the manuscript. The authors have tried to address the reviewer's concern.
The point-by-point response to the reviewer is attached in a PDF file
Author Response File: Author Response.pdf
Reviewer 3 Report
See the attachment.
Comments for author File: Comments.pdf
Author Response
Thank you very much for your valuable comments. Your suggestions have improved the quality of the manuscript. The authors have tried to address the reviewer's concern.
The point-by-point response to the reviewer is attached in a PDF file
Author Response File: Author Response.pdf
Reviewer 4 Report
This paper provides valuable results, but the current document has several weaknesses that must be strengthened in order to obtain a documentary result that is equal to the value of the publication.
General considerations:
(1) This paper proposes SPO and APF algorithm to detect and avoid the obstacle. The effectiveness of the algorithm is verified through Continuous Obstacle Avoidance in Simulator. The figure shows that the obstacle detection and avoidance are relatively accurate at low speed.
(2) And the key issues of obstacle detection and avoidance methods are summarized, including problem definition, Simulator construction and experiment quality evaluation. In addition, an experiment quality evaluation system combining subjective visual experience and objective evaluation is introduced, to comprehensively evaluate the performance of collision avoidance. Some important existing challenges and open-minded issues are introduced to provide insightful guidance for further research.
(3) There is a problem with the annotation of some figures. Figure 3 exists in both lines 143 and 209.
Abstract
(4) The abstract is complete and well-structured and explains the contents of the document very well. Nonetheless, the part relating to the results could provide numerical indicators obtained in the research.
Introduction
(5) This is called unstructured environment when we don’t have any prior information about the obstacle. Obstacle collision detection and contact force estimation problem in unstructured environment need to be described clearly.
(6) The importance of the paper is not apparent enough. In the introduction section, please highlight the contribution of your work by placing it in context with the work that has done previously in the same domain.
(7) There are some punctuation errors in this section, please correct them.
System Description, Dynamic model, and Controls
(8) This section introduces Nuclear Power Plant Simulator. this have used the Simscape Contact force library make RVI wall a solid contact.
(9) In line 164 of section 2.3, the meaning of sat function should be indicated.
SPO Based Collision Detection and Obstacle Avoidance using APF
(10) This section presents the formulation for disturbance observer, force estimation and motion planner for obstacle avoidance.
(11) In line 192-195 of section 3.1.2, “play their role” Repetitive writing.
(12) In line 202-204 of section 3.1.2, There is a problem with the superscript and subscript of the formula, and the meaning of angle ()and length () in the formula is not pointed out.
(13) In line 249 of section 3.2,is is the Jacobian matrix of order 6*5, not a square matrix, and has no inverse matrix ().
(14) In line 279-281 of section 3.3, the meaning of should be indicated and there is a problem with bold .
(15) In line 290-292 of section 3.3, the meaning of should be indicated.
Simulations and Results
(16) This section performs simulations in MATLAB, Simulink Simscape Multibody toolbox.
(17) In section 4.2, the movement process (such as direction and speed) of the end actuator should be pointed out, preferably in the figure.
Conclusions
(18) Although the work of this paper is important, it should provide a more detailed vision of the future.Overall, this is an important and comprehensive review.
Author Response
Thank you very much for your valuable comments. Your suggestions have improved the quality of the manuscript. The authors have tried to address the reviewer's concern.
The point-by-point response to the reviewer is attached in a PDF file
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The 1st Refereence "J.-J. Park, H.-S. Kim and J.-B. Song" maybe J. J. "Park, H. S. Kim and J. B. Song"
The last Refereence "Y. C. Xiangrong Xu," also maybe not exactly correct.
May use the same style for all refereence will be better.
Author Response
Thank you for your valuable suggestions and commnets.
The references have been checked and corrected. First and last reference has changed and corrected. All the references are in the same style now.
Author Response File: Author Response.pdf
Reviewer 3 Report
The revised paper is acceptable.
Author Response
Thank you for your valuable suggestions and comments
The English is corrected by the native speaker.
