Dynamics Parameter Identification of Articulated Robot
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis work presents a numerical method to establish a dynamics model based on the Newton-Euler formula and derives a linearized dynamics model through decoupling. Validation of the robot's dynamics parameters identification is performed through simulation and experimentation on a 500kg six-degree-of-freedom robot platform. Two methods are employed to verify the inertia parameters. A complete dynamics parameters identification scheme is established and validated through experimentation. Some issues should be addressed before this manuscript could be considered for publication.
1) The contribution of this work should be further clarified. The limitation of the previous wors should be stated.
2) Regarding the simulation analysis, the software, setting and parameters should be specified.
3) Line 89. It seems wrong “Dynamics Parameters”; perhaps: Kinematics Parameters?
4) Line 99. It seems wrong “Kinematic Model”; perhaps: Dynamic Model?
5) The main specifications for the robot, the motors, encoders, drivers, and motion control system should be provided.
6) The control strategies should be presented and justified.
7) The data instrumentation system should be specified.
8) What are the limitations and issues to address for the practical implementation of this method?
9) A Conclusion section should be included, providing quantitative results, advantages and disadvantages, limitations, and recommendations for the implementations. Recommendations and guidelines for future work should be provided.
Author Response
Dear reviewer,
Thank you for your patience and careful work. As for the revised paper and the reply to the comments, I have attached them to this message, check it, please.
Yin Zhehang
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThis study employs non-symbolic numerical methods and the Newton-Euler formula for dynamic modeling, deriving a linearized dynamic model by decoupling. It concludes with identified values for robot inertia parameters. The review comments are as follows:
1. The introduction's discussion of related research is too generic, merely stacking references without demonstrating specific deficiencies in the field or clearly articulating the significance of this study. The authors should categorize and analyze existing research to help readers understand the progress, characteristics, and shortcomings of dynamic parameter identification in this field, thereby highlighting the study's significance.
2. In Section 3.2, regarding the friction model, the authors did not propose novel methods for handling friction. Coulomb friction is a well-known model, so referencing literature at the Coulomb friction point is unnecessary, especially since the cited references are not primary sources for Coulomb friction knowledge.
3. Regarding the paper's citation methods and the quality of the references cited, the authors need a better understanding of the purpose and significance of citing references. Some of the references cited are quite old (1988, 1990, 1955, 1986...). While not discounting the relevance of older literature, this suggests that the authors have not thoroughly reviewed and summarized the literature in this field.
4. Each method cited in the paper relies on existing knowledge, for example, "In the references [18,19], a method for obtaining minimum inertial parameters is described in the symPybotics toolkit based on Python..."; "...In terms of robot control, the main factors to consider for friction include Coulomb friction [20] and viscous friction..."; "...For the identification of robot dynamics parameters, the periodic finite Fourier series is commonly adopted for the excitation trajectory of the experiment [19]...". However, after citing existing knowledge, the paper does not clearly state the innovation and differences of its methods, which diminishes its impact. The authors need to thoroughly describe the novelty of their methods to meet research paper standards.
5. Figure 4 depicts trajectories obtained through genetic algorithms; the process of obtaining hinge point trajectories via genetic algorithms needs to be added.
6. In line 251, "P=|theoretical value-simulation value|", this expression seems inappropriate. Additionally, at the end of Section 5, the conclusion states, "The minimum inertial parameters obtained through the simulation are consistent with the theoretical values". Although Table 4 shows only five non-zero results for P, the authors need to provide criteria for judging when simulation and experimental results can be considered consistent. Furthermore, should Section 5 be necessary? Can it be merged with Section 6? The authors should consider this further.
7. According to "The average of the data shown in Table 5.2 is found to be 22.69.", I did not find Table 5.2; I presume it refers to Table 6, and I personally calculated and confirmed the average as 22.69 from Table 6. Furthermore, references to "-209.96" and "213.42" were not found, necessitating the authors to annotate and highlight these key comparative values in the curves. These expressions can confuse readers...
8. The clarity of the figures needs improvement, such as in Figures 10, 11, 14.
Overall, this manuscript's topic and research are meaningful, but it fails to clearly articulate the study's innovations and superiority over current research in the field, falling short of journal paper standards.
Author Response
Dear reviewer,
Thank you for your patience and careful work. As for the revised paper and the reply to the comments, I have attached them to this message, check it, please.
Yin Zhehang
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe paper deals with the identification of dynamic parameters of an industrial robot with many degrees of freedom. The manuscript contains an introduction, a short theoretical part and the results of simulation and experimental studies.
Below are my comments on the manuscript:
1. The first section "Introduction" needs to be improved. The literature review lists many articles and describes in one sentence what each paper is about. There is no substantive synthesis of this literature review that would justify the authors' research. The motivation for addressing the topic is the statement: "Despite the progress in dynamics parameter identification, there is often a lack of cohesive overview of the entire process in literature." is insufficient.
2. The authors write that this paper fills the gap by providing a comprehensive identification scheme. So what's new in the manuscript?
3. Why do the authors use the term "500kg industrial robot"?
4. The titles of section 2 are inappropriate. It is about kinematics and dynamics, and the title of section 2 is Robot Kinematics Model. Then there is section "2.1 Dynamics Parameters" which describes kinematics, then there is section "2.2 Kinematic Model" which describes both kinematics and dynamics.
5. Lines 140 and 141 state that a linearised model is used. Isn't it about a linear model with respect to parameters? Because it's not the same. If the model were linearised, the problem would be trivial, but not relevant to real robots. Please consider this comment carefully.
6. Please demonstrate the relationship between equation (11) and the previous ones. As it stands, there is no relationship between the subsections.
7. Use correct equation references in lines 147, 150, 199.
8. The first sentence on line 160 is incorrect.
9. What is the purpose of the statement on lines 194-196?
10. The terms in equation (17) and the origin of the equation are unclear.
11. Subsection 3.3, which is supposed to be the heart of the article, is less than a page long and is not well explained.
12. No reference to Figure 9.
Author Response
Dear reviewer,
Thank you for your patience and careful work. As for the revised paper and the reply to the comments, I have attached them to this message, check it, please.
Yin Zhehang
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe authors addressed the recommendations, the manuscript has been sufficiently improved and could be considered for publication
Reviewer 2 Report
Comments and Suggestions for AuthorsThe author has made a lot of revisions to the questions raised in the last round, and the manuscript quality has been greatly improved.
Reviewer 3 Report
Comments and Suggestions for AuthorsI would like to thank the authors for the corrections they have made. However, not all answers are clear to me and some are insufficient.
The most important thing, however, is that after the authors' response I made sure that the proposed approach uses a linearisation of the robot dynamics model. Such a linearised model does not represent the dynamics of the robot in the whole workspace. Since there have been methods for years to identify non-linear models that allow to obtain a dynamics model that is adequate for any robot positions and any states, I propose to reject this manuscript.
