High-Precision Control of Control Moment Gyroscope Gimbal Servo Systems via a Proportional–Integral–Resonant Controller and Noise Reduction Extended Disturbance Observer

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper deals with the problem of high-fidelity speed control of a permanent magnets synchronnous motor, aiming at suppression of external lumped disturbance with both low-frequency and high-frequency components.

Although there are no novel theoretical contributions, the paper provides a compact and easily understandable description of how a conventional PI controller can be enhanced with a disturbance observer and resonant controller at the same time. Also, the comparison of conventional and noise-robust observer versions provides some valuable insights to the differences between the two methods.

I have two minor comments regarding the clarity of the presentation which should be taken into account while preparing the final version:

1. The claim that the NREDO part does not affect system stability, stated in Section 3.3, line 242,  is overly simplified and misleading. This actually holds only in the case of a perfect plant model. Any parametric or dynamic inaccuracy introduces additional closed-loop dynamics and potential instability. There are numerous previous works dealing with the robust stability of disturbance observers. You should make clear that you assume a perfect plant model in your analysis to avoid confusion.
2. Where does the Nyquist diagram in Fig. 5 come from? Is it a plot for particular values of plant and controller parameters? How did you tune the PIR part? Please describe this part in more detail as it introduces more questions than answers. Also, since you know the open-loop plant model and it is of finite order, the closed-loop poles can be evaluated directly without having to employ the Nyquist criterion. The Nyquist plot could be used to evaluate stability margins, which would be a valuable addition to the paper.

Overall, Section 3.3 is the weakest part of the manuscript and should be improved prior to publication.

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

In this paper, a control method based on proportional-integral-resonant (PIR) controller and noise-reducing extended disturbance observer (NREDO) is designed to address the problem that the speed control accuracy of flywheel servo system is affected by complex disturbances. Moreover, it seems that the desired effect is realized from the simulation results. However, there are still some language and formatting problems in the paper. Thus, a major revision is required, and the final decision cannot be made until the following problems are solved.

The following are the comments.

• The innovations of this paper are not yet clear enough. It is recommended that the authors organize and summarize the innovations in the introduction section and present them in points at the end of the introduction.
• It is recommended that the authors optimize the typography of the equations in this paper to ensure that the equals signs are aligned to improve the overall aesthetics. For example, the alignment of equations (20) and (21) could be further adjusted to improve readability and consistency.
• This article has a high repetition rate and the author needs to be aware of this. The authors need to reduce the repetition rate of this paper.
• This paper has a lot of abbreviations of terms in the introduction section, and it is recommended that the authors reduce the abbreviations to improve the reading experience.
• In this paper, some of the figures exceed the margins, for example, Figure 2, and the author is advised to resize the figures.

 

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

After the first revision, the manuscript has shown notable improvement. However, there are still some formatting issues that need further attention. Therefore, the paper requires minor revisions.

The following are the comments.

• The title of Figure 4 and the figure itself are not on the same page. It is recommended that the author adjust the layout so that the figure and its title appear on the same page for better readability and presentation.
• The current similarity index of the paper is still relatively high (20%). It is recommended that the author pay attention to this issue and reduce the repetition to improve the originality of the manuscript.
• Some of the figure titles in the paper are too brief. It is recommended that the author revise the titles to better summarize the content of the figures, providing clearer context for the readers.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf