Research on the Trajectory Tracking of Adaptive Second-Order Sliding Mode Control Based on Super-Twisting

Round 1

Reviewer 1 Report

The manuscript entitled “Research on the trajectory tracking of adaptive second-order sliding mode control based on Super-Twisting” has been investigated in detail. The topic addressed in the manuscript is potentially interesting and the manuscript contains some practical meanings, however, there are some issues which should be addressed by the authors:

1)    In the first place, I would encourage the authors to extend the abstract more with the key results. As it is, the abstract is a little thin and does not quite convey the interesting results that follow in the main paper.

2)    The readability and presentation of the study should be further improved. The paper suffers from language problems. The paper should be proofread by a native speaker or a proofreading agent.

3)    The Introduction section needs a major revision in terms of providing more accurate and informative literature review and the pros and cons of the available approaches and how the proposed method is different comparatively. Also, the motivation and contribution should be stated more clearly.

4)    The importance of the design carried out in this manuscript can be explained better than other important studies published in this field. I recommend the authors to review other recently developed works.

5)    What makes the proposed method suitable for this unique task? What new development to the proposed method have the authors added (compared to the existing approaches)? These points should be clarified.

6)    Some mathematical notations and presentations are not rigorous/clear enough to correctly understand the contents of the paper.

7)    The authors should clearly emphasize the contribution of the study. Please note that the up-to-date of references will contribute to the up-to-date of your manuscript. The studies named- Model predictive control of three-axis gimbal system mounted on UAV for real-time target tracking under external disturbances; Metaheuristic optimization-based path planning and tracking of quadcopter for payload hold-release mission; Performance of metaheuristic optimization algorithms based on swarm intelligence in attitude and altitude control of unmanned aerial vehicle for path following- can be used to explain the proposed approach in the study or to indicate the contribution in the “Introduction” section.

8)    “Discussion” section should be added in a more highlighting, argumentative way. The author should analysis the reason why the tested results is achieved.

9)    The convergence analysis of the proposed system is not given. This analysis should be given.

10) The effect of the parametric uncertainty is not discussed in detail. How did the comparison methods perform with or without the uncertainty?

11) It will be helpful to the readers if some discussions about insight of the main results are added as Remarks.

This study may be proposed for publication if it is addressed in the specified problems.

Author Response

Please refer to the attachment for the reply.

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper uses an expectation-based approach to determine the ideal steering wheel angle. It focuses on the trajectory tracking problem of autonomous vehicles and employs a multiple criteria optimization with three selection principles to select the best preview time. The controller designed in this paper seems to have a good control effect and the actual trajectory basically matches the ideal trajectory curve.

The paper is interesting and I enjoyed reading it.

The sentence "reaching the level of fully autonomous driving in the movies" gives the impression that autonomous driving is science fiction. Please change this sentence.

You write "After extensive simulations, the parameters were finally adjusted to ?1=0.2, ?2=0.05, ?3=0.75". It would be nice to show these simulations in the paper.

Figure 2 appears twice and also the graph in this figure does not have labels for the axes.

The paper is actually about "Absolute Positioning" which is explained in Y. Wiseman, "Autonomous Vehicles", Encyclopedia of Information Science and Technology, Fifth Edition, Vol. 1, Chapter 1, pp. 1-11, 2020, available online at: https://u.cs.biu.ac.il/~wisemay/Autonomous-Vehicles-Encyclopedia.pdf    as "A system that is able to locate the precise autonomous vehicle position, so the vehicle will be able to know where it should make its turns.". I would encourage the authors to cite this encyclopedia entry and to explain that this is the issue of their paper.

Author Response

Please refer to the attachment for the reply.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

All my comments have been thoroughly addressed. It is acceptable in the present form.

Reviewer 2 Report

The authors made a decent effort and the paper is certainly publishable so I would recommend accepting the paper.