Adaptive Finite-Time Trajectory Tracking Control for Coaxial HAUVs Facing Uncertainties and Unknown Environmental Disturbances

Round 1

Reviewer 1 Report

In this paper, the problems of system designing, dynamics modeling and trajectory tracking control of coaxial Hybrid Aerial-Underwater vehicles (HAUVs) with time-varying model parameters and composite marine environment disturbance are investigated.Although the author's work is fairly goo , there are still some minor parts should be improved:

1.Please add a table of variables, as for too much symbols are used in this paper.

2.In 2.3.1 (5), is the form of $k_s$ too simple for its real physical processes?

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Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

This paper examines the problems of design, modelling, and trajectory tracking control of HAUVs with time-varying parameter sets and composite marine environment disturbances. Position and attitude controllers are designed using a nonsingular fast terminal sliding mode control scheme combined with adaptive strategy. Lyapunov theory is used to demonstrate the finite time stability of the controlled system.

I found the paper to be well organized and sound scientifically. As far as methodology is concerned, some suggestions should be made to improve the paper's structure.

 

1-      In general, the English writing and editing are satisfactory, however, some typographical errors need to be corrected. In order to make the paper easier to read, some sentences should be more concise. ( see for example Line 251, something is missing, line 355 where delta_i (i=1, 3, 5…1) should be directly after equation (23b), so the adaptive parameter A may increase, Line 374-375: The system can be considered is finite-time stable.)

2-      The paper contains several acronyms, which should be presented in a table at the beginning.

3-      How realistic is it in practice for the authors to assume lamped uncertainties are bounded?

4-      Lemma 1 is written in a poor way, Please revise.

5-      The analytical development in equation (31) is not clear. Please check.

6-      How does the author select the Water-exit trajectory as equation (44)?

7-      To validate the efficiency of the designed controller, authors must show the attraction domain in relation to the designed controller.

8-      Some qualitative indicators are necessary to evaluate the control strategy as: the control effort, several error standards…

9-      There appears to be a significant reduction in the initial conditions. As a result, the trajectory can be tracked perfectly. It is recommended that the authors increase the initial conditions in order to validate the control design.

10-  The performance of the controller should be evaluated on the basis of a comparative analysis.

An accurate revision of the paper editing must be performed.

Author Response

Please see the attachment,

Author Response File: Author Response.docx