A Robust Observer—Based Adaptive Control of Second—Order Systems with Input Saturation via Dead-Zone Lyapunov Functions

Round 1

Reviewer 1 Report

This paper interviews a robust observer based adaptive control of second order systems with Input saturation via dead-zone Lyapunov functions, the comments are listed as follows:

• There are a vast of observer involving no discontinuous signals, such as extended state observer, neural network-based observer, unknown system dynamics estimator and so on. Why do you choose the state observer and what are the advantages over extended state observer?
• Many of the plots in simulation results are unsatisfactory and should be revised. In Fig.2 (a), the solid green line should be placed below the blue dotted line to see all lines by readers. In Fig.3(d), the curve is outside the border.
• Despite the fact that the provided state of the art is quite complete, the author is missing some important works involving IEEE Transactions on Aerospace and Electronic Systems, DOI: 10.1109/TAES.2020.3040519; IEEE Transactions on Industrial Electronics, DOI: 10.1109/TIE.2020.3026297;

Author Response

We want to thank the anonymous reviewer for his/her revision that led to a further improvement of our manuscript. Replies for all queries presented by reviewer #1 are given in the attached document

 

 

Author Response File: Author Response.pdf

Reviewer 2 Report

In this paper, the authors present an observer coupled to a control law for a second order system with an unknown input. The study is interesting but suffers from a lack of description and a lot of calculations. The comments on the numerical tests are weak.

Comments

1) The introduction contains references and presents the problem of each design of these references. The main idea and problem that this paper solves is not explained or detailed. Can you explain more about the why and how of your contribution as you did in the abstract.

2) In the Model Description section, the model seen as generic for this type of system. A brief introduction of this system at the beginning of the section, based on the remark in assumption 5, would be helpful.

3) You can also rewrite the model as a nonlinear state system, it is more readable and compact for the rest of the paper.

4) The step from (2) to (7b) is not easy, the term a_2 is not described.

5) Equations 19d and 19f are the same.

6) Before the numerical simulation, can you summarize the whole design (observer and control law) to have a good overview of the design.

7) Put the grid on your graph, it is easier to read and comment.

8) In figures 3 and 4, put the tracking error cap x_1 - y_d.

9) The numerical results are not commented and what are the differences between all these tests.

10) how fast is this system? less than 5 minutes?

Author Response

We want to thank the anonymous reviewer for his/her revision that led to a further improvement of our manuscript. Replies for all queries presented by reviewer #2 are given in the attached document. 

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The authors have been increase the introduction part. In this revised version, the main idea and problem that this paper solves is explained and detailed in the introduction and give a better view of what the authors solve.

 The authors show that the two experiments work and comments them.