Adaptive Predefined Time Control for Strict-Feedback Systems with Actuator Quantization

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The work exposes a novel adaptive control for systems with actuator quantization. Mathematical foundation is well developed. Authors report simulations of the proposed controller applied to a nonlinear system. However, they do no report comparison to other schemes, which prevent readers to fairly evaluate the performance of the proposed scheme.

1. In line 63, authors refer to the manuscript as “thesis”. 

2. Please give more context to understand the problem of “singularities of system” as is referred in line 73. 

3. In line 133, functions g_k(tested x_k), were not previously defined. For better clarity of the exposition, it has to be expressed whether it refers to g_s(tested x_s) or not.

4. In line 184 it says Step s, as a suggestion it could say Step s-th, similarly to the way that is expressed in line 197.

5. Exposed simulation results seem satisfactory but cannot be objectively assessed since there is no comparison to another control scheme. I think that this lack of comparison is an important drawback of the exposed work.

Comments on the Quality of English Language

Use of English language must be improved. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript deals with the problem of feedback control where the actuator has a quantized nature.

Detailed comments:

1) Some language grammatical errors occur. Therefore the manuscript should be checked thoroughly once again.

2) In the first part called "Prior knowledge", there are some missing descriptions, e.g.: on page 2, line 84: "beta", "K" are not defined.

3) page 3, eq. (3): I don't know how the fourth line of the inequality is derived.

4) page 4, lines 100 and 102: equations (28) and (43) shouldn't be referred to before they appear in the text of the manuscript.

5) page 12, Table 1: I'm not convinced that the "Protective resistance" is the correct term in this context. here.

6) In the simulations sections, there are no detail regarding the control system structure (maybe some block diagram would be helpful here), the method of simulation, and parameters (sampling time).

7) in a practical case, if we compare the inputs of the system without quantization and quantized (Fig. 7) we see that the shape is very similar. What gives us this quantization in this case? In my opinion in practice if we take such an electromechanical system we will introduce some higher-order harmonics to the system,  and this brings more problems. The authors should clarify why the proposed method is more efficient than existing approaches.

In my opinion, the manuscript is interesting and could be suitable for publication after revisions.

 

Comments on the Quality of English Language

Some language grammatical errors occur. Therefore the manuscript should be checked thoroughly once again.

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

All previous comments have been addressed. However, in response to comment 5 regarding the lack of comparison to other works, authors include a comparison to other control scheme proposed in a cited reference ([50]), but they do not explain the proposal of the cited work neither why this work is an adequate benchmark for the proposed control scheme. It would be better if authors take the time to describe the cited work and justify why is an adequate and fair comparison.

Comments on the Quality of English Language

English Language has been improved.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf