Adaptive Internal Model Control Based on Parameter Adaptation

Round 1

Reviewer 1 Report

Introduction

- firstly, refers to the PID controllers and the effect of these in processes/systems control;

- then, the authors refers to the IMC control method and to the professors Marari and Garcia (i.e. Morari and Garcia);

- here, maybe, a reference title on Morari and Garcia would be fair;

- the observations about the use of the PID algorithm in industry are correct (and also well known);

- the importance and the researches oriented on the fixed-wing UAVs are presented, at first sight, without connection with the topic of the paper (here, the term UAV is not defined);

- the fields where MRAC systems have been used most successfully are suggestive;

- the studies in the field and the connection with references are well formulated;

- the Introduction section seems to be unfinished (see the sentences Paper organization must be mentioned here,……);

Internal Model Control Algorithm

- in the beginning, presents the IMC structure, the equivalent IMC structure and the significance of the blocks/signals; here, the block diagram in not entirely visible (see Figure 1); also, the text refers to the dashed box (feedback controller), but it is not visible (see Figure 2);

- the dependence of the output signal on setpoint and disturbance is clear, as a consequence of the transfer functions algebra;

- in the IMC design, the reference to the equation (9) isn't clear; the equation (9) is below; between (8) and (9) it is another unnumbered equation;

- the design of the IMC PID controller is known from the literature; here, at least one connection to a reference in the field would be fair;

- the adaptive IMC structure is an interesting an achievable proposal; here, the role of the sum block on the direct path in not clear (Figure 3);

- the mathematical approach related to the adaptation algorithm is quite well presented; maybe, a better description of the used symbols/equations would be helpful;

Simulation Example

- starts with an suddenly finished sentence (...algorithm.);

- the measured units on Figure 4 are missing;

- the experiments of simulation refers to the UAV control, described by the state equation; here, some terms are not explained and a connection to the reference is missing; also, in the text, Figure 2 is Figure 5.

Conclusions

- refers, mainly to the IMC control in general and close to nothing to the performances of the proposed method in terms of steady state error, overshot etc.

The References are quite suggestive for the topic. Random check for: [3] Liu, W; [7] Jasmin, V.; [10] Jin, X.; [11] Tanaskovic, M.; [16] Rupp, D.; [23] Salfi, M. I.;

However, some suggestive titles/studies would be necessary.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Topic and area of ​​research:

Due to its great control effect, internal model control has attracted a lot of interest in the field of control, undeniable. According to the authors, under ideal circumstances, it can perfectly suppress external disturbances and ensure that the output exactly matches the input. A two-degree-of-freedom internal model control was created using the internal model control as a foundation.

In contrast to conventional feedback control, the internal model control structure embeds an internal model that is consistent with the control object in the control object. As a result, the quality of the control effect is determined by the deviation between the internal model and the control object.

In this paper, the authors suggest that the internal model be changed to an adjustable parameter model, and the model parameters are altered in real-time using the parameter adaptive algorithm, in order to minimize or, in the best case scenario, eliminate the model output error.
According to the authors, compensation based on the MRAC theory is utilized to address the interference's impact on the system.

Review of the work:

A well-described issue of control algorithms through the presentation of indicated research and advantages in Adaptive Technology. Also designed level of improved PID controller the use of internal model control principles is apostrophized.

However, although the topic of using drones for military and civilian purposes is seemingly extensively covered, many different control algorithms are used for drones that are not specified (LQR, SMC, "Control System Integrated Script" or "Control System Python Script", etc.). Therefore, some more significant works from that area should be added to the list of literature and the list in the introduction chapter should be expanded.

Although the structure and mathematical model of the IMC algorithm is described correctly and in detail, there are too many tipfellers and missing spaces between words in the text that this imperfection interferes with reading and hinders concentration of the reader (line 260, 297, 318, 323, 327, 338, 333-Pade, 366, 368-370, 426, 448, 449, 465, 491, 492, repeating one sentence in lines 522-523 and 524-525).

It is very important to notice that the description of the organization of the articles and the clarification of the chapters are missing.

Unfortunately, a clear description of the signal and description of the coordinate axes in Figure 4 is missing.

Figures 6 and 7 are too small in resolution and prevent a clearer representation of the signals. Also data impretation is missing.

In general, the lack of pictures, hardware, software, equipment and description of the circumstances during the conduct of the experiments is inexcusable.

It is indicated in just one sentence that the experiment was performed in ideal conditions and in a space that is not described, so that the environmental and initial conditions are not known, which is important for reproducibility and proving the correctness of the procedure, methodology and results indicated in the paper.

Related to the earlier remark, in the Conclusion chapter it should be indicated that the imperative of the indicated algorithm is to become a reliable and highly applicable control algorithm.

Related to the previous remark, in the Conclusion chapter it should be pointed out that the imperative of the mentioned algorithm is to become a reliable and highly applicable management algorithm.

Tip: Also, a recommendation for future work (if possible) is to add an additional (second) low-pass filter in logical paralel connection to compensate for the wide control performance at different frequencies, improving the correlation of the transfer function and the result at the end.

Mandatory recommendations:

1. Significant expansion of the list of reference literature.

2. Indication of the conditions and environment of the performed experiment.

3. More graphic data and graphs as evidence of successful research and confirmation of safe and reliable operation of the described algorithm (sufficient pictorial and numerical evidence).

4. Change of the description under the picture 1, 2 and 4.: Design of Control structure ...

Conditional/non-binding recommendations (Examples of possible extensions to the list of references):

1. Author: Alvaro Ortiz et al.; Comparative Study of Optimal Multivariable LQR and MPC Controllers for Unmanned Combat Air Systems in Trajectory Tracking

2. Author: YAVAN.F.D. et al.; A New, Tentative, Modified YOLOv4 Deep Learning Network for Vision‐Based UAV Recognition

3. Author: Kotarski, D. et al.; Performance analysis of fully actuated multirotor unmanned aerial vehicle configurations with passively tilted rotors 

4. Author: Kotarski, D. et al.; A Modular Multirotor Unmanned Aerial Vehicle Design Approach for Development of an Engineering Education Platform

5. Author: Raja, V.; Conceptual design and multi-disciplinary computational investigations of multirotor unmanned aerial vehicle for environmental applications 

6. Author: Veyna, U. et al.; Quadcopters testing platform for educational environments 

7. Zhigang Gao et al.; Using an Integrated Script Control Unit (ISCU) to Assist the Power Electronics Education

Other similar themes like „Control System Integrated Script“ or „Control System Python Script“ ... Ect.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Assessment of implemented amendments:

Although several points have been further clarified and the authors have improved the text and image connections, Figure 5 regrettably lacks a detailed description of parameters a1, a2, b1, and b2.

Additionally, Figures 6 and 7 are absurdly small and difficult to read.
It's unclear if the scenario in Figure 7 represents a simulation under disruptive environmental conditions with a downwind of 6 m/s or 10 m/s. I advise enlarging and dividing group Figures 6 and 7 into individual quarters.

The free line behind the explanation in picture 5 is missing, and the description font in image 1 is too large.

There needs to be more visual evidence of successful simulation to demonstrate the security and dependability of the algorithm presented in the research (sufficient figural and numerical evidence).

Author Response

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Author Response File: Author Response.pdf

Round 3

Reviewer 2 Report

Figure 5:

The resolution of the "Control structure of longitudinal direction" design in Figure 5 is very small and illegible. I recommend enlarging the image of the control design.

The remaining images are now of much better resolution and can be read and analyzed.

 

Author Response

The Figure 5 has been updated.