System Design Navigation for an Explorer Robot with System Continuous Track Type Traction

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear colleagues,

 

Would you please consider the following comments, in addition to the comments mentioned in the attached file.

1- with the present PID controller design, would it be possible to consider some uncertainty on the mobile robot parameters, and show the dynamic performance of the mobile robot.

2- exhibit the robot dynamic performance in a 2D-Space (x, y, theta).

3- show the dynamic performance of the mobile robot for an eight and flower shapes.

4- it would be of an interest to show the dynamic performance of the mobile robot, of (band 3), in the presence of parameters mismatch of the mobile robot.

5- explain how the wheels angular speed has been obtained (what is the encoder resolution).

 

Best Regards

Comments for author File: Comments.pdf

Author Response

Dear Reviewer,

I am pleased to inform you that the majority of your recommendations and comments have been carefully considered and incorporated into the revised version of the paper.

In the attached file, you will find a PDF with the corrections highlighted has been included.

This PDF uses three highlight colors:

• Blue indicates the corrections based on the comments you uploaded in the attached file.

• Green highlights the modifications or key sections that address your five main comments.

• Yellow corresponds to the revisions made in response to the other reviewer.

In this letter, I have also included a brief response to each of your comments.

Comment 1: with the present PID controller design, would it be possible to consider some uncertainty on the mobile robot parameters, and show the dynamic performance of the mobile robot.

Response 1: We have provided a more detailed explanation of which parameters may involve uncertainty, and we have presented the robot’s dynamic performance. This comment was addressed jointly with Comment 4.

 

Comment 2: exhibit the robot dynamic performance in a 2D-Space (x, y, theta).

Response 2: Even though the main objective of this work was teleoperated navigation—without the intention of performing trajectory tracking—the robot's behavior in the plane has been included in Figure 24 for reference. This behavior corresponds to the velocity commands shown in Figures 22 and 23.

 

Comment 3: show the dynamic performance of the mobile robot for an eight and flower shapes.

Response 3: Unfortunately, this comment could not be fully addressed, as this work does not aim to perform trajectory tracking. Implementing such a feature would require additional considerations, especially for the physical implementation.

To follow predefined paths like the eight or flower shapes, it would be necessary to use sensors such as LIDAR to map the environment and generate the trajectories—resources that are not available in this study. Additionally, a separate control loop would be required to minimize the error between the desired and actual positions, where the actual position could be estimated using the robot’s odometric equations. However, since this setup lacks the necessary sensors, this aspect was beyond the scope of the current work.

Therefore, the dynamic performance of the mobile robot for eight and flower-shaped trajectories could not be included.

 

Comment 4: it would be of an interest to show the dynamic performance of the mobile robot, of (band 3), in the presence of parameters mismatch of the mobile robot.

Response 4: The dynamic behavior of the robot in the presence of parameter mismatches has been included in Figures 25 and 26. However, I would like to clarify that I did not fully understand what is meant by “band 3” in this comment. If you could provide more context or clarify the term, I would be happy to address it further.

 

Comment 5: explain how the wheels angular speed has been obtained (what is the encoder resolution).

Response 5: It is important to clarify that the angular speeds refer to the motors and were obtained using Equations (5) and (6). In addition to this explanation, the encoder resolution has been included and highlighted in Subsection 2.2.2, specifically on line 358. Furthermore, the sampling time used for this encoder is explained on line 393.

 

If you have any doubts or further recommendations, please do not hesitate to let me know.

Thank you very much for your valuable feedback.

Sincerely,
Adrian Geovanny Urgiles Rojas

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The paper presents an interesting study on automation and control systems, with a focus on the application of a PID controller. To enhance the paper, some minor revisions are necessary.

To enhance the literature review and broaden the discussion on advanced control methods that integrate fuzzy logic and neural networks (ln.71-72), the authors should consider incorporating key references that are currently absent. Notably, the following studies could add depth to the discussion: "Trajectory Tracking Control of a Mobile Robot Using a Fuzzy Logic Controller with Optimal Parameters", "A Fuzzy Control Strategy for Multi-Goal Autonomous Robot Navigation" and “An ANFIS-Based Strategy for Autonomous Robot Collision-Free Navigation in Dynamic Environments”. These works propose alternative controllers for robot navigation, addressing challenges similar to those discussed in this paper.

Regarding PID controller selection, the paper implies that it was chosen due to its superior performance. However, the criteria for "better performance" are not explicitly defined. How was this determined? The authors should provide a clearer justification by either comparing PID with alternative controllers (e.g., PD, PI) or citing relevant studies that support the claim of PID superiority in this context.

While the study presents substantial work in Gazebo simulation, ROS programming, controller design, and physical implementation, it is unclear how these components are interconnected. To strengthen the validity of their approach, the authors should provide more details on system integration, along with visual representations of the robot and its environment.

Several critical methodological details are missing concerning system parameters, hardware/software used, and experimental duration. The authors should include information about hardware components (e.g., sensors, actuators, microcontrollers), software tools (e.g., MATLAB, Simulink), duration and number of trials etc.

In addition, the tuning method is not explicitly stated. Was Ziegler-Nichols used? or manual tuning? The authors should specify the method and provide a brief justification for its selection.

The authors are urged to clearly outline the experimental setup, including test conditions, data collection methods, and control variables.

Author Response

Dear Reviewer,

I am pleased to inform you that the majority of your recommendations and comments have been carefully considered and incorporated into the revised version of the paper.

In the attached file, you will find a PDF with the corrections highlighted has been included.

This PDF uses three highlight colors:

• Yellow corresponds to your comments.

• Blue indicates the corrections based on the comments from the other reviewer, which were uploaded in an attached file.

• Green corresponds to the revisions made in response to the other reviewer.

In this letter, I have also included a brief response to each of your comments.

 

Comment 1: To enhance the literature review and broaden the discussion on advanced control methods that integrate fuzzy logic and neural networks (ln.71-72), the authors should consider incorporating key references that are currently absent. Notably, the following studies could add depth to the discussion: "Trajectory Tracking Control of a Mobile Robot Using a Fuzzy Logic Controller with Optimal Parameters", "A Fuzzy Control Strategy for Multi-Goal Autonomous Robot Navigation" and “An ANFIS-Based Strategy for Autonomous Robot Collision-Free Navigation in Dynamic Environments”. These works propose alternative controllers for robot navigation, addressing challenges similar to those discussed in this paper.

Response 1:  The bibliography has been revised, and we believe it contributes to the state of the art for this work. Therefore, it has been included specifically in line 74.

 

Comment 2: Regarding PID controller selection, the paper implies that it was chosen due to its superior performance. However, the criteria for "better performance" are not explicitly defined. How was this determined? The authors should provide a clearer justification by either comparing PID with alternative controllers (e.g., PD, PI) or citing relevant studies that support the claim of PID superiority in this context.

Response 2: A comprehensive explanation of why the PID controller was selected has been added. You can find this explanation in the document between lines 329 and 360. It was not necessary to compare the PID controller with alternative controllers, as the reasons for this choice are clearly outlined in the text.

 

Comment 3: While the study presents substantial work in Gazebo simulation, ROS programming, controller design, and physical implementation, it is unclear how these components are interconnected. To strengthen the validity of their approach, the authors should provide more details on system integration, along with visual representations of the robot and its environment.

Response 3: To provide a better understanding of the methodology followed in this work and how the components you mentioned are interconnected, a more detailed explanation of the steps followed has been added in Section 2. Additionally, a flow diagram of the methodology has been included just after the aforementioned text.

In Section 3.1, which corresponds to the Gazebo simulation, a screenshot of the robot in the Gazebo environment has been added. Unfortunately, it is not possible to include a photo of the robot in a real environment, as the robot has not yet been constructed.

 

Comment 4: Several critical methodological details are missing concerning system parameters, hardware/software used, and experimental duration. The authors should include information about hardware components (e.g., sensors, actuators, microcontrollers), software tools (e.g., MATLAB, Simulink), duration and number of trials etc.

Response 4: In Section 2, the software and hardware used for this work have been included. Unfortunately, I do not have the exact duration times or the number of trials for the experiments, so this information has not been included.

 

Comment 5: In addition, the tuning method is not explicitly stated. Was Ziegler-Nichols used? or manual tuning? The authors should specify the method and provide a brief justification for its selection.

Response 5: The tuning method (pole-zero cancellation) has been specifically highlighted in the section where the PID controller is selected, particularly in line 370.

 

Comment 6: The authors are urged to clearly outline the experimental setup, including test conditions, data collection methods, and control variables.

Response 6: A more detailed explanation of the experiments, including the test conditions, data collection methods, and control variables, has been provided in Subsection 3.3.

 

If you have any doubts or further recommendations, please do not hesitate to let me know.

Thank you very much for your valuable feedback.

Sincerely,
Adrian Geovanny Urgiles Rojas

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Colleagues,

Would you please consider different controller design approach (Adaptive Control, LQR, Backstepping controller, Sliding Mode Control etc.).

 

Best Regards

Author Response

Comment 1: Would you please consider different controller design approach (Adaptive Control, LQR, Backstepping controller, Sliding Mode Control etc.).

Response 1:
We appreciate the reviewer’s suggestion to consider alternative control strategies. However, after careful evaluation, we respectfully choose to maintain the use of the PID controller in this study. The justification for this decision is detailed in the manuscript (Section 2.2.2) and further elaborated in the cover letter attached to this response, where we explain the practical limitations of implementing state-space-based controllers on the current hardware platform, as well as the significant scope shift that such a change would imply.

Author Response File: Author Response.pdf