Transforming Robots into Cobots: A Sustainable Approach to Industrial Automation

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Excellent research, within the conceptual-theoretical framework, on the possible advantages that the updating of industrial robotic equipment would present through different suggested layers. Just some observations.

• Regarding the theoretical framework for the reconversion of obsolete industrial robotic systems, adjusting them to "intelligent", sustainable and collaborative systems through artificial intelligence is possible, but this would be a cost benefit in most cases that not everyone would dare to take, since between adjusting to these changes and acquiring another new equipment with all the implemented technology, the new one would be taken because there would no longer be any mechanical or technical problems to face.
• However, when the purchase of collaborative robots is not feasible, a layered retrofit strategy based on modular modernization becomes a practical and strategic solution or measure, but the costs of its implementation remain significant (discussed in section 4.2 Evaluation Steps and Benchmarking Criteria).
• Return on Investment: Economic viability also depends on whether the upgrade will result in a positive return on investment (ROI).
• On the other hand, there is operational feasibility, since converting a conventional robot into a Cobot would require reconfiguring its programming logic to allow for greater autonomy and adaptability.
• Furthermore, the updated and optimized robot must not only be able to perform preprogrammed tasks but also adapt to unexpected changes in the work environment. This is more challenging for a traditional industrial robot, which does not have pre-integrated machine learning algorithms, described by the layers described throughout the work.
• As a final conclusion in the analysis of the research work, it is indeed feasible to upgrade a conventional industrial robot to function as a Cobot using techniques, optimization methods, and artificial intelligence, but its feasibility would depend on several factors mentioned previously, such as cost, the complexity of the upgrade, and the available technology. A suitable approach could allow for hardware upgrades, as well as software and safety improvements, but the process can be costly and challenging depending on the age of the industrial robot and the variables in its workspace. As highlighted in this paper from a doctoral research perspective, this approach stands out for being transdisciplinary, combining principles of mechanical engineering, artificial intelligence, computer vision, and the circular economy.
  However, as concluded in this paper, given the lack of empirical validation, the work is in its initial stages. From an advanced research perspective, this requires critical reflection on the methodological risks associated with the connection between conceptual design and real-world implementation.

Author Response

We would like to thank the constructive comments from the reviewers, which clearly contributed to the improvement of this manuscript. For a quick reference to the reviewers' comments, we first provide in boldface and blue the verbatim comment of the reviewer, giving our response after each comment in color black.

Excellent research, within the conceptual-theoretical framework, on the possible advantages that the updating of industrial robotic equipment would present through different suggested layers. Just some observations.

• Regarding the theoretical framework for the reconversion of obsolete industrial robotic systems, adjusting them to "intelligent", sustainable and collaborative systems through artificial intelligence is possible, but this would be a cost benefit in most cases that not everyone would dare to take, since between adjusting to these changes and acquiring another new equipment with all the implemented technology, the new one would be taken because there would no longer be any mechanical or technical problems to face.
• However, when the purchase of collaborative robots is not feasible, a layered retrofit strategy based on modular modernization becomes a practical and strategic solution or measure, but the costs of its implementation remain significant (discussed in section 4.2 Evaluation Steps and Benchmarking Criteria).
• Return on Investment: Economic viability also depends on whether the upgrade will result in a positive return on investment (ROI).
• On the other hand, there is operational feasibility, since converting a conventional robot into a Cobot would require reconfiguring its programming logic to allow for greater autonomy and adaptability.
• Furthermore, the updated and optimized robot must not only be able to perform preprogrammed tasks but also adapt to unexpected changes in the work environment. This is more challenging for a traditional industrial robot, which does not have pre-integrated machine learning algorithms, described by the layers described throughout the work.
• As a final conclusion in the analysis of the research work, it is indeed feasible to upgrade a conventional industrial robot to function as a Cobot using techniques, optimization methods, and artificial intelligence, but its feasibility would depend on several factors mentioned previously, such as cost, the complexity of the upgrade, and the available technology. A suitable approach could allow for hardware upgrades, as well as software and safety improvements, but the process can be costly and challenging depending on the age of the industrial robot and the variables in its workspace. As highlighted in this paper from a doctoral research perspective, this approach stands out for being transdisciplinary, combining principles of mechanical engineering, artificial intelligence, computer vision, and the circular economy.
  However, as concluded in this paper, given the lack of empirical validation, the work is in its initial stages. From an advanced research perspective, this requires critical reflection on the methodological risks associated with the connection between conceptual design and real-world implementation.

Thank you for your valuable and detailed feedback. We recognize that upgrading traditional industrial robots into intelligent, collaborative systems through artificial intelligence is technically feasible but often limited by cost-benefit considerations. While new collaborative robots offer full integration and fewer risks, the proposed layered retrofit strategy provides a practical alternative when new purchases are not viable. This approach, discussed in Section 4, involves significant costs and requires reprogramming to enable autonomy and adaptability, challenges typical for legacy systems.

In summary, the research shows that upgrading conventional robots to cobots is possible but depends on factors like cost, complexity, and technology availability. We agree on the need for critical reflection on methodological risks and empirical validation, and have added relevant discussion as recommended. Your comments have helped improve the clarity and depth of the paper, and we greatly appreciate your input.

Reviewer 2 Report

Comments and Suggestions for Authors

1. It seems too many keywords in the abstract.
2. In line 73，The methodological approach is structured into four core stages. The four aspects here are not discussed in detail, and the number of titles in this chapter does not correspond.
3. What is the reference number between the 65th and 68th references in Table 1?
4. All ISO standards cited in the text should be listed as references.

Author Response

We would like to thank the constructive comments from the reviewers, which clearly contributed to the improvement of this manuscript. For a quick reference to the reviewers' comments, we first provide in boldface and blue the verbatim comment of the reviewer, giving our response after each comment in color black.

1. It seems too many keywords in the abstract.

Thank you for your observation. In response, we have carefully reviewed and reduced the number of keywords in the abstract, retaining only the most representative and essential terms: Collaborative Robotics, Industrial Robot Retrofitting, Human-Robot Interaction, Sustainable Robotics, and Framework. Keywords that were considered broader or less specific to the core focus of the paper were removed to improve clarity and relevance.

2. In line 73，The methodological approach is structured into four core stages. The four aspects here are not discussed in detail, and the number of titles in this chapter does not correspond.

Thank you for your valuable observation. We have corrected the number of core methodological stages from four to three to accurately reflect the structure of the methodology chapter. Additionally, we updated the subsection reference from 4.2 to Section 5 to align with the revised document organization. Furthermore, the title “Evaluation Steps and Benchmarking Criteria” has been corrected to “Theoretical Impact and Framework Evaluation Criteria” for greater clarity and precision. These changes improve the consistency and clarity of the manuscript’s structure.

3. What is the reference number between the 65th and 68th references in Table 1?

Thank you for pointing out the potential discrepancy regarding the references between entries 65 and 68 in Table 1. In response to your observation, Table 1 has been thoroughly reviewed to identify any omissions, errors, or duplicate citations. We confirm that both Reference 66 and 67 are indeed present in the reference list:

• Reference 66: Romero, S.; Valero, J.; García, A. V.; Rodríguez, C. F.; Montes, A. M.; Marín, C.; Bolaños, R.; Álvarez-Martínez, D. Trajectory Planning for Robotic Manipulators in Automated Palletizing: A Comprehensive Review. Robotics 2025. https://doi.org/10.3390/robotics14050055.
• Reference 67: Cárdenas, P.; García, J.; Begazo, R.; Aguilera, A.; Dongo, I.; Cardinale, Y. Evaluation of Robot Emotion Expressions for Human–Robot Interaction. Int. J. Soc. Robotics 2024, 2019–2041. https://doi.org/10.1007/s12369-024-01167-5.

Their inclusion has been verified, and their citation in Table 1 has been corrected to ensure accurate and sequential numbering. In addition, a check for duplicate references was conducted, and no repetitions were found.

It is worth noting that, due to the inclusion of new bibliographic sources in other sections of the document, the numbering of the cited references has been modified

4. All ISO standards cited in the text should be listed as references.

We appreciate this observation. All ISO standards mentioned in the manuscript have now been properly added to the reference list, as well as included in the section on regulations and standards, to ensure proper citation and traceability.

 

Reviewer 3 Report

Comments and Suggestions for Authors

• Introduction: No changes are needed. It already presents the motivation for choosing the topic well, as well as its impact on industry and on the environment.

• Methodology: It is clearly explained and does not require any modifications.

• Chapter 3: It would be interesting to add more information about the European project RobERTO (2016–2018) and the commercial AIRSKIN technology.
  You also included Table 1, which organizes a series of works into five sections—Security, Control, Interaction, Detection, Requirements. Here it would be much better to provide a concise summary of what each section actually contributes, drawing on the most representative papers.

• Chapter 4: This chapter should present very clearly what you intend to do for the reader. You could include a performance comparison between a traditional (non-collaborative) industrial robot and a collaborative robot such as a Universal Robots arm, KUKA LBR iiwa, ABB YuMi, etc.

• Conclusions: You need to add the future research directions—how this work could be further developed, what the next steps are, and what contributions this study could make.

Author Response

We would like to thank the constructive comments from the reviewers, which clearly contributed to the improvement of this manuscript. For a quick reference to the reviewers' comments, we first provide in boldface and blue the verbatim comment of the reviewer, giving our response after each comment in color black.

• Introduction: No changes are needed. It already presents the motivation for choosing the topic well, as well as its impact on industry and on the environment.

We thank the reviewer for the positive feedback. We are pleased that the introduction effectively conveys the motivation and relevance of the topic, including its potential industrial and environmental impact.

• Methodology: It is clearly explained and does not require any modifications.

We appreciate the reviewer’s positive assessment of the methodology section. While the original structure and clarity have been maintained, some minor modifications were made to this section to align it with updates introduced in other parts of the manuscript (e.g., adjustments related to implementation feasibility and cost-benefit considerations). These changes aim to enhance coherence and ensure consistency across the entire document.

• Chapter 3: It would be interesting to add more information about the European project RobERTO (2016–2018) and the commercial AIRSKIN technology.
  You also included Table 1, which organizes a series of works into five sections—Security, Control, Interaction, Detection, Requirements. Here it would be much better to provide a concise summary of what each section actually contributes, drawing on the most representative papers.

We appreciate your observation regarding Chapter 3. In the revised version of the manuscript, we have expanded the information on the European project RobERTO (2016–2018) and the commercial AIRSKIN technology by incorporating the main available sources of information for both developments. Since much of the existing information on RobERTO and AIRSKIN is of a general nature, it has been integrated in a concise and relevant way to contextualize their impact in the field.

Additionally, regarding Table 1, we have included a summary following the table that highlights the most representative works within each of the five categories (Safety, Control, Interaction, Detection, Requirements). For each category, key publications are presented along with a brief description of the main focus or contribution of each work, in order to enhance the reader’s understanding of the structure and value of the proposed classification and the presented table.

• Chapter 4: This chapter should present very clearly what you intend to do for the reader. You could include a performance comparison between a traditional (non-collaborative) industrial robot and a collaborative robot such as a Universal Robots arm, KUKA LBR iiwa, ABB YuMi, etc.

Thank you for your valuable suggestion regarding Chapter 4. In response, we have included at the beginning of the chapter an introduction that states the objectives and intended contributions of this section for the reader’s understanding.

Additionally, we have incorporated a detailed performance comparison between a traditional industrial robot and collaborative robots (such as the Universal Robots UR5e, KUKA LBR iiwa, and ABB YuMi). This comparative analysis is based on key characteristics and requirements established for cobots, highlighting the differences in collaboration capabilities, safety features, perception, programming, and integration.

This addition aims to contextualize the motivation for the proposed retrofit strategy and clarify the chapter’s focus on progressively enhancing traditional robots to approach the functionalities of modern cobots.

• Conclusions: You need to add the future research directions—how this work could be further developed, what the next steps are, and what contributions this study could make.

We deeply appreciate the comment regarding the need to include a clear projection of the future steps and potential contributions of the study. In response to this valuable observation, the "Future Research Directions" section has been incorporated as Section 8 of the manuscript, outlining the guidelines and projections that will shape the continuation of this line of research. Additionally, the final paragraph of the Introduction has been revised to reflect the inclusion of this new section, and the internal cross-references throughout the document have been carefully reviewed to ensure structural coherence and smooth navigation of the content.

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The overall logic of the article should have a roadmap to enhance readability

Author Response

The overall logic of the article should have a roadmap to enhance readability.
We appreciate your insightful observation regarding the inclusion of a roadmap to improve the overall logic and readability of the article. In response, we have revised the final paragraph of the Introduction to include a clear and detailed overview of the paper’s structure. This addition is intended to guide the reader through the progression of the content across the sections and to support a more coherent and accessible reading experience. We are grateful for this suggestion, which has contributed to strengthening the organization of the manuscript from the outset.