Design and Implementation of a Low-Cost IoT-Based Robotic Arm for Product Feeding and Sorting in Manufacturing Lines

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

First of all thank you for providing me a chance to review your paper. I have found some flaws in your paper. Those flaws are provided below in the form of pointers.

1. Do not use abbreviations in the keywords section, Always use only the full forms.
2. After the introduction section please provide a related works section.
3. On the right or left side of the figure 1 please provide a sectioned flow diagram that can explain that how the whole process will execute.
4. Change the caption of figure, my suggestion is (Proteus based circuit diagram of our opted system model).
5. In figure3 providing just one side of the 3D view is not enough, provide the captured images of all the four sides and the top view, So in total it will 5 diagrams in one figure, and place all those figures as one clutch as subplots of one figure.
   1. And providing a figure without labeling serves no purpose at all, so also provide appropriate labeling on the figure too.
6. Figure 4 is also not properly labeled, however you have discussed it properly in the associated section, So please provide the labeling too.
   1. Also revise the caption and make it a little elaborative
7. Figure 7 is provided very beautifully, I would suggest to make the figure 5 also in this understandable format for the better and ease of understanding of the readers. Or if you want you can make and present it in a pipeline format too.
8. Please provide the pseudo codes of your work. So that if someone want to recreate this whole process for their own analysis, than they may do so.
9. Separate the conclusion and discussion section, because its not a good practice to use referencing in the conclusion section.
   1. Secondly do not make too much small paragraph in the conclusion section, write in a unison, at max in two paragraphs format.
10. There is no need to make a separate heading of future direction, take all this info to the discussion section when you make a separate one above the conclusion section.
11. Please provide the mathematical and the control models of your research.
12. Your have not discussed in any way the cybersecurity aspect of your device as you may know that if your are dealing with IoT than it’s a compulsory thing to discuss.
13. You have not provided any information on the scalability of the model.
14. You have not provided any information on the stress testing analysis, because this will basically prove the statistical reliability of your product.
15. Please provide some comparative analysis, with same application based robotic arm that are developed with either (PLC or any other controlling units), and in that discussion provide the info that why have you chosen this board to work with.
16. Provide the analysis for both the power and energy consumption of your system.
17. In your article you have mentioned multiple time that your system is a low-cost IoT, but to prove this claim you should provide a table of comparison with other system that are created and used for almost the same purpose by other researchers all over the world.

Comments on the Quality of English Language

English must be improved

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Dear authors, 

congratulations on your paper about the design and implementation of a low-cost robotic arm. The subject is of great interest and your results could improve the future of industry. 

I have some suggestions in order for you to improve the paper:

-the references should be placed in the reference section in  the order in which they are cited in the text

-Figure 2 is not readable...please split the system model in more then one image in order to be easier to observe them

-when you talk about other robotic arms in the scientific literature I think is better to have a table with pros and cons about their operation and to compare them with your model, highlighting your contribution and what is new in your robotic arm

-reference 11 you say it is from 2026, but we still are in 2025...how is it possible?

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Dear authors, in the next paragraphs, my comments about your manuscript.

 

The manuscript shows a good technical integration between ESP32 control, RFID identification, and a 4 DOF manipulator, backed up by an electronic architecture with proper isolation through PC817 optocouplers and a safety sequencing based on a DPDT relay (HLS-14F3L-DC5V-C). The method shows the engineering maturity, especially in the creation of the fail-safe locking with the main relay, which makes the supply of the servos impossible when the emergency circuit is opened. The use of analog movements via incremental loops is another technical aspect which is very relevant because it prevents jitters and reduces peak current in the SG90s, thus leading to more stable operation. The simulation phase, done in Proteus and Factory I/O, is very favorable and indicates a structured virtual commissioning flow, a common practice in modern industrial robotic cells. The presentation of quantitative metrics (e.g., angular error ±1.2°, shutdown in 45 ms, RFID accuracy of 98.7%) not only strengthens the experimental credibility of the system but also shows its compatibility with small-scale industrial environments.

 

Points for Improvement

1. The literature review is comprehensive, but it does not possess a clear-cut structure; as a result, it is hard to pinpoint the contributions of greatest importance.
2. The technologies that are directly related to industrial sorting with automatic identification and motion control in low-cost architectures should be outlined and emphasized in the recommended synthesis and reorganization.
3. The control loop's stability with different acceleration profiles can be analyzed, along with measuring the dynamic current of the servos under load, which would increase the reliability of the results section.
4. It is also important to conduct a study on the circuit's operation during power fluctuations, such as a brown-out, since the ESP32 can be affected by rapid drops in the 3.3 V line. This is particularly true when the AMS1117 is working near the thermal limit, which is the case when the ESP32 is powered this way.
5. The experimental characterization, while sufficient, might benefit from including stress tests, repeatability at different weights in the gripper, and comparison of RFID performance at different orientations and distances.
6. Lastly, it would be beneficial to further address the issue of the system's scalability for multiple actuators, as well as the need for EMI shielding between the SG90 cables and the RC522 module, as this kind of interference is typical in industrial environments.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf