Independent Control Spraying System for UAV-Based Precise Variable Sprayer: A Review

Round 1

Reviewer 1 Report

In recent years, agricultural UAVs have developed rapidly. This article is a review on independent control spraying system for UAV-based precise variable spraying. As far as I can judge, this article exists the following problems:

1. Line 182 thinks that eight rotors are the best application structure of plant protection UAV. This conclusion is too arbitrary. Four rotors are the main structure of plant protection UAV in the market, while the use of eight rotors is not much. Four rotors have simple structure, small space occupation, simple and stable wind field, and their occupancy is far higher than that of eight rotors;

2. The use of the spraying method does not mention that the nozzle is directly below the rotor, which is one of the main nozzle layout methods for plant protection UAVs;

3. The type of plant protection UAV should be increased. As a review article, there are too few research objects, mainly focusing on the pressure spray system of plant protection UAV, and few research on the centrifugal spray system of plant protection UAV.

4.The logic of this article is not good enough, and the continuity of the research contents is insufficient, content description is scattered.

5. As the main content is the spray system, I think the author has not quoted enough paper in this field, also did not focus enough on the spray system.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

The paper is a review of the independent control system of UAV for precise variable sprayer. The reviewer thinks that the structure and depth of the content need to be greatly improved, detail as follows:

1. Too many irrelevant content, such as UAV in agriculture area, the use of the spraying method, Spraying deposition data acquisition methods, WSP data processing methods in Part 2. Independent control system is the main point of the article, not the species of drone, nozzles, droplet measurement methods and so forth.

2. The main idea review of the article in Part 3 is too small and old. Most of the author's references in this part are more than 5 years old, related research in the last 5 years is the best. UAV means unmanned aerial vehicle. Why does the author discuss land machinery in the article? Such as Figure 14, Figure 15 and the content relevant to them. The author should use a lot of new references to focus on the technologies, methods and applications of independent control system of UAV for precise variable sprayer.

3. Putting pictures in the introduction is inappropriate and the Part name of 2 and 3 in the article is inappropriate. Reference comments should use upper corner marks.

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

See the attached file

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Accept in present form.

Reviewer 3 Report

All my comments have been answered.

Minor corrections:

Table 2: 10 min is not unit of speed. Correct 5kg as 5 kg (leave a space)

Table 4: pressure values are more readable if expressed in MPa (mega pascal) rather than Pa. In addition, convert 13.61 g/(30 s) into g/s.

L272: coefficient of variation (rather than variance)