An Optimal Footprint Based Coverage Planning for Hydro Blasting Robots

Round 1

Reviewer 1 Report

The authors discuss a coverage planning for hydro blasting robots on hulls. The problem is well described, and the authors are thoroughly describing the state-of-the-art. However, the impression of the reader may be at the end, that there is an unbalance between the line-sweep and stop-sweep strategies. The line-sweep is a classical problem, that has roots to CNC machining, while the stop-sweep is slightly an artificially composed problem. The authors do not answer the main question, if any of these to strategies is superior or not. The authors also lack to address the question of how coverage is calculated (I suppose this not only depending on where the head position is located, but also that how much rust/contamination should be removed).

My comments and remarks to the authors:

• Section 2. Hornbill Architecture should have a reference to [1]. Many figures are from that source.
• Comparison of the results to [2].
• What does area mean in Table 1?
• Compare LS to SS like in Table 1.
• Define criteria for cleaning in GA.

[1] V. Prabakaran et al., "Hornbill: A Self-Evaluating Hydro-Blasting Reconfigurable Robot for Ship Hull Maintenance," in IEEE Access, vol. 8, pp. 193790-193800, 2020, doi: 10.1109/ACCESS.2020.3033290.

[2] Anh Vu Le, Phone Thiha Kyaw, Prabakaran Veerajagadheswar, M.A. Viraj J. Muthugala, Mohan Rajesh Elara, Madhu Kumar, Nguyen Huu Khanh Nhan, Reinforcement learning-based optimal complete water-blasting for autonomous ship hull corrosion cleaning system, Ocean Engineering, 2020, 108477, ISSN 0029-8018, https://doi.org/10.1016/j.oceaneng.2020.108477.

 

Author Response

Respected reviewer,
We sincerely thank you for your time and valuable comments in reviewing our paper, I greatly
appreciate it. We have revised the paper taking into account the reviewer comments seriously.
We are now submitting the revised manuscript for review and publication. The changes in the
manuscript has been highlighted in cyan color.
Sincerely,
Thejus Pathmakumar

Author Response File: Author Response.pdf

Reviewer 2 Report

Article in subject of Sensors Journal.

 

The paper is difficult to read. Article consist many bugs need improve.

 

Some my observations I present using many comments. The are prepared mainly in order of reading

 

General comment

In article I found many mistakes. The main problem is in description of figures. Need improve this problem to improve an article read ability. My advice autors can find in detailed prepared comments.

Comment 1

You wrote

Figure 1.(a) Isometric View of Open Arm Hornbill, (b)Isometric View of Enclosed Hornbill

If author agree I propose use of main description of Figure 1  and next to describe of (a) and (b)

For example

Figure 1. Robot Hornbill: (a) isometric view of open arm, (b) view of enclosed robot

I propose also to increase of font of text for description of robots parts

 

Comment 2

Figure 3. I propose increase font size

 

Comment 3

122 line

For the fixed arm Hornbill robot, the blasting nozzles are attached to two fixed arms. In such a case, a lawn-mower type area coverage is suitable, which is termed as line-sweep (LS) strategy (c.f. Fig.6).

i propose use Figure 6

For the fixed arm Hornbill robot, the blasting nozzles are attached to two fixed arms. In such a case, a lawn-mower type area coverage is suitable, which is termed as line-sweep (LS) strategy (c.f. Figure.6).

 

Comment 4

Please number of of relation in 6 page.

After relation I propose descript of parameter

n_s, W, f_r

I propose use of description of relation in other form

n_s – int(W/f_r)+1

You no need to describe of function “floor”

 

Comment 5

A simple but effective coverage strategy will be to stop at fixed lengths (B); sweep the nozzle through a predefined angle (−α2−α2); and repeat the process till the complete length L is covered (c.f.Fig 7).

(−α2−α2) is it realy true ?  I suppose that it is (−α2, α2)

 

Comment 6

The time taken for an LS strategy depends on the robot velocities. Similarly, the time taken for the blasting and the required energy demand varies with different sweeping angles, even though the sweeping angle is kept within 60⁰.

Sweeping angle  please use also  meaning

 

Comment 7

Please renumber of relation

Tblast=Tsweep+Ttranslation+Trotation (1)

 

Comment 8

You wrote

In this strategy, the robot moves without the nozzle rotations. So, the sweep time is equal to the time required for translations. Hence,

Tswee p=Ttranslation=nsLvl

Where n

s is the number of strips along the total area,vlis the linear velocity of the robot.

The number of strips required for complete area coverage can be derived as:

ns=W/dn

where dn is the diameter of the nozzle.

 

Please number of relation in order

Also please improve of pdf file…  I see in all relations  --  but when I copy I get =

Please check all relations in paper and number all !!

 

Comment 8

Please increase some of figure 8. Please descript of left and right graphs as a) and b) and write in Figure 8 description

Figure 8.Time taken for hydro basting in line sweep strategy: a)….., b)……..

 

Comment 9

For the case of Stop-Sweep cleaning strategy, the total time for hydro-blasting depends upon more than one factor including sweep angle alpha and wa sweep. Hence the functional footprint of the for this robot is defined by the alpha and wa.

 

In article and Figure 7 you not use alpha but a. Please check it and improve in

all article

 

Comment 10

Please consider to present Procedure NSGA II using schemat algorithm

 

Comment 11

You wrote

Figure 9.Pareto solution and Design Space for for a population of 50

Please describe the left and right graphs as a) and b)

Figure 9.Pareto solution and Design Space for for a population of 50: a)…., b)…..

That same Figure 10, 11, 12, 13, 14 and Figure 15-17

 

Comment 12

Line 267

Increasing of initial population to 1000 gives more number ofx1andx2. Figure [] shows the outcome of optimization where the algorithm is initialised with a population of 1000.

Please improve number of cited figure

 

Comment 13

Line 259

The area has been fixed as10x10meters, angular velocity of the arm and maximum sweeping angle are fixed atpi/3 rad 1 rad/sec respectively.

Order was false

The area has been fixed as10x10meters, angular velocity of the arm and maximum sweeping angle are fixed at 1 rad/sec pi/3 rad respectively.

 

Comment 14

You present graphs Figure 9 -11. You show results in different space

(min and max value of x1 x2). In Figure 11 you wrote in design space graphs coordinations  f1 f2 ????

 

Comment 15

Figures 12-14  has the same description

Figure 12.Pareto solution and Design Space for for a population of 50

Figure 13.Pareto solution and Design Space for for a population of 50

Figure 14.Pareto solution and Design Space for for a population of 50

You need show in description of figure the difference of figures (an area)

That same for figures 15-17

Figure 15.Pareto front and Design Space for for a population of 1000

Figure 16., Objective Space  and Design Space for for a population of 1000 ????

Figure 17.Pareto front and Design Space for for a population of 1000

You need show in description of Figure the difference of figures (sweep angle)

You make many mistakes in this descriptions

 

Comment 16

General advice for description for all figures from analysis

You present double graphs in Figures 9-14 descripted  that same as

Figure xx.Pareto Solution and Design Space for a population of  YYYY

You not presented which graphs is Pareto which is Design Space

It need to show as a) and b)

In description you not write for which parameter you present graph

You don't show units, that is, they are relative values

For Figure 15 and 17 you wrote  Pareto Front and Design Space for a population …..

Is it difference it is other parameter as for previous figures

But for Figure 16

Figure 16.Objective Space and Design Space for for a population of 1000

Is it different from Figure 15 and 17

 

Comment 17

I propose add nomenclature to article

Author Response

Respected reviewer,
We sincerely thank you for your time and valuable comments in reviewing our paper, I greatly
appreciate it. We have revised the paper taking into account the reviewer comments seriously.
We are now submitting the revised manuscript for review and publication. The changes in the
manuscript has been highlighted in cyan color.
Sincerely,
Thejus Pathmakumar

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors have replied to all answers from the reviewers. The quality and presentation of the article has been increased.

Author Response

Respected reviewer,

We sincerely thank you for your time and valuable comments in reviewing our
paper, I greatly appreciate it. We have revised the paper taking into account
the reviewer comments seriously. We are now submitting the revised
manuscript for review and publication. The changes in the manuscript has
been highlighted in green color.

Sincerely,
Thejus Pathmakumar

Author Response File: Author Response.pdf

Reviewer 2 Report

Article was improved. I have only some editorial advice.

 

Comment 1

You wrote  

"....... achieve the Pareto-Optimal solution, there225exists different Multi-Objective Evolutionary algorithms (MOEA) including NSGA[29], NSGA-II[30],226MOEA/D[31], PESA-II[32] etc. However, the NSGA-II algorithm is known for its simplicity of227implementation and effectiveness. NSGA-II algorithm is an improved version of NSGA using the fast228non-dominated sorting concept [30]. The steps for NSGA-II explained below."

Please add space before [ ]

NSGA [29], NSGA-II [30],226MOEA/D [31], PESA-II [32] etc.

Please check it in all paper

and Figure 9 need citation in text

The steps for NSGA-II explained in Figure 9.

Comment 2

You wrote

Author Contributions: Conceptualization, Thejus Pathmakumar. and Madan Mohan Rayguru.; methodology,
 Sriharsha Ghanta and Madan Mohan Rayguru.; software, Thejus Pathmakumar and Sriharsha Ghanta.; validation,
 Manivannan Kalimuthu, Madan Mohan Rayguru. and Rajesh Mohan Elara.; analysis, Thejus Pathmakumar.
 Madan Mohan Rayguru; Manivannan Kalimuthu and Rajesh Mohan Elara; Original draft, Thejus Pathmakumar,
 Madan Mohan Rayguru, Sriharsha Ghanta, Manivannan Kalimuthu, and Mohan Rajesh Elara

 

Please use short

Thejus Pathmakumar T.P.

please add it to list authors of article 

Engineering Product Development Pillar, Singapore University of Technology and Design, Singapore;
[email protected], (T.P.); [email protected], (M.R.);

Comment 3

Please check spaces after dot "."  in paper

Please check spaces after comma "," in paper

Author Response

Respected reviewer,

We sincerely thank you for your time and valuable comments in reviewing our
paper, I greatly appreciate it. We have revised the paper taking into account
the reviewer comments seriously. We are now submitting the revised
manuscript for review and publication. The changes in the manuscript has
been highlighted in green color (line numbers ​ 21, 29, 63, 95, 117, 180, 217,
220, 265, 271, 284, 287, 298, 301 and 308​ )

Sincerely,
Thejus Pathmakumar

Author Response File: Author Response.pdf