Real-Time Estimation for Roll Angle of Spinning Projectile Based on Phase-Locked Loop on Signals from Single-Axis Magnetometer
Round 1
Reviewer 1 Report
Review Comments
Referring to manuscript
Introduction
1.) Paper is appropriate for sensors. Using single measurement for roll estimation has interesting applications and is useful to the community.
2.) Page 2 line 65 "in" is shown twice - consider revising.
3.) Page 2 line 79 - "we" is used - consider removing personal pronouns. This is standard for technical papers.
4.) References in introduction is substantial but I feel it would be important to discuss the scale of the projectile you are discussing and what angular rates your model is effective. Are these ICBMs or perhaps direct fire tank rounds? The audience should know. In addition are these fin stabilized or spin stabilized rounds? I would guess spin stabilized but again a small paragraph explaining the specific application is important.
Measurement System Modeling
1.) Equation 1 notation is kind of wierd. You have F as a vector and decompose it into components called H (which is a vector) and then F_D which is a scalar. The naming convention is also pretty bad. Finally using the x symbol to denote multiplication is a horrible idea given the confusion with a cross product. In technical papers multiplication is implied an an x or * is not needed.
2.) You may want to mention that the WMM and IGRF models both require GPS to function. Thus this method would not work in a GPS denied environment.
3.) Figure 2a looks like an HTK round. Again suggest mentioning what kinds of rounds your model works for and which it does not. If it is indeed an HTK round I would reference Mark Costello who has worked on alot of guided missile control laws for the HTK.
4.) Why are you using beta, theta, and gamma for yaw, pitch and roll? Standard aeroscape convention is to use psi, theta and phi. Typically beta is used for the sideslip angle and gamma is used for the glideslope.
5.) Equations 2,3,4 again remove the x to avoid the disambiguation with a cross product.
6.) Equations 5-7 have dots now. Your mathematical notation needs to be completely overhauled.
7.) Equation 8 is not a mathematical equation. You need to use the inverse tangent function. Atan2 is a numerical representation of an analytic equation and has no place in a scientific journal. Equations should be equations. Not programming languages.
8.) Page 5 - Lines 133 - 138 - The sentences are so fragmented I have no idea what you are trying to say.
9.) Figure 3 does nothing to help the reader. Consider removing.
10.) Page 5 - line 147 - 20 rad/s not r/s.
11.) Figure 4 - Why is FontSize in the legend???? This is really poor quality.
Method of Obtaining the Rolling Information
1.) Page 6 - 173 - And should not be at the beginning of a sentence.
2.) Figure 5 introduces many new symbols without any explanation of what they are.
3.) F(s) is the loop filter transfer function and is shown in Figure 6 correct? If so this is not clear in the text.
4.) Loop filter is denoted as F(s) in Figure 5 but then shown as Fp(s) and Ff(s)
5.) Figure 5 has ud(t) as the input to the FLL and PLL but Figure 6 has OMEGA_E and PHI_E as inputs. No explanation is given as to what Frequency and Phase Descriminator is.
6.) Figure 8 should be moved to the beginning for better explanation.
skipping ahead.
7.) Font size on Figures 13 are too small
8.) Equation 27 - Atan2 must be replaced with inverse tangent.
9.) Figure 15 seems to add no help to the reader.
10.) Figure 16 has too many figures and should be broken out.
11.) Table 4 seems much better suited as a Figure rather than a Table.
Overall I think the paper has good results and is useful to the readers but the entire paper needs major revisions to be considered for publications.
Referring to *.zip file provided.
1.) Data provided is in Hex format. Not sure that helps anyone.
2.) Code provided duqu.m throws an error because 11hal.txt cannot be found. Once again it is not very helpful to include code that does not work.
Author Response
Dear Professor,
Thank you so much for your patience on revision and we are benefited a lot from your suggestions. We have corrected mistakes you mentioned one by one and revised paper as your instructions. Responses to your comments are shown in the attached PDF file.
Sincerely yours,
Qiang shen
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The paper presents the problem of real time estimation of roll angle of spinning projectile using single axis magnetometer. The paper is very extensive and analyzed problem is iteresting. A review of previous works is very well prepared, and references are good choosen and cited. However, there are a lot of mistakes and inconsistencies in the work:
line 16, 34, 66 abbreviations used for the first time require clarification (here – DoF, GNSS, EKF),
line 18, „It indicates the …”, rather „It indicates that …”,
line 19, lack of unites of SD,
fig. 1, lack of some markings in Figure, e.g. I, D, FD. Figure can be larger and more detailed,
The numbering of equations is mixed up from eq. (8), this numer is two times, and all further eq. have incorrect numbers. In consequence, references to equations in the text are also incorrect.
Fig. 5 – what is input to phase-locked loop?? Bz (see line 172-173), or something else?? Angle „theta” is connected with „pitch” and not with „roll”,
Fig. 5 and equations (11), (12) (in text (10) and (11)) - different way of writing variables, operator „s” small or big??
What is it „Troll” in fig. 6 – please explain after first use,
Eq. (13), (14), (15) and (16) (proper numbers) – something wrong in the writting of exponents,
Line 207, compensation angle „fi”, in eq. (8) was „epsilon” for what new mark,? The same in fig. 7,
How corresponds fig.5 and fig. 7 – what is the output, „theta” or „gamma”???
Eq. (17), (19) – different ways of writting of pulsations,
Eq. (18) what is it small „s”, E(s) and R(s)??? please explain.
Transition from (18) to (19) is not clear,
Fig. 9b – „Amplitude” – lack of unites. The same in fig. 10b – why now is „Magnitude”?
Line 255 – is „fig.7”, should be „fig. 6”,
Line 258, 300 – way of writting variables „T”, „omega” and in many other places,
Table 2 – mass is in „kg” not in „Kg” – the same in other places,
Fig.13 – unites of Amplitude in (a),
What is it „alpha” in (23)?
Line 341 – what is it „sigma A”?
Lines 343, 344 – variables – way of writting,
Line 351 – „sigma tPLL” or „sigma tFLL”??
Eq. (28), (29) and (30) are the same as (8), …..maybe reference is enougth??
Line 367, 375, 377, 385, 555 … – not „Km” but „km”,
Fig. 15 is not good quality,
Line 387 – unites of SD (0.15 degree), the same in line 423, 521, 523, 532, 566 …
Fig. 18 – „fi” means the same as in (28)?? „alpha” is the same as in (23)???
Line 437 – what is it „lambda”? resolution? How understand it??
Line 441 – the style of text,
Line 481, 483, not „KHz” but „kHz”
Lines 581-583 - ???????
Some positions of references need corrections (nr of pages, e.g. 14, 17, 22 …)
the work need editorial corrections in many places.
I think that the paper must be revised, and after that need re-review.
Author Response
Dear Professor,
Thank you so much for your patience on revision and we are benefited a lot from your suggestions. We have corrected mistakes you mentioned one by one and revised paper as your instructions. Responses to your comments are shown in the attached PDF file.
Sincerely yours,
Qiang Shen
Author Response File: Author Response.pdf
Reviewer 3 Report
This review concerns an article entitled: Real-Time Estimation for Roll Angle of Spinning Projectile Based on Phase-Locked Loop on Signals from Single-Axis Magnetometer which describes the results of a real-time estimation of roll angle of spinning projectile. In the method a single axis magnerometer is used as a supporting element of the system with second order Frequency-Locked Loop (FLL) and third order Phase-Locked Loop (PLL).
Generally, the achieved results are interesting and worth publishing in the Sensors journal. Nevertheless, some parts of the article should be improved or extended.
First of all, the title seems too long and rather vague, it is difficult what the text is about.
Please correct:
Page 1
Line 5, Diffident font type usage;
Line 40 (...12000g), please separate measurement units from the numbers with non-breaking space, remove extra space;
Line 40 (10 r/s ), font size error;
Page 2
Line 83 (magnetometer’s output), Please check the Saxon genitive;
Figure 1. Please correct the Nx symbol used for X-axis reference;
Line 108 (figure1), separate the number 1;
Page 3
Line 102 etc.( On), Please normalize the subscript style in the whole text. In some cases Authors use italic subscript font type in other cases not;
Page 5
Line 141 and 143, Please remove extra spaces in the text;
Line 135: atan2 function returns a single angle θ value such as the interval is -π <θ ≤ π. Is the function interval properly written here?
Figure 4, What does FontSize mean in the chart caption? Please correct the Y-axis description;
Figure 3, It is not easy to analyze presented results in such a form especially for Yaw values bigger than 200 deg;
Line 166: "Then, pitch, yaw, rolling speed based on six degrees of freedom (6DoF) are set as the input of the tracking loop" - Please specify parameters used in the analysis 6 DoF;
Page 6
Line 153: Please remove extra spaces in the text;
Page 7
Line 206 etc. Please verify text removing extra spaces;
Eq 12, 13 etc, please verify the consistency and the size of mathematical symbols in the whole text;
Page 8
Line 215, Fast Fourier transform;
Page 9
Figure 9 and 10: please correct figure (a) axis description, and add spaces before (a) and (b) in the figure description;
Line 223: where=when - unclear / confusing expression;
Page 10
Line 253: and the whole article: please separate measurement quantities and numbers with non-breaking spaces;
Page 11
Please use the International System of Units (SI). It is unacceptable to use incorrect prefixes for measurement units. Term K represents 1024 (binary) , while k - 1000 (SI kilo).
Line 283: An unclear description of Figure 11, which means "Specifications 6 DoF.....Description of the trajectory of projectile;" what kind of specification/description is it?
Figure 12: It is difficult to determine what the Authors had in mind when writing: "Description of the part of pic. (a)." Was the signal sampling frequency appropriate? By analyzing the graph in Figure 12 (b), I have the impression that the sampling frequency is too low.
Please correct the manuscript. The article has a lot of syntax errors in the text as well as in the formulas. Please, keep the symbols in the consistent form, this will significantly simplify the analysis of the content presented here.
Page 12
I'm not sure if a standard deviation measure is a good solution to use in this case. Error values from 0 to 10 seconds are relatively large compared to the average error value. In this way, the standard deviation will take on a large value. Almost the same applies to drawings 17.
Please, justify in a few sentences using this statistical measure for calculations in the article.
Page 18
In the figure "Figure 19. Experiments on rotary table." The authors present the same position as in the previous article "Roll Angle Measurement for a Spinning Vehicle Based on GPS Signals Received by a Single-Patch Antenna - Figure 20. Experiments on a single-axis rotary table. ". Please add a reference.
Author Response
Dear Professor,
Thank you so much for your patience on revision and we are benefited a lot from your suggestions. We have corrected mistakes you mentioned one by one and revised paper as your instructions. Responses to your comments are shown in the attached PDF file.
Sincerely yours,
Qiang Shen
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
I think the changes are suitable and should be accepted into publication.
Author Response
Dear Professor,
Thank you so much for your patience and suggestions on revision, from which we are benefited a lot, and we are so appreciated for your positive comment on our efforts.
Sincerely yours,
Qiang Shen
Author Response File: Author Response.pdf
Reviewer 2 Report
The paper presents the problem of real time estimation of roll angle of spinning projectile using single axis magnetometer. The paper is very extensive and analyzed problem is interesting. A review of previous works is very well prepared, and references are good choosen and cited.
Some aspects that need small editorial corrections:
Line 20, which is an unit of error?
Fig. 1 should be better quality,
Line 147 – is „..figure 4”, should be „..fig. 3”
Fig.4 is not referred to in the text,
Line 239, now is „fig. 9” shoud be 8
Fig.12a – unites in Y axis
Line 325 – fig 13 insted fig 14,
Eq. (26) very important difference according to previous version in this eq. (which version is proper??)
Line 403, unites for deviation, e.g. 0.15 ????, the same in line 439, 549, 583
Paragraph 4.3 - are the angles correctly marked in the drawing and in the text ??
Line 494 – editorial correction needed,
Line 530 – nr of fig. should be 21
Author Response
Dear Professor,
Thank you so much for your patience and suggestions on revision, from which we are benefited a lot, and we are so appreciated for your positive comment on our efforts. We have finished the minor revision as your instructions.
Sincerely yours,
Qiang Shen
Author Response File: Author Response.pdf
Reviewer 3 Report
This review concerns a corrected version of an article entitled: Real-Time Estimation for Roll Angle of Spinning Projectile Based on Phase-Locked Loop on Signals from Single-Axis Magnetometer. Thank you for a deep correction of your manuscript, nevertheless my suggestion is to correct some minor imperfections.
Please correct:
Please remove some extra spaces
line 108: surface of earth ;…
line 116: total vector f ,…
line 132: Define y ,q ,j as…
line 142 and j . Moreover, it is irrelevant with total field intensity f but depends on the D , I and y ,q ….
line 151: e ( 1 e ), constant difference between the phase of BZ ( BY 151 )…
line 158: of BZ 158 . In…
line 177: cross section ( BZ 177 ) …
etc. etc….
line 135: (superscript T indicates transposition) – in my opinion it is an obvious information for reader, and I am not sure that is needed
line 241: Figure 8 please add the Amplitude unit
line 251: Figure 8 please add the Amplitude unit
line 294: Figure 12. Tracking results: improper Y axis description. Please use scheme-> parameter (measurement unit). Please standardize measurement units without mixing a o sign with a degree word, see figure 12, Figure 14, Figure 16, etc.
line 490: Please separate measurement units from measured values e.g. designed to supply 8V and 5V DC…. line 581: of nominal speed 5Hz a…
line 543: Figure 22 and Figure 23. Please correct all axis description!!!!
Author Response
Dear Professor，
Thank you so much for your patience and suggestions on revision, from which we are benefited a lot, and we are so appreciated for your positive comment on our efforts. We have finished the minor revision as your instructions.
Sincerely yours,
Qiang shen
Author Response File: Author Response.pdf
