setting up quarto

This commit is contained in:
Anson 2022-04-23 01:08:01 -07:00
commit b15dc55b7a
11 changed files with 3625 additions and 0 deletions

4
.prettierrc.toml Normal file
View File

@ -0,0 +1,4 @@
# .prettierrc.toml
printWidth = 100
proseWrap = "always"

BIN
Figures/assembly.jpg Normal file

Binary file not shown.

After

Width:  |  Height:  |  Size: 876 KiB

BIN
Figures/current_process.png Normal file

Binary file not shown.

After

Width:  |  Height:  |  Size: 169 KiB

BIN
Figures/inertia3d.png Normal file

Binary file not shown.

After

Width:  |  Height:  |  Size: 24 KiB

BIN
Figures/kmeans.png Normal file

Binary file not shown.

After

Width:  |  Height:  |  Size: 16 KiB

BIN
Figures/pca.png Normal file

Binary file not shown.

After

Width:  |  Height:  |  Size: 18 KiB

26
citations.bib Normal file
View File

@ -0,0 +1,26 @@
@misc{eberlyPolyhedralMassProperties2002,
title = {Polyhedral {{Mass Properties}} ({{Revisited}})},
author = {Eberly, David},
year = {2002},
month = dec,
copyright = {CC BY 4.0},
url = {https://www.geometrictools.com/Documentation/PolyhedralMassProperties.pdf}
}
@inproceedings{DebriSat2019,
title = {Analysis of the DebriSat Fragments and Comparison to the NASA Standard Satellite Breakup Model},
author = {Murray, James and Cowardin, Heather and Liou, J-C and Sorge, Marlon and Fitz-Coy, Norman and Huynh, Tom},
booktitle = {International Orbital Debris Conference (IOC)},
number = {JSC-E-DAA-TN73918},
year = {2019},
url = {https://ntrs.nasa.gov/citations/20190034081}
}
@online{interfluo6UCubeSatModel,
title = {{{6U CubeSat}} Model | {{3D CAD Model Library}} | {{GrabCAD}}},
author = {{Interfluo}},
url = {https://grabcad.com/library/6u-cubesat-model-1},
urldate = {2022-02-15}
}

2688
report.html Normal file

File diff suppressed because one or more lines are too long

296
report.log Normal file
View File

@ -0,0 +1,296 @@
This is XeTeX, Version 3.141592653-2.6-0.999993 (MiKTeX 21.8) (preloaded format=xelatex 2021.10.31) 23 APR 2022 00:47
entering extended mode
**./report.tex
(report.tex
LaTeX2e <2021-06-01> patch level 1
L3 programming layer <2021-07-12> (C:\Users\albig\AppData\Roaming\MiKTeX\tex/la
tex/koma-script\scrartcl.cls
Document Class: scrartcl 2021/11/13 v3.35 KOMA-Script document class (article)
(C:\Users\albig\AppData\Roaming\MiKTeX\tex/latex/koma-script\scrkbase.sty
Package: scrkbase 2021/11/13 v3.35 KOMA-Script package (KOMA-Script-dependent b
asics and keyval usage)
(C:\Users\albig\AppData\Roaming\MiKTeX\tex/latex/koma-script\scrbase.sty
Package: scrbase 2021/11/13 v3.35 KOMA-Script package (KOMA-Script-independent
basics and keyval usage)
(C:\Users\albig\AppData\Roaming\MiKTeX\tex/latex/koma-script\scrlfile.sty
Package: scrlfile 2021/11/13 v3.35 KOMA-Script package (file load hooks)
(C:\Users\albig\AppData\Roaming\MiKTeX\tex/latex/koma-script\scrlfile-hook-3.34
.sty
Package: scrlfile-hook-3.34 2021/11/13 v3.35 KOMA-Script package (using LaTeX h
ooks)
(C:\Users\albig\AppData\Roaming\MiKTeX\tex/latex/koma-script\scrlogo.sty
Package: scrlogo 2021/11/13 v3.35 KOMA-Script package (logo)
))) (C:\Program Files\MiKTeX\tex/latex/graphics\keyval.sty
Package: keyval 2014/10/28 v1.15 key=value parser (DPC)
\KV@toks@=\toks16
)
Applying: [2021/05/01] Usage of raw or classic option list on input line 252.
Already applied: [0000/00/00] Usage of raw or classic option list on input line
368.
)) (C:\Users\albig\AppData\Roaming\MiKTeX\tex/latex/koma-script\tocbasic.sty
Package: tocbasic 2021/11/13 v3.35 KOMA-Script package (handling toc-files)
\scr@dte@tocline@numberwidth=\skip47
\scr@dte@tocline@numbox=\box50
)
Package tocbasic Info: babel extension for `toc' omitted
(tocbasic) because of missing \bbl@set@language on input line 135.
Class scrartcl Info: You've used standard option `oneside'.
(scrartcl) This is correct!
(scrartcl) Internally I'm using `twoside=false'.
(scrartcl) If you'd like to set the option with \KOMAoptions,
(scrartcl) you'd have to use `twoside=false' there
(scrartcl) instead of `oneside', too.
Class scrartcl Info: File `scrsize11pt.clo' used instead of
(scrartcl) file `scrsize11.clo' to setup font sizes on input line 224
2.
(C:\Users\albig\AppData\Roaming\MiKTeX\tex/latex/koma-script\scrsize11pt.clo
File: scrsize11pt.clo 2021/11/13 v3.35 KOMA-Script font size class option (11pt
)
) (C:\Users\albig\AppData\Roaming\MiKTeX\tex/latex/koma-script\typearea.sty
Package: typearea 2021/11/13 v3.35 KOMA-Script package (type area)
\ta@bcor=\skip48
\ta@div=\count178
Package typearea Info: You've used standard option `letterpaper'.
(typearea) This is correct!
(typearea) Internally I'm using `paper=letter'.
(typearea) If you'd like to set the option with \KOMAoptions,
(typearea) you'd have to use `paper=letter' there
(typearea) instead of `letterpaper', too.
Package typearea Info: You've used standard option `oneside'.
(typearea) This is correct!
(typearea) Internally I'm using `twoside=false'.
(typearea) If you'd like to set the option with \KOMAoptions,
(typearea) you'd have to use `twoside=false' there
(typearea) instead of `oneside', too.
\ta@hblk=\skip49
\ta@vblk=\skip50
\ta@temp=\skip51
\footheight=\skip52
Package typearea Info: These are the values describing the layout:
(typearea) DIV = 11
(typearea) BCOR = 0.0pt
(typearea) \paperwidth = 614.295pt
(typearea) \textwidth = 446.76004pt
(typearea) DIV departure = -14%
(typearea) \evensidemargin = 11.49748pt
(typearea) \oddsidemargin = 11.49748pt
(typearea) \paperheight = 794.96999pt
(typearea) \textheight = 582.20026pt
(typearea) \topmargin = -37.40001pt
(typearea) \headheight = 17.0pt
(typearea) \headsep = 20.40001pt
(typearea) \topskip = 11.0pt
(typearea) \footskip = 47.6pt
(typearea) \baselineskip = 13.6pt
(typearea) on input line 1743.
)
\c@part=\count179
\c@section=\count180
\c@subsection=\count181
\c@subsubsection=\count182
\c@paragraph=\count183
\c@subparagraph=\count184
\scr@dte@section@maxnumwidth=\skip53
Class scrartcl Info: using compatibility default `runin=bysign'
(scrartcl) for `\section on input line 4852.
Class scrartcl Info: using compatibility default `afterindent=bysign'
(scrartcl) for `\section on input line 4852.
\scr@dte@part@maxnumwidth=\skip54
Class scrartcl Info: using compatibility default `afterindent=false'
(scrartcl) for `\part on input line 4860.
\scr@dte@subsection@maxnumwidth=\skip55
Class scrartcl Info: using compatibility default `runin=bysign'
(scrartcl) for `\subsection on input line 4870.
Class scrartcl Info: using compatibility default `afterindent=bysign'
(scrartcl) for `\subsection on input line 4870.
\scr@dte@subsubsection@maxnumwidth=\skip56
Class scrartcl Info: using compatibility default `runin=bysign'
(scrartcl) for `\subsubsection on input line 4880.
Class scrartcl Info: using compatibility default `afterindent=bysign'
(scrartcl) for `\subsubsection on input line 4880.
\scr@dte@paragraph@maxnumwidth=\skip57
Class scrartcl Info: using compatibility default `runin=bysign'
(scrartcl) for `\paragraph on input line 4891.
Class scrartcl Info: using compatibility default `afterindent=bysign'
(scrartcl) for `\paragraph on input line 4891.
\scr@dte@subparagraph@maxnumwidth=\skip58
Class scrartcl Info: using compatibility default `runin=bysign'
(scrartcl) for `\subparagraph on input line 4901.
Class scrartcl Info: using compatibility default `afterindent=bysign'
(scrartcl) for `\subparagraph on input line 4901.
\abovecaptionskip=\skip59
\belowcaptionskip=\skip60
\c@pti@nb@sid@b@x=\box51
Package tocbasic Info: babel extension for `lof' omitted
(tocbasic) because of missing \bbl@set@language on input line 6076.
\scr@dte@figure@maxnumwidth=\skip61
\c@figure=\count185
Package tocbasic Info: babel extension for `lot' omitted
(tocbasic) because of missing \bbl@set@language on input line 6091.
\scr@dte@table@maxnumwidth=\skip62
\c@table=\count186
Class scrartcl Info: Redefining `\numberline' on input line 6258.
\bibindent=\dimen138
) (C:\Program Files\MiKTeX\tex/latex/amsmath\amsmath.sty
Package: amsmath 2021/04/20 v2.17j AMS math features
\@mathmargin=\skip63
For additional information on amsmath, use the `?' option.
(C:\Program Files\MiKTeX\tex/latex/amsmath\amstext.sty
Package: amstext 2000/06/29 v2.01 AMS text
(C:\Program Files\MiKTeX\tex/latex/amsmath\amsgen.sty
File: amsgen.sty 1999/11/30 v2.0 generic functions
\@emptytoks=\toks17
\ex@=\dimen139
)) (C:\Program Files\MiKTeX\tex/latex/amsmath\amsbsy.sty
Package: amsbsy 1999/11/29 v1.2d Bold Symbols
\pmbraise@=\dimen140
) (C:\Program Files\MiKTeX\tex/latex/amsmath\amsopn.sty
Package: amsopn 2016/03/08 v2.02 operator names
)
\inf@bad=\count187
LaTeX Info: Redefining \frac on input line 234.
\uproot@=\count188
\leftroot@=\count189
LaTeX Info: Redefining \overline on input line 399.
\classnum@=\count190
\DOTSCASE@=\count191
LaTeX Info: Redefining \ldots on input line 496.
LaTeX Info: Redefining \dots on input line 499.
LaTeX Info: Redefining \cdots on input line 620.
\Mathstrutbox@=\box52
\strutbox@=\box53
\big@size=\dimen141
LaTeX Font Info: Redeclaring font encoding OML on input line 743.
LaTeX Font Info: Redeclaring font encoding OMS on input line 744.
\macc@depth=\count192
\c@MaxMatrixCols=\count193
\dotsspace@=\muskip16
\c@parentequation=\count194
\dspbrk@lvl=\count195
\tag@help=\toks18
\row@=\count196
\column@=\count197
\maxfields@=\count198
\andhelp@=\toks19
\eqnshift@=\dimen142
\alignsep@=\dimen143
\tagshift@=\dimen144
\tagwidth@=\dimen145
\totwidth@=\dimen146
\lineht@=\dimen147
\@envbody=\toks20
\multlinegap=\skip64
\multlinetaggap=\skip65
\mathdisplay@stack=\toks21
LaTeX Info: Redefining \[ on input line 2923.
LaTeX Info: Redefining \] on input line 2924.
) (C:\Program Files\MiKTeX\tex/latex/amsfonts\amssymb.sty
Package: amssymb 2013/01/14 v3.01 AMS font symbols
(C:\Program Files\MiKTeX\tex/latex/amsfonts\amsfonts.sty
Package: amsfonts 2013/01/14 v3.01 Basic AMSFonts support
\symAMSa=\mathgroup4
\symAMSb=\mathgroup5
LaTeX Font Info: Redeclaring math symbol \hbar on input line 98.
LaTeX Font Info: Overwriting math alphabet `\mathfrak' in version `bold'
(Font) U/euf/m/n --> U/euf/b/n on input line 106.
)) (C:\Program Files\MiKTeX\tex/latex/lm\lmodern.sty
Package: lmodern 2009/10/30 v1.6 Latin Modern Fonts
LaTeX Font Info: Overwriting symbol font `operators' in version `normal'
(Font) OT1/cmr/m/n --> OT1/lmr/m/n on input line 22.
LaTeX Font Info: Overwriting symbol font `letters' in version `normal'
(Font) OML/cmm/m/it --> OML/lmm/m/it on input line 23.
LaTeX Font Info: Overwriting symbol font `symbols' in version `normal'
(Font) OMS/cmsy/m/n --> OMS/lmsy/m/n on input line 24.
LaTeX Font Info: Overwriting symbol font `largesymbols' in version `normal'
(Font) OMX/cmex/m/n --> OMX/lmex/m/n on input line 25.
LaTeX Font Info: Overwriting symbol font `operators' in version `bold'
(Font) OT1/cmr/bx/n --> OT1/lmr/bx/n on input line 26.
LaTeX Font Info: Overwriting symbol font `letters' in version `bold'
(Font) OML/cmm/b/it --> OML/lmm/b/it on input line 27.
LaTeX Font Info: Overwriting symbol font `symbols' in version `bold'
(Font) OMS/cmsy/b/n --> OMS/lmsy/b/n on input line 28.
LaTeX Font Info: Overwriting symbol font `largesymbols' in version `bold'
(Font) OMX/cmex/m/n --> OMX/lmex/m/n on input line 29.
LaTeX Font Info: Overwriting math alphabet `\mathbf' in version `normal'
(Font) OT1/cmr/bx/n --> OT1/lmr/bx/n on input line 31.
LaTeX Font Info: Overwriting math alphabet `\mathsf' in version `normal'
(Font) OT1/cmss/m/n --> OT1/lmss/m/n on input line 32.
LaTeX Font Info: Overwriting math alphabet `\mathit' in version `normal'
(Font) OT1/cmr/m/it --> OT1/lmr/m/it on input line 33.
LaTeX Font Info: Overwriting math alphabet `\mathtt' in version `normal'
(Font) OT1/cmtt/m/n --> OT1/lmtt/m/n on input line 34.
LaTeX Font Info: Overwriting math alphabet `\mathbf' in version `bold'
(Font) OT1/cmr/bx/n --> OT1/lmr/bx/n on input line 35.
LaTeX Font Info: Overwriting math alphabet `\mathsf' in version `bold'
(Font) OT1/cmss/bx/n --> OT1/lmss/bx/n on input line 36.
LaTeX Font Info: Overwriting math alphabet `\mathit' in version `bold'
(Font) OT1/cmr/bx/it --> OT1/lmr/bx/it on input line 37.
LaTeX Font Info: Overwriting math alphabet `\mathtt' in version `bold'
(Font) OT1/cmtt/m/n --> OT1/lmtt/m/n on input line 38.
) (C:\Program Files\MiKTeX\tex/generic/iftex\iftex.sty
Package: iftex 2020/03/06 v1.0d TeX engine tests
) (C:\Users\albig\AppData\Roaming\MiKTeX\tex/latex/unicode-math\unicode-math.st
y (C:\Program Files\MiKTeX\tex/latex/l3kernel\expl3.sty
Package: expl3 2021-07-12 L3 programming layer (loader)
(C:\Program Files\MiKTeX\tex/latex/l3backend\l3backend-xetex.def
File: l3backend-xetex.def 2021-08-04 L3 backend support: XeTeX
()
\c__kernel_sys_dvipdfmx_version_int=\count199
\l__color_backend_stack_int=\count266
\g__color_backend_stack_int=\count267
\g__graphics_track_int=\count268
\l__pdf_internal_box=\box54
\g__pdf_backend_object_int=\count269
\g__pdf_backend_annotation_int=\count270
\g__pdf_backend_link_int=\count271
))
Package: unicode-math 2020/01/31 v0.8q Unicode maths in XeLaTeX and LuaLaTeX
(C:\Users\albig\AppData\Roaming\MiKTeX\tex/latex/unicode-math\unicode-math-xete
x.sty
Package: unicode-math-xetex 2020/01/31 v0.8q Unicode maths in XeLaTeX and LuaLa
TeX
(C:\Program Files\MiKTeX\tex/latex/l3packages/xparse\xparse.sty
Package: xparse 2021-08-04 L3 Experimental document command parser
) (C:\Program Files\MiKTeX\tex/latex/l3packages/l3keys2e\l3keys2e.sty
Package: l3keys2e 2021-08-04 LaTeX2e option processing using LaTeX3 keys
) (C:\Program Files\MiKTeX\tex/latex/fontspec\fontspec.sty
Package: fontspec 2020/02/21 v2.7i Font selection for XeLaTeX and LuaLaTeX
(C:\Program Files\MiKTeX\tex/latex/fontspec\fontspec-xetex.sty
Package: fontspec-xetex 2020/02/21 v2.7i Font selection for XeLaTeX and LuaLaTe
X
\l__fontspec_script_int=\count272
\l__fontspec_language_int=\count273
\l__fontspec_strnum_int=\count274
\l__fontspec_tmp_int=\count275
\l__fontspec_tmpa_int=\count276
\l__fontspec_tmpb_int=\count277
\l__fontspec_tmpc_int=\count278
\l__fontspec_em_int=\count279
\l__fontspec_emdef_int=\count280
\l__fontspec_strong_int=\count281
\l__fontspec_strongdef_int=\count282
\l__fontspec_tmpa_dim=\dimen148
\l__fontspec_tmpb_dim=\dimen149
\l__fontspec_tmpc_dim=\dimen150
(C:\Program Files\MiKTeX\tex/latex/base\fontenc.sty
Package: fontenc 2021/04/29 v2.0v Standard LaTeX package
)
! Interruption.
\__keyval_trim:nN #1->\__keyval_trim_auxi:w #1
\s__keyval_nil \s__keyval_mark...
l.3532 \newfontlanguage{Moksha}{MOK}
Here is how much of TeX's memory you used:
6387 strings out of 411276
157379 string characters out of 2833273
600564 words of memory out of 3000000
26830 multiletter control sequences out of 15000+600000
403438 words of font info for 28 fonts, out of 8000000 for 9000
1348 hyphenation exceptions out of 8191
108i,1n,108p,10631b,270s stack positions out of 5000i,500n,10000p,200000b,80000s
No pages of output.

151
report.qmd Normal file
View File

@ -0,0 +1,151 @@
---
title: "Characterization of Space Debris using Machine Learning Methods"
subtitle: "Advanced processing of 3D meshes using Julia, and data science in Matlab."
author: Anson Biggs
date: "4/30/2022"
latex-auto-install: true
format:
html:
self-contained: true
pdf: default
# reference-location: margin
citation-location: margin
bibliography: citations.bib
---
## Gathering Data
To get started on the project before any scans of the actual debris are made available, I opted to
find 3D models online and process them as if they were data collected by my team. GrabCAD is an
excellent source of high-quality 3D models, and all the models have, at worst, a non-commercial
^[This is a test] license making them suitable for this study. The current dataset uses three
separate satellite assemblies found on GrabCAD, below is an example of one of the satellites that
was used.
![Example CubeSat Used for Analysis](Figures/assembly.jpg)
## Data Preparation
The models were processed in Blender, which quickly converted the assemblies to `stl` files, giving
108 unique parts to be processed. Since the expected final size of the dataset is expected to be in
the magnitude of the thousands, an algorithm capable of getting the required properties of each part
is the only feasible solution. From the analysis performed in
[Report 1](https://gitlab.com/orbital-debris-research/directed-study/report-1/-/blob/main/README.md),
we know that the essential debris property is the moments of inertia which helped narrow down
potential algorithms. Unfortunately, this is one of the more complicated things to calculate from a
mesh, but thanks to a paper from [@eberlyPolyhedralMassProperties2002] titled
[Polyhedral Mass Properties](https://www.geometrictools.com/Documentation/PolyhedralMassProperties.pdf),
his algorithm was implemented in the Julia programming language. The current implementation of the
algorithm calculates a moment of inertia tensor, volume, center of gravity, characteristic length,
and surface body dimensions in a few milliseconds per part. The library can be found
[here.](https://gitlab.com/MisterBiggs/stl-process) The characteristic length is a value that is
heavily used by the NASA DebriSat project [@DebriSat2019] that is doing very similar work to this
project. The characteristic length takes the maximum orthogonal dimension of a body, sums the
dimensions then divides by 3 to produce a single scalar value that can be used to get an idea of
thesize of a 3D object.
![Current mesh processing pipeline](Figures/current_process.png)
The algorithm's speed is critical not only for the eventual large number of debris pieces that have
to be processed, but many of the data science algorithms we plan on performing on the compiled data
need the data to be normalized. For the current dataset and properties, it makes the most sense to
normalize the dataset based on volume. Volume was chosen for multiple reasons, namely because it was
easy to implement an efficient algorithm to calculate volume, and currently, volume produces the
least amount of variation out of the current set of properties calculated. Unfortunately, scaling a
model to a specific volume is an iterative process, but can be done very efficiently using
derivative-free numerical root-finding algorithms. The current implementation can scale and process
all the properties using only 30% more time than getting the properties without first scaling.
```txt
Row │ variable mean min median max
─────┼───────────────────────────────────────────────────────────────────
1 │ surface_area 25.2002 5.60865 13.3338 159.406
2 │ characteristic_length 79.5481 0.158521 1.55816 1582.23
3 │ sbx 1.40222 0.0417367 0.967078 10.0663
4 │ sby 3.3367 0.0125824 2.68461 9.68361
5 │ sbz 3.91184 0.29006 1.8185 14.7434
6 │ Ix 1.58725 0.0311782 0.23401 11.1335
7 │ Iy 3.74345 0.178598 1.01592 24.6735
8 │ Iz 5.20207 0.178686 1.742 32.0083
```
Above is a summary of the current 108 part with scaling. Since all the volumes are the same it is
left out of the dataset, the center of gravity is also left out of the dataset since it currently is
just an artifact of the `stl` file format. There are many ways to determine the 'center' of a 3D
mesh, but since only one is being implemented at the moment comparisons to other properties doesn't
make sense. The other notable part of the data is the model is rotated so that the magnitudes of
`Iz`, `Iy`, and `Ix` are in descending order. This makes sure that the rotation of a model doesn't
matter for characterization. The dataset is available for download here:
- [scaled_dataset.csv](https://gitlab.com/orbital-debris-research/directed-study/report-3/-/blob/main/scaled_dataset.csv)
## Characterization
The first step toward characterization is to perform a principal component analysis to determine
what properties of the data capture the most variation. `PCA` also requires that the data is scaled,
so as discussed above the dataset that is scaled by `volume` will be used. `PCA` is implemented
manually instead of the Matlab built-in function as shown below:
```matlab
% covaraince matrix of data points
S=cov(scaled_data);
% eigenvalues of S
eig_vals = eig(S);
% sorting eigenvalues from largest to smallest
[lambda, sort_index] = sort(eig_vals,'descend');
lambda_ratio = cumsum(lambda) ./ sum(lambda)
```
Then plotting `lambda_ratio`, which is the `cumsum`/`sum` produces the following plot:
![PCA Plot](Figures/pca.png)
The current dataset can be described incredibly well just by looking at `Iz`, which again the models
are rotated so that `Iz` is the largest moment of inertia. Then including `Iy` and `Iz` means that a
3D plot of the principle moments of inertia almost capture all the variation in the data.
The next step for characterization is to get only the inertia's from the dataset. Since the current
dataset is so small, the scaled dataset will be used for rest of the characterization process. Once
more parts are added to the database it will make sense to start looking at the raw dataset. Now we
can proceed to cluster the data using the k-means method of clustering. To properly use k-means a
value of k, which is the number of clusters, needs to be determined. This can be done by creating an
elbow plot using the following code:
```matlab
for ii=1:20
[idx,~,sumd] = kmeans(inertia,ii);
J(ii)=norm(sumd);
end
```
Which produces the following plot:
![Elbow method to determine the required number of clusters.](Figures/kmeans.png)
As can be seen in the above elbow plot, at 6 clusters there is an "elbow" which is where there is a
large drop in the sum distance to the centroid of each cluster which means that it is the optimal
number of clusters. The inertia's can then be plotted using 6 k-means clusters produces the
following plot:
![Moments of Inertia plotted with 6 clusters.](Figures/inertia3d.png)
From this plot it is immediately clear that there are clusters of outliers. These are due to the
different shapes and the extreme values are slender rods or flat plates while the clusters closer to
the center more closely resemble a sphere. As the dataset grows it should become more apparent what
kind of clusters actually make up a satellite, and eventually space debris in general.
## Next Steps
The current dataset needs to be grown in both the amount of data and the variety of data. The most
glaring issue with the current dataset is the lack of any debris since the parts are straight from
satellite assemblies. Getting accurate properties from the current scans we have is an entire
research project in itself, so hopefully, getting pieces that are easier to scan can help bring the
project back on track. The other and harder-to-fix issue is finding/deriving more data properties.
Properties such as cross-sectional or aerodynamic drag would be very insightful but are likely to be
difficult to implement in code and significantly more resource intensive than the current properties
the code can derive.

460
report.tex Normal file
View File

@ -0,0 +1,460 @@
% Options for packages loaded elsewhere
\PassOptionsToPackage{unicode}{hyperref}
\PassOptionsToPackage{hyphens}{url}
\PassOptionsToPackage{dvipsnames,svgnames,x11names}{xcolor}
%
\documentclass[
letterpaper,
DIV=11,
numbers=noendperiod,
oneside]{scrartcl}
\usepackage{amsmath,amssymb}
\usepackage{lmodern}
\usepackage{iftex}
\ifPDFTeX
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{textcomp} % provide euro and other symbols
\else % if luatex or xetex
\usepackage{unicode-math}
\defaultfontfeatures{Scale=MatchLowercase}
\defaultfontfeatures[\rmfamily]{Ligatures=TeX,Scale=1}
\fi
% Use upquote if available, for straight quotes in verbatim environments
\IfFileExists{upquote.sty}{\usepackage{upquote}}{}
\IfFileExists{microtype.sty}{% use microtype if available
\usepackage[]{microtype}
\UseMicrotypeSet[protrusion]{basicmath} % disable protrusion for tt fonts
}{}
\makeatletter
\@ifundefined{KOMAClassName}{% if non-KOMA class
\IfFileExists{parskip.sty}{%
\usepackage{parskip}
}{% else
\setlength{\parindent}{0pt}
\setlength{\parskip}{6pt plus 2pt minus 1pt}}
}{% if KOMA class
\KOMAoptions{parskip=half}}
\makeatother
\usepackage{xcolor}
\IfFileExists{xurl.sty}{\usepackage{xurl}}{} % add URL line breaks if available
\IfFileExists{bookmark.sty}{\usepackage{bookmark}}{\usepackage{hyperref}}
\hypersetup{
pdftitle={Characterization of Space Debris using Machine Learning Methods},
pdfauthor={Anson Biggs},
colorlinks=true,
linkcolor={blue},
filecolor={Maroon},
citecolor={Blue},
urlcolor={Blue},
pdfcreator={LaTeX via pandoc}}
\urlstyle{same} % disable monospaced font for URLs
\usepackage[left=1in,marginparwidth=2.0666666666667in,textwidth=4.1333333333333in,marginparsep=0.3in]{geometry}
\setlength{\emergencystretch}{3em} % prevent overfull lines
\setcounter{secnumdepth}{-\maxdimen} % remove section numbering
% Make \paragraph and \subparagraph free-standing
\ifx\paragraph\undefined\else
\let\oldparagraph\paragraph
\renewcommand{\paragraph}[1]{\oldparagraph{#1}\mbox{}}
\fi
\ifx\subparagraph\undefined\else
\let\oldsubparagraph\subparagraph
\renewcommand{\subparagraph}[1]{\oldsubparagraph{#1}\mbox{}}
\fi
\usepackage{color}
\usepackage{fancyvrb}
\newcommand{\VerbBar}{|}
\newcommand{\VERB}{\Verb[commandchars=\\\{\}]}
\DefineVerbatimEnvironment{Highlighting}{Verbatim}{commandchars=\\\{\}}
% Add ',fontsize=\small' for more characters per line
\usepackage{framed}
\definecolor{shadecolor}{RGB}{241,243,245}
\newenvironment{Shaded}{\begin{snugshade}}{\end{snugshade}}
\newcommand{\AlertTok}[1]{\textcolor[rgb]{0.68,0.00,0.00}{#1}}
\newcommand{\AnnotationTok}[1]{\textcolor[rgb]{0.37,0.37,0.37}{#1}}
\newcommand{\AttributeTok}[1]{\textcolor[rgb]{0.40,0.45,0.13}{#1}}
\newcommand{\BaseNTok}[1]{\textcolor[rgb]{0.68,0.00,0.00}{#1}}
\newcommand{\BuiltInTok}[1]{\textcolor[rgb]{0.00,0.23,0.31}{#1}}
\newcommand{\CharTok}[1]{\textcolor[rgb]{0.13,0.47,0.30}{#1}}
\newcommand{\CommentTok}[1]{\textcolor[rgb]{0.37,0.37,0.37}{#1}}
\newcommand{\CommentVarTok}[1]{\textcolor[rgb]{0.37,0.37,0.37}{\textit{#1}}}
\newcommand{\ConstantTok}[1]{\textcolor[rgb]{0.56,0.35,0.01}{#1}}
\newcommand{\ControlFlowTok}[1]{\textcolor[rgb]{0.00,0.23,0.31}{#1}}
\newcommand{\DataTypeTok}[1]{\textcolor[rgb]{0.68,0.00,0.00}{#1}}
\newcommand{\DecValTok}[1]{\textcolor[rgb]{0.68,0.00,0.00}{#1}}
\newcommand{\DocumentationTok}[1]{\textcolor[rgb]{0.37,0.37,0.37}{\textit{#1}}}
\newcommand{\ErrorTok}[1]{\textcolor[rgb]{0.68,0.00,0.00}{#1}}
\newcommand{\ExtensionTok}[1]{\textcolor[rgb]{0.00,0.23,0.31}{#1}}
\newcommand{\FloatTok}[1]{\textcolor[rgb]{0.68,0.00,0.00}{#1}}
\newcommand{\FunctionTok}[1]{\textcolor[rgb]{0.28,0.35,0.67}{#1}}
\newcommand{\ImportTok}[1]{\textcolor[rgb]{0.00,0.46,0.62}{#1}}
\newcommand{\InformationTok}[1]{\textcolor[rgb]{0.37,0.37,0.37}{#1}}
\newcommand{\KeywordTok}[1]{\textcolor[rgb]{0.00,0.23,0.31}{#1}}
\newcommand{\NormalTok}[1]{\textcolor[rgb]{0.00,0.23,0.31}{#1}}
\newcommand{\OperatorTok}[1]{\textcolor[rgb]{0.37,0.37,0.37}{#1}}
\newcommand{\OtherTok}[1]{\textcolor[rgb]{0.00,0.23,0.31}{#1}}
\newcommand{\PreprocessorTok}[1]{\textcolor[rgb]{0.68,0.00,0.00}{#1}}
\newcommand{\RegionMarkerTok}[1]{\textcolor[rgb]{0.00,0.23,0.31}{#1}}
\newcommand{\SpecialCharTok}[1]{\textcolor[rgb]{0.37,0.37,0.37}{#1}}
\newcommand{\SpecialStringTok}[1]{\textcolor[rgb]{0.13,0.47,0.30}{#1}}
\newcommand{\StringTok}[1]{\textcolor[rgb]{0.13,0.47,0.30}{#1}}
\newcommand{\VariableTok}[1]{\textcolor[rgb]{0.07,0.07,0.07}{#1}}
\newcommand{\VerbatimStringTok}[1]{\textcolor[rgb]{0.13,0.47,0.30}{#1}}
\newcommand{\WarningTok}[1]{\textcolor[rgb]{0.37,0.37,0.37}{\textit{#1}}}
\providecommand{\tightlist}{%
\setlength{\itemsep}{0pt}\setlength{\parskip}{0pt}}\usepackage{longtable,booktabs,array}
\usepackage{calc} % for calculating minipage widths
% Correct order of tables after \paragraph or \subparagraph
\usepackage{etoolbox}
\makeatletter
\patchcmd\longtable{\par}{\if@noskipsec\mbox{}\fi\par}{}{}
\makeatother
% Allow footnotes in longtable head/foot
\IfFileExists{footnotehyper.sty}{\usepackage{footnotehyper}}{\usepackage{footnote}}
\makesavenoteenv{longtable}
\usepackage{graphicx}
\makeatletter
\def\maxwidth{\ifdim\Gin@nat@width>\linewidth\linewidth\else\Gin@nat@width\fi}
\def\maxheight{\ifdim\Gin@nat@height>\textheight\textheight\else\Gin@nat@height\fi}
\makeatother
% Scale images if necessary, so that they will not overflow the page
% margins by default, and it is still possible to overwrite the defaults
% using explicit options in \includegraphics[width, height, ...]{}
\setkeys{Gin}{width=\maxwidth,height=\maxheight,keepaspectratio}
% Set default figure placement to htbp
\makeatletter
\def\fps@figure{htbp}
\makeatother
\newlength{\cslhangindent}
\setlength{\cslhangindent}{1.5em}
\newlength{\csllabelwidth}
\setlength{\csllabelwidth}{3em}
\newlength{\cslentryspacingunit} % times entry-spacing
\setlength{\cslentryspacingunit}{\parskip}
\newenvironment{CSLReferences}[2] % #1 hanging-ident, #2 entry spacing
{% don't indent paragraphs
\setlength{\parindent}{0pt}
% turn on hanging indent if param 1 is 1
\ifodd #1
\let\oldpar\par
\def\par{\hangindent=\cslhangindent\oldpar}
\fi
% set entry spacing
\setlength{\parskip}{#2\cslentryspacingunit}
}%
{}
\usepackage{calc}
\newcommand{\CSLBlock}[1]{#1\hfill\break}
\newcommand{\CSLLeftMargin}[1]{\parbox[t]{\csllabelwidth}{#1}}
\newcommand{\CSLRightInline}[1]{\parbox[t]{\linewidth - \csllabelwidth}{#1}\break}
\newcommand{\CSLIndent}[1]{\hspace{\cslhangindent}#1}
\KOMAoption{captions}{tableheading}
\makeatletter
\makeatother
\makeatletter
\@ifpackageloaded{caption}{}{\usepackage{caption}}
\AtBeginDocument{%
\ifdefined\contentsname
\renewcommand*\contentsname{Table of contents}
\else
\newcommand\contentsname{Table of contents}
\fi
\ifdefined\listfigurename
\renewcommand*\listfigurename{List of Figures}
\else
\newcommand\listfigurename{List of Figures}
\fi
\ifdefined\listtablename
\renewcommand*\listtablename{List of Tables}
\else
\newcommand\listtablename{List of Tables}
\fi
\ifdefined\figurename
\renewcommand*\figurename{Figure}
\else
\newcommand\figurename{Figure}
\fi
\ifdefined\tablename
\renewcommand*\tablename{Table}
\else
\newcommand\tablename{Table}
\fi
}
\@ifpackageloaded{float}{}{\usepackage{float}}
\floatstyle{ruled}
\@ifundefined{c@chapter}{\newfloat{codelisting}{h}{lop}}{\newfloat{codelisting}{h}{lop}[chapter]}
\floatname{codelisting}{Listing}
\newcommand*\listoflistings{\listof{codelisting}{List of Listings}}
\makeatother
\makeatletter
\@ifpackageloaded{caption}{}{\usepackage{caption}}
\@ifpackageloaded{subcaption}{}{\usepackage{subcaption}}
\makeatother
\makeatletter
\@ifpackageloaded{tcolorbox}{}{\usepackage[many]{tcolorbox}}
\makeatother
\makeatletter
\@ifundefined{shadecolor}{\definecolor{shadecolor}{rgb}{.97, .97, .97}}
\makeatother
\makeatletter
\@ifpackageloaded{sidenotes}{}{\usepackage{sidenotes}}
\@ifpackageloaded{marginnote}{}{\usepackage{marginnote}}
\makeatother
\makeatletter
\makeatother
\ifLuaTeX
\usepackage{selnolig} % disable illegal ligatures
\fi
\title{Characterization of Space Debris using Machine Learning Methods}
\usepackage{etoolbox}
\makeatletter
\providecommand{\subtitle}[1]{% add subtitle to \maketitle
\apptocmd{\@title}{\par {\large #1 \par}}{}{}
}
\makeatother
\subtitle{Advanced processing of 3D meshes using Julia, and data science
in Matlab.}
\author{Anson Biggs}
\date{4/30/2022}
\begin{document}
\maketitle
\ifdefined\Shaded\renewenvironment{Shaded}{\begin{tcolorbox}[interior hidden, borderline west={3pt}{0pt}{shadecolor}, boxrule=0pt, enhanced, breakable, sharp corners, frame hidden]}{\end{tcolorbox}}\fi
\hypertarget{gathering-data}{%
\subsection{Gathering Data}\label{gathering-data}}
To get started on the project before any scans of the actual debris are
made available, I opted to find 3D models online and process them as if
they were data collected by my team. GrabCAD is an excellent source of
high-quality 3D models, and all the models have, at worst, a
non-commercial license making them suitable for this study. The current
dataset uses three separate satellite assemblies found on GrabCAD, below
is an example of one of the satellites that was used.
\begin{figure}
{\centering \includegraphics{Figures/assembly.jpg}
}
\caption{Example CubeSat Used for Analysis}
\end{figure}
\hypertarget{data-preparation}{%
\subsection{Data Preparation}\label{data-preparation}}
The models were processed in Blender, which quickly converted the
assemblies to \texttt{stl} files, giving 108 unique parts to be
processed. Since the expected final size of the dataset is expected to
be in the magnitude of the thousands, an algorithm capable of getting
the required properties of each part is the only feasible solution. From
the analysis performed in
\href{https://gitlab.com/orbital-debris-research/directed-study/report-1/-/blob/main/README.md}{Report
1}, we know that the essential debris property is the moments of inertia
which helped narrow down potential algorithms. Unfortunately, this is
one of the more complicated things to calculate from a mesh, but thanks
to a paper from (Eberly
2002)\marginpar{\begin{footnotesize}\leavevmode\vadjust pre{\protect\hypertarget{ref-eberlyPolyhedralMassProperties2002}{}}%
Eberly, David. 2002. {``Polyhedral {Mass Properties} ({Revisited}).''}
\url{https://www.geometrictools.com/Documentation/PolyhedralMassProperties.pdf}.\vspace{2mm}\par\end{footnotesize}}
titled
\href{https://www.geometrictools.com/Documentation/PolyhedralMassProperties.pdf}{Polyhedral
Mass Properties}, his algorithm was implemented in the Julia programming
language. The current implementation of the algorithm calculates a
moment of inertia tensor, volume, center of gravity, characteristic
length, and surface body dimensions in a few milliseconds per part. The
library can be found
\href{https://gitlab.com/MisterBiggs/stl-process}{here.} The
characteristic length is a value that is heavily used by the NASA
DebriSat project (Murray et al.
2019)\marginpar{\begin{footnotesize}\leavevmode\vadjust pre{\protect\hypertarget{ref-DebriSat2019}{}}%
Murray, James, Heather Cowardin, J-C Liou, Marlon Sorge, Norman
Fitz-Coy, and Tom Huynh. 2019. {``Analysis of the DebriSat Fragments and
Comparison to the NASA Standard Satellite Breakup Model.''} In
\emph{International Orbital Debris Conference (IOC)}. JSC-E-DAA-TN73918.
\url{https://ntrs.nasa.gov/citations/20190034081}.\vspace{2mm}\par\end{footnotesize}}
that is doing very similar work to this project. The characteristic
length takes the maximum orthogonal dimension of a body, sums the
dimensions then divides by 3 to produce a single scalar value that can
be used to get an idea of thesize of a 3D object.
\begin{figure}
{\centering \includegraphics{Figures/current_process.pdf}
}
\caption{Current mesh processing pipeline}
\end{figure}
The algorithm's speed is critical not only for the eventual large number
of debris pieces that have to be processed, but many of the data science
algorithms we plan on performing on the compiled data need the data to
be normalized. For the current dataset and properties, it makes the most
sense to normalize the dataset based on volume. Volume was chosen for
multiple reasons, namely because it was easy to implement an efficient
algorithm to calculate volume, and currently, volume produces the least
amount of variation out of the current set of properties calculated.
Unfortunately, scaling a model to a specific volume is an iterative
process, but can be done very efficiently using derivative-free
numerical root-finding algorithms. The current implementation can scale
and process all the properties using only 30\% more time than getting
the properties without first scaling.
\begin{Shaded}
\begin{Highlighting}[]
\NormalTok{ Row │ variable mean min median max}
\NormalTok{─────┼───────────────────────────────────────────────────────────────────}
\NormalTok{ 1 │ surface\_area 25.2002 5.60865 13.3338 159.406}
\NormalTok{ 2 │ characteristic\_length 79.5481 0.158521 1.55816 1582.23}
\NormalTok{ 3 │ sbx 1.40222 0.0417367 0.967078 10.0663}
\NormalTok{ 4 │ sby 3.3367 0.0125824 2.68461 9.68361}
\NormalTok{ 5 │ sbz 3.91184 0.29006 1.8185 14.7434}
\NormalTok{ 6 │ Ix 1.58725 0.0311782 0.23401 11.1335}
\NormalTok{ 7 │ Iy 3.74345 0.178598 1.01592 24.6735}
\NormalTok{ 8 │ Iz 5.20207 0.178686 1.742 32.0083}
\end{Highlighting}
\end{Shaded}
Above is a summary of the current 108 part with scaling. Since all the
volumes are the same it is left out of the dataset, the center of
gravity is also left out of the dataset since it currently is just an
artifact of the \texttt{stl} file format. There are many ways to
determine the `center' of a 3D mesh, but since only one is being
implemented at the moment comparisons to other properties doesn't make
sense. The other notable part of the data is the model is rotated so
that the magnitudes of \texttt{Iz}, \texttt{Iy}, and \texttt{Ix} are in
descending order. This makes sure that the rotation of a model doesn't
matter for characterization. The dataset is available for download here:
\begin{itemize}
\tightlist
\item
\href{https://gitlab.com/orbital-debris-research/directed-study/report-3/-/blob/main/scaled_dataset.csv}{scaled\_dataset.csv}
\end{itemize}
\hypertarget{characterization}{%
\subsection{Characterization}\label{characterization}}
The first step toward characterization is to perform a principal
component analysis to determine what properties of the data capture the
most variation. \texttt{PCA} also requires that the data is scaled, so
as discussed above the dataset that is scaled by \texttt{volume} will be
used. \texttt{PCA} is implemented manually instead of the Matlab
built-in function as shown below:
\begin{Shaded}
\begin{Highlighting}[]
\CommentTok{\% covaraince matrix of data points}
\VariableTok{S}\OperatorTok{=}\VariableTok{cov}\NormalTok{(}\VariableTok{scaled\_data}\NormalTok{)}\OperatorTok{;}
\CommentTok{\% eigenvalues of S}
\VariableTok{eig\_vals} \OperatorTok{=} \VariableTok{eig}\NormalTok{(}\VariableTok{S}\NormalTok{)}\OperatorTok{;}
\CommentTok{\% sorting eigenvalues from largest to smallest}
\NormalTok{[}\VariableTok{lambda}\OperatorTok{,} \VariableTok{sort\_index}\NormalTok{] }\OperatorTok{=} \VariableTok{sort}\NormalTok{(}\VariableTok{eig\_vals}\OperatorTok{,}\SpecialStringTok{\textquotesingle{}descend\textquotesingle{}}\NormalTok{)}\OperatorTok{;}
\VariableTok{lambda\_ratio} \OperatorTok{=} \VariableTok{cumsum}\NormalTok{(}\VariableTok{lambda}\NormalTok{) }\OperatorTok{./} \VariableTok{sum}\NormalTok{(}\VariableTok{lambda}\NormalTok{)}
\end{Highlighting}
\end{Shaded}
Then plotting \texttt{lambda\_ratio}, which is the
\texttt{cumsum}/\texttt{sum} produces the following plot:
\begin{figure}
{\centering \includegraphics{Figures/pca.png}
}
\caption{PCA Plot}
\end{figure}
The current dataset can be described incredibly well just by looking at
\texttt{Iz}, which again the models are rotated so that \texttt{Iz} is
the largest moment of inertia. Then including \texttt{Iy} and
\texttt{Iz} means that a 3D plot of the principle moments of inertia
almost capture all the variation in the data.
The next step for characterization is to get only the inertia's from the
dataset. Since the current dataset is so small, the scaled dataset will
be used for rest of the characterization process. Once more parts are
added to the database it will make sense to start looking at the raw
dataset. Now we can proceed to cluster the data using the k-means method
of clustering. To properly use k-means a value of k, which is the number
of clusters, needs to be determined. This can be done by creating an
elbow plot using the following code:
\begin{Shaded}
\begin{Highlighting}[]
\KeywordTok{for} \VariableTok{ii}\OperatorTok{=}\FloatTok{1}\OperatorTok{:}\FloatTok{20}
\NormalTok{ [}\VariableTok{idx}\OperatorTok{,\textasciitilde{},}\VariableTok{sumd}\NormalTok{] }\OperatorTok{=} \VariableTok{kmeans}\NormalTok{(}\VariableTok{inertia}\OperatorTok{,}\VariableTok{ii}\NormalTok{)}\OperatorTok{;}
\VariableTok{J}\NormalTok{(}\VariableTok{ii}\NormalTok{)}\OperatorTok{=}\VariableTok{norm}\NormalTok{(}\VariableTok{sumd}\NormalTok{)}\OperatorTok{;}
\KeywordTok{end}
\end{Highlighting}
\end{Shaded}
Which produces the following plot:
\begin{figure}
{\centering \includegraphics{Figures/kmeans.png}
}
\caption{Elbow method to determine the required number of clusters.}
\end{figure}
As can be seen in the above elbow plot, at 6 clusters there is an
``elbow'' which is where there is a large drop in the sum distance to
the centroid of each cluster which means that it is the optimal number
of clusters. The inertia's can then be plotted using 6 k-means clusters
produces the following plot:
\begin{figure}
{\centering \includegraphics{Figures/inertia3d.png}
}
\caption{Moments of Inertia plotted with 6 clusters.}
\end{figure}
From this plot it is immediately clear that there are clusters of
outliers. These are due to the different shapes and the extreme values
are slender rods or flat plates while the clusters closer to the center
more closely resemble a sphere. As the dataset grows it should become
more apparent what kind of clusters actually make up a satellite, and
eventually space debris in general.
\hypertarget{next-steps}{%
\subsection{Next Steps}\label{next-steps}}
The current dataset needs to be grown in both the amount of data and the
variety of data. The most glaring issue with the current dataset is the
lack of any debris since the parts are straight from satellite
assemblies. Getting accurate properties from the current scans we have
is an entire research project in itself, so hopefully, getting pieces
that are easier to scan can help bring the project back on track. The
other and harder-to-fix issue is finding/deriving more data properties.
Properties such as cross-sectional or aerodynamic drag would be very
insightful but are likely to be difficult to implement in code and
significantly more resource intensive than the current properties the
code can derive.
\end{document}