[HN Gopher] I built an ROV to solve missing person cases
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I built an ROV to solve missing person cases
Author : craydandy
Score : 179 points
Date : 2024-06-09 12:02 UTC (1 days ago)
(HTM) web link (suanto.com)
(TXT) w3m dump (suanto.com)
| dang wrote:
| As you can see, this is long:
|
| https://suanto.com/2024/06/06/the-time-I-built-an-ROV-02/
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| https://suanto.com/2024/06/06/the-time-I-built-an-ROV-03/
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| https://suanto.com/2024/06/06/the-time-I-built-an-ROV-04/
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| https://suanto.com/2024/06/06/the-time-I-built-an-ROV-05/
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| https://suanto.com/2024/06/06/the-time-I-built-an-ROV-06/
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| https://suanto.com/2024/06/06/the-time-I-built-an-ROV-07/
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| https://suanto.com/2024/06/06/the-time-I-built-an-ROV-08/
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| https://suanto.com/2024/06/06/the-time-I-built-an-ROV-09/
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| https://suanto.com/2024/06/06/the-time-I-built-an-ROV-10/
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| https://suanto.com/2024/06/06/the-time-I-built-an-ROV-11/
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| https://suanto.com/2024/06/06/the-time-I-built-an-ROV-12/
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| https://suanto.com/2024/06/06/the-time-I-built-an-ROV-13/
|
| But we got an email from a (unrelated) user saying it's good, so
| I've put it in the SCP
| (https://news.ycombinator.com/item?id=26998308).
|
| ROV = remotely operated vehicle btw
| lxgr wrote:
| Would be great to be able to read all of these as a single
| article! (I'm intrigued, but I'm not saving 13 blog posts to my
| read-it-later app. Even stitched together, it wouldn't be the
| longest in my list by a long shot.)
| dang wrote:
| I agree and sometimes email authors to ask if they would
| compile (or should I say link?) a multipart article into a
| single piece before we put it into the second-chance pool.
| But even I was afraid of how long this one would turn out to
| be.
| thecatspaw wrote:
| Thanks for giving it a second chance. I read all of it, and it
| was very interesting indeed
| cryptonector wrote:
| TFA is nothing short of amazing and absolutely deserves
| attention.
|
| The author (and his brother) built (from scratch!) a side-scan
| sonar remote controlled boat and an ROV (a remote controlled
| submersible) with a camera and a light, and with this they
| found TWO missing persons' cars under water. Real products of
| these sorts would have cost enormous amounts of money, but they
| built their own for the cost of parts and labor (sure, lots of
| labor). They did this on a lark.
| aredox wrote:
| The technical details are in part 4 and 6.
| fusslo wrote:
| I love these long-form build logs.
|
| I just started reading, and I am making the faux-pas of
| commenting before finishing.
|
| But, I'm wondering what the challenges are of automating the ROV
| to map a body of water's floor in a pattern. like a grid pattern,
| or whatever is most efficient.
|
| At first I was thinking currents would cause displacement. but
| can't we sense the current moving us in undesirable ways and
| correct with thrusters?
|
| And then I thought.. do lakes have currents? Do they have tides?
| can a ROV sense the boundary of a lake?
|
| just further down the rabbit hole, realizing how little I've
| learned about the natural environment!
| mzs wrote:
| recent HN discussion on an earlier SAR that was the spark for
| this glorious mad Finn:
|
| https://news.ycombinator.com/item?id=34676129
| tamimio wrote:
| I loved the project!! I also like how "messy" the room is,
| reminded me of my room (1) when I was working from home years
| ago.
|
| I haven't read the whole thing but I will, however, I did go
| through the technical details, some notes:
|
| > This model didn't have a long enough range on the analog sticks
|
| I see you are using Radiomaster tx16s, pro tip: You can use ELRS
| 2W model on BOTH transmitter and the receiver, don't use the
| typical receiver unit, use another transmitter and flash it as a
| receiver, and you would have 2W on both sides, preferably 900mhz
| not 2.4ghz, and you would've hundreds of kilometers of range and
| strong obstacles penetration.
|
| For the camera and the tether, technically you can get rid of the
| tether and use wireless comms, but probably what you did is the
| best for bucks solution.
|
| Overall, looks great!
|
| (1) https://tamim.io/professional_projects/nerds-heavy-lift-
| dron...
| rrr_oh_man wrote:
| _Access denied - The owner of this website (tamim.io) does not
| allow hotlinking to that resource_
| tamimio wrote:
| Sorry my bad, I added an exclusion rule, thanks.
| jonah wrote:
| I took the comment[1] on the analog sticks to be referring to
| the game controller pictured directly above:
| https://suanto.com/assets/2024/03/the-ROV-controller.jpg
|
| I'm guessing that the range of resistance values over the full
| swept range of the sticks was small, and so getting precise
| enough values/smooth enough change out of it wasn't possible.
| (Assuming these things basically have X and Y potentiometers
| for each stick.)
|
| [1] https://suanto.com/2024/06/06/the-time-I-built-an-ROV-06/
| jonah wrote:
| The quest he mentions as inspiration - Tom Mahood's "The Hunt for
| the Death Valley Germans" - is a fascinating read and worth your
| time.
|
| https://www.otherhand.org/home-page/search-and-rescue/the-hu...
|
| I first read it seven years ago and similar to the author, it
| inspired me to join my local Search & Rescue team which has been
| incredibly rewarding. I highly recommend doing that to anyone who
| wants to combine a love of the outdoors, specialized skills,
| serving the community, and helping people in their worst moments.
| (And doesn't mind getting up at 3am in pouring rain and going out
| and pushing through dense underbrush for hours!)
| netsharc wrote:
| Ouch, I'm sort of annoyed that the author was inspired to be
| long-winded and have 16 or more parts to his story. I'm up to
| part 2 and there's a fear of disappointment that it'll be a
| boring waste of time. (In comparison to the Death Valley
| Germans story, which was captivating!)
| jonah wrote:
| I just finished the ROV series of posts. It was sufficiently
| captivating. I enjoyed his narrative - I can see that he was
| inspired by Mahood's writing style as well as his quest.
| noman-land wrote:
| It's really good. Keep reading.
| lnwlebjel wrote:
| Is there a fitness test for SAR? Do you train to stay fit
| enough for it?
| jonah wrote:
| Yes. It varies from team to team. Ours is a 4.1 mile hike
| (with 2,500+ ft. Elevation gain) carrying a 25 lb pack in
| under 2 and 1/2 hours.
|
| I'm also a volunteer firefighter and the "pack test" level of
| Work Capacity Test for wildland firefighters is 3 mi on flat
| ground carrying a 45 lb pack in 45 minutes.
|
| It is pretty important to be in shape as you are often
| carrying a lot of gear and don't want to bonk and cause an
| issue that would jeopardize yourself, your teammates, or the
| mission.
| lemonlime0x3C33 wrote:
| This was incredibly well written and the project itself was super
| cool to see come together. I worked on building UAV's in
| University but seeing the unique challenges with dealing with
| water from a signals perspective was really intriguing.
|
| Good luck with any future cases and can't wait to see what
| upgrades you make!
| HanClinto wrote:
| Absolutely fantastic read. The author got nerd-sniped HARD by
| these missing-person cases and his approach and accomplishments
| are inspiring, to say the least. Very well done!
| octernion wrote:
| having built autonomous ROVs in college, i'm absolutely
| astonished at what this person accomplished essentially on their
| own. they are so finicky and piloting them is a whole skill set
| on its own.
|
| and, what perseverance; it really did read like a detective story
| and what a good job distilling the cases down to their basics.
|
| what a cool read and an absolute triumph of an accomplishment.
| spathi_fwiffo wrote:
| I would suggest defining any acronyms in the title of an article
| in the introduction section of the article.
|
| Had to get to PART 6 to answer my first question: What is an
| "ROV"?
|
| "The solution was to use an ROV, Remote Operated Vehicle "
| scrozier wrote:
| It is my futile mission in life to help people understand that
| initials, acronyms, and abbreviations are real barriers to
| communication.
| klondike_klive wrote:
| Sorry buddy, you might be SOL
| ryanisnan wrote:
| They mean the Roman god personifying the sun, FYI.
| mindslight wrote:
| Funny, because I'd say that jargon is a facilitator of
| communication between knowledgeable people. It can always be
| looked up by those with the interest but not the knowledge. I
| end up doing this all the time, and appreciating reading
| dumps of domain knowledge and perspective. Meanwhile, writing
| everything for a lowest common denominator audience creates
| real barriers to communication - both destroying
| communications bandwidth, and also encouraging experts to
| retreat to less visible forums.
| IncreasePosts wrote:
| Awesome story! The first case had me thinking "These nerds are
| wasting their time...why not just a gopro on a long stick". But
| hearing about the details of the second story, it would have been
| impossible without the sonar and ROV!
| Fauntleroy wrote:
| Posts like these really get down to the essence of Hacker News
| for me. Doing amazing, previously impossible things through sheer
| nerdy effort. What a deeply impressive story!
| y-curious wrote:
| An incredible read! Thank you so much. It even has the famous
| Finnish humility downplaying his huge achievements
| deanresin wrote:
| > So where was he going? I saw two possibilities: either to
| Tikkakoski to visit his ex-girlfrind he was on the phone with or;
| just to drive around with a new powerful car, to shake off the
| heated phone call.
|
| I don't understand how suicide isn't at the top of the list here.
| He was obviously very upset emotionally. He didn't care for his
| belongs other than his phone. He didn't care to steal someone's
| car or answer for it. He never shows up anywhere.
| aetherson wrote:
| I think very few people commit suicide by driving a car into a
| river.
| sitkack wrote:
| Excellent writing. The next ROV should have a magnetometer.
| danw1979 wrote:
| This series of articles is genuinely thrilling to read. What a
| fantastic and truly worthwhile bit of detective work. Very well
| written up.
| andrelaszlo wrote:
| This is amazing. A Finnish man gets curious about a missing
| persons case. He does some great detective work, and builds an
| ROV with side scanning sonar and video. The outcome, with some
| help from his brother, is just spectacular. I couldn't stop
| reading!
| edm0nd wrote:
| OP should have not felt bad about contacting family members and
| done it to yield more information to help them in their cases.
| noman-land wrote:
| I didn't expect to read this whole piece but it was completely
| gripping. Outstanding work and a really great write up.
| westurner wrote:
| /? underwater infrared camera:
| https://www.google.com/search?q=underwater+infrared+camera
|
| r/rov: https://www.reddit.com/r/rov/
|
| Bioradiolocation: https://en.wikipedia.org/wiki/Bioradiolocation
|
| FMCW: https://en.wikipedia.org/wiki/Continuous-wave_radar
|
| mmWave (60 Ghz) can do heartbeat detection above water FWIU. As
| can WiFi.
|
| mmwave (millimeter wave), UWA (Underwater Acoustic)
|
| Citations of "Analysis and estimation of the underwater acoustic
| millimeter-wave communication channel" (2016)
| https://scholar.google.com/scholar?cites=8297460493079369585...
|
| Citations of "Wi-Fi signal analysis for heartbeat and metal
| detection: a comparative study of reliable contactless systems"
| https://scholar.google.com/scholar?cites=3926358377223165726...
|
| /? does WiFi work underwater?
| https://www.google.com/search?q=does+wifi+work+underwater
|
| https://scholar.google.com/scholar?cites=1308760257416493671...
| ... "Environment-independent textile fiber identification using
| Wi-Fi channel state information", "Measurement of construction
| materials properties using Wi-Fi and convolutional neural
| networks"
|
| "Underwater target detection by measuring water-surface vibration
| with millimeter-wave radar"
| https://scholar.google.com/scholar?cites=1710768155624387794... :
|
| > UWSN (Underwater Sensor Network)
|
| I'm reminded of Baywatch S09E01; but those aren't actual trained
| lifeguards. The film Armageddon works as a training film because
| of all of the [safety,] mistakes:
| https://www.google.com/search?q=baywatch+s09e01
| ac2u wrote:
| While I'm sure they did this to try to combine their talents and
| interests with altruism, what they got out of the end of that was
| both of those but also a legacy.
|
| Most of us only wish we could tell stories like that as a result
| of the technical work we do.
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