
Ask HN: Best technologies for indoor position tracking? - benjaminogles
I have a hobby project in mind but I&#x27;m not sure which technologies will give me the most bang for my buck long term.<p>I want to track my 3D position accurately within my apartment. My first use case is to track how long I sleep and how long I watch TV etc. without using some sort of reporting mechanism. I would like to incrementally add more advanced features such as gesture recognition for integration with smart devices etc.<p>I have read about using RF signals and signal processing to track 3D motion indoors without using wearables (https:&#x2F;&#x2F;www.emeraldinno.com&#x2F;publications). There must be ways to do it with wearables and bluetooth. Posyx (https:&#x2F;&#x2F;www.pozyx.io&#x2F;) works with UW signals.<p>Has anyone had experience with a similar project?  Which technologies did you use? Is there specific hardware you would reccommend?
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NetOpWibby
I used to work for an IoT startup on Boston that worked on this exact thing
and then the company folded four days after I got married, two years ago. Fun
times.

Anyhoo, we used Impinj readers and RFID tags to track things indoors. One of
our clients was a Norwegian shipyard who wanted to keep track of their tools
because apparently, tools for fixing ships are expensive and people like
stealing.

You put the Impinj readers on the ceiling on both sides of a doorway and make
sure your API throttles the reads so you can make sense of the data deluge.

I just wrote/designed the dashboards and interfaced with our internal API. If
you have more questions I can ping the guys that worked on the back-end.

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2_listerine_pls
Does it work for accurate positioning though?

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LFOD1
Many thanks for your question! It prompted me to rethink a problem in Home
Telehealth and Elder-Care having to do with tracking Dementia patients.
Anyway, a PubMed paper published 2018-1-24 titled: Passive Infrared
(PIR)-Based Indoor Position Tracking for Smart Homes Using Accessibility Maps
and A-Star Algorithm
([https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5855945/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5855945/))
may help you.

The paper is about using passive infrared sensors (active badge etc.) to
accomplish indoor position tracking. This may be overkill for your need but I
figured I'd put it out there for you anyway. I hope to have some follow up
information in a couple of days and will revisit this question.

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pbalau
I tried to do this, I wanted to track my cats. My problem was that I was
trying to fix this by using one tech. I did a fair bit of research on
Bluetooth, cheap 433mhz radio, accelerometers etc. All had drawbacks, from
size, cost, availability, missing features (eg the signal strenght) and I gave
up when I moved to London.

If I try this again, and by that I mean when I try this again, I will go a
different route. The core will be a pair of accelerometers, with a nfc tag,
sending to a central unit the acceleration data and wifi signal strenght. A
network of nfc readers will send info about what tags are they seeing. Maybe
even some cameras.

The acceleration data will provide fine movement data and the rest is supposed
to allow for data calibration and coarse tracking. Not an easy project, but
should be fun.

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adampk
If you don't mind me asking why would you want to do this? We are working on
technology for a "digital twin" and have not really thought about applying it
to inside the home. What benefits are there of knowing where you/other people
are around the home?

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benjaminogles
Good question, my main motivation is to learn more about how such a system
would work. I am interested in signal processing and especially radar like
systems so implementing one would be a fun experience.

In general, systems based on radar are trying to replace wearables for sleep
states tracking, elderly fall detection etc. But I'm not sure yet what other
applications it might have. The ability to track my location just seemed like
a good first step.

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pacifiedcitizen
If you don't mind wearing a Hololens all day, it orients itself by turning
your entire surroundings into ~1m mesh blocks that serve as its internal map.
As a bonus, you can retrieve the current mesh from the device's internal web
server in order to visualize against it.

Cons: Wearing Hololens all day, spending thousands on a hobby project. :-/
Fascinating if you manage to borrow one though.

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pietroglyph
A smaller and less expensive V-SLAM option would be the Intel RealSense T265
camera.

Tracking accuracy can sometimes drift quite a bit with this if you’re not
careful, but it can perform pretty well, especially if loop closing is
enabled.

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PentiumBug
A small set of well-placed cameras, image processing, and some number
crunching. You know... draw the rest of the owl ;)

