Localization is actually the common term, frequently used in robotics and autonomous vehicles. There's a really interesting field of research here [0].
Cool project.
I have tried using both wifi and IMU motion sensors for mapping indoor and it's not really that impressive yet. This is still a very hard problem to solve.
Google seems to be working on it: https://www.google.com/atap/project-tango/
For now, External distance cameras (Kinect-like) seems to be the most accurate and usable method. Something like what these quadcopters use: https://www.youtube.com/watch?v=AiCFtmdrvHM
Accelerometer and gyroscope are enough to do a pretty decent mapping of indoor locations without GPS and the like. Its all differential, so the longer it goes without a point of reference the lower the confidence is, but its possible.
Interesting question. Principally image-based location tracking, though also with an inertial measurement unit (IMU) and laser rangefinder, all off-the-shelf components.
It's interesting how localization is still among the biggest challenges, despite some great new technology like UWB (for instance, https://www.decawave.com/product/dwm1000-module/). Visual SLAM is obviously difficult in an environment where most of the visual mass (containers) moves.
If you check out SLAM positioning, you can do some really amazing stuff even if all you know is how far away from the wall you are. Given a decent floor plan, you simply take frequent distance measurements as you wander around, using dead reckoning (the accelerometer will help) to keep track of your relative positions. You rapidly build up a local map of the walls near you, which eventually will map uniquely to one location on the floor plan. Our robot only had to wander for a few seconds to figure out where it was, and that was just using a few ultrasonic rangefinders.
I haven't heard of such a thing, but I imagine you could do something similarly cool with the camera of your phone. Or, even the accelerometer and compass, combined with a knowledge of the locations of doors and the available walking paths, may be able to give a reasonably good approximation of your current location--if you walked north for 30 meters, then turned left and walked another 20 meters, then north for an additional 5, in a typical mall that's going to limit the number of points you could be occupying.
You don't need to know the positions of the beacons unless you want an instant location fix. You can use SLAM with inertial odometry or visual inertial odometry to find a precise position using UWB beacons at unknown positions. SLAM algorithms will also give you the positions of the beacons. The catches are that it requires compute, and it requires you to move around for the model to converge.
GPS is one of the most amazing technical onions I've ever dealt with. I've just been scratching the surface of it with understanding positioning for a robotics project. I kind of wish I had an opportunity to do more paid work with it. But it seems to be the realm of PHDs.
One of StarLink's biggest overlooked opportunities I think is radically re-engineering a GPS like system that can work indoors and outdoors as well as offering some pose estimation capability. It would make implementing robots way easier.
Not sure how practical it would be on a large scale, like city wide or larger, but in smaller areas such as a storage facility this could probably be used by forklifts and similar. Especially if combined with something more coarse like Wifi or Bluetooth based networks.
This reminds me of visual odometry from a backup camera, there where a bunch of papers on that subject about a decade ago. I don't know if it was ever used in practice, I suspect dead reckoning from accelerometers and gyros combined with map data is good enough in tunnels and other short term GPS denied environments.
I've tried to do position triangulation with RFID signal strength and had pretty terrible results. I suspect wifi would be just as bad. An infrared system would probably work well I think. (I know you addressed this)
That being said, sign me up. I have a friend with an oculus dev kit and it has blown me away time and time again. I can see this kind of thing becoming reality. Just stick foam padding all over the place and you're golden.
Not OP, but I suspect this is a simple combination of AR and precise device location awareness. The former comes in the form of ARKit. I’m not aware of a framework for locating devices, but it wouldn’t surprise me if there were one.
Thanks for those links - I think they frame the progress on localization really nicely. They also make clear the improvements are based on fusion of GPS + wifi + IMU/sensors. Adding IMu data to the existing mix is a clear win, but there's a major difference between that and using the IMU for dead reckoning alone. I think that's worth clarifying since the thread started out talking about localization with wifi disabled (although disabled clearly doesn't quite mean what you think it might in this context.)
I mean GPS repeaters are a thing, but there's even better options, you could install small radio beacons in the tunnels and triangulate using those. Much more precise, and cheaper than GPS repeaters.
[1] https://en.wikipedia.org/wiki/Simultaneous_localization_and_...
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