Comment by adgjlsfhk1
3 hours ago
yeah Phones have pretty good IMUs. the TLDR is you combine accelerometers and gyros (preferably a bunch of them to minimize error) with GPS which gives you pretty accurate position and can also give you velocity data with some tricks)
But if you don't have GPS, then you don't have a high-confidence low-precision absolute position input to your system? Whereas with wheels you already get a lot of data about that when they are not turning at all.
A friend tried to make a phone ruler app (using IMU) and the experience was that it didn't take very long for the distance to shoot to the horizon. So, thought I should try how this kind of solution would work with the hardware of today, but it turns out there seem to be zero such apps in the Play Store.. The tools of that category all seem to use a camera.
I think the lack of these tools is a testament to the approach not really working.