Hello,
Helping out on a project around locating a bot in an open field (probably about 100'x100'), outdoors, and returning the bot to another location (base). Just looking for some additional guidance on the data/options I've gathered. I know there are a lot of these threads out there, all slightly different, but I thought I'd ask again since we are in 2017 and tech is always improving. I have a limited budget for the piece of the project and wouldn't want to go past $200 if it's even possible.
GPS -> A few articles/hope about inch level accuracy, but it seems anything commercially available < $100 will at best give you a few meter accuracy.
BLE/Wifi -> Nothing to give you pin point accuracy.
IR -> Range limitations and probably issues with Sun outdoors.
RF -> Lot of demos out there on trying to follow a signal, multiple receivers trying to figure out where the signal is coming from. Seems most promising, but also not that elegant/simple.
Video/Image Processing -> Using OpenCV/object tracking software to sense the bots location and have the software figure out what direction it needs to go to bring it home. Seems like the best future option for being able monitor multiple bots and have them work together, much like the multi-drone demonstrations being done today. I'd like to go this route, but development seems more difficult and costs go up with cameras/video etc. Not sure if consumer grade tablet cameras would work over this large of an area either.
Other ideas:
Combination of above (GPS + IR?)
Are there any sort of GPS modules which would act like a satellite. You could stick in the 4 corners of your play area to provide exact reference points. Then the onboard GPS would work off those to determine it's exact location?
Follow a wire? Have the play area outlined by some sort of wire (not underground). Make the bot run into the wire and follow it like a wall until there is a break, which would be the base.
Thanks for your help! Any crazy ideas are appreciated.