triangulating signals to navigate a robot

[zoomkat]

I want it to be accurate within a quarter inch.

Below are post on similar projects. Possible, but 99.9% chance it is not going to happen.

https://www.google.com/search?hl=en&as_q=lawnmower&as_epq=&as_oq=&as_eq=&as_nlo=&as_nhi=&lr=&cr=&as_qdr=all&as_sitesearch=http%3A%2F%2Farduino.cc%2Fforum&as_occt=any&safe=images&tbs=&as_filetype=&as_rights=