I have no experience using ultrasonic triangulation so I hope to hear from someone who has. I haven't used ultrasonic outdoors but some range finders are made for outdoors.
I am building a robot mower so I am interested in your ideas. I am thinking of using a digital compass for navigating in rows while mowing. This might be accurate enough for a small yard. I have been reading about triangulation with ultrasonic signals and wondered if anyone has actually tried this.
QuoteI have no experience using ultrasonic triangulation so I hope to hear from someone who has. I haven't used ultrasonic outdoors but some range finders are made for outdoors.To use triangulation, the signal has to bounce off of hard surfaces that form the boundary. That hardly seems like the scenario that will be present in your yard.Unless you are trying to minimize the time needed to mow the yard, a roomba or pool cleaner process would work - mow in some direction until you can't go any farther; turn some random amount, and mow some more. Sooner or later, the whole yard is mowed. Of course, it might look like a drunk did it, but the grass will be short, and you can drink while the yard is being mowed.
For the triangulation I should be able to place 3 transmitters in the yard and use a receiver on the mower and measure time of flight from the transmitters to determine current location. I have never tried this so I'm of the issues I will face.
http://en.wikipedia.org/wiki/UltrasoundGrrr, lost my message twice now!Boiled down - have each transmitter determine distance from reflector equipped mower, send the distance to the mower (via RF I would think). Mower would be along an arc of distance from each transmitter, do the math to determine where the 3 arcs intersected.That might be doable.
You could map out your lawn and have the robot go a set path, so long as it doesn't have any interference.