Sumthing about robotic lawn mower...

Hi,
I'm now doing a robotic lawn mower project for my diploma final project and i found that the navigation system of the lawn mower is control by a sensor and also a perimeter wire to lead the robot.
Can anyone tell me what sensor is that? Or can i replace that sensor instead of RF circuit? If so, can u pls give me some example of that circuit?? thx....

Hopefully u guys can understand my english... lol... :lol:


UltimateKillingMachine

I don't know much about what the pickup type actually is. I'm pretty sure it's very similar to the Invisible Pet Fence dog shock collars.

I have a Robomower and have taken it apart a number of times. The sensor is simply a small drum choke (maybe 3/8" x 3/8"?) on a PCB right over a substantial piece of what appears to be iron. There's one in each of the 4 corners.

The lawn's wire must make a complete loop.
The sensor can tell definitively if it's inside or outside the wire loop. It is not a promixity thing, it's got a sense of inside & outside. It won't run if placed 6" outside the wire, but it'll run in the middle of the zone 20 ft from any wire.

I have just obtained a broken Robomow which has a broken main board. i am going to try to understand how they have wired their wire sensors so i can try to make them work on my own lawn mower. if any one knows how they or their transmitter work then any information will be a help.