How to sense steering wire

Projects General Guidance
1

I have a robot mower which cuts my lawn up to a border wire, leaving 20cm outside the wire uncut.
I would like to design a buggy to trundle round the border following the perimeter wire carrying a head salvaged from a conventional cordless trimmer.

My question is how to best sense the border wire which I laid in a cut in the lawn about 2-3 cm deep (as recommended by the mower manufacturer) and this steer the buggy keeping it central on the wire.
The loop wire has a voltage of about 30v on it and a resistance from end to end of about 10 ohms.

Any suggestions?

2

Electricians and comms people (commedians?) use tone and probe (fox and hound) for following (chasing) wires. For example:

3

Post a link to the border wire transmitter data sheet or product page.

4

This article may give you some ideas:

5

Hi @dbp ,

usually a simple AM radio might help.

See here on YouTube

https://www.youtube.com/watch?v=lJOJHi6Yk2M

I used it successfully with a broken loop wire for a Husqvarna automower 305 several years ago.

You may give it a try ...

Good luck!
ec2021

6

Whichever way you go, build for ruggedness. You may even want/need to use a potting compound to protect the components from multiple hazards.

YMMV

7

Move the boundary wire or the mower sensor