Robot plugging in itself

Other Hardware Home Automation
1

I am looking for solutions about devices that plug themselves in a charging station.
The scenario is this:

In a vast yard, on a aerial wire, a device hangs and can be controlled remotely. The device would move along the wire, similarly to a chairlift. Once in a while it should get back to a charging station.

Any suggestions for such charging station and charging method?

2

Grounded aerial wire, metal body to device, wire brushes at charging station

3

"Any suggestions for such charging station and charging method?"

In its simplest form the bot might move to a position where two charging wires on the bot touch two charging wires from the charging source.