Most robot mowers require a perimeter wire laid around the edge of the lawn to identify where to mow. This is the main reason why robot mowers aren’t currently widely used in NZ, as installation is difficult and the wires often get cut by the mower itself. As the robots don’t know where they are, they randomly navigate within the perimeter wire.
RTK mowers know where they are and are set up by driving the mower around the edge of the lawn with a remote control. This allows them to cut in straight lines, and you can control exactly when and how it mows.