Best robot lawn mowers without a perimeter wire

Without a wire the mower has to know by itself where the lawn ends, and it does so in one of three ways. RTK takes a satellite fix and corrects it to a few centimetres against a reference, so it wants open sky; LiDAR measures the garden with light and works in shade and at night; a camera tells grass from not-grass and needs daylight. A machine often combines two of them, and the groups below sort every wire-free mower in the catalogue by the combination the maker names, so each one appears once. The RTK ranking and the LiDAR ranking score each technology on its own.

RTK with a camera

Satellites fix the position and draw the map; the camera reads the edge of the grass and spots what is in the way. The choice for an open lawn with clear sky from every corner.

RTK with LiDAR

Satellites for the position, a laser for the map and the obstacles, and a camera alongside on the machines here; the LiDAR carries the mower through the shaded corner where the satellite fix drops. The most sensors of the three groups, and the choice for a large lawn with trees along part of it.

Camera or LiDAR without satellites

No satellite fix at all: the mower builds its own map from what it sees, by camera, by laser or by both, so there is nothing to site and nothing that minds a tree canopy. The group for a garden the sky cannot see; a camera-only machine still wants daylight.

Only if it positions by RTK, and then only with some systems. An RTK mower corrects its satellite fix against a reference. The first generation put that reference on an antenna in the garden, mounted with a clear view of the sky, which means a mast, a power lead and a map to redraw if the antenna ever moves; the newer systems take the correction from a reference network over a built-in mobile link, so there is nothing to site, though the mower itself still has to see the sky.

A LiDAR or camera machine needs no antenna at all, because it never uses satellites: its map is what the sensors see. The positioning guide walks through the three systems and where each one fails, and the RTK ranking scores the satellite machines, antenna or not. The group below lists the RTK mowers in the catalogue that need no antenna of their own, with the navigation on each row.

RTK mowers without a reference antenna

The list above is not split by size. For a garden of up to 1,000 m² the small-lawn ranking weights ease of setup and value, and for 2,000 m² and above the large-lawn ranking weights navigation, coverage and reliability; the sizes between are served by the list above and by the large-lawn page. The two groups below pick out the ends of the range by the maker's published maximum, with the figure on each row: the very small garden, where a flagship is wasted, and the very large one, where that maximum is the first thing to check.

Up to 500 m²

Over 2,000 m²