Guides
Robot mower glossary
RTK, LiDAR, perimeter wire, dB(A), IPX and the rest of the jargon, each explained in a sentence or two.
terms explained46
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- 4G connectivity
- A built-in or add-on mobile data connection that lets the mower talk to the app away from Wi-Fi range. It is used for remote control, alerts, GPS theft tracking and sometimes network RTK, and may need a paid data plan after an included period.
A
- All-wheel drive (AWD)
- A drive system that powers every wheel rather than just the rear pair. It gives more grip on steep, bumpy or damp ground, which is why AWD mowers usually carry the highest slope ratings.
- App mapping
- Setting up the lawn boundary, zones and no-go areas on a map in the manufacturer's app, usually by steering the mower round the edge with your phone. It replaces laying a wire on wire-free mowers.
B
- Battery capacity (mAh and Wh)
- Battery size, given either as charge in milliamp-hours (mAh) or as energy in watt-hours (Wh). Wh is the fairer comparison between mowers because it accounts for voltage: Wh equals Ah times volts.
- Bumper (collision) sensor
- A sensor in the floating body shell that detects when the mower has bumped into something, so it stops and changes direction. It is the basic safety system on most robot mowers and relies on contact.
C
- Charging station
- The dock the mower drives back to when its battery runs low or a session ends. On wired mowers it also generates the signal in the perimeter wire, and it needs a nearby mains socket.
- Cutting disc
- The spinning plate under the mower that carries the blades. Some mowers have one disc, others two for a wider cut or a second disc offset towards the edge.
- Cutting height
- How long the mower leaves the grass, set by raising or lowering the cutting disc. Some mowers adjust it by hand with a dial, others electrically from the app, which also allows different heights for different zones.
E
- Edge cutting
- How close a mower can cut to the edge of the lawn. Most robot mowers leave an uncut strip of a few centimetres along walls and fences because the blades sit inside the body, so manufacturers describe edge cutting as full, partial or none.
- Edge-cut mode
- A dedicated run in which the mower follows the lawn boundary to tidy the border, rather than mowing the middle. Some mowers use an offset or second cutting disc for this; Husqvarna calls its version EdgeCut.
- EPOS
- Husqvarna's name for its wire-free, RTK-based satellite navigation. Depending on the model it takes corrections from Husqvarna's cloud service over the internet or from a Husqvarna reference station in the garden, and some wired Automowers can be converted with an EPOS add-on.
G
- Geofence
- A virtual boundary set around your property; if a GPS-equipped mower leaves it, the app sends an alert. It's mainly a theft-protection feature and usually needs a 4G connection.
- GNSS
- The general name for satellite positioning systems such as GPS, Galileo, GLONASS and BeiDou. On its own GNSS is accurate to a few metres, which is why robot mowers add RTK corrections to reach centimetre accuracy.
- GPS theft tracking
- A feature that shows the mower's location on a map in the app, so a stolen mower can be traced. It needs GPS and a mobile data connection, so it typically depends on built-in 4G or an add-on module.
- Guide wire
- An extra wire on many wired mowers that runs from the charging station across the lawn to the perimeter wire. The mower follows it back to charge and out to remote parts of the garden, which helps with narrow passages and separate lawn areas.
I
- IP rating
- An international code for how well a device keeps out dust (first digit) and water (second digit). A higher second digit means better water resistance; IPX6, for example, means it withstands powerful water jets.
- IPX
- An IP rating where the X means the product wasn't tested for dust, only for water. Most robot mowers are IPX4 to IPX6: IPX4 resists splashing, IPX5 low-pressure jets and IPX6 strong jets, which affects whether you can hose the mower down.
L
- LiDAR
- A sensor that measures distance by timing laser pulses bounced off surroundings. On a robot mower it builds a 3D picture of walls, trees and obstacles, helping the mower position itself where satellite signals are weak.
- Lift and tilt sensors
- Sensors that stop the blades within a second or two if the mower is lifted or tipped beyond a set angle. They are a key safety feature and a common part of the European safety standard for robot mowers.
M
- Minimum passage width
- The narrowest gap the manufacturer says the mower can drive through to get from one lawn area to another. Measure your tightest point, such as a path beside the house, and allow some margin above the stated figure.
- Mowing zones
- Separate areas on the mower's map that can have their own schedule, cutting height or mowing pattern. The spec figure is the most zones the app lets you create, which matters for gardens split into several lawns.
- Mulching
- Leaving very short clippings on the lawn to break down and return nutrients to the soil. Robot mowers mulch by design, since they cut a few millimetres at a time and have no grass box.
- Multi-map
- Storing more than one separate map in the app, for example a front and back garden that aren't connected. You usually carry the mower between them, and some mowers need a second charging or RTK station.
- Multi-zone and multi-lawn mowing
- The ability to mow several separate lawn areas, either by driving between them along a passage or channel, or by being carried between them. Wire-free mowers usually link zones with a drawn channel; wired mowers use guide wires or secondary areas.
N
- How a robot mower knows where the lawn ends and where it has already been. The main types are a buried perimeter wire, satellite positioning with RTK corrections, camera vision and LiDAR, and many newer mowers combine two or more.
- Network RTK
- RTK corrections delivered over the internet from a network of reference stations, instead of from a base station in your own garden. The mower usually needs a 4G or Wi-Fi connection to receive them.
- No-go zone
- An area inside the lawn that the mower must avoid, such as a pond, flower bed or play area. On wire-free mowers you draw it in the app; on wired mowers you usually loop the perimeter wire round it.
- Noise level (dB(A))
- The mower's noise figure in A-weighted decibels, a scale adjusted to how human hearing works. Every 10 dB(A) step sounds roughly twice as loud, and manufacturers quote either sound power or sound pressure, so figures from different brands aren't always directly comparable.
O
- OTA update
- Software updates sent to the mower over Wi-Fi, Bluetooth or 4G, with no dealer visit. They can fix bugs and add features, though they can also change how a mower behaves.
P
- Perimeter wire
- A low-voltage wire pegged down or buried around the lawn edge and around flower beds. It carries a signal from the charging station, and the mower turns back when it senses the wire.
- PIN code lock
- A code that must be entered on the mower or in the app before it will work, which makes a stolen mower much less useful to a thief. Some mowers also lock to the owner's account.
- Pivoting razor blades
- Small, thin blades screwed loosely to the cutting disc so they swing back if they hit something hard. They cut cleanly while little and often, are cheap, and are changed every few weeks to months.
R
- Rain sensor
- A sensor that detects rain and sends the mower back to its dock, or delays mowing. Some mowers use a weather forecast in the app instead of, or as well as, a physical sensor.
- Random mowing
- The traditional robot mower pattern: drive in a straight line until reaching the boundary or an obstacle, turn at a random angle and carry on. Given enough hours it covers the whole lawn evenly but can't show where it has been.
- Rated area
- The largest lawn the manufacturer says a mower can keep cut, in square metres. It assumes a fairly simple lawn and regular mowing, so pick a mower rated at least 20% above your actual lawn size, more if the garden is complex or sloping.
- Robot mower garage
- A roof or cover fitted over the charging station to shade the mower from sun and keep off rain, leaves and bird droppings. It isn't required by most manufacturers but can help keep sensors clean.
- RTK (real-time kinematic)
- A way of correcting satellite positioning to within a few centimetres, using a fixed reference receiver whose exact location is known. RTK mowers need a reasonably clear view of the sky, so accuracy can drop under trees or beside tall buildings.
- RTK base station
- A fixed satellite receiver mounted in or near the garden that sends positioning corrections to an RTK mower. It needs power and a clear view of the sky. Some brands also use 'base station' to mean the charging dock.
S
- Slope percentage
- How steep a slope is, given as the vertical rise divided by the horizontal distance, times 100. A 100% slope is 45 degrees, not vertical; 50% is about 27 degrees and 35% is about 19 degrees.
- Spot mowing
- A mode that mows a small area intensively, often a spiral around the mower's current position. It is used for patches of longer grass the normal schedule hasn't kept up with.
- Systematic mowing
- Mowing in straight, parallel rows, like a person with a push mower, rather than at random. It is normal on RTK, LiDAR and some vision mowers and can finish a lawn in fewer hours.
T
- Theft alarm
- A loud alarm that sounds if the mower is lifted or carried off without the PIN being entered, often with an app alert. It is a deterrent rather than a way to recover the mower.
U
- Ultrasonic sensor
- A sensor that sends out high-frequency sound and times the echo to detect objects ahead. It lets a mower slow down or turn before it touches something large, but it can miss small, low or soft objects.
V
- Navigation using one or more cameras to recognise grass, lawn edges and obstacles, sometimes with no wire or satellite positioning at all. It needs daylight or infrared help and can be confused by very patchy lawns or unclear edges.
- VSLAM
- Simultaneous localisation and mapping: a technique that builds a map while working out the mower's position in it, from camera (visual SLAM) or LiDAR data. It lets mowers navigate without a wire and without a clear view of the sky.
W
- Wire-free (boundary-wire-free)
- A mower that works out the lawn edge without a perimeter wire, using satellite positioning with RTK, cameras, LiDAR or a mix. You usually set the boundary by driving the mower round the edge in the app.