“RTK-GNSS centimeter navigation.” “LiDAR obstacle avoidance.” “Electronic geofence.” The specifications on an autonomous mower datasheet read like a robotics lab. If you are a dealer, a farm manager or a municipal buyer, the fair question is simpler: what actually happens when the machine drives into the field? This article explains, in plain machinery terms, how an RTK-GNSS robotic mower finds its position, how LiDAR obstacle avoidance keeps it out of trouble, what the virtual wall replaces, and where the human stays in charge.
The old way: boundary wires and bump sensors
First-generation robotic mowers — the small domestic machines — navigate by a buried boundary wire, random-bounce inside it, and back off when they physically bump into something. In an orchard or on an embankment, that approach collapses: burying wire around tree rows is a project, replanting or tilling cuts it, random paths leave missed strips, and “detecting” a tree by hitting it is not acceptable in a working grove.
Professional autonomous mowers replaced all three limitations with satellite positioning, a real obstacle sensor, and software-defined boundaries. Here is each piece.
RTK-GNSS: how the machine knows where it is, to 2 cm
GNSS is the satellite navigation family behind GPS — ordinary phone-grade positioning is accurate to a few metres, which is fine for driving to a town and useless for mowing straight rows. RTK (Real-Time Kinematic) adds a correction signal that refines the satellite reading down to ±2 cm. That is centimetre-level: close enough for the machine to follow the centre of a mowing pass, hold a fixed offset from the previous cut, and trace the headland without drift.
In practice the system works like this:
The machine receives satellite signals
GNSS antennas on the mower compute position continuously as it moves.
A correction source cancels the error
RTK corrections refine the raw satellite fix to the ±2 cm the machine uses for path tracking.
The planner builds the route
Within the area you define, the machine plans efficient mowing paths itself — systematic coverage instead of random bouncing.
It resumes where it stopped
If the battery is swapped or the job is interrupted, break-point resume means the machine returns to the exact point and continues the missed zone, not the whole field.
The practical payoff shows up in the output: the R1 cuts 2,000 m²/h at a 790 mm deck — coverage that systematic paths make possible, because random mowing wastes a large share of its time driving over already-cut grass.
LiDAR obstacle avoidance: seeing the world without touching it
Positioning tells the machine where it is. It does not tell it what moved into the path since the map was drawn — a person, a dog, a fallen branch, a parked bin, a deer in tall grass. That is the job of LiDAR (laser scanning): the sensor emits laser pulses and reads the reflections, building a real-time picture of objects around the mower.
When LiDAR detects an obstacle in the working path, the machine does not bump it. It classifies the object as “do not drive through,” slows or stops as the distance closes, and reroutes around it, then returns to the planned cut. This is what makes unmanned operation defensible in a shared working environment: orchards with pickers, parks with public access, embankments where walkers appear. Bump-sensor mowers stop on contact; a professional mower should never make contact in the first place.
Electronic geofence: the virtual wall that replaces boundary wire
The third piece is how you tell the machine where it is allowed to go. WANJI uses patented electronic-geofence virtual-wall technology: you define the working blocks, no-go zones and keep-out strips — the pond, the road, the young sapling nursery, the toe of the embankment — on the controller, and the navigation system treats them as hard boundaries. No wire to bury, no wire to find and repair, and nothing to redo when you change the orchard layout.
- Setup is a drawing, not an installation. New blocks and new sites take minutes to define, not a day of trenching.
- Boundaries can be updated for every cut. A temporary no-go zone around a wedding in the park or a harvest pad in the orchard costs nothing.
- The machine self-limits near hazards. Combine the geofence with LiDAR rerouting and the safety case is structural, not dependent on the operator watching every second.
The human stays in charge: remote, app and manual override
Autonomous does not mean unsupervised or unreachable. Three controls keep a person in the loop:
- 7-inch touchscreen remote with a live camera feed — you see what the mower sees and drive it manually at any moment, for moving between blocks, tricky corners or showing a customer the machine.
- Smartphone app and fleet dashboard — set working areas, check where machines are and what they have cut, across a fleet from one screen.
- Manual override — the autonomy can always be interrupted by the operator; on steep embankments the standard operating pattern is remote supervision from the crest, as covered in our slope mowing guide.
Putting it together on the R1
The technology only earns its place when it ships on a machine that is also good machinery. On the R1 autonomous wheeled electric mower, the full stack — RTK-GNSS at ±2 cm, LiDAR avoidance, electronic geofence, break-point resume — runs on a 118 kg, 4WD servo-drive platform with zero-turn steering, a 790 mm deck, a 20–100 mm cutting-height range, IP54 rating, and removable LiFePO4 packs (not hot-swappable) good for 2 hours / 4,000 m² each, with automatic dock recharge. The same navigation stack runs on the tracked T1-900A for slopes. Both lines are in mass production and at work in 30+ countries, which is the difference between a demonstration and a product you can service. Full specifications are on the autonomous mowers page, and the operational questions — dock charging, daily output, training — are in the Buyer FAQ.
Quick answers
What happens if the satellite signal is poor?
RTK needs open sky for full ±2 cm accuracy. Sites with deep terrain shadow or heavy overhead cover are worth flagging when you spec the job; LiDAR and remote override keep the machine safe in the meantime. Most farm, park and embankment work is open-sky work.
Can it hurt animals or people?
LiDAR detects people and animals in the path and reroutes or stops before contact; the geofence keeps the machine inside defined blocks, and manual override is always available to the operator.
Do I need any technical background to run it?
No — documentation and remote support come with the order, and the touchscreen remote is built for field crews, not programmers. Dealers receive full support materials.