Robotic Lawn Mower

Overview

A robotic lawn mower keeps a lawn trimmed automatically, navigating on its own, cutting little and often, and returning to a dock to recharge. This model combines differential-drive wheels with a spinning blade disc and navigates by GPS-RTK positioning backed up by a buried boundary wire.

The Chassis & Body is a weatherproof body that carries the drivetrain, electronics, and battery beneath a floating cover. The cover is spring-suspended so that a collision or a lift shifts it and trips the Lift/Tilt Sensor, cutting the blade motor; an emergency stop button sits underneath. The Main Controller Board runs the show: a compute SoC handles mapping and navigation while an MCU runs the real-time drive, blade, and safety loops and the motor power stages.

How it works

The Drive System uses two independently driven geared wheel motors for propulsion and steering, plus free-rolling front casters. Each wheel motor reduces a BLDC through a gearbox and reports rotation through a Hall encoder for odometry. The Cutting System spins a lightweight disc carrying three pivoting razor blades; centrifugal force flings the blades out to cut, and they swing clear when they strike a hard object.

To stay inside the lawn, the Navigation & Sensing pack fuses GPS-RTK fixes with inductive boundary-wire pickups, an IMU for heading and slope, and collision and rain sensors. Power comes from the Battery Pack, a managed lithium-ion pack.

Construction

The operator schedules and configures the mower through the UI Panel, a sealed keypad and display gated by a PIN lock against theft. When the battery runs low the mower follows the boundary wire home to the Charging Station, a mains-powered base that energises the perimeter loop and recharges the mower through spring-loaded dock contacts.