u-blox ZED-F9P RTK GNSS
Centimetre-level positioning outdoors given a correction stream. Multi-band, multi-constellation, and the module behind most affordable outdoor robot localisation.
The role it plays
Sensors split into proprioception — encoders, IMUs, joint torque, motor current — which tells the robot about itself, and exteroception — LiDAR, depth, force, GNSS — which tells it about the world. Build proprioception first. A robot that does not know where its own joints are cannot use a good world model anyway.
Typical use: Outdoor AMR, survey robots, drone return-to-home.
What the numbers actually mean
The headline figure is GPS, GLONASS, Galileo, BeiDou (constellations), with 1 cm + 1 ppm (RTK fixed) as the next most load-bearing number (accuracy). At $220 in the sensors tier it sits in the mid range: enough money that you should plan the mounting and wiring before ordering, but not so much that one mistake ends the project.
How it compares
Same subsystem, closest alternatives. The primary spec column is usually the one that decides it.
| Part | Price | Primary spec | Second spec |
|---|---|---|---|
| u-blox ZED-F9P RTK GNSSRTK positioning | $220 | GPS, GLONASS, Galileo, BeiDou | 1 cm + 1 ppm (RTK fixed) |
| AS5600 magnetic encoderAbsolute rotary encoder | $3 | 12-bit (4096 counts/rev) | I²C (also analog / PWM out) |
| AS5047P magnetic encoderAbsolute rotary encoder | $10 | 14-bit (16384 counts/rev) | SPI + ABI quadrature + UVW |
| CUI AMT102-VCapacitive incremental encoder | $25 | up to 2048 PPR (configurable) | Quadrature A/B/Z |
| BNO085 9-DOF IMUIMU with onboard fusion | $25 | 3-axis accel + gyro + magnetometer | Quaternion / Euler / rotation vector, plus raw |
Where it shows up
Platforms in this atlas that use something in this class: Agrobot field rover.