Hardware

Magnetometer

A magnetometer is a sensor that measures magnetic field strength and direction, used in robotics primarily to estimate absolute heading from the Earth's magnetic field as the third component of nine-axis inertial measurement units. Readings require calibration for hard-iron and soft-iron distortions, and they degrade near motors, ferrous structures, and power electronics, which limits reliability indoors and on electrically noisy platforms.

Why it matters for physical AI

Drift-free heading is the hardest component of orientation estimation to obtain; magnetometers provide it cheaply outdoors, while their indoor unreliability drives the need for visual or LiDAR-based heading correction.