Hardware

Accelerometer

An accelerometer is a sensor that measures proper acceleration, the acceleration of a body relative to free fall, typically along one to three orthogonal axes. MEMS accelerometers sense the deflection of a microscopic proof mass and are cheap, small, and ubiquitous. In robotics they are almost always packaged with gyroscopes in an inertial measurement unit (IMU) and used for state estimation, vibration monitoring, and impact detection.

Why it matters for physical AI

Accelerometer data feeds the high-rate proprioceptive state estimates that legged locomotion controllers and learned policies depend on, and it provides contact and slip cues that cameras cannot capture at millisecond timescales.