gyroscope

A gyroscope is a sensor that measures how fast something is turning — its rate of rotation. Where an accelerometer feels being pushed in a straight line, a gyroscope feels spinning. If a robot pivots quickly to the left, its gyroscope reports a high turning speed; when the robot holds still, the gyroscope reads near zero. It does not say which way the robot is facing, only how fast that facing is changing right now, like a speedometer for rotation rather than an arrow on a compass.

Like its accelerometer cousin, a modern gyroscope is a MEMS chip, with tiny vibrating structures etched into silicon. The trick is subtle but elegant: when a vibrating object is turned, a faint sideways force appears on it (the Coriolis effect), and the chip measures that force to figure out the turning speed. There is no real spinning wheel inside — just microscopic parts buzzing back and forth, sensing the gentle push that rotation creates.

Knowing the turning rate, a robot can work out its actual heading by adding up the rotation over time — a process called integration, which is just continuous accumulation, like keeping a running total of every small turn. The snag is drift: each reading carries a sliver of error, and accumulating thousands of them per second lets the angle estimate creep away from the truth, so a gyro left alone slowly "thinks" it has turned when it has not. That is why a gyroscope is usually teamed with an accelerometer inside an IMU, so the steady pull of gravity can keep nudging the estimate back honest.