Gyroscopes

Gyroscopes are devices that exploit the conservation of angular momentum to measure or maintain orientation. A rotor is spun at high speed, and its angular momentum vector tends to stay fixed in space. When an external torque is applied, the resulting motion is a precession of the rotation axis, typically at right angles to the torque, rather than a direct tilting of the axis.

Traditional mechanical gyroscopes consist of a spinning rotor mounted in one or more gimbals, allowing it to rotate freely about multiple axes. Their behavior is described by L = Iω, where changes in angular momentum produce precession. Rate gyroscopes sense angular velocity rather than orientation. Modern MEMS gyroscopes use vibrating microstructures to detect angular velocity in very small packages, making them common in consumer electronics.

Applications include inertial navigation systems for aircraft, ships, submarines, and spacecraft, where gyroscopes help track attitude when external references are unavailable. They are also used for stabilization and steering in cameras, telescopes, ships, and gimballed platforms. In handheld devices, MEMS gyroscopes enable screen orientation, motion sensing, and gesture recognition.

Limitations include the need for calibration and re-referencing, since gyroscopes do not provide a fixed reference by themselves. Mechanical friction, drift, bias, and wear can degrade accuracy, while MEMS devices may be sensitive to temperature and shocks. Gyro drift accumulates over time and is typically corrected with other sensors such as accelerometers.

History notes that the gyroscope was developed in the 19th century and has since become a core component in navigation, attitude control, and stabilization systems. Advances include optical, fiber-optic, and MEMS devices that broaden use from aerospace to consumer electronics.