MEMS gyroscope

A MEMS gyroscope is a microelectromechanical systems (MEMS) sensor that measures angular velocity, or the rate of rotation around one or more axes. The device uses the Coriolis effect, where a vibrating mass experiences a deflection force proportional to the angular velocity when the sensor rotates. This deflection is detected using capacitive sensing elements and converted into an electrical signal. MEMS gyroscopes use silicon micromachined sensing structures produced through semiconductor fabrication processes together with dedicated ASICs that process and interpret the sensor signals.

MEMS gyroscopes serve as critical components in automotive motion sensing and control systems. Their signals are used in electronic stability control (ESC) systems to detect vehicle rotation and improve vehicle stability, as well as in rollover detection systems to identify potential rollover events. Advanced driver assistance systems (ADAS) use gyroscopic measurements for lane departure warning, adaptive cruise control, and collision avoidance functions.

In autonomous driving applications, MEMS gyroscopes provide essential angular velocity data for sensor fusion algorithms that combine input from cameras, radar, and LiDAR systems. Navigation systems integrate gyroscope measurements with GPS signals to maintain positioning accuracy during signal loss or in urban canyon environments. The sensors also enable precise steering angle detection and vehicle dynamics monitoring for traction control systems.

Modern vehicles typically incorporate multiple gyroscopes in inertial measurement units (IMUs) that measure rotation around all three spatial axes, supporting functions from basic stability control to fully autonomous navigation.

MEMS gyroscopes measure angular velocity (rotation rate), while accelerometers measure linear acceleration. This fundamental distinction makes gyroscopes sensitive to rotational motion and accelerometers sensitive to linear motion, including gravitational acceleration.

The sensing mechanisms differ significantly between these devices. Gyroscopes rely on the Coriolis effect acting on a vibrating proof mass, requiring active excitation of the sensing element. Accelerometers typically use a suspended proof mass that deflects under acceleration, operating as a passive sensing system.

Both sensors complement each other in automotive applications, with gyroscopes detecting vehicle rotation while accelerometers measure forward/backward and side-to-side acceleration forces. Combined systems provide complete six-degree-of-freedom motion sensing.

Bosch operates semiconductor fabs that produce MEMS sensors, including gyroscopes for automotive applications. The company develops inertial measurement sensors that integrate gyroscopes with accelerometers for vehicle dynamics control and navigation systems. These sensors support electronic stability control, ADAS functions, and autonomous driving applications in electric and conventional vehicles.

The company’s MEMS manufacturing capabilities extend to foundry services, providing fabrication infrastructure for both internal product development and external customers. Bosch combines materials science expertise with system-level integration knowledge to develop sensors that meet automotive qualification requirements for temperature, vibration, and long-term stability.