Differences between MEMS accelerometers and MEMS gyroscopes

1.       Mems gyroscopes are used to measurethe angular velocity.

2.       MEMS accelerometers are used to measure linear acceleration.

MEMS gyroscopes use the Coriolis force, which is the tangential force on a rotating object when it has radial motion. Assuming the rotating object has a radial velocity Vr, a tangential Coriolis acceleration will be generated.

The measurement value of MEMS accelerometer is correct in the long term, but has errors in the short term due to the existence of signal noise. Gyroscope is more accurate in the short term, but has errors due to drift in the long term. Therefore, both are needed (mutual adjustment) to ensure the correct heading.

At present, general inertial applications in attitude, such as IMU (Inertial Measurement Unit), are composed of a three-axis gyroscope and a three-axis accelerometer.

MEMS accelerometers and MEMS gyroscopes are two common micro-electromechanical system (MEMS) sensors, which have obvious differences in sensing principles and application fields. The main function of MEMS accelerometers is to measure the linear acceleration of an object. It works on the principle of force balance and calculates the acceleration value by detecting the force exerted on the mass block during movement. In contrast, MEMS gyroscopes are used to measure the angular velocity of an object. Their working principle is based on the principle of inertia and detects rotational motion through Coriolis force.

The two sensors (MEMS accelerometers & Mems gyroscopes) are different in design and operating principle. MEMS accelerometers typically detect acceleration based on displacement or strain measurements of tiny masses, while MEMS gyroscopes use tiny vibrating structures or angular displacement measurements to detect rotation and angular velocity. In addition, the two also have different characteristics in terms of time stability. MEMS accelerometers are more accurate in longer-term measurements, but may be affected by signal noise and produce errors in shorter periods of time. Conversely, MEMS gyroscopes are more accurate in shorter periods of time, but may have drift errors over time.

Although both MEMS accelerometers and MEMS gyroscopes are sensors which used to measure motion, they have significant differences in their working principles, application areas, and characteristics. These differences make them play their own roles in different systems, and they may also need to be used in combination to improve the accuracy of navigation and positioning.