Inertial Measurement Unit

An inertial measurement unit (IMU) measures a body’s linear accelerations, angular rates, pitch & roll angle using a combination of the latest MEMS sensor technology, such as accelerometers, gyroscopes, and magnetometers. It is generally installed in an inertial navigation system to calculate attitude, angular rates, linear velocity, and position relative to a global reference frame, based on the measurements gathered by an IMU sensor. IMUs are configured with sensor fusion software that links data from multiple sensors to provide the reading of orientation and heading of the object in the frame.

An IMU sensor generally provides 2 to 6 DOF (Degrees of Freedom) based measurement on an object throughout the 3-D space. An accelerometer measures linear acceleration across a single axis in a particular direction. Gyroscopes measure angular velocity on three axes: pitch (x-axis), roll (y-axis), and yaw (z-axis). It mainly determines an object’s orientation within the 3D space. A magnetometer can detect fluctuations in Earth’s magnetic field by measuring the air’s magnetic flux density at the sensor’s point in space. This data can be used with the accelerometer and gyroscope data to determine absolute heading. 

The IMU sensors are used in applications that require motion and orientation monitoring, such as in automotive, military, aerospace, and marine operations. They are integral components in commercial and military vehicles such as crewed aircraft, missiles, ships, submarines, and satellites. They are also incorporated in the guidance and control of unmanned systems such as UAVs, UGVs, and UUVs.