Inertial Measurement Unit

An Inertial Measurement Unit which is also known as the IMU is an electronic device that measures and records, reports about acceleration, orientation, angular rates, and other gravitational forces. It is composed of 3 accelerometers, 3 gyroscopes, and also depending upon the heading requirement 3 magnetometers. IMUs are typically used to maneuver aircraft as an attitude and heading reference system including unmanned aerial vehicles (UAVs) and spacecraft including satellites and landers. Recent development allows the production of IMU which enables the GPS devices feature. It allows GPS receivers to work when GPS signals are unavailable in places such as in tunnels, inside buildings or when electronic interference is present.

Operational principles of IMU

• An Inertial Measurement Unit (IMU) is a measurement electronic device which detects the linear acceleration using one or more accelerometer and rotational rate using one or more gyroscope. It also includes a magnetometer which is used when heading reference is needed. Its configuration contains one accelerometer, gyro, and magnetometer per axis for each of the three principles axes i.e. pitch, roll, and yaw.

Uses

• It is used for navigation and control of many commercial and military vehicles such as manned aircraft, missiles, ships, submarines, and satellites. IMUs are also important components in the guidance and control of unmanned systems such as UAVs, UGVs, and UUVs.
• The data collected from the computer to track a craft’s position, using a method known as dead reckoning.
• In land vehicles, an IMU can be integrated into GPS based automotive navigation system or for vehicle tracking system which gives the system a dead reckoning capability and it also can gather as much accurate data as possible about vehicle’s current speed, turn rate, heading, inclination, and acceleration.
• Almost all smartphones and tablets contain IMUs as part of the sensor. Fitness tracking and other wearables may also include IMUs sensors to measure the motion such as running, etc.
• They are complete technology for use in motion capture technology.
• In the navigation system, the data reported by the IMU is fed into a processor which calculates attitude, velocity, and position.