IMU

Inertial Measurement Unit

Inertial measurements are the measurements of inertial parameters such as acceleration and rotational rates encountered by a given body. IMU s are generally used in Land / Sea / Air vehicles to calculate the states of the vehicle such as position, velocity and orientation

Modern IMUs are known as strap down IMUs. They use MEMS accelerometers and gyros which are attached rigidly to the body of the vehicle. The measurements from IMS sensors are rarely used in their raw nature. Often DSP based filtering algorithms combine these raw measurements together in the optimal manner considering various factors such as the dynamics of the vehicle, noise in sensors etc. Kalman filter and Complimentary filter are two such popular (and powerful) algorithms. An IMU combined with such an algorithm is often referred to as an Inertial Navigation System (INS)

Off-the-shelf IMU hardware solutions are generally available with features like 3 axis accelerometers and 3 axis gyros. Some also contain analog and/or digital signal processing on-board.