Kalman filter imu position

1. Can an IMU measure position?
2. What is Kalman filter in IMU?
3. How does an IMU know which way it's facing?
4. How do you reduce IMU drift?

Can an IMU measure position?

IMUs are often incorporated into Inertial Navigation Systems which utilize the raw IMU measurements to calculate attitude, angular rates, linear velocity and position relative to a global reference frame.

What is Kalman filter in IMU?

The Kalman filter estimates orientation angles using all of the sensor axis contributions within the IMU.

How does an IMU know which way it's facing?

As the name might suggest an IMU is capable of measuring orientation data and to achieve this it uses a combination of three sensors, namely Accelerometer, Gyroscope, and Magnetometer. Before moving on to how these work some definitions are necessary (yeah boring things):

How do you reduce IMU drift?

This drift can sometime make the IMU data unreliable and useless. One well known method to overcome this drift is to use other low drift data (for example poses computed from the vision images) and then fuse the two data together.