Quaternion IMU Drift Compensation: Magnetometer

  One of the most important sensors on a vehicle that needs to navigate between physical locations is a magnetometer.  Like a person who uses a compass for land navigation, the magnetometer provides a static reference toward magnetic north allowing for movement in a desired direction.  The information from this sensor comes in the the form of 3 orthogonal values that give a representation of the magnetic field surrounding it.  In the following post I will explain its benefits, its challenges and how I use it in my complementary filter.

Complimentary Filter Example: Quaternion Based IMU for Accel+Gyro sensor

  In this post I am going to post the code for a simple 6 degree of freedom version of my complimentary filter.  This should give anyone who wants to better understand what is going on an opportunity to play with the actual code.  In future posts I will explain how to add a magnetometer and then give the code for a 9dof complimentary filter.

Quaternion IMU Drift Compensation: Accelerometer

  I will now explain how I perform gyro drift compensation in the pitch and roll directions using the output of an accelerometer.  In a future post I will discuss using a magnetometer to counter gyro drift in the yaw direction.  Before going into the theory and math, here's a quick overview of what an accelerometer is.