Accurate Attitude Inizialization Procedure based on MEMS IMU and Magnetometer Integration

The paper presents an innovative strategy to measure the initial heading of a vehicle in the local reference frame by means of a tactical-grade MEMS-based inertial measurement unit and a low-cost MEMS magnetometer. The developed system allows not only to pointing the North direction but also to assure the stability of the attitude estimates overcoming bias and drift errors affecting the measures of this type of sensors and keeping the advantages of the MEMS sensors technology such as small volume, lightweight and flexibility. The proposed integrated solution exploits an indirect gyrocompassing strategy through an error-state Kalman Filter algorithm for the coarse alignment aided by the magnetic Earth field measurements. The system performance is preliminarily assessed in static conditions and compared with a certified reference system in order to verify its compliance with the requirement for Small Unmanned Aerial System.