Avoiding Magnetic Disturbances in the Determination of Inclination Angles using Unscented Kalman Filter-based Method

Magnetic and inertial measurement units are promising tools to calculate the attitude of objects. However, once there exists a magnetic disturbance in the magnetometer measurement, the determination accuracy of pitch and roll would be drastically reduced. a strategy designed to provide continuous quaternion estimation results is proposed. In its attitude prediction stage, the quaternion is predicted using gyroscope measurements, whereas, in its attitude update stage, the Euler angles converted from the predicted quaternion are revised using accelerometer and magnetometer measurements. Eventually, the updated Euler angles are converted back to quaternion. The estimated quaternion can be used directly but can also be converted to Euler angles; if this occurs, the estimation accuracy of pitch and roll will not be influenced by the magnetic disturbance. Through simulations and experiments, the effectiveness of the suggested strategy is demonstrated by comparing it to eight competing strategies.