Maneuvering acceleration assisted extended Kalman filter for attitude and heading reference system

The low cost AHRS (attitude and heading reference system) commonly adopt 6-state EKF (extended Kalman filter) based on the gravity field and the magnetic field vector observations. When the carrier maneuvered with a long time, the model presented big errors and 6-state EKF could not get stable attitude accuracy. The maneuvering acceleration is described with current statistical model. A 9-state EKF is introduced with 9 states of three attitude errors, three-axis gyroscopes bias errors and three-axis maneuvering acceleration errors. The observations includ three-axis acceleration errors and three-axis magnetic filed errors of the earth. When AHRS rotates with acceleration centripetal of 0.6 g on the rotation table, the experimental results show that 9-state EKF could get stable estimation of three-axis maneuvering accelerations and the attitude accuracy is better than 1 degree.