An extended Kalman particle filtering algorithm for HRG-based strapdown inertial attitude determination system

To prevent the accumulated error of the inertial attitude solution, according to the trigonometric function relationship between attitude angles, three variables replaced the roll and the pitch as state variants. With the restrained equation among state variables and the forward motion speed, one extended Kalman particle filter (EKPF) algorithm was proposed to solve the attitude angles. The EKPF algorithm was applied to our inertial attitude reference unit based on the hemispherical resonator gyroscope (HRG), which was made in China. Simulation results indicated that the root mean square error values of the roll angle and the pitch angle of the proposed EKPF were less than the half of those of the standard extended Kalman filter (EKF).