Abstract:In this paper, a robust design of 9D-MIMU/GPS integrated navigation system based on two-stage EKF is presented. In view of the problem that magnetometer is susceptible to external interference when it is used in low-cost mini-UAV and affects the accurate estimation of other states of navigation system, and the problems of manufacturing error, external hard iron error, soft iron error and magnetic dip angle of magnetometer are solved. Experiments show that the design of this paper can effectively correct the errors contained in the original measurement data of magnetometer, and achieve the navigation state estimation accuracy similar to that of commercial navigation module.