Nonlinear filter algorithm for GPS/DR integrated positioning

A filter model and its algorithm based on UKF (unscented Kalman filter) for GPS/DR (global positioning system/dead reckoning) integrated positioning in land vehicle navigation system were established. Aiming at the system characteristic of linear state equation and nonlinear measurement equation, the algorithm which combines UKF with EKF (extended Kalman filter) was proposed. Compared with general UKF, the operation time used for the phase of time updating is less than that of general UKF. The error caused by the linearization of EKF is eliminated and the precision is improved contributing to processing the nonlinear problem with unscented transform. The simulation result demonstrates that the algorithm has better filtering precision than EKF, and reduces computing time, which is fit for integrated navigation system demanding for little resource and high precision.