A fault-tolerant integrated navigation method for land vehicle

A fault-tolerant integrated navigation method for land vehicle is researched in this paper, which is based on inertial measurement unit (IMU), global positioning system (GPS) and dead reckoning system (DRS). Firstly, position and velocity outputs of IMU and GPS are taken to construct measurements of IMU/GPS integrated navigation, and IMU/GPS Kalman filtering algorithm is deduced and designed. At the same time, position outputs of IMU and DRS are taken to construct measurements of IMU/DRS integrated navigation, and its Kalman filtering algorithm is also designed. Then IMU/GPS/DRS federated filter frame is designed, and the global optimal fusion algorithm of the master filter is researched. Thus estimations of system states from IMU/GPS and IMU/DRS local filters are sent to the master filter independently. Consequently global optimal estimations of system states are given in the master filter. Lastly, based on the federated filter frame, the fault detection and isolation algorithm for IMU/GPS/DRS integrated navigation system is designed. Simulation results show that, position accuracy of this integrated navigation method reaches ±4.8m, and velocity accuracy reaches ±0.09m/s. And simulation results also show that, this integrated navigation method has strong fault-tolerance, and it can keep high accuracy when GPS or DRS is out of order.