Method of improving the positioning precision about inertial positioning and heading system for land vehicle

In order to ensure the battlefield survivability and autonomy of the weapons and equipments for land vehicle, an inertial positioning and heading system for land vehicle should not do zero-velocity update or use GPS as much as possible to improve the precision. In this paper, by studying the error models of navigation system, it is concluded that the errors of dead reckoning system changed slowly with time, though the system's precision is high in short time. A method for improving the system precision was proposed. In this method, the errors of vehicle installing and odometer scale factor are estimated and compensated by inertial navigation system, and the inertial navigation system is corrected by dead reckoning system. The weight function is used to bring a better precision positioning. Theory study and simulation show that this method can estimate out the scale factor error and installing error by no more than 2 min, and the estimation precision can reach more than 90% of preset values, the weighted position errors are no more than 0.2% of mileage.