Vehicle Navigation System Error Correction Method

Vehicle navigation technology is very important in either military or civil field ,multi-sensor integrated navigation technology is the direction in which vehicle navigation technology is going.This paper studied Zero-Velocity correct technology for INS ,based on analysis of INS error equation ,it concluded the method by which we can use INS velocity output to estimate the attitude angle error when the vehicle halted ,then it contrasted two schemes of conic approximation of attitude angle error and put forward a method to decide the approximation coefficient by time range .Then this paper introduced the main method in multi-sensor integrated navigation-Kalman Filtering method ,and a Two-level optimization multi-sensor Information Fusionstructure-Combined Filter which was originated by Carlson and Kerr ,based on thestructure of Combined Filter ,it studied the method of navigating by the multi-sensor navigation system integrated by INS milemeter altimeter and piloting ,then analyzed the effect of several filters .Simulation proved that when altimeter were integrated ,the height error was reduced a lot ,and the Combined Filter is more effective than one-level Kalman filter.Because the INS error equation is unstable,some initial states error will cause error floating and error accumulating ,if the filter observations were only position error,Kalman Filter will converge very slowly ,and some states error (such as yaw error) will be great . Since the milemeter altimeter and piloting could only output position information,this paper put forward a method ,firstly estimateing states and then Kalman filtering ,to improve filtering effect. Simulation proved that this method could effectively reduce the system states error,quicken filtering convergence and improve filtering precision.