Tactical Missile Technology

Considering that traditional strap-down inertial/celestial integrated navigation method( SINS/CNS) cannot accurately estimate the accelerometer bias,which can cause the divergence of navigation errors,a modified integrated navigation algorithm is proposed. The proposed method introduces the height angle error and azimuth angle error related to position and the height error which is obtained by the pressure altimeter into the measurement equation of the system. The method inhibits the divergence of position error and solves the problem existing in the accelerometer estimation of the position error in the traditional method. Based on the above principle,the linear model of the integrated navigation system which is used in the ballistic missile is constructed. Finally,the estimation of the state of system is realized through the Kalman filter. The simulation results indicate that the precision of navigation based on the proposed method is better than that of the traditional method and corrects the navigation error caused by the accelerometer bias effectively,which shows the validation of the proposed method.