Study On FOG SINS/SS Integrated Navigation System Applied In Missile

In order to improve the accuracy of navigation in long working state,some key technologies of Strap-down Inertial Navigation System and Star Sensor(SINS/SS)are studied for missile in this paper.Main research contents are that error propagation characteristic of SINS and SS,initial alignment technique for integrated navigation system,filter algorithm for integrated navigation,integration technology for integrated navigation system.First.In order to establish the filter model of integrated navigation for SINS/SS,derivate the error equation of SINS in detail and study the error propagation characteristic of SINS and SS.In the last,fiber-optic gyro noise and zero-bias affecting navigation in long working state is primarily studied.Second.It is studied of initial alignment technique for integrated navigation system.When the SS can’t be used for the influence of external environment,it is mainly studied of Kalman Filter(KF)alignment and parameter-identification alignment.the process of strict reverse navigation is applied in regular backtracking alignment method on first.According to different situation of missile,the algorithm is proved correct and advantageous,which is studied by off-line simulation in the situation of static and shaking state.Third.Filter algorithm for integrated navigation is deeply studied in this paper.And it is established of state mode,measurement mode,correcting attitude mode.Algorithm of KF and Model Predictive Filter(MPF)is mainly studied.Because the missile has the feature of large motor and disturbed electromagnetic environment,a nonlinear filter “MPF+KF” applying to the project is proposed based on the study on nonlinear filter.The offline test of integrated navigation is carried on in static and dynamic state,and it is proved that integrated algorithm is feasible and practical to improve the accuracy of long-time navigation.Last.Integrated technology is the main method for improving the measurement accuracy,real-time characteristic and small scale of integrated navigation.Key technique of structural integration,circle integration and software integration is preliminarily studied and explored.Model of structural integration is simulated to indicate that integrated structure has higher fundamental frequency and it can meet the needs of large-motor situation.Integrated process of circle is detailed analysis and the number of circle is forty percent less than before.A multi kernel Digital Signal Processing(DSP)is detailed designed and the function of every kernel is concretely divided.It is meet the needs of complex operating.These studies can provide reference for the design and development of integrated prototype later.