Researching On Optimal Design Method For Transfer Alignment And Integrated Navigation Filter

In recent years,the comprehensive strength of the country has been gradually strengthened.In order to protect the national security and maintain regional peace and stability,our army has more and more high requirements for improving the performance of the weapon system,especially the Precision Strike ability of the weapon system over the horizon.Inertial navigation system is the key equipment of the most missile weapon systems.The initial alignment accuracy determines the performance of the navigation system in pure inertial state.The battlefield situation is changeable and unexpected,which requires the weapon system to meet the requirements of short preparation time,high precision and simple operation and maintenance.How to optimize the system design scheme to achieve the balance between the accuracy of weapon inertial navigation system alignment and speed,reliability,and simplified operation is a difficult task in the field of inertial technology.At the same time,with the improvement of military actual combat requirements,the demand for low cost and high precision weapon system is increasing.The two generation of the Beidou satellite navigation system in our country is becoming more and more perfect,making the application of the satellite navigation technology no longer restricted and constrained by other countries.With the progress of the technological level,the stability and accuracy of the micro mechanical inertial sensors are gradually improved,making it possible to develop a low cost GNSS/INS integrated navigation system.Based on the above analysis,this paper focuses on the optimization design method of the inertial navigation transfer alignment system and the inertial satellite integrated navigation system.The main research work is as follows.First of all,the transformation relationship between two kinds of common fast transfer alignment system models is analyzed and proved.Using the models conversion relation ingeniously,a fast and high precision transfer alignment method for gliding takeoff,which can restrain the flexure deformation of the wing,is presented,which simplifies the process of air transfer alignment and is beneficial to the improvement of the weapon system.Based on the analysis of the deviation sources of the transfer alignment linearization system model,the differential attitude observer model and the direct compensation method of the linearized state model deviation is proposed,which effectively improves the accuracy of transfer alignment and meets the requirements of the tactical weapons.In order to further solve the problem of high precision transfer alignment of strategic weapons,a transfer alignment method based on virtual master inertial navigation reference is proposed.On the premise of not changing the linear transfer alignment system model,only a little adjustment of the calculation process is needed,that is,it can achieve high precision transfer alignment at the arc-second level,which is convenient for engineering application and popularization.Secondly,the optimization design method of inertial navigation transfer alignment system is studied in depth.According to the analysis of the Kalman filter’s bandwidth,the prior information and the influence of the non-stationary random process on the performance of the filter,taking into account the relationship between the attitude motion characteristics and the observability of the alignment system,a transfer alignment adaptive Kalman filtering method based on the attitude spectrum and the innovation sequence is proposed.Through the analysis of the attitude spectrum,the basic parameters of the filter are searched and the variable parameters of the filter are dynamically adjusted by the covariance analysis of the innovation sequence.This makes the system more robust against non-Gaussian measurement noise,while largely solve the problem of poor stability of the adaptive filter of innovation sequence.On the basis of the traditional multi model adaptive filtering method,in order to achieve the balance of the global stability and the accuracy of the filter,combined with the inherent characteristics of the state parameters of the transfer alignment filter,the multi model adaptive Kalman filter weighted fusion allocation strategy is improved.The new multi filter weighted fusion allocation factor is constructed by using the state estimation stability and the two order central moment of the state estimation mean as the comprehensive measurement index.This method can optimize the comprehensive performance of the system.In addition,for the time delay problem of data transfer alignment engineering application and on-line precision evaluation requirements,a delay processing method for the transfer alignment system based on the attitude phase covariance as a cost function was proposed.The online accuracy of transfer alignment accuracy was deduced.The error performance curves given by numerical simulation verify the effectiveness of the algorithm.At last,the optimization design method of low cost GNSS/INS integrated navigation system is studied.Based on the analysis of the error source and error modeling of satellite navigation,combined with the positive correlation of tropospheric delay and the troposphere thickness of the signal transmission path,a multi-order positioning algorithm based on the adaptive estimation of tropospheric delay is presented.By analyzing of the coupling characteristics of inertial navigation deviation,a new design scheme of "horizontal + Course + elevation" sub channel joint system is proposed to balance the precision of the model,computation complexity and filter stability.The covariance shaping adaptive filtering method is used to design the integrated navigation system filter to suppress the influence of the time-dependent colored noise on the system accuracy.The navigation performance of the combined system is enhanced.In summary,starting from analyzing the characteristics of inertial navigation deviation coupling and the pseudo range error of satellite navigation measurements,this paper takes the innovation sequence analysis,the multiple-model fusion optimization and covariance matching analysis as the breakthrough point,focusing on the optimization design method of the transfer alignment and the integrated navigation system.It provides a reference for the design of fast high precision transfer alignment system and the design of low cost and high precision GNSS/INS integrated navigation system,which has a strong practical value in engineering.