| SINS(Strapdown Inertial Navigation System)/SS(Star-sensor)integrated navigation system combines the advantages of INS and SS,which respectively include continuous information,good stability,fast update rate,short-time high precision,and small size,light weight,flexible operation,high accurate attitude without accumulated error and drift.On the basis of autonomous,passive,concealed and effective during wartime,SINS/SS can realize rapid and accurate target counter attack and destroy,so it has a superb prospect in the application of strategic weapons,which will make it become one of the key to vanquish the enemy for strategic weapons in the new era.SINS/SS is directly forced under the dynamic characteristics of the carrier,which makes it not only suffer from the accumulated error caused by initial error and instrumental error,but also suffer from the observation error caused by observation environment and observation situation.Aiming at the problems mentioned above,and combining the requirements of rapid maneuver launching and long-range precision strike in the modern war,research on autonomous navigation method to raise the accuracy,stability and adaptability of navigation system for strategic weapons has an important significance.In this thesis,regarding the error of SINS/SS in the operation period and in the mission profile as research object,aiming to optimize the navigation system in the entire process and in the whole cycle,on the basis of the comprehensive and systematic analysis of error mechanism,error source and error effect,the researches on data optimization processing,independent autonomous positioning of SS and all-time initial alignment and mutual correction of SINS/SS will be conducted to improve the accuracy,stability and correction efficiency of navigation system.Details are as follows.Aiming at the stepwise isolation,restraint,elimination of internal operation noise error and principle error,the research on data optimization processing of SS is conducted.Firstly,error phenomena and excitation source are analyzed through measured data.Secondly,based on the error model,an optimization method for star-sensor data based on multiplex methods fusion is proposed through trial and error.Finally,the optimization procedure is designed and utilized to verify the validity of the method and the objectivity of the data through measured data.This research can provide high precision and high stability data reference of SS attitude.Aiming at the problem of the accuracy and speed of INS initial alignment is restrained by alignment duration,the research on all-time initial alignment of integrated navigation system is conducted,and the SS data is introduced to complete initial alignment.Firstly,aiming at the problem of installation angle separation between SINS/SS,the quaternion filter model is established and then the quaternion filter algorithm is derived.Secondly,the model of auxiliary reference is established,and the relationship between auxiliary reference and integrated navigation system is derived,then an initial alignment method based on auxiliary reference measurement regardless of observation environment.Finally,an initial alignment procedure is proposed to complete several experiments and realize the evaluation of initial alignment accuracy.This research can provide rapid and accurate initial information.Aiming at the problem that the traditional SS positioning method needs the external auxiliary information and has low precision,the research on independent autonomous positioning of SS is conducted.Firstly,the model of SS with multiple FOVs(Field of Views)is established,and then the methods of fusion stellar map establishment and recognition are proposed.Secondly,on the basis of satellite identification,separation and matching,a positioning method based on satellite recognition is proposed,and its corresponding procedure is given.Finally,in the situation of stellar measurement and satellite simulation,the evaluation of positioning accuracy is completed.This research can provide redundant and high precision position information for navigation correction.Aiming at the problem that SS is affected by the external observation noise,the research on SS correction in SINS/SS is conducted,and the INS auxiliary information is introduced to complete the transfer,superimposition,fusion and compensation of faculae.Firstly,the influence of gray grid error is analyzed through the simulation,and the model of error is established.Secondly,the isoline method which adapts to gray grid is proposed to evaluate the quality of facula,and then the isoline segmentation procedure and centroid calculation algorithm are given.Thirdly,according to the distribution characteristics of facula,the distribution function is derived,and then facula fitting reconstruction method and the centroid calculation method are proposed.Finally,the tightly integrated navigation SS correction method which can reduce the recognition and matching threshold is proposed,and then its applicable environment is given.This research can provide high precision attitude information which has observation environmental interference immunity.Aiming at the combination property optimization problem of integrated navigation system,the research on INS correction in SINS/SS is conducted.Firstly,the error source of gyroscope is analyzed,and the models of installation misalignment parameters and calculation error angle are established,on the basis of introducing SS information,the online calibration algorithm of gyroscope is derived.Secondly,based on attitude quaternion,the system state space described by attitude quaternion is derived,and the loosely integrated navigation system based on two stage filtering is proposed.Thirdly,the tightly integrated navigation method which adapts to navigation system mission allocation is proposed,and so is its corresponding procedure,and then the mission allocation and dynamic mission reallocation mechanisms are designed.Finally,the performance of tightly integrated navigation system is tested through static,semi-dynamic and dynamic experiments which simulate missile borne life cycle environment.This research can solve the problem of error in SINS/SS thoroughly. |
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