Research On Several Techniques Of SINS/CNS Position Integrated Navigation System

In the field of ballistic missile,Strapdown Inertial Navigation System(SINS)that the precision of navigation will diverge with time.Therefore,this dissertation devotes to the integrated navigation system consisting of SINS and Celestial Navigation System(CNS)and proposes an available method which intermittently amend the results getting from SINS by extracting the position information from CNS.The details are presented as follows:1.The analysis of the principle of the SINS/CNS integrated navigation system:firstly,the error equations and the positioning principles of SINS and CNS are analyzed respectively,then a system equation whose state variable space is 15 degreed is constructed according to the above principles.To overcome the deficiency that CNS just supply the position information of longitude and latitude but not altitude,the height information is acquired from pressure altimeter to make of the completed observation equation.2.This dissertation proposes a triangle star map pattern recognition algorithm that takes S-vector into consideration in the face of the drawbacks of the traditional methods,i.e.the traditional triangle star map pattern recognition algorithm need to undertake an unacceptable reserve burden of guide star catalog,and the noise covariance of position information in star map is too significant to recognize effectively.The proposed method will construct a eigenvector S in terms of the principle of optimal projection axis.Then calculate the characteristic matrixSS~T and the maximal eigenvector.Finally,put the maximal eigenvector and S point multiplication as the matching information into the guide star catalog to replace the traditional triangle star pattern library.Though the proposed method,could the problems of the unacceptable reserve burden and the low efficiency of recognition be solved.