Research On SINS/CNS Integrated Navigation Algorithm

In modern navigation systems,SINS has the advantage of strong autonomy,strong anti-interference ability,and high data update frequency,which is widely used in various fields.However,As inertial device errors accumulate over time,their navigation accuracy gradually decreases over time.Celestial navigation positioning with high accuracy,high device reliability,autonomy,and other characteristics,and the error does not accumulate over time,In recent years,which is more and more used in navigation systems.However,Celestial navigation has the disadvantages of low update rate,affected by atmospheric environment and can't navigate independently.Therefore,it is possible to improve the navigation accuracy of the navigation system by synthesizing the advantages of the two methods of inertial navigation and celestial navigation.This paper takes SINS/CNS Integrated Navigation System as the research object,and mainly uses the drone flying in the atmosphere as the carrier platform for research.Based on the celestial navigation positioning method based on celestial observation angle,a integrated navigation algorithm based on celestial observation angle is studied.The main research content includes:1.This paper mainly studies the basic principle of strapdown inertial navigation system,introduces the common coordinate system in the navigation solution process,analyzes the updated algorithm of strapdown inertial navigation system,and analyzes the origin of the error of SINS.With its error characteristics,an error model for SINS was established.2.This paper studies the basic principles of the celestial navigation system were studied,and introduces the commonly used coordinate systems and time concepts in celestial navigation.The commonly used star-sensitive celestial navigation method and its attitude measurement principle are analyzed.3.This paper mainly studies the celestial navigation and positioning principle based on the celestial observation angle,and briefly introduces the navigation triangle and height difference positioning method.On the basis of the height difference method,this paper analyzes the integrated navigation scheme based on angular error of celestial observation.This scheme constructs the Kalman filter's quantity measurement by using the error of the celestial observation angle caused by the error of inertial navigation solution,and completes the SINS/CNS integrated navigation algorithm.Compared with traditional algorithms,this integrated navigation algorithm also has better navigation accuracy when only one star can be observed in the field of view.And this algorithm has been verified by simulation in MATLAB.