Research On Key Technology Of Fib Er Optic Gyro Strapdown Inertial Navigation

In recent years,with the development of inertial navi,ation technology fiber optic gyro(FOG)strapdown inertial navigation system(SINS)has been widely researched from experts and scholars in the field of inertial navigation due to its powerful versatility.Based on the self-developed FOG SINS of the laboratory,this dissertation conducts deep research on the key technologies of FOG SINS from production to application.Firstly,a universal FOG SINS design scheme is proposed.The principle and characteristics of fiber optic gyro and quartz flexible accelerometer are introduced.The traditional integrated architecture is introduced,and a modular architecture is proposed.The common coordinate system for SINS is defined.The basic equations of navigation solution are introduced,and they are transplanted into the mainboard of the navigation computer.The prototype of SINS is completed.Secondly,the calibration technology of SINS is researched.The traditional discrete calibration and systematic calibration methods are introduced,and their respective advantages and disadvantages are analyzed.Based on the deficiencies of the existing calibration methods,a new calibration method based on modulo observation and gravity vector observation is proposed.The new method is easy to analyze the error excitation,and the calibration path is easy to implement in engineering.The effectiveness of the method is verified by simulation verification and three-axis turntable test using the self-developed SINS.Thirdly,the initial alignment technology of SINS is researched.The traditional analytical coarse alignment and fine alignment are introduced.Focused on the problem that the angular velocity of the earth's rotation under the shaking base is difficult to identify,the alignment based on inertia space has been studied.The classic alignment method based on QUEST is introduced.The algorithm requires precise latitude to construct the reference vector of the inertial frame,because of this,a smooth latitude solution is derived.Moreover,an alignment algorithm based on vector operation is introduced.This method does not need the latitude and directly estimate the attitude.However,the current method has an insufficient accuracy,a solution based on gradient descent is proposed.It is proved by simulation and experiment that the proposed method is better than the current solution.