Research On The Error Of Fiber Optic Gyroscope North-seeking System

In the popular north-seeking methods,only the inertia North-seeker could not be interfered by the natural conditions or the environment,but completes the north-seeking tasks independently,and also has a continuous long working hours and high accuracy.Traditional Gyro North Finder while high precision,but higher accuracy is at the price of the longer north—seeking time and high cost price.So how to solve the contradiction between precision and fast has become all important topic in the current study to improve accuracy of searching the North.With the research and development in recent years,the ilnprovement of fiber optic gyroscope has also been developed rapidly.FOG its small size,light weight,low cost,easy operation and maintenance of the characteristics of being more and more attention of researchers,especially in the less demanding accuracy requirements , the low-precision applications,the fiber optic gyroscope and fiber optic gyroscope North-Finder has good development prospects and high research value.This dissertation bases on the fiber optic gyroscope(FOG)in Ship'S inertial navigation system(SINS)developed by our lab.FOG,accelerometers,turntable and computer are composed to be a north—seeking system,the mathelnatical model of the errors is established,the error existed in the system is analyzed,and tile appropriate compensation methods are used to compensate for various errors.Through the study of the dissertation , the accuracy of the north—seeking system is improved effectively;meanwhile the time of seeking the north is shortened.Firstly,the dissertation overviews the development status of the inertial north-seeking technology,the application of FOG North—seeker is introduced,and the key practical technology.Then the principle of FOG North—seeker and the mathematical model of the output of north—seeking are analyzed.Different solution methods to seeking the north are given.Secondly,according to the actual FOG north—seeking system in the lab,the main errors existed in the system are analyzed,the error model of the drift and the noise of FOG north-seeker'S output and the static error model of the accelerometer are given.The influence of the installation error,the transposition error,the physical error,the drift,as well as the nose to the output of the north-seeking is analyzed.Find out the final errors to be compensated.Thirdly,the appropriated compensation method is given to different errors. Much work is done on studying the compensation methods to the drift and the physical error.The north-seeking methods of two-position and four-position are given,under different circumcetants.The application of wavelet filtering in the elimination of random noise is introduced.Analyzes the actual inhibitory effect of the wave filter on FOG random error used Allan variance.Finally,the software and the hardware that conduct the FOG north—seeking experiment system are introduced.The data from experimental result is carefully compared and analyzed.So the effect of the error on the experimental results is obtained,and the actual compensation effects of the various methods are given. Key words:North-seeker;North-seeking accuracy;Error model;Fiber Optic...