Design Of Indexing North Finder Based On Single-axis Fiber Optic Gyroscope

With the continuous development of navigation,people's requirements for real-time and high-precision positioning devices are getting higher and higher.At present,there are more north-seeking devices at home and abroad than laser gyroscopes and micro-mechanical gyroscopes;and fiber-optic gyroscope north-seeking devices are in the development stage.The thesis designs a high-precision indexing north-seeking system for single-axis fiber-optic gyroscopes.The attitude angle of the carrier is displayed on the host computer in real time.According to the technical indicators of the north finder,the thesis uses a single-axis fiber optic gyroscope as an important sensor for acquiring attitude angle,and XC7Z020 as the main control chip of the lower computer.It is mainly responsible for fiber optic gyroscope data collection,accelerometer data collection,and temperature sensor DS18B20 data.The data is collected and framed,and the data is sent to the upper computer programmed with Qt through the RS232 bus,and the attitude angle of the carrier is displayed on the upper computer in real time.In order to improve the accuracy of north finding,this system adopts indexing control module to improve indexing accuracy of fiber optic gyroscope in the process of north finding.This module adopts PID model compensation method to eliminate indexing errors generated during the rotation of the turntable,so as to improve the optical fiber.The four-position method and multi-position method used in gyro north-seeking are the accuracy of the angle of the rotating turntable during the experiment;in addition to the north-seeking error caused by the physical structure,temperature drift and other noises will interfere with the accuracy of the fiber-optic gyro north-seeking;in order to eliminate the temperature North seeking accuracy error caused by drift,the thesis uses temperature drift compensation model to eliminate the drift of north seeking due to temperature changes.For other noises,the thesis uses ALLAN variance analysis method to model and analyze other noises,and uses wavelet filtering algorithm to suppress and eliminate other noises;display the carrier attitude angle on the host computer to test the filtering effect of each model.Finally,a four-position north-seeking model for the fiber optic gyro north-seeking attached to a tilted carrier is established.Through the above test,the optical fiber gyro index north finder designed by this system fully meets the technical index requirements,and the north-seeking accuracy is 0.01°.