The Design And Implementation Of The North Seeking Algorithm Of Single Axis Fiber Optic Gyroscope

In the field of inertial navigation,compared with traditional mechanical gyro,fiber optic gyro based on sagnac effect has become the main inertial device due to its higher sensitivity,lighter weight,larger dynamic range,shorter preheating time,longer service life and lower cost.The north finder based on fiber optic gyro can find the true north direction quickly and independently without depending on the external environment.Nowadays,it is widely used in national defense,and it has very important use value in the civil field.For improving the accuracy of FOG north finder,this paper focuses on the design and implementation of the fiber optic gyro north finder.It contains the following main work:First of all,the static and dynamic north finding solutions are derived and studied theoretically,and the static north finding solutions model is established under the angle of inclination,and the various north finding solutions are compared.Secondly,the error of the north system of fiber-optic gyroscope has been studied.The relationship between installation error,transposition error,inclination angle measurement error,latitude error,random drift of FOG and north finding accuracy is deduced.Then,the base disturbance makes the data of FOG contains noise,which leads to the deterioration of north finding accuracy.An improved method of wavelet threshold denoising combined with weighted filtering is proposed to remove noise from the output of FOG.Finally,the overall structure design scheme of the fiber optic gyroscope is proposed,and the design and implementation of the software hardware are carried out.The hardware module based on FPGA combined with DSP is designed.And the software which contains the data collection part and calculation part is compiled.The north finding experiment of eight positions was conducted.