Research On Optical Path Control Of Interferometric Fiber Optic Gyroscope

As the core device in the inertial navigation system,the gyroscope does not need to rely on external information,and can calculate the angular velocity of the carrier only based on the measurement of internal components.Fiber Optic Gyroscope(FOG)occupies an important position in aerospace,military and defense fields and civilian industries due to its small size,no locking effect,stability and high integration.In order to be able to adapt to the requirements of new weapons and equipment and expand the application fields of fiber optic gyroscopes,rapid response has become one of the goals of fiber optic gyroscope development.Therefore,this article combines the requirements of the actual model products in the institute and takes the medium and low-precision fiber optic gyroscopes as the research object to conduct application research on this technology.On the basis of in-depth analysis of the basic principles of fiber optic gyroscopes and digital closed loop technology,based on the existing optical path structure and circuit modules,a light path control scheme is proposed: combining the light source driving circuit with the digital demodulation circuit,and introducing a new closed loop to achieve Dynamic control and real-time adjustment of optical power on the entire optical path.After determining the optical path control scheme,FPGA(EP2C20F256I8N)is used as the core hardware processing platform,and the light source is driven by digital circuit conversion to realize the rapid and stable optical signal in the interference system and provide algorithm basis for the closed-loop software design.Under the guidance of the above ideas,build a hardware circuit system.The hardware circuit system includes digital current source circuit,digital temperature control circuit,signal acquisition circuit,FPGA-based core processing circuit and back-end communication circuit.According to the function and design requirements of each circuit,select the main function chip and use Altium Designer software to The overall hardware circuit is designed on the PCB board level.After the hardware system is built,in the Quartus ? development environment,using the top-down modular design method and Verilog HDL language programming,the software module is designed to realize the closed-loop function of the gyro.On this basis,an experimental prototype using the principle of the optical path control scheme was successfully built,and its function was debugged and verified,and the results showed that its closed-loop function was normal.The thesis compares the stability of the optical path performance under different light source drive control,and tests the main indicators of the gyroscope.The results show that the response speed is effectively improved under full temperature conditions,and the performance is also significantly improved,which provide a reference for future engineering design implementation.