Design Of Dedicated Chip For Digital Control Of Fiber Optic Gyroscope

Fiber optic gyroscope is a high-precision angular velocity sensor based on the Sagnac effect.It has a series of advantages such as small size,low cost,long life,low power consumption,and large dynamic range.Fiber optic gyroscopes have a wide range of applications in military and civilian fields such as aviation,aerospace,land,and navigation.However,the key components of fiber optic gyroscopes are almost all imported from the United States,and the domestic production rate is far below the 95%requirement.It is of great significance to design special fiber optic gyroscope chips with independent intellectual property rights.This paper optimizes and integrates the digital circuit of the interferometric closed-loop fiber optic gyroscope,designs a dedicated chip for digital control of the fiber optic gyroscope,and realizes the urgent need for the localization of the fiber optic gyroscope circuit.The main research contents are as follows:The basic principles and basic structure of the interferometric digital closed-loop fiber optic gyroscope are analyzed.Based on the two-state square wave modulation and four-state square wave modulation technology,the simulation model of the interferometric digital closed-loop fiber optic gyroscope is built,and the transfer function of the digital closed-loop control system is studied.The optimal control open loop gain of the fiber optic gyroscope is 0.2.Analyzed and optimized the original digital closed-loop fiber optic gyroscope control circuit,designed a new digital closed-loop fiber optic gyroscope circuit schematic diagram and PCB circuit board based on Altium Designer,and systematically analyzed the functional requirements and design indicators of the fiber optic gyroscope digital control chip.Based on the Verilog HDL hardware description language,a digital closed-loop fiber optic gyroscope digital control circuit is designed,including a clock module,a modem module,a DAC external timing interface module,and a serial communication module.In the Modelsim software environment,a test verification platform was built to verify the digital control circuit of the fiber optic gyroscope.And based on FPGA to test on the digital closed-loop fiber optic gyroscope,the three performances of the digital closed-loop fiber optic gyroscope's zero-bias stability,scale factor nonlinearity and angular random walk have been improved by 50% on the original basis.Under the Linux operating system,use DC tools to integrate the digital closedloop fiber optic gyroscope control circuit into a GTech basic unit,and optimize the circuit according to the frequency,area and power consumption required for the design of the fiber optic gyroscope digital control chip to obtain the corresponding gate-level network Table.Using tsmc TSMC's 90 nm process library node,and designing the digital closed-loop fiber optic gyroscope digital dedicated chip layout through Innovus automatic placement and routing.