| As the core component of inertial navigation system,fiber optic gyroscope(FOG)has many advantages,such as low power consumption,small size,high precision and all solid state.Especially in the weapon and equipment system,the localization rate of key electronic components is required to reach 100%.In addition,in order to meet the needs of micro-integrated fiber optic gyroscopes for integrated dedicated chips,it is urgent to accelerate the national production of dedicated integrated chips for fiber optic gyroscopes.Based on the in-depth study of the digital control circuit of the fiber optic gyroscope,this thesis optimizes the special chip for the digital control of the fiber optic gyroscope.A special chip for digital control of fiber optic gyro with different ring lengths and different precision is realized.The optimized chip has the functions of automatic intrinsic frequency test,baud rate adjustment,RLS adaptive filtering,parameter storage and so on.The main content of this thesis is as follows:1.The development status of miniaturization and integration of fiber optic gyroscope is analyzed.The relevant theory and basic structure of fiber optic gyroscope are studied,two modulation methods of two-state square wave modulation and four-state square wave modulation are studied deeply,and the general expression of optical intensity error signal is obtained.And the optimization of the digital closed-loop control of the fiber optic gyroscope is realized through the integral control and the feedback phase.2.Put forward the function index and performance index of the fiber optic gyro digital control chip,and further optimize the chip based on the existing functions.And completed the architecture design of the chip and determined the specific scheme of the chip.3.Carry out RTL design for the digital control circuit of the fiber optic gyroscope,and realize functions such as digital closed-loop control,automatic test of eigenfrequency,adjustable serial communication baud rate,RLS adaptive filtering,and parameter storage.And use SMIC 180nm CMOS craft to physically realize the special chip for digital control of fiber optic gyroscope.4.Verify the layout file after layout and wiring,including physical rule check,schematic layout consistency check,static timing analysis and formal verification.Finally,the layout of the special chip for digital control of the fiber gyro is obtained.The area of the layout is about 2.32 mm~2,and the power consumption of the chip is about 37.98 m W.Compared with the original special chip for digital control of the fiber gyro,the area is reduced by about 50%,and the power consumption is reduced by about26.7%.5.The experimental platform of fiber optic gyroscope was built to verify the designed algorithm.The test results show that the design proposed in this paper can improve the performance of the gyroscope to some extent.The bias stability of the fiber optic gyroscope is increased by about 50%,the phase delay is reduced by about 30%,and the nonlinearity of the scale factor is reduced by about 30%.Almost equal,the test error is less than 10 Hz. |
