FPGA-based full-digital
processing closed-loop
fiber optic gyro is composed of an
optical path part and a circuit part. The
optical path part is composed of a
broadband light source, a
fiber optic coupler, a multifunctional integrated optical
chip and a
fiber optic coil. The circuit part is composed of an amplification filter circuit, A / D conversion, Composed of FPGA logic circuit, D / A converter, etc., the FPGA logic circuit completes the
processing of digital signals, and the sum of the
square wave modulation and digital ladder wave feedback
signal generated by it is added to the multifunctional integrated optical
chip after passing through the D / A converter. On one arm, the
fiber coil is a single-mode fiber with lyot depolarizers added at one or both ends. Because the present invention adopts the addition of a lyot
depolarizer on the basis of the single-mode
fiber coil, the polarization evolution along the single-mode fiber will no longer affect the output of the
gyroscope, which improves the zero-bias stability of the fiber-optic
gyroscope, and then makes the
gyroscope The accuracy is greatly improved; in addition, the modulation and
demodulation method of the single-mode
fiber coil with
depolarizer is the same as that of the polarization-maintaining fiber, but its cost is only one tenth of the price of the polarization-maintaining fiber.