Research On Space Radiation Effect And Protection Technology Of Fiber Optic Gyroscope

As a new type of inertial sensing device,the Fiber Optic Gyroscope(FOG)has the advantages of light weight,small size,long service life,low power consumption and high sensitivity.So it is widely used in aviation,aerospace,navigation and other fields.But in the space application of FOG,the FOG is mainly composed of optical devices and electronic devices,high-energy particles,space of rays,the electromagnetic environment will adversely affect the fiber optic gyro,such as increasing the loss of optical fiber,the drift of light source wavelength,the drop of optical power and the logic flip ring of electronic devices in optical fiber gyro,which results in the performance degradation and even permanent damage.In this paper,the influence of space radiation effects on FOG and the anti-irradiation scheme are studied.The main work of this paper is as follows:The basic principle of fog and the analysis of space radiation environment are introduced.The basic principle of fog is introduced,which provides the basis for analyzing the influence of radiation environment on gyroscope.The effects of space radiation environment and radiation effects on the optoelectronic devices of spacecraft are analyzed.Research on the influence of space radiation on FOG:the influence of irradiation environment on the optical path and circuit of gyro is studied respectively.In the space radiation environment,and increase the fiber loop loss wavelength shift,optical power attenuation,photoelectric detector dark current increases and other problems will optical fiber gyroscope,change the output wavelength will lead to gyro scale factor is not stable,the output optical power attenuation would lead to the increase of the gyro random walk coefficient,resulting in a decline in the performance of FOG;space radiation environment,electronic devices will be affected by the main gyro single particle effect,resulting in logic flip device,lock or even burned.In addition,the additional electromagnetic interference caused by the radiation environment will have a negative impact on the gyro circuit and the transmission of gyro data.In view of the adverse effects of space radiation on fog,corresponding protection techniques need to be carried out.Researching on space radiation effect for FOG circuit: Analyzing the mechanism of space radiation effects on FOG circuit in electronic components,electronic devices mainly affected by single event effect(SEE)in the space radiationenvironment,resulting in fiber optic gyro electronic device logic flip,lock or even burned.The SEU belongs to soft errors,which can be designed by software and hardware to repair.According to the above we can adopt the third mock exam redundancy(TMR)scheme,tripling the key device of gyroscope,thereby reducing the performance degradation of gyro due to space radiation.While for the electronic device lock or burned are hard errors,the event will be irreversible,which we need to make reasonable shielding design for electronic devices.Design and verification of anti radiation scheme for FOG: anti radiation scheme is designed for gyro light path and circuit respectively.In order to solve the space radiation that the output light wavelength drift and average optical power attenuation of light path,first has carried on the whole design of gyroscope light path: due to the optical gyro in the light path are polarization maintaining device,the radiation environment will cause gyro optical produce "color center",Instead of the polarization maintaining FOG system,using the photonic crystal fiber and design the light path can enhance the stability of the gyro optical radiation environment.After that,the fiber ring and the light source are designed: because the photonic crystal fiber is made of pure material,doped little,it is less sensitive to radiation.Therefore,the use of photonic crystals in the preparation of optical fiber gyro in space will have better adaptability.In view of the drift of the average wavelength of the output light of the light source,the output spectrum of the gyro light source is shaped,and the near Gauss type spectral output light source is adopted to ensure the stability of the average wavelength of the output light of the light source.For the circuit of gyroscope design,we design the hardware and software of FOG.The hardware design of the gyro includes module device selection,circuit design.Then design the key parts of the circuit of FOG using redundancy of the third mock exam(TMR)method,to ensure the stability of the gyroscope circuit in the space radiation environment.In addition,the software adds the cyclic redundancy check(CRC)algorithm to the data transmission of gyro,which improves the stability of the data transmission under irradiation.Finally,the whole system of FOG is built and verified by experiments.The design and design of the gyroscope random walk coefficient are tested and analyzed,and the designed scheme meets the requirement of gyro space application.