Research On Error Characteristic Of Ring Laser Gyroscope And Inertial Navigation System In Multiphysics Coupling Field

At present,the design and manufacturing technology of mechanically dithered ring laser gyroscope(MDRLG)have matured,the strapdown inertial navigation systems(SINS)with MDRLG have been widely used in military and business scope.The research of this thesis includes the error analysis and suppression method of MDRLG and the SINS with MDRLG under the conditions of the coupling effect of multi-physics field by using the multi-sources and high-order error model,in order to improve the precision of long-endurance SINS in our country.The research work includes the following five aspects:1.Study on the error characteristics of RLG under the effect of multi-physics field.Based on the error mechanism of RLG,the kinetic model of RLG is built and the error of dither axis misalignment of RLG is researched and measured for the first time.For solving the deformation of RLG under the condition of overload,a support structure along with the optimization method is provided to stabilize the input axis of RLG.The thermal sensitivity character of RLG is analyzed and the RLG bias is compensated using the particle swarm optimization tuning support vector machine(PSO-SVM)based on the multi-point temperatures gradient.The theory and characteristic of magnetic sensitivity of RLG is introduced.Research is mainly focused on the simulation and experiment of magnetic shield of RLG.The magnetic sensitivity of RLG with different magnetic materials have been compared and 1J85 is found to be better than 1J50.2.Study on the error suppression method of MDRLG under the conditions of the coupling effect of multi-physics field.The error model of thermal mechanics coupling of combining prism in RLG has been built.The photoelectric conversion circuit used for sampling the differential output of laser AC signal is designed and optimized.By using this circuit and the LS-SVM algorithm,the RLG bias is compensated well in quick changing temperature environment.Study on the characteristic of magnetic sensitivity of RLG coupled with temperature.The measurement of magnetic sensitivity of RLG on full-temperature range is perfected and a method of temperature compensation of RLG bias caused by the magnetic is introduced.By using multi-sensor information fusion technology,the data sampled from different sensors is effectively fused.The proper kernel functions of SVM are selected in consideration of the characteristics of different type of information in order to compensate the RLG bias,which makes good result.3.Study on the error characteristics and the suppression methods of SINS under the conditions of the coupling effect of multi-physics field.The error characteristics and suppression method of multibody dynamics coupling in SINS are studied.Isotropic and eight point damping method is proposed in double-axis rotation modulation INS,which decoupled the six free dimension of inertial sensors assembly(ISA).The secondary temperature compensation method is proposed under the condition of cold start-up and quick navigation.After using this method,the maximum navigation positioning error is 0.3 nautical mile during the 8 hours under different temperatures of cold start-up.The composite magnetic shielding of of SINS is designed and simulated.The magnetic field distribution of planar ring resonators of RLG and the effectiveness of composite magnetic shielding of SINS are analyzed.The maximum magnetic sensitivity of RLG in three directions in the dual layers magnetic shielding is 0.0015°/h/mT under different magnetic fields.Based on the study of the error characteristics and the suppression methods of SINS under the conditions of the coupling effect of multi-physics field,a SINS is designed and tested under the static and dynamic navigation experiments.The maximum positioning error is 0.4 nm during 8 hours in static navigation;0.8nm during 12 hours in sway testing,which also has attitude keeping precision of 0.4'in three directions;0.2nm during 1 hour and 0.7nm during 8 hours in dynamic automobile navigation.4.The RLG non-damping attitude measuring system based on the composite material is designed and tested.Different assembling configurations with different materials are accessed by introducing the concept of dithered sensitivity of RLG.Two types of RLG non-damping attitude measuring system with different material installation brackets are simulated and tested,the result shows that the precision of attitude achieved from the system with composite material installation brackets is double higher than the system with aluminums one.5.Two types of double-axis rotation modulation INS with 50-type RLG and 90-type RLG are designed and fabricated by using the isotropic,eight point damping and center installation configuration.The IMUs of these two types of system are simulated and tested in static in laboratory.The results show that the double-axis rotating navigation experiment using 50-type RLG has achieved the accuracy of maximum error close to 1 nm/5 days.The precision of maximum error 0.7 nm/5 days is achieved by using the damping technology.The double-axis rotating navigation experiment using 90-type RLG has achieved the accuracy of maximum error 0.8 nm both in 12 days and 14 days.