Research On Single Point Calibration For Laser-gyroscope Inertial Navigation System

The application envirornment of ships and submarines require that the Inertial Navigation System to work for days or even months.However,based on the principle of inertial navigation systems,the excessive accumulated divergence errors would lead to the system loses the navigation capability,thus to ensure long-endurance high-precision inertial navigation capability is crucial.Studies have shown that the inertial device is the core of inertial navigation system,to meet the demand of high-accuracy inertial navigation system,the key point is to improve the precision of inertial device.Considering the technical costs and the research & development cycle,to develop high-precision inertial component is undesirable.Therefore,we need to take system-level compensation technology to achieve high precision.Rotating modulation technology belongs to the category of the automatical system compensate,which can eliminate a number of laser gyroscope inertial navigation error factors and make the system output errors contain only the random drift and residual error.Working in the level damping mode,the influence of random drift can be eliminated.Taking the residual error as constant,the direct correspondent relationship between the position/heading Angle error and the gyro constant drift can be derived by setting up the error equation,and thus the residual constant error can be eliminated by single point calibration technology.In this way the high-accuracy and long endurance inertial navigation capabilatility can be realized.In this thesis,firstly focusing on the laser gyro strapdown inertial navigation system,the mechanism of biaxial rotating the compensation effect of error and biaxial rotating laser gyro inertial navigation system residual error mechanism are analyzed.Furthermore,the sixteen-sequence two-axis indexing scheme and feasibility of its implementation are studied.The error form of the rotary strapdown inertial navigation system and the principle of the external speed horizontal damping algorithm based on modern control theory to eliminate Shuler oscillation are analyzed.Horizontal damping mode ensures the reasonable relationship between the position error and gyro constant drift.Through analysis,considering single point position correction theory and method under conditions of limited external position information,four kinds of mathematical models of single-point calibration method are derived.Based on optimal conversion principles a smooth transition process is implemented.After algorithm analysis and modeling of biaxial horizontal damping mode laser gyro inertial navigation system and single-point calibration,system simulation mathematical model is constructed,MATLAB simulation is implemented.Through comparative analysis,the feasibility and effectiveness of the algorithm is verified,and the advantages and disadvantages of the four kinds of single-point calibration method is analyzed.