Research On Rotation Modulation Attitude Error Model Of Rotational Inertial Navigation System

Inertial navigation uses inertial sensors(gyroscopes and accelerometers)to measure the angular velocity and acceleration of the vehicle to calculate navigational information such as the speed,position and attitude of the vehicle.However,the inertial sensor component error such as the zero-bias effect of the gyroscope may cause navigation system error.For the self-compensation of inertial device error,an effective method is to use the rotary modulation technique,but the rotary modulation technique will cause additional rotational modulation attitude error.It directly affects the attitude measurement accuracy,and lays a theoretical foundation for the real-time compensation of the rotational modulation attitude error.The paper studies the rotational modulation attitude error law and establishes the error model to comprehensively describe the real-time attitude error caused by the error sources of the inertial navigation system.This study introduces the principle of rotational modulation inertial navigation error modulation and attitude measurement.Based on this,the error parameters causing real-time attitude error are comprehensively analyzed: gyroscope constant value drift,scale factor error,inertial device mounting error,angle measurement error and rotating device.Installation error,etc.,and establish an error coordinate system to comprehensively describe the influence of the error parameters on the attitude measurement matrix;In order to verify the real-time attitude error model,based on the single-and two-axis rotational inertial attitude measurement principle,the relationship between the error parameter and the attitude output is derived,and the equation of state of the attitude error related to the rotational modulation angle,navigation time and rotation order is established;The analytical solution of the rotational modulation attitude error caused by the error parameter is comprehensively derived,and the relationship between the error parameter and the rotational modulation attitude error period and amplitude is analyzed,and then the real-time model of the rotational modulation attitude error is established,and the variation law of the attitude error is clarified,and the simulation method is used.Verify its laws and theoretical results;In this paper,the error parameter calibration based on the rotational modulation attitude error model is proposed and the error parameter calibration algorithm is given.In order to verify the effectiveness of the proposed theory for the accuracy compensation of the rotating navigation system,the uniaxial rotary modulation model with continuous positive and negative reversal is selected.Based on the two-axis rotary modulation model of sixteen-order rotation,the full-precision error model and the navigation real-time attitude error model of single and dual-axis rotary modulation are constructed respectively.Combined with the real-time attitude error model of rotational modulation,the error parameter calibration of navigation system is studied.Algorithm,simulation results verify the feasibility of the error model.