Research On Composite Calibration And Alignment Of Micro Inertial Components In High Dynamic Environment

For the calibration and compensation of MIMU in the field of navigation and missile navigation,the initial alignment between static base and moving base has been a hot and difficult issue at home and abroad.During the initial alignment,alignment accuracy and alignment time control are the key technologies.In this paper,MEMS inertial devices pretreatment and the initial alignment under dynamic and static base conditions were studied:1.The pre-processing is done before the initial alignment.After analyzing the working principle and error of the gyroscope and accelerometer,the experiment is carried out by combining dynamic and static methods.The least square method is used to solve the parameters.Gyro and accelerometer calibration and compensation.2.Although the MIMU(micro-inertial measurement unit)compensated by the error model has reached a certain precision,in practical application,the carrier flight process is a composite attitude movement in pitch,roll and yaw direction.In this paper,the error model of a gyroscope in a micro inertial component is established for a specific flight environment.A compound calibration method is proposed to solve the coupling parameters.The coupling error in the original data is removed to improve the output accuracy of the device.3.The initial alignment method under the condition of static base is studied.Using the method under the condition of the combination of accelerometer and magnetometer in the coarse alignment stage.The calculation of pitch angle and roll angle depends on the accelerometer,the solution of the heading angle uses the magnetic sensor.In the fine alignment stage,the 10-dimensional state variables are selected,and the equation of state is derived from the error equations of velocity and misalignment angle.Choosing observations to establish the observation equations.Then,the kalman filter is used to estimate the state variables.4.Aiming at the method of coarse alignment under the condition of moving base,Firstly,the matrix of the strapdown is decomposed,and the problem of alignment is transformed into the problem of finding eigenvectors by using the recursive dynamic algorithm.This eigenvector is used to update the quaternions.Carrying out vehicle-mounted experiments for data acquisition and using real data for simulation verification.