Strapdown Inertial Navigation System Error Calibration Method

In recent years,strapdown inertial navigation system is rapidly developing to replace the platform inertial navigation system.The gyroscope and accelerometer is the main navigation information measuring unit of the strapdown inertial navigation system, its precision directly determines the precision of the strapdown inertial navigation system.The development of inertial measuring element has decisive to the development of navigation system.In the 1980 s, with the development of semiconductor technology, micro mechanical inertia measuring unit,low cost, can be mass production,has developing rapidly.In this paper, the micro mechanical IMU STIM300 as test object,analysis and research the error sources of inertia navigation system, error model and error calibration method.Through the analysis of error sources, use scale factor error and random error,installation error and bias error as a gyroscope and accelerometer static error model of the error parameter.Using rate testing and 12 position testing to separate calibration for IMU, combined with the least-square, to identify the scale factor, the installation error and bias error.Providing the way to examine and correct installation error and bias error.Micro mechanical gyro,has a lots of random noise, is an important affected to the accuracy of inertial measuring component.In order to analyze and eliminate the influence of random error, this article the using time series analysis method to set up the ARMA model of random error and using Allan variance analyzing the composition of the random error.Design Kalman filter to eliminate random error, and it can improve the navigation accuracy.For systematic calibration,under the condition of static base, establishing the velocity error calibration method for the observation information in the Laboratory.prove that the 24 error coefficient of accelerometer and gyroscope can be observed and identified,giving a way of test scheduling.