Research On Mathematical Problems Related To The Attitude Test System Based On Magnetometer

Attitude test of flying projectile is so important to the research and development and theprecision of weapon. The traditional sensors of attitude test mainly are accelerometer,gyroscope and GPS etc. This article is to test the flying attitude of projectile bymagnetometer. Compared with the traditional sensors of attitude test, magnetometer has thefollowing three advantages:(1) simple structure;(2) anti-overload;(3) anti-interference.Therefore, based on magnetometer system, this paper shows a research about the attitude test,trying to seek more accurate attitude testing methods.Due to the limited flight distance of tactical projectile, we assuming that magnetic field isunchangeable in the projectile’s flight area and that the projectile will flight in the samevertical plane, then it will be feasible to test the attitude of projectile by using magnetometer.Attitude test mathematical model, which was established based on the knowledge of advanceddynamics, is an over-determined nonlinear equation. Finally, based on the Matlab software,we can solve the over-determined nonlinear equation by Fletcher algorithm, proving that theabove mathematical model and the attitude test are accurate and feasible.During the attitude test, signal of magnetometer inevitably will generate random noise,which affects the accuracy of the attitude test seriously. So using appropriate noise-reductionmethod to reduce the random noise, which generates by signal outputting process ofmagnetometer, is an absolutely necessary process to improve the accuracy of the attitude test.This paper also shows a new noise-reduction method, which based on the combination ofadvanced local mean decomposition and of Wavelet. Through the signal noise-reduction test,we found that the new noise-reduction methods is better than the method of transformingWavelet directly and the method of transforming wavelet based on ensemble empirical mode decomposition, which also been proved by the test of reducing magnetometer’s signal noise.As a result of all the above factors combined, this paper adopts the new noise-reduction method,which based on the combination of advanced local mean decomposition and of Wavelet, topreprocess the data.