Investigation On Date Fusion Method Based On Magnetometer/Gyro Combined Measurement Of Projectile's Flying Attitudes

The measurement of flying projectile's attitudes must have to be resolved in design of guided projectile. The projectile's flying attitudes is measured with magnetometer/gyro combined method in this thesis, and the sensor signals are processed by two different data fusion methods respectively, one is based on weight coefficient and the other based on Kalman filtering, at last, build two projectile attitude angle's analytic and computable methods based on weight coefficient and UKF.During the process of resolving attitude angle, let the yaw angle can be ignored or can't be ignored, the initial attitude angle and real-time attitude angle's analytic and computable method is build respectively. The simulation results demonstrate that the resolving error gained under this two situations are about the same. But when the yaw angle is ignored, the projectile's attitude angle can be determined only use magnetometer sensor without the help of gyro signal. That means if the gyro signal is abnormal, the projectile's attitude still can be fixed, and vice versa.On the study of data fusion method based on weight coefficient, after the initial attitude angles are determined, the projectile's real-time attitude angle can be fixed via integrating gyro's signal, and then regard the yaw angle which obtained from calculation as known quantity, so the real-time pitch angle and roll angle can be obtained from magnetometer signal. At last, the weight coefficient is determined by using weight distribution of least variance estimation method, a projectile attitude angle's calculating solution based on weighted coefficient is built. On the study of data fusion method based on Kalman filtering, magnetometer and gyro combination method measurement system's measuring equation is built on the basis of magnetometer and gyro's installing method, test theory and different coordinates systems'transformational relation. With the discrete measuring equation and the state equation as system's model, the projectile attitude angle's analytic and computable model based on the UKF is framed.The simulation results demonstrate that towards the uncontrolled flying projectile, the method based on UKF can real-time estimate projectile's attitude angle with higher precision after the magnetometer and gyro combined measuring system tracking the projectile's flight 10s, what's more, the steady error after convergence is less than the error obtained by using weight coefficient method; for the controlled flying projectile, the method based on UKF can also real-time estimate projectile's attitude with higher precision after the magnetometer and gyro combined measuring system tracking the projectile's flight a short time, and when the control plane occurs instant change, it can also track the signal's change quickly and calculate the projectile's real time attitude angle which meets required precision.