Attitude Determination Based On Geomagnetic Field And Its Application On Precision Guidance Ammunition

Attacking accuracy is an important technical evaluation indicator of weapon equipment. Artillery plays an important role in the weapons to every country, many researches focus on the attack accuracy of artillery. For the ordinary artillery, the ammunition is uncontrollable after launch, which results in the dispersion of the falling point of ammunition. This result can’t meet the requirement of precision accuracy. To solve this problem people use lots of methods to accomplish the task of guidance and navigation of artillery ammunition, among th ose methods there is the geomagnetic navigation. This thesis wants to find a possible way using geomagnetic for the artillery ammunition.Firstly, the research focuses on the model of the kinematics of the uncontrolled flying ammunition. According to the ballistic theory for vacuum situation and air situation, we obtain the kinematic equations. Using the kinematic equations we can have a general understanding about its kinematics.Secondly, the knowledge of geomagnetic navigation is an essential part of thi s work. We use the geomagnetic field to accomplish the task of guidance and navigation, the cognitive of those characteristics is useful. With the help of geomagnetic model, we calculate the geomagnetic field map. Then the magnetic sensors are introduced to find a good way for measuring. Our research group have already developed a precise magnetometer.Thirdly, two kinds of methods are proposed to accomplish the attitude determination of artillery ammunition. One method use the magnetic field data acquired from the three axes magnetometer to compute the attitudes directly by the kinematic. The other method use optimal estimation to get those parameters that we concerned such as attitudes and location. We build the system modle in state-space. Due to the nonlinear feature of the system, this method choose extended kalman filter, unscented kalman filter and some other kind of filters. The first method can measure the attitudes, the second can obtain attitudes and location.Finally, after simulations of those two methods, we begin the ground test experiment. In consideration of the conditons that we own, we put forward the experimental scheme. To accomplish the experiment, we debug the experiment equipments and write the control program. The experiment prove the effectiveness of the method we proposed.