Research On Impulse Thrust Vector Control Technology

With the development of the missile guidance and control techniques, impulse vector control technique has been vigorously developed and widely researched, which has many advantages including insensitivity to the surroundings and fast responding. And impulse vector control is able to solve the problem that insufficient acceleration in the terminal phase of the intercept missiles. Impulse correction motor based on the impulse vector control technique could obtain high accuracy with simple structure at a low cost, has been widely applied in low-cost weapons. With the laser guided mortar missile as study object, the key techniques such as mathematical modeling, guidance law based on impulse control are studied.Firstly, a mathematical model of the impulse correction motor is established. The coordinate systems for setting up the mathematical model are defined and the exchange relations are discussed. Then the 6-DOF mathematical model including kinetic equations, motion equations, mass equations and geometric equations are established. Based on this model, the uncontrolled trajectory characteristics are analyzed, and the factors influencing the distribution of uncontrolled trajectory are discussed.Then, the form and approach of weapon terminal correction motor projectile system are introduced, the model of laser detector is established and its detecting principle is discussed. To study the impulse vector’s influence to dynamics of the missile body, a dynamic model of the missile body is established, and a double-impulse ignition method is proposed to suppress the projectile oscillating. The correction capability of one impulse engine is discussed, which provides a reference to parameter determination of the engines.Thirdly, guidance laws of the impulse correction motor are discussed. Two traditional guidance laws, velocity pursuit guidance law and body pursuit guidance law are introduced and contrast analyzed. To suppress projectile oscillating’s influence to the body pursuit law, a fake-velocity pursuit law base on the body pursuit is put forward, and a trajectory tracking guidance law based on the error angle is proposed to improve the guidance accuracy. The simulation results show that the guidance laws are able to decrease miss distance significantly.The last, the approach to design the missile autopilot and guidance law based on impulse attitude control is discussed. An approach of impulse attitude control is proposed, and the two-loop autopilot based on the discrete and keep way. The trajectory simulation with the proportional navigation guidance indicates that impulse force control could increase the response speed and maneuvering capability effectively.