Research On Compound Control Technique With Direct Thrust And Aerodynamic Force For Air Defence Missile

The compound control with direct lateral thrust and aerodynamic force for advanced air defence missile is a key technique of guidance and control in the terminal phase of interception. It is also the most effective way to intercept high-speed maneuvering targets, possess the ability of missile-defense and even develop into kinetic energy interceptor. Therefore, the research on the above mentioned crucial problem is systematically and deeply carried out in this dissertation.The six-degree-of-freedom (6DOF) trajectory models of final interception are established. The forms of line-of-sight rotating rate in different coordinate systems are discussed on conditin of slow spin. The state space model of relative motion is derived in consideration of target maneuverability and the adaptive sliding-mode guidance law (ASMG) of defensing maneuvering targets is investigated hereby, it can greatly eliminate the miss distance. Based on the matching condition of variable structure system, the robustness of ASMG is proved theoretically with respect to perturbation and disturbance. For the sake of improving guidance accuracy, the method for weakening flutter of ASMG is put forward by using fuzzy control theory through adjusting intensity of variable structure part according to target maneuverability. Taking the divergence of line-of-sight rotating rate in ending interception into consideration, the guidance law with predictive miss distance is studied and the way of calculating predictive miss distance is presented correspondingly.The attitude stabilization systems of the roll channel and lateral channel for air defence missile are designed combined with research backgrounds. For the purpose of the roll channel, slow spin requirements in final interception are analysed and the state space model is built. Founded on the internal model principle, it is designed that the attitude stabilization system with floating tracking control theory in time domain, then the closed loop poles are collocated in accordance with dominant poles. Simulation results show that the attitude stabilization system of the roll channel has enough robustness to ensure the stabilization of roll angular rate. To the lateral channel, the combination form of compound control is expounded based on the lateral jet interference of attitude control rockets. The attitude stabilization system of compound control is designed by using linear quadratic regulator and the feedback gain coefficient is ascertained. Amplitude limiting loops are introduced, the stability is proved through the nonlinear tolerance to the compound control system and the stability margin is obtained theoretically in virtue of frequency domain conditions. Inner loop simulation results show that the compound control system has perfect dynamic behavior at the characteristic points, its response time is less than 0.1 second. As practical situation concerned, an adaptive algorithm for the engineering application is investigated by choosing flight velocity and altitude as dispatching variables in order to improve the character of compound control system more better.It is studied that the impulsive thrust vector control of attitude control rockets for air defence missile in its launch-phase. The target function is presented and the method for computing control parameters is brought forward under the condition of flight state variables prediction. It is known that this control method can enlarge the battle sky and decrease the lateral overload of midcourse flight.In order to offer a way of trying to simulate actual flight environment, a comprehensive simulation software for the 6DOF trajectory of final interception with compound control is developed. Taken the helical maneuverable target as an example, obtained are the following conclusions by the simulative computation and analysis: 1) The results under standard conditions show that the trajectory models, ASMG and attitude stabilization system of compound control are correct and rational; 2) The influence which the measurement error of radar seeker has done on the miss distance is analysed and the performance index of survey precision is put forward; 3) By using the statistical methods of Maximum error and Monte-Carlo, the miss distance of interception is analysed, the results show that the compound control system with direct lateral thrust and aerodynamic force can meet the need of hit-to-kill.The above mentioned research results will do important help to the guidance and control scheme of kinetic energy interceptor.