Research On Attitude Control Law Of Endo-Atmospheric Missile

Kinetic kill vehicle (KKV) is the primary weapon of the antimissile and antisatellite defence system, the rapidity and the stationary of attitude control system are the key whether KKV can intercept the target or not. The actuators of attitude control system employ constant thrust on-off jets on the stern, and then the issue to control the attitude of KKV is how to design the on-off logic of the attitude thrusters.Firstly,this paper describes the back round of my paper and the generation, characteristics, questions of variable structure control . Then some coordinate frames which are needed in the research are defined and the switch relations between these coordinates are also introduced. We analysis the forces which are acted on the missile, build up models which can describe the missile's nonlinear dynamics and then the math models are predigested under some hypothesizes.Secondly, we give the basic concepts, main contents, usual design methods of sliding variable structure control and an chattering phenomenon of is studied in this dissertation, some ways used to eliminate the twitter. This paper studies the design of attitude control law for KKV using dynamic sliding-mode variable structure approach .The pitching model is established firstly.Then the control law is designed using sliding-mode variable structure control theory. Develop a new method for designing interceptor controller, while the interceptor is anon-linear, strong coupling and variation system and its engine force has nonlinear specialty. The structure, design process and the way of calculating the parameter are presented also. Considering constraint of minimum thrust impulse,the control law is corrected. This law can be carried out easily.At last this paper researches the system's simulation problem and presents the simulation result under my designed control law. The simulation result shows that the variable structure automatic pilot for KKV is high attitude control accuracy, which satisfies the requirements, the sat function used here eliminate the twitter. Then the simulation methods prove that the controller has satisfactory performance, simple structure and it is facility to actualize when the initial input and aerodynamic coefficients are changed.