Gain Scheduling Based Control System Design Of Surface To Air Missile

A hit-to-kill interceptor achieves direct collision with a maneuverable target by precision guidance, and destroys the target with kinetic energy. At about 20km altitude, the aerodynamic shape of the interceptor is able to create a desired divert acceleration for precision guidance, but the response to a guidance command is getting much slower because of the control fin's weak effectiveness. The blended control, which means the combination of lateral thrust control and aerodynamic control, can evidently increase the response speed of the interceptor's control system. In this thesis, the design of aerodynamic and lateral thrust blended control law using the gain scheduling method is investigated.First of all, the nonlinear model of interceptor with lateral thrust is deduced. Then the plant is linearized around different operating points, and which leads to the linear parameter-varying model. With the pitch loop as an example, we design the missile's lateral thrust and aerodynamics blended control system.Assuming that the lateral thrust is provided by impulse thrusters, we design the control system with the following strategy. The tail fin's controller is designed independently, and then all the continuous parts, including the fin's controller, are reunited into a new controlled plant of the ignition number of the impulse thrusters which is in discrete-time form. A dynamic gain scheduling method is employed in the system design. Compared with the static gain scheduling and fixed gain method, the dynamic gain scheduling gives better transient performance and improves the transient performance of tail fins.The problem about how to save the impulse thrusters is discussed. Theoretically, we give the possibility of decreasing the use of impulse thrusters. Then we use simulation to verify the idea.Finally, we simulate the interception processes against an airplane or a reentry ballistic missile target from the mid-course guidance to the engagement. The simulation results prove that the interceptor can hit the target effectively.