Design On Altitude Control System Of Cruise Missile Based On Fuzzy Logic

This dissertation research the altitude control system of the cruise missile when it is cruising. In modern times the flying height of the cruise missile is below 30 meters. So the flying height of the missile is an important parameter of the control system. The traditional design method of missile is PID control, but the PID controller is based on the accurate mathematical model of the missile. The missile is a high rank, nonlinear, time-varying system, so it is very hard to build up its mathematical model accurately. The fuzzy control does not depend on the accurate mathematical model of the controlled objects, has fine robustness, could adapt to the changes of system parameters. So this paper adopt fuzzy controller to control the flying height of the missile, make a useful study.The model of the missile's altitude loop is derived by reasonable simplification of the movement equation and the transfer function. The PID controller of the altitude loop is designed, use the Nonlinear Control Design Blockset of the Matlab to optimize the PID parameters, the simulation result is given. After analyze the theory of the fuzzy control, design general fuzzy controller which adopts Mamdani fuzzy logical reasoning and modifiable fuzzy controller which adopts Sugeno fuzzy logical reasoning. The simulation result show that the two fuzzy controllers respond faster than PID controller. Both the general fuzzy controller and the modifiable fuzzy controller use the error and the variable rate of the error as inputs, So they could be looked as special kinds of PD controller. They do not have integrators, when change the parameters of the controlled objects or when there is jamming the accuracy will be affected. To overcome this disadvantage, design a fuzzy-PID control system, this system tune the PID parameters real-time by using fuzzy controller. The simulation result show that fuzzy-PID controller respond faster than PID controller and have less...