Abstract:

when airplanes fly in large flight envelope, it is often required that their control systems have robust property because of the variation of aerodynamics and structure parameters. If using classical control theory, it would be very difficult to design a flight control system to meet pre-determined performance indices for each flight envelope. This paper is to apply variable structure system （VSS） theory to flight control system design, A general technique for scalar VSS CAD is suggested and special attention is paid to engineering application. A numerical example is given and is compared with original PD control by simulation.It is obvious that the variable structure flight control system is insensitive to the flight parameters change and external disturbances.

Key words: variable structure, robust, control system