Design of H∞ proportional-integral thrust controller for ramjet engine

This paper presents the design of a thrust controller for a ramjet engine. The mathematical model for controller synthesis is based on a numerical solution of a set of nonlinear equations. Transfer functions of the engine are found for certain operation points defined by the altitude, Mach number and angle of attack. Local controllers are developed by using H∞ control methodology, finally reduced to proportional-integral (PI) controllers. For gain scheduling, linear interpolation of parameters of the local PI controllers is used. Next, simulations are performed in order to show performances of the presented control algorithm.