Application of h∞ robust control to the RM12 jet engine

Abstract Turbojet engines are becoming increasingly complex, with more control variables, to meet future demands on performance, fuel consumption and functionality. To utilise the potential of the engines, it is also necessary to use more advanced control concepts than are conventionally used today. The trend is towards control concepts often referred to as ‘Smart Engines’. Multivariable controllers are most often the core of these systems. A multivariable control concept for a jet engine is proposed and investigated in this paper. The feedback control law is based on H ∞ -design. The control concept is applied to the RM12 jet engine for the Swedish fighter aircraft JAS 39 Gripen in a research program for future advanced control. The controller has so far been developed for the core engine operating range, at sea-level static conditions, and evaluated via simulation with a detailed non-linear model. This evaluation clearly shows the potential of using more advanced control methods in the area of jet engine control. Finally, suggestions on how to continue the research program towards a future advanced control concept are given.