Reduced Order H ∞/ LTR Method for Aeroengine Control System

This paper proposes a new loop recovery method to solve the reduced order problem of H ∞/ LTR method. The resulted lower order controller shares almost the same performance and robustness as the original H ∞/ LTR controller. Further more, this paper develops a new order reduction method: slow-fast mode order reduction (SFMOR) method. This order reduction method is particularly effective for those controllers whose modes can be divided into a slow part and a fast part according to their velocities. Application of these methods to a benchmark example and a certain turbofan engine is described.