Robust digital control of a high-performance engine

The design of a robust digital multivariable feedback control system for the F-100 turbofan jet engine is considered. The control system design problem is posed, and conditions for satisfying performance specifications and stability robustness are stated. The discrete LQG/LTR methodology is used to design a compensator that meets the stated specifications. New results for multi-input LQR loop shaping are derived. To get a reasonably low-order compensator, frequency-weighted reduced-order models are exploited, with the reduction error treated as an uncertainty.