Gain-Scheduled Multivariable Control for the GE-21 Turbofan Engine using the LQG/LTR Methodology

This paper presents a feasibility study related to the design of a global nonlinear multivariable compensator for a model of the GE-21 double-bypass variable cycle jet engine. The nonlinear engine dynamics are linearized at nine distinct operating conditions. Scaling of variable units and Singular Value Decomposition at DC identified the subset of controls and outputs for dynamic control. At each operating condition an LQG/LTR compensator is designed; the parameters of the LQG/LTR compensator are then scheduled to produce a global dynamic compensator. Transient simulations are included to illustrate the characteristics of the nonlinear multivariable control system.