METHOD AND SYSTEM FOR MODEL BASED CONTROL FOR VARIABLE PITCH FAN ENGINES AND TURBO-SHAFT, TURBO-PROPELLER ENGINES

摘要

A method and control system for an aircraft engine comprising a gas turbinedriving a fan propeller with a mechanical gear-train and a dedicated pitchchangemechanism for the fan propeller includes a fuel flow signal input; a pitchchangemechanism signal input; a controlled plant for relating a pitch changemechanism pitchangle (BetaP) and a fuel flow (Wf) to at least two controlled outputs and aset ofconstraints. A decoupling control decoupling the controlled plant and/or theconstraintsinto two separate single-input single-output (SISO) control loops for thefirst and secondcontrolled outputs and a decoupling control decoupling the constraints fromthedecoupled controlled outputs and the constraints from one another provide gasturbineand fan propeller coordinate control while coordinately controllingconstraints andoutputs. A feedforward control can compensate the load change effect on enginespeedand fan propeller rotor speed control.