Turbine engine thrust scheduling
AssigneeROLLS-ROYCE plc
InventorAngela J. Shepler
Life of this patent
Estimating the term…
Abstract
This invention relates generally to gas turbine engine thrust scheduling, and more particularly to systems and methods for smoothing thrust inputs to gas turbine engines. In one embodiment, a method for operating a gas turbine engine comprises, upon disengagement of an auto-throttle system, determining a first trim setting corresponding to a TLA setting, determining a second trim setting where the second trim setting reduces to zero during successive manual throttle lever movements, determining a third trim setting comprising a combination of the first trim setting and the second trim setting, and applying the third trim setting to the TLA setting to smoothly transition from auto-throttle to manual operation of the engine while maintaining engine thrust.
Claims21
A method for operating a gas turbine engine, comprising:
- before disengagement of an auto-throttle system, receiving, by an engine controller, a Throttle Lever Angle (TLA) setting and a TLA fine trim setting applied by the auto-throttle system that together provide a desired engine thrust;
- upon disengagement of the auto-throttle system, determining, a first trim setting corresponding to the TLA setting;
- determining, by the engine controller, a second trim setting defined from the first trim setting and the TLA fine trim setting, wherein the second trim setting gradually reduces to zero during successive manual throttle lever movements;
- determining, by the engine controller, a third trim setting comprising a combination of the first trim setting and the second trim setting;
- and
- applying the third trim setting to the TLA setting as a substitute for the fine trim setting to smoothly transition from auto-throttle to manual operation of the engine while maintaining engine thrust.
A method for operating a gas turbine engine, comprising:
- upon disengagement of an auto-throttle system, determining by an engine controller, a Throttle Lever Angle (TLA) trim setting corresponding to a measured TLA, wherein the TLA trim setting gradually reduces to zero during successive manual throttle lever movements;
- and
- applying the TLA trim setting to the measured TLA to transition from auto-throttle to manual operation of the engine while maintaining engine thrust;
- a lookup cycle corresponding to a current measured TLA, wherein for each lookup cycle, the engine controller creates a lookup table comprising a plurality of TLA trim settings as a function of TLA, wherein the engine controller determines a current TLA trim setting corresponding to the current measured TLA;
- wherein the engine controller sets the TLA trim setting in the lookup table equal to zero for TLA's corresponding to engine idle thrust and to maximum takeoff thrust, and to the current TLA trim setting for TLA's between engine idle thrust and maximum takeoff thrust;
- wherein the engine controller is a computer processor.
A method for operating a gas turbine engine, comprising:
- automatically maintaining engine thrust when transitioning to manual operation of the engine following disengagement of an aircraft auto-throttle system, comprising
- substituting a first Throttle Lever Angle (TLA) trim setting computed by an engine controller for a last TLA trim setting provided by the auto-throttle system;
- adding, by the engine controller, the first TLA trim setting to a measured TLA setting to form a new TLA setting;
- and
- applying the new TLA setting to the engine to maintain engine thrust, wherein subsequent manual throttle movements gradually reduces the first trim setting to zero.
Dependencies are inferred from the claim text.