US Patent 11047253 Model-based rotor speed keep out zone control

A system for keep out zone control includes a gas turbine engine and a controller operable to determine a closing threshold with respect to an upper limit and an opening threshold with respect to a lower limit of a movement range of an effector of the gas turbine engine based on an on-board model, where the upper limit and the lower limit define a keep out zone of a target parameter of the gas turbine engine. The controller determines a projected state of the target parameter absent a correction command to the effector, applies a closing correction to the effector based on determining that the projected state of the target parameter would result in being above the closing threshold, and applies an opening correction to the effector based on determining that the projected state of the target parameter would result in being below the opening threshold.