Abstract: A rate controlled noise filter according to the present invention comprises a transient detector adapted to receive an input signal and detect the rate at which the input signal is changing. The transient detector may be, for example, a filter having a second order filtered rate. The output of the transient detector is input to a function generator which outputs a signal indicative of the rate of change of the input signal. A noise filter, including a controllable time constant, also filters the input signal. The output of the function generator controls the time constant of the noise filter.

Abstract: This invention eliminates overshoot of critical engine operating limits by preventing windup in a control system thus avoiding the difficulties of maintaining stability or transient response associated with conventional dynamic compensation. A slave-datum controller is limited by imposing a limit indicative of the distance between the engine's operating line and the maximum or minimum constraints imposed on the engine to avoid surge and combustor "blowout".