Abstract: Variable elements of a turbine engine such as variable inlet guide vanes, variable bleed valves and variable stator vanes can be adjusted to provide a desired level of power and/or efficiency for the turbine engine across a range of operating conditions. The variable element settings typically determined through experimentation when the engine is new. Unfortunately, over the life cycle of the turbine engine, as wear occurs, the original variable element settings may no longer provide a desired level of power and efficiency. To correct this problem, offsets to the original variable element settings are calculated based on observable operational conditions which provide a measure of the wear that has occurred. The offsets are applied to the original variable element settings to generate corrected variable element settings. These corrected variable element settings are then used to configure the turbine engine.

Abstract: A method of monitoring a physical parameter comprises receiving a sensor signal representative of an actual value from each of a plurality of sensors. The method further comprises calculating confidence value for each sensed value and a weighted average of actual values of the sensor signal by weighting each sensed value by the respective confidence value. The weighted average is used to determine a corresponding value of the sensed parameter.