A method and system is provided for identifying in-range sensor faults in
a gas turbine engine, by observing the tracked component qualities in an
embedded model and recognizing anomalous patterns of quality changes
corresponding to sensor errors. An embedded model of the engine is
employed to estimate sensed parameters such as rotor speeds, temperatures
and pressures, as well as other parameters that are computed based on
input parameters. Each major rotating component of the engine, including
the fan, compressor, combustor, turbines, ducts and nozzle is
individually modeled. Sensor failures are detected by identifying
anomalous patterns in component quality parameters. A library of
anomalous patterns is provided for comparing quality parameters generated
by a tracking filter with the library of anomalous patterns. If a pattern
is matched, a sensor may be eliminated from the tracking filter and the
estimated model parameter used to avoid corrupting the model quality
parameters.