Gas Turbine Diagnostics Signal Processing and Fault Isolation

Widely used for power generation, gas turbine engines are susceptible to faults due to the harsh working environment. Most engine problems are preceded by a sharp change in measurement deviations compared to a baseline engine, but the trend data of these deviations over time are contaminated with noise and non-Gaussian outliers. Gas Turbine Diagnostics: Signal Processing and Fault Isolation presents signal processing algorithms to improve fault diagnosis in gas turbine engines, particularly jet engines. The algorithms focus on removing noise and outliers while keeping the key signal features that may indicate a fault. The book brings together recent methods in data filtering, trend shift detection, and fault isolation, including several novel approaches proposed by the author. Each method is demonstrated through numerical simulations that can be easily performed by the reader. Coverage includes: Filters for gas turbines with slow data availability Hybrid filters for engines equipped with faster data monitoring systems Nonlinear myriad filters for cases where monitoring of transient data can lead to better fault detection Innovative nonlinear filters for data cleaning developed using optimization methods An edge detector based on gradient and Laplacian calculations A process of automating fault isolation using a bank of Kalman filters, fuzzy logic systems, neural networks, and genetic fuzzy systems when an engine model is available An example of vibration-based diagnostics for turbine blades to complement the performance-based methods Using simple examples, the book describes new research tools to more effectively isolate faults in gas turbine engines. These algorithms may also be useful for condition and health monitoring in other systems where sharp changes in measurement data indicate the onset of a fault.

IntroductionBackgroundSignal ProcessingTypical Gas Turbine DiagnosticsLinear FiltersMedian FiltersLeast-Squares ApproachKalman FilterInfluence CoefficientsVibration-Based DiagnosticsIdempotent Median FilterWeighted Median FilterCenter Weighted Median FilterCenter Weighted Idempotent Median FilterTest SignalError MeasureSummaryMedian-Rational Hybrid FiltersTest SignalsRational FilterMedian-Rational FilterNumerical SimulationsSummaryFIR-Median Hybrid FiltersFIR-Median Hybrid (FMH) FiltersWeighted FMH FilterTest SignalNumerical SimulationsSummaryTransient Data and the Myriad FilterSteady-State and Transient SignalsMyriad FilterNumerical SimulationsGas Turbine Transient SignalWeighted Myriad AlgorithmAdaptive Weighted Myriad Filter AlgorithmSummaryTrend Shift DetectionProblem FormulationImage Processing ConceptsMedian FilterRecursive Median FilterCascaded Recursive Median FilterEdge DetectionNumerical SimulationsTrend Shift Detection SummaryOptimally Weighted Recursive Median FiltersWeighted Recursive Median FiltersTest SignalsNumerical SimulationsTest Signal with OutliersPerformance ComparisonThree- and Seven-Point Optimally Weighted RM FiltersSimulationsKalman FilterKalman Filter ApproachSingle-Fault IsolationNumerical SimulationsSensor Error CompensationSummaryNeural Network ArchitectureArtificial Neural Network ApproachKalman Filter and Neural Network MethodsAutoassociative Neural NetworkSummaryFuzzy Logic SystemModule and System FaultsFuzzy Logic SystemDefuzzificationProblem FormulationFuzzificationRules and Fault IsolationNumerical SimulationsSummarySoft Computing ApproachGas Turbine Fault IsolationNeural Signal Processing—Radial Basis Function Neural NetworksFuzzy Logic SystemGenetic AlgorithmGenetic Fuzzy SystemNumerical SimulationsSummaryVibration-Based DiagnosticsFormulationsNumerical SimulationsSummaryReferencesIndex

Dr. Ranjan Ganguli is a professor in the Aerospace Engineering Department of the Indian Institute of Science (IISc), Bangalore. He received his MS and Ph.D. degrees from the Department of Aerospace Engineering at the University of Maryland, College Park, and his B.Tech. degree in aerospace engineering from the Indian Institute of Technology. He has worked at Pratt & Whitney on engine gas path diagnostics and, during his academic career at IISc, has conducted sponsored research projects for companies such as Boeing, Pratt & Whitney, Honeywell, and HAL. He has authored or coauthored three books, published more than 140 papers in refereed journals, and presented more than 80 papers at conferences. He is a fellow of the American Society of Mechanical Engineers, the Royal Aeronautical Society, and the Indian National Academy of Engineering, and an associate fellow of the American Institute of Aeronautics and Astronautics. He received the Alexander von Humboldt Fellowship and the Fulbright Fellowship in 2007 and 2011, respectively. He is an associate editor of the AIAA Journal and the Journal of the American Helicopter Society.