Fault detection of flight critical systems

Describes initial results of a project developing fault tolerant control systems for critical aircraft systems and focuses on the early detection of faulty components. The main goal is the use of signal processing techniques to analyze sensor information and data-mine changes that could be attributable to faulty behavior. The approach compares well with residual-based techniques but requires only output data. Hence, it could be applied to situations where residual-based approaches are not feasible. We present the use of orthogonal filter banks as the processing elements to create fault indicators. The case study is an F14 jet fighter. Using computer simulations we create various faults and monitor the plane angle of attack. The filter bank creates a number of orthogonal components, some of which have a clearly distinct pre and post fault behavior. This behavior changes with the type of fault suggesting that it is possible to classify the faults. Another issue addressed is the generation of alarm signals based on the results of the fault detector. The paper discusses how the information in the components can be processed to create automatic alarm systems.