Recovery of Fault Signatures in Diesel Engines 880824

Cylinder combustion and fuel injector pump pressures and forces due to impacts of valve and seat and piston slap are signals of interest for diesel engine diagnostics. The vibration signals that these forces generate are easier to measure than the forces themselves, but unfortunately the signals are greatly changed as they travel through the engine structure. In addition, the vibration transmission of engine structures varies from one copy of the engine to another. Signal processing procedures for the recovery of fault signatures from vibration signals must take both the structural variability and the complexity of the transfer function into account. A robust/adaptive process that uses cepstrum windowing, singular value decomposition, and Kalman filtering as elements of its procedures has been applied to recovery of the combustion pressure pulse in a diesel engine.