Fault detection and identification in dynamic systems with noisy data and parameter modeling uncertainties

A probabilistic approach is presented which can be used for the estimation of system parameters and unmonitored state variables towards model-based fa ult diagnosis in dynamic systems. The method can be used with any type of i nput-output model and can accommodate noisy data and/or parameter/modeling uncertainties. The methodology is based on Markovian representation of syst em dynamics in discretized state space. The example system used for the ill ustration of the methodology focuses on the intake, fueling, combustion and exhaust components of internal combustion engines. The results show that t he methodology is capable of estimating the system parameters and tracking the unmonitored dynamic variables within user-specified magnitude intervals (which may reflect noise in the monitored data, random changes in the para meters or modeling uncertainties in general) within data collection time an d hence has potential for on-line implementation. (C) 1999 Elsevier Science Ltd. All rights reserved.