Fault detection and isolation in nonlinear dynamic systems: A combined input-output and local approach

The problem of fault detection and isolation (FDI) is addressed for nonlinear dynamic systems modeled by polynomial differential-algebraic equations. Ritt's algorithm is used to obtain an input-output representation of the monitored system by eliminating unknown variables. A local approach to change detection is then applied to the input-output representation for FDI residual generation and evaluation. Simulation results on a microbial growth process are provided, which illustrate the relevance of the proposed FDI method. (C) 1998 Elsevier Science Ltd. All rights reserved.