A modified observer scheme for fault detection and isolation applied to a poorly observed process with integration

This paper investigates the application of the dedicated observer scheme (DOS) to a real tank system. As described, this system is not 'DOS-instrument-fault-detectable' due to the location of the sensors and the dynamical characteristics of the system itself. In order to overcome such a difficulty, this work proposes a dedicated observer scheme with periodic resetting (DOSPR). The design of the observers and the new algorithm are detailed in the paper. The new procedure was tuned and tested on a pilot plant. A complete nonlinear model with physical parameters measured from the plant are included. Some results are discussed in the paper. (C) 1997 Elsevier Science Ltd.