Dynamic threshold generators for fault detection in uncertain systems

Authors:	Johansson Andreas, Luleå University of Technology, Sweden Bask Michael, Luleå University of Technology, Sweden
Topic:	6.4 Safeprocess
Session:	Active fault diagnosis/ Decision system design
Keywords:	Fault detection, thresholds, uncertain linear systems, flotation

Abstract

The problem of developing robust thresholds for fault detection is addressed. An inequality for the solution of a linear system with uncertain parameters is provided and is shown to be a valuable tool for developing dynamic threshold generators for fault detection. Such threshold generators are desirable for achieving robustness against model uncertainty in combination with sensitivity to small faults.The usefulness of the inequality is illustrated by developing an algorithm for detection of clogging in the valves of a flotation process. Simulations with measurement data show that the algorithm detects faults without generating false alarms.