Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

Fault diagnosis with unprecise data using temporal bands

The aim of the CHEM project was to develop and implement advanced Decision Support Systems (DSS) for process monitoring, data and event analysis, and operation support in industrial processes. The systems are synergistic integration of innovative software tools, which improve the safety, product quality and operation reliability as well as reduce the economic losses due to faulty states, mainly in refining, chemical and petrochemical processes.

The CHEM applications consist of integrated sets of software toolboxes that provide robust detection and diagnosis of process problems in real-time. The systems assist operators in assessing process status and responding to abnormal events. The project provides a flexible architecture and a methodology in order to facilitate the development of such applications on many processes.

The diagnosis of analog systems raises many specific difficulties, which justify the development of specific methods. This toolbox provides a fault detection and isolation procedure especially well adapted because no derivative approximation is required and imprecise data continuously varying over time are considered using temporal band sequences. Due to those particularities, no false alarms are ensured. Based on the Model-based diagnosis approach, results are deduced from the evaluation of residuals consistency and allow multiple faults isolation.

The piecewise nature of the processed residuals allows to model many real-life systems, including models defined by diagrams. Intermediary states (brutal changes in the structure of the system, such as opening of valves) which are generally very badly known, can be described by very rough models without limiting the diagnostic power of the method since the evaluation process is based on integration and hence the contribution of intermediary states in the value of the residuals remain negligible.

During past years, THALES Airborne Systems has developed research in the field of continuous dynamic systems aiming at the automation of analog circuits diagnosis. Last have been proved valuable for analog electronics circuits.

From numerous discussions with the process community it is expected that these features can be of some value for the diagnosis of chemical processes.

Reported by

THALES Airborne Systems
1, boulevard Jean-Moulin
78852 Elancourt
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