Jan Maciej Kościelny

Fault isolation in industrial processes by the dynamic table of states method

Abstract A method of fault isolation in industrial processes is presented: the dynamic table of states (DTS) method. This method allows one to apply various known ways of fault isolation with the help of an object-independent universal algorithm of diagnostic reasoning. It makes it possible to detect and isolate both single and multiple faults, and enables one to formulate a diagnosis even in cases of changes in the set of available signals. An example of the application of the DTS method is also presented.

A New Approach to Multiple Fault Diagnosis: A Combination of Diagnostic Matrices, Graphs, Algebraic and Rule-Based Models. The Case of Two-Layer Models

A New Approach to Multiple Fault Diagnosis: A Combination of Diagnostic Matrices, Graphs, Algebraic and Rule-Based Models. The Case of Two-Layer Models The diagnosis of multiple faults is significantly more difficult than singular fault diagnosis. However, in realistic industrial systems the possibility of simultaneous occurrence of multiple faults must be taken into account. This paper investigates some of the limitations of the diagnostic model based on the simple binary diagnostic matrix in the case of multiple faults. Several possible interpretations of the diagnostic matrix with rule-based systems are provided and analyzed. A proposal of an extension of the basic, single-level model based on diagnostic matrices to a two-level one, founded on causal analysis and incorporating an OR and an AND matrix is put forward. An approach to the diagnosis of multiple faults based on inconsistency analysis is outlined, and a refinement procedure using a qualitative model of dependencies among system variables is sketched out.

Fuzzy Logic Application to Diagnostics of Industrial Processes

Summary The paper presents application of fuzzy logic for fault detection and isolation in industrial processes, and especially for generation of residuals on the grounds of fuzzy models, residual values evaluation, description of a faults-symptoms relation, as well as diagnostic inference. Advantages of diagnostic algorithms based on fuzzy logic have been taken into considerations.

Current Diagnostics of Power Boiler System with Use of Fuzzy Logic

Abstract The paper presents diagnostics of power boiler system performed with use of the DIAG system. Fuzzy and neural local models of particular systems have been applied for fault detection. Obtained results of control valve and attemperator modelling have been presented. Fault isolation has been performed with use of the F-DTS method that bases on fuzzy appreciation of residuals and fuzzy reasoning. An example of fault isolation in a steam superheater and attemperator has been presented.

Advanced monitoring and diagnostic system 'AMandD'

Abstract The paper presents structure and functional properties of the Advanced Monitoring and Diagnostic System ‘AMandD’ dedicated for large scale industrial processes. The system arose within the framework of research project ‘CHEM’ of 5th European Framework Program. Applied in the system up-to-date algorithms of modelling methods and fault detection and isolation were described in the paper. Also a brief description of used IT solutions was presented. As a conclusion, the further directions of development and researches were mentioned.

APPLICATION OF FUZZY LOGIC FAULT ISOLATION METHODS FOR ACTUATOR DIAGNOSIS

Abstract Four fuzzy logic fault isolation methods suitable for implementation in smart final control elements are proposed. The methods are suited for real time diagnostics applications considering computing power limitations typical for applications in intrinsically safe zones. The comparison of isolability features of presented algorithms is given in examples.

CURRENT DIAGNOSTICS OF THE EVAPORATION STATION

Abstract The paper presents structure and algorithms of the system of current diagnosis of the evaporation station in the Lublin Sugar Factory. The applied fault detection algorithms are based on the set of partial parametric models, the set of heuristic dependencies describing process behaviour and the hardware redundancy. The isolation algorithm implements fuzzy reasoning based on the diagnostic rules given by the expert. All the diagnostic algorithms are carried out by the modules of Advanced Monitoring and Diagnostic System AMandD. The achieved fault detectability and isolability analysis and some test results are also presented.

Fault Isolation Method Based on Time Sequences of Symptom Appearance

Abstract The method of fault isolation in large scale industrial processes is considered. The paper introduces description of the diagnosed object in form of an information system. The proposed algorithm takes into account the dynamics of the symptoms. The result of such approach is augmentation of fault discernment and speed of fault isolation.

On-Line Fault Isolation Algorithm for Industrial Processes

Abstract The paper presents the solutions of main problems that appear in diagnostics of large scale processes in chemical, petrochemical, pharmaceutical, power and other industry utilised in applied diagnostic software. In addition to description of reasoning rules based on fuzzy logic and taking into account the dynamics of symptoms forming the following topics where raised: decomposition of diagnostic system, dynamical creation of FI threads and multiple fault isolation assuming single fault scenarios.

Smart Positioner with Fuzzy Based Fault Diagnosis

Abstract The decentralisation of the diagnostic tasks could be achieved when the automatic and technological equipment devices will be provided with class of smart autonomous diagnostic units. In this case the functions of the central diagnostic system may be simplified. This class may be represented by smart positioner with actuator fault diagnosis. In the paper an idea of smart positioner with actuator fuzzy based fault diagnosis is presented. The scheme of the residuum vector generation based on the fuzzy models is given, as well as with the scheme of diagnostics decision making procedure for the positioner.