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1

A New Class of Fuzzy Petri Nets for Knowledge Representation and Reasoning

Suraj Z.

Fundamenta Informaticae

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2013

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Vol. 128, nr 1-2

193--207

EN

This paper presents a new class of Petri nets called generalised fuzzy Petri nets. The new class extends the existing fuzzy Petri nets by introducing three operators in the form of triangular norms, which are supposed to function as substitute for the min, max and * (algebraic product) operators. To demonstrate the power and the usefulness of this model, an application of the generalised fuzzy Petri nets in the domain of train traffic control is provided. The new model is more flexible than the classical one as in the former class the user has the chance to define the input/output operators. The proposed approach can be used for knowledge representation and reasoning in decision support systems.

2

The Fault Diagnosis for Power System Using Fuzzy Petri Nets

Pamuk N., Uyaroglu Y.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 7a

99-102

EN

A rapid and correct fault diagnosis is crucial for power system network. As the complexity of power system increases, fault diagnosis becomes very difficult task in the limited short time. This situation has made it necessary to develop intelligent systems to support operators in their decision making process. The paper mainly investigates fault diagnosis of power system by using Fuzzy Petri Nets (FPN) technology. FPN is used for accurately fault diagnosis in power system when some incomplete and uncertain alarm information of protective relays. It is shown from several cases that the faulted system elements can be diagnosed correctly by use of these models. By suggested method, it is possible to decline diagnosis time according to traditional methods. Finally, the suggested method can easily be adapted to different power system network. It is practicable an impressive for fault diagnosis in power system.

PL

W artykule opisano metodę diagnostyki sieci energetycznej przy wykorzystaniu technologii rozmytych sieci Petriego FPN. Pokazano na kilku przykładach prawidłowe wykrycie błędów systemu przy czasie analizy krótszym niż to oferują systemy tradycyjne.

3

Sprzętowo-programowa realizacja rozmytej interpretowanej sieci Petriego

Gniewek L., Hajduk Z.

Pomiary Automatyka Kontrola

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2012

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R. 58, nr 12

1113-11116

PL

W artykule przedstawiono algorytm sterowania mieszalnikiem, który przygotowano w formie rozmytej interpretowanej sieci Petriego. Algorytm ten zaimplementowano w specjalizowanym sterowniku programowalnym, zbudowanym w oparciu o struktury programowalne FPGA, co znacznie skróciło czas wykonywania kodu. Sterownik programowany jest zgodnie z normą IEC 61131-3 dzięki środowisku inżynierskiemu CPDev. Zaprezentowano ogólny sposób realizacji rozmytej interpretowanej sieci Petriego w języku tekstowym ST, co pozwala uzyskać przenośność programów pomiędzy sterownikami PLC różnych producentów.

EN

Fuzzy Interpreted Petri Net is a synchronized, low-level net, which can be used for formal description of control algorithms. Formal bases of the net and a transformation method to the logic circuit were presented in [1]. Software realization of the net, using Siemens Step 7 language, was described in [2]. Some practical application of the net for controls and diagnostics can be found in [3]. In this article, general realization method of Fuzzy Interpreted Petri Net in ST language was proposed. The method directly uses the transition firing and dynamic equations of the net. As a hardware, specific programmable controller, based on FPGA struc-tures, was applied. Description of main CPU unit of the controller is shortly presented in this article. More detail of the controller can be found in [6], [7, 10]. Prototype of the controller was shown in [12] as well. FPGA programmable controller is programmed using CPDev control software [4]. Example of Fuzzy Interpreted Petri Net for control of the mixer plant is also included in this article. The net consists of 18 places p', 5 places p" and 17 transitions. Total computation time of the control algorithm, implemented in FPGA programmable controller, is very short and equal to 86žs. Such a time is almost unreachable to the typical, industrial PLCs. Another advantage of proposed realization method of Fuzzy Interpreted Petri Net is a portability of the code between PLCs of different producers, which is impossible to obtain using PLC programming languages, such as LD or FBD.

4

Sprzętowa implementacja rozmytego systemu ekspertowego

Dec G., Hajduk Z.

Pomiary Automatyka Kontrola

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2005

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R. 51, nr 1

34-36

PL

W pracy zaproponowano metodę syntezy układu sterującego, specyfikowanego za pomocą rozmytego systemu ekspertowego, zawierającego reguły działania. Przedstawiono sposób modelowania i badania właściwości SE przy użyciu rozmytej sieci Petriego. Pokazano praktyczny przykład zastosowania metody do syntezy sterownika, wykonanego w układzie FPGA.

EN

This paper presents a synthesis method of a control system, that is modeled by a production-rule-based expert system. As a tool for analysis properties of the expert system a fuzzy Petri net is proposed. We show practical application of the described method to develop a parallel controller, that is implemented in a FPGA.

5

Fuzzy Petri nets as control systems

Kluska J., Gniewek L.

Pomiary Automatyka Kontrola

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2005

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R. 51, nr 1

7-10

EN

Industrial processes can often be modelled using Petri nets. If all the process variabless are assumed to be two-valued signals, then it is possible to obtain a control device, which works according to the algorithm described by conventional Petri net. However, the values of real signals are contained in some bounded interval, and therefore they can be interpreted as events, which are true in some degree from the interval [0,1]. Such a natural interpretation concerns sensor outputs, control signals, time expiration, etc. It leads to the idea of the fuzzy Petri net as a controller, which is able to process both analog, and binary signals. Such the net is presented in this paper.

PL

Procesy przemysłowe często mogą być zamodelowane za pomocą sieci Petriego. Jeżeli zmienne procesowe są traktowane jako dwuwartościowe, to można otrzymać urządzenie sterujace, które działa według algorytmu opisanego przez konwencjonalną sieć Petriego. Jednak wartości sygnałów rzeczywistych zawarte są w pewnym skończonym przedziale, więc mogą być zinterpretowane jako zdarzenia prawdziwe w pewnym stopniu z przedziału [0,1]. Taka naturalna interpretacja dotyczy wyjść czujników, sygnałów sterujących, upływu czasu itd. Prowadzi to do idei rozmytych sieci Petriego jako układów sterowania, przetwarzających zarówno sygnały analogowe, jak i binarne. Takie sieci są przedstawione w niniejszym artykule.

6

On Fuzzy Reasoning Using Matrix Representation of Extended Fuzzy Petri Nets

Fryc B., Pancerz K., Peters J.F., Suraj Z.

Fundamenta Informaticae

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2004

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Vol. 60, nr 1-4

143--157

EN

In 1990 Shyi-Ming Chen et al. presented a new approach to knowledge representation using fuzzy Petri nets (FPN). A fuzzy Petri net model allows a structural representation of knowledge and has a systematic procedure for supporting fuzzy reasoning. In this paper we propose an algebraic (matrix) representation of FPNs. We use this representation in a fuzzy reasoning algorithm which is simple to implement in modern programming languages such as C++, C# or Java. Furthermore, there exists MATLAB - a computer system which makes it possible to solve many computing problems, especially those with matrix and vector formulations. We present also an approach enabling us to carry out a fuzzy reasoning process using the MATLAB environment.