Authors: None

Abstract:

Keywords:

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.90001

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: ---

Authors: None

Abstract:

Keywords:

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.90002

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: ---

Authors: Demongodin, Isabel; Giua, Alessandro

Abstract: In this paper we consider Generalised Batches Petri nets (GBPN) and develop new linear algebraic techniques for the analysis of this model. Two main contributions are presented. The first contribution lies in the fact that although we consider the same GBPN model that has already be presented in the literature, we associate to this model a different semantics considering that the instantaneous firing flow of continuous and batch transitions are control variables that can take an arbitrary value provided they satisfy given constraints. The second contribution consists in the analysis of the steady state behavior of GBPN. We show that under the assumption that no discrete transition fires, a steady state can be characterized by solving a linear programming problem that takes into account the net structure and the initial marking.

Keywords: continuous Petri nets,hybrid Petri nets,discrete event systems

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00003

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 1-6

Authors: Vazquez, C. Renato; Silva, Manuel

Abstract: The classical structural boundedness and repetitiveness properties for discrete and untimed models are reconsidered here for timed continuous Petri nets (TCPN), under infinite server semantics. The timing is also involved in the analysis, by taking advantage of its matricial characterization. Properties analogous to conservativeness and consistency, in which the timing is involved, are defined. It is shown that such properties are sufficient for timed boundedness and timed liveness, respectively, even if the untimed model does not exhibit such properties. The rest of the paper is devoted to the study of these timing-dependent boundedness and liveness.

Keywords: Petri-nets,continuous systems,safety analysis,concurrent systems

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00004

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 7-14

Authors: Cano, Elia E.; Rovetto, Carlos A.; Colom, José-Manuel

Abstract: Minimal siphons in the class of S4PR nets have become a conceptual and practical central tool. Therefore the availability of efficient algorithms to compute the minimal siphons is very important. In this paper we try to take advantage from the particular properties of the siphons in S4PR to obtain an efficient algorithm. These properties allow to express minimal siphons as the union of pruned minimal siphons containing only one resource. The pruning operation is defined as a relation and represented in a graph. The computation of the minimal siphons is based in the maximal strongly connected components of this graph. The algorithm is very economic in memory in all intermediate steps with respect to the classical algorithms.

Keywords: Petri-nets,structural analysis,siphons,graph theory,strongly connected component

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00005

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 15-20

Authors: Júlvez, Jorge; Mahulea, Cristian

Abstract: This paper presents a MATLAB embedded package for continuous Petri nets called SimHPN. It offers a collection of tools devoted to simulation, analysis and synthesis of dynamical systems modeled by continuous Petri nets. Its embedding in the MATLAB environment provides the considerable advantage of creating powerful algebraic, statistical and graphical instruments exploiting the high quality routines available in MATLAB.

Keywords:

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00006

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 21-26

Authors: Bollue, Kai; Slaats, Michaela; Abrahám, Erika; Thomas, Wolfgang; Abel, Dirk

Abstract: In Bollue et al. (2009), a methodology was introduced for the synthesis of behavioral controllers for discrete-event systems. The approach is based on NCES-like Petri net models of the uncontrolled plant and additional goal and safety specifications given by linear marking constraints. This paper presents different approaches to improve the synthesis process with respect to efficiency and applicability. One focus is the use of satisfiability checking of systems of integer linear inequations in the preprocessing of the model for the elimination of unnecessary complexity during the process. Further, several improvements of the synthesis algorithm itself are discussed, which increase the efficiency by applying an advanced guided search and by reusing already found partial solutions.

Keywords: Petri nets,algorithms,synthesis,efficiency,controllers,discrete-event systems

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00007

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 27-34

Authors: Taringoo, Farzin; Caines, Peter E.

Abstract: This paper provides a geometrical analysis of autonomous hybrid systems optimal control (HSOC) by studying the properties of optimal hybrid system trajectories and the manifolds on which they switch between controlled vector fields. First, results previously obtained in Taringoo and Caines [2009a], Taringoo and Caines [2009c] on the parameter optimization of switching manifolds are reviewed. Second, we analyse (i) the geometric properties of switching manifolds and (ii) the sensitivities of optimal control trajectories and their connections with the Hessians of the value function of hybrid optimal control problems (HOCP).

Keywords: hybrid systems,necessary conditions for optimality,value function sensitivity,switching surface geometry,curvatures,second order conditions

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00008

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 35-40

Authors: Azhmyakov, V.; Velazquez, R.; Galvan-Guerra, R.

Abstract: In this contribution, we propose a numerical approach to optimal control processes governed by some specific switched systems. Our principal computational scheme can be characterized as an extension of the conventional proximal point method to optimal control problems (OCPs) with switched dynamical models. We study proximal based constructive approximations of the initial OCPs and establish the numerical stability (numerical consistency) of the resulting algorithm. We also discuss the practical implementability of the elaborated method and point some possible generalizations of our idea in the context of hybrid control systems.

Keywords: switched control systems,optimal control,numerical stability,proximal point algorithm

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00009

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 41-46

Authors: Giua, Alessandro; Seatzu, Carla; Wardi, Yorai

Abstract: Recently there has been a considerable interest in the application of Infinitesimal Perturbation Analysis (IPA) to continuous queues, where its sample derivatives (gradients) were shown to be unbiased for a large class of systems. This paper extends the investigation to a class of hybrid Petri nets, where the special algebraic structure of continuous transitions yields simple algorithms for the IPA derivatives. We derive such algorithms for the performance functions of throughput and average workload, and show them to be model-free and easily computable from the sample paths.

Keywords: infinitesimal perturbation analysis,hybrid Petri nets,stochastic hybrid systems

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00010

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 47-52

Authors: Gromov, Dmitry; Caines, Peter E.

Abstract: A systematic approach to the modelling of thermodynamic systems with phase transitions is presented. It is shown that the dynamics of these systems can be adequately represented within the regional hybrid systems framework. This means that the discrete state changes autonomously at fixed submanifold boundaries. Furthermore, we assume that in each single phase the system's dynamics can be described in terms of equilibrium thermodynamics. This allows for the application of well developed methods from contact geometry. The minimisation of entropy plays a central role in all processes involving energy transformation and storage. So for this class of systems, there is a natural optimal control problem, namely that where the increase of entropy is used as a criterion to be minimised. To illustrate these ideas a hybrid model of a simple thermodynamic system with a liquid-vapour phase transition is presented; the system-theoretic properties of this model are analysed and a hybrid optimal control problem is formulated.

Keywords: hybrid control systems,equilibrium thermodynamics,phase transitions

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00011

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 53-58

Authors: Yao, Chen; Cassandras, Christos G.

Abstract: We establish some conditions under which Infinitesimal Perturbation Analysis (IPA) for general Stochastic Hybrid Systems (SHS) becomes particularly simple and efficient. We then apply IPA to a class of stochastic non-cooperative games termed "resource contention games" modeled through Stochastic Flow Models (SFMs), where two or more players (users) compete for the use of a sharable resource. Simulation examples are provided for a simple version of such games to illustrate and contrast system-centric and user-centric optimization.

Keywords: stochastic flow model,perturbation analysis,stochastic hybrid system,resource contention games

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00012

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 59-64

Authors: Twu, Philip; Martin, Patrick; Egerstedt, Magnus

Abstract: Research in multi-agent systems has supplied a diverse collection of decentralized controllers to accomplish specific tasks. When agents execute a sequence of these controllers, the network behaves as a hybrid system, where the dynamics in each mode evolve according to a single controller in the sequence. This paper presents a formal specification for such a system that describes the underlying graph process associated with the information flow amongst agents in each mode. Since many decentralized controllers require specific information graph topologies in order to function properly, a problem that arises is that the information graph at the termination of one mode may not be sufficient to initiate the next mode in the sequence. We propose a Graph Process Specification (GPS) framework that describes the graph process. Furthermore, if two modes cannot be executed consecutively, a GPS provides a way to determine which modes can be inserted in between them to make the resulting sequence executable. We formally define a GPS, describe its execution, and provide examples that showcase its usage in composing together multiple decentralized controllers within a multi-agent system.

Keywords: decentralized control,formal specification,graph theoretic models,hybrid modes,network topologies

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00013

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 65-70

Authors: Basile, F.; Chiacchio, P.; De Tommasi, G.

Abstract: The problem of diagnosability of a fault after the firing of a finite number of observable events (i.e., K-diagnosability) is tackled in this paper. This problem corresponds to diagnosability of a fault within a finite delay in the context of discrete event systems (DESs). Two results for DESs modeled as labeled Petri nets are given: the first is a sufficient condition for K - undiagnosability of fault, while the second is a necessary and sufficient condition for K-diagnosability. The proposed results exploit the mathematical representation of Petri nets and the Integer Linear Programming standard optimization tool.

Keywords: diagnosability,Petri nets,integer linear programming

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00014

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 71-77

Authors: Saboori, Anooshiravan; Hadjicostis, Christoforos N.

Abstract: In this paper, we propose and analyze reduced-complexity methodologies for verifying initial-state opacity in modular discrete event systems. Initial-state opacity requires that the membership of the system initial state to a given set of secret states S remains opaque (uncertain) to an intruder who has complete knowledge of the system model and observes system activity through some natural projection map. In the modular setting we consider, the given system is modeled as a composition (synchronous product) of M modules {G1,G2,..., GM} where each module Gi is a non-deterministic finite automaton with Ni states with the set of secret states S is of the form S = {(x1, x2,..., xM)|xi ∈ Si}, where Si is the set of secret states for module Gi. Assuming that the pairwise shared events are pairwise observable and that the intruder observes events that are observable in at least one module, we provide a modular algorithm for verifying initial-state opacity with O(MNM-12N2) state and time complexity, where N = maxi Ni. This is a considerable reduction compared to the O(2(NM)2) state and time complexity of the centralized verification method, which verifies initial-state opacity by considering the composed system as a monolithic system.

Keywords: opacity,discrete event systems,automata,modular methods

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00015

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 78-83

Authors: Carvalho, Lilian Kawakami; Basilio, João Carlos; Moreira, Marcos Vicente

Abstract: The modeling of physical systems using discrete event models assumes that a set of sensors always report the event occurrences correctly. However, bad sensor operation can result in loss of observability of the events associated with the malfunctioning sensors. If one or more sensors fail, it may be possible that either the diagnoser stands still or provide wrong information on the fault occurrence. This paper assumes that intermittent sensor failures may occur and deals with the problem of fault diagnosis in the presence of intermittent sensor failures. To this end, an automaton model for intermittent sensor failures based on a newly proposed language operation (language dilation) is presented in the paper. Necessary and sufficient conditions for robust diagnosability against intermittent sensor failure are also given in the paper. The development of a robust diagnoser that copes with intermittent sensor failures is another contribution of the paper.

Keywords: discrete event systems,fault diagnosis,intermittent sensor failures,robust diagnosability

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00016

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 84-89

Authors: Lima, Saulo T. S.; Basilio, João C.; Lafortune, Stéphane; Moreira, Marcos V.

Abstract: One approach to online fault diagnosis of discrete-event systems is through the use of the diagnosers. Diagnosers are deterministic automata whose states are sets formed with the states of the plant together with labels that indicate if the trace that has occurred so far possesses or not the fault event. The decision regarding fault occurrence is taken based solely on observable events, i.e., events whose occurrences can be recorded by sensors. However, if one or more sensors that provide information on event occurrences fail, the diagnoser may either come to a halt or may even provide wrong information regarding fault occurrence. In order to overcome this deficiency, this paper proposes a robust diagnoser that deploys the redundancy that may exist in a set formed of diagnosis bases (set of events that guarantee fault diagnosability) with a view to ensure the fault diagnosis even in the occurrence of permanent sensor failures.

Keywords: discrete-event systems,fault diagnosis,sensor failures,robust diagnosability

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00017

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 90-97

Authors: Schmidt, Klaus; De Queiroz, Max H.; Cury, José E. R.

Abstract: This paper extends previous results on the hierarchical and decentralized control of multitasking discrete event systems (MTDES). Colored observers, a generalization of the observer property, together with local control consistency, allow to derive sufficient conditions for synthesizing modular and hierarchical control that are both strongly nonblocking (SNB) and maximally permissive. A polynomial procedure to verify if a projection fulfills the above properties is proposed and in the case they fail for a given projection an algorithm is proposed to find an extension of the set of events to be projected, in order to fulfill the sufficient conditions for SNB and maximally permissive hierarchical control.

Keywords: discrete event systems,hierarchical control,multitasking,maximal permissiveness

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00018

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 98-103

Authors: Leduc, Ryan; Malik, Robi

Abstract: Hierarchical Interface-based Supervisory Control (HISC) decomposes a discrete-event system into a high-level subsystem which communicates through interfaces with several low-level subsystems. The framework provides a set of local conditions that can be checked for each subsystem individually to conclude global conditions such as nonblocking and controllability. The size of HISC systems that can be verified automatically is primarily limited by the size of the largest subsystem. To overcome this limitation, this paper proposes the use of compositional verification. Most of the HISC conditions can be verified efficiently using existing methods for compositional verification, but a few are more challenging. This paper shows how these more challenging conditions can be expressed equivalently as generalized nonblocking problems, so the compositional approach for generalized nonblocking developed by the authors in (Malik and Leduc, 2009) is applicable. This makes all the HISC conditions amenable for compositional verification, considerably increasing the size of systems that can be handled using the framework.

Keywords: discrete event systems,large-scale systems,hierarchical control,finite state machines,verification

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00019

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 104-110

Authors: Komenda, Jan; Masopust, Tomáš

Abstract: In this paper, we study hierarchical supervisory control with partial observations. In particular, we are interested in preservation of supremal normal and supremal controllable and normal sublanguages from the abstracted system (high level) in the original (low level) system. Sufficient conditions are formulated under which the supremal normal or the supremal controllable and normal sublanguage computed at the high level (for the abstracted plant) is implementable at the low level, i.e., in the original plant.

Keywords: discrete event system,supremal normal sublanguage,supremal controllable and normal sublanguage,hierarchical supervisory control,natural projection

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00020

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 111-116

Authors: Kovács, Gábor; Pietrac, Laurent; Niel, Eric

Abstract: This paper reports a supervisory control design methodology based on the multi-face modelling of discrete-event systems in order to allow rapid prototyping and flexible implementation of controllers for reactive systems. Although Supervisory Control Theory assures that the closed loop system meets the prescribed requirements, it uses ordinary finite state machines as process models, which results in complicated and large-scale controllers. A new modelling methodology simplifies modelling by introducing functional models based on tasks, which allow the reduction of component models. The paper presents a multi-level supervisory control architecture for systems modelled in the framework and derives the properties of the overall control system. Propositions for the implementation of such supervisory architectures are also made.

Keywords: discrete event systems,supervisory control,rapid control prototyping

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00021

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 117-122

Authors: Cabasino, Maria Paola; Giua, Alessandro; Paoli, Andrea; Seatzu, Carla

Abstract: In this paper we deal with the problem of failure diagnosis of discrete event systems with decentralized information. The decentralized architecture that we use is composed by a set of sites communicating their diagnosis information with a coordinator that is responsible of detecting the occurrence of failures in the system. In particular, first we present a protocol that defines the communication rules between the sites and the coordinator. Secondly, we prove that this protocol does not produce false alarms. Moreover, we give sufficient conditions for diagnosability based on the notion of failure ambiguous strings. Finally, we compare the protocol here presented with two other protocols that we presented in a previous work.

Keywords: decentralized fault diagnosis,discrete event systems,Petri nets

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00022

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 123-128

Authors: Raisch, Jorg; Moor, Thomas; Bajcinca, Naim; Geist, Stephanie; Nenchev, Vladislav

Abstract: The topic of this paper is distributed state estimation for time-invariant systems with finite input and output spaces. We assume that the system under investigation can be realised by a hybrid I/S/O-machine, where some of the discrete states may also represent failure modes. Our approach is based on previous work, e.g., Moor and Raisch (1999); Moor et al. (2002), where l-complete approximations were proposed as discrete event abstractions for hybrid dynamical systems. In particular, it has been shown that l-complete approximations can be used to provide set-valued estimates for the unknown system state. Estimates are conservative in the sense that the true state can be guaranteed to be contained in the set-valued estimate. In this contribution, we show that for a class of hybrid systems the same estimate can be obtained via a distributed, or decentralised, approach involving several less complex approximations, which are run in parallel. For a larger class of systems, it can be shown that this approach provides an outer approximation of the estimate provided by a monolithic l-complete estimator. The proposed procedure implies significant computational savings during estimator synthesis, with an only modest increase in on-line effort. The latter is a result of "assembling" the global estimate from the available local estimates. The resulting computational trade-off is explicitly discussed.

Keywords: hybrid systems,discrete event systems,approximations,abstractions,behaviours,state estimation

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00023

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 129-134

Authors: Khoumsi, Ahmed

Abstract: We develop a decision-making framework for DES, which is unifying in two ways. Firstly, it unifies the architectures: we develop a decision-making system for a generic well-formed architecture; and then, we specialize the framework for centralized and decentralized architectures. Secondly, it unifies supervisory control, diagnosis and prognosis: we develop a framework for a generic well-formed decision-maker; and then, we apply the framework to the three subjects. We hope that this unifying framework will contribute to a better understanding of the decision-making mechanism, and will promote its development.

Keywords: discrete event systems,unifying decision-making,well-formed architecture,decidability,centralized architecture,decentralized inference architecture,supervisory control,diagnosis,prognosis

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00024

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 135-142

Authors: Ye, Lina; Dague, Philippe

Abstract: Diagnosability is a crucial system property that determines at design stage how accurate any diagnosis algorithm can be on a partially observable system. The existence of two indistinguishable behaviors, i.e. holding the same observations, with exactly one of them containing the fault violates the diagnosability property. A classical approach for diagnosability verification consists in constructing a finite state machine called twin plant to search for a path representing such indistinguishable behaviors, called a critical path. To avoid the unrealistic hypothesis about the monolithic model of a complex system, recent work constructs local twin plants and then incrementally synchronizes some of them until diagnosability is decided without computing the impractical global twin plant. In this paper, we optimize the distributed approach by abstracting necessary and sufficient diagnosability information from local twin plants to check the existence of critical paths. Thus diagnosability can be analyzed with as small search space as possible. Furthermore, our approach describes how to improve the diagnosis algorithm by using our diagnosability results in a formal way when the system is verified to be diagnosable. Finally, when the system is not diagnosable, the algorithm returns some useful information about its indistinguishable behaviors, which can help in upgrading system diagnosable level.

Keywords: discrete event systems,fault diagnosis,models,algorithms,distributed systems

Digital Object Identifier (DOI): 10.3182/20100830-3-DE-4013.00025

Conference: 10th International Workshop on Discrete Event Systems (2010)

Location: Technische Universität Berlin, Germany

Start Date: Mon Aug 30 2010 - End Date: Wed Sep 01 2010

Page Numbers: 143-148