{"title":"Model checking embedded system designs","authors":"E. Brinksma, A. Mader","doi":"10.1109/WODES.2002.1167682","DOIUrl":"https://doi.org/10.1109/WODES.2002.1167682","url":null,"abstract":"We survey the basic principles behind the application of model checking to controller verification and synthesis. A promising development is the area of guided model checking, in which the state space search strategy of the model checking algorithm can be influenced to visit more interesting sets of states first. In particular, we discuss how model checking can be combined with heuristic cost functions to guide search strategies. Finally, we list a number of current research developments, especially in the area of reachability analysis for optimal control and related issues.","PeriodicalId":435263,"journal":{"name":"Sixth International Workshop on Discrete Event Systems, 2002. Proceedings.","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123357804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effective computation of an L/sub m/(G)-closed, controllable, and observable sublanguage arising in supervisory control","authors":"S. Takai, T. Ushio","doi":"10.1109/WODES.2002.1167666","DOIUrl":"https://doi.org/10.1109/WODES.2002.1167666","url":null,"abstract":"In this paper we study nonblocking, supervisory control of discrete event systems under partial observation. A nonblocking supervisor can be synthesized for the supremal L/sub m/(G)-closed, controllable, and normal sublanguage of a given (non-closed) marked language. However, such a supervisor may be too restrictive as a solution to the supervisory control problem. We identify a subclass of observable sublanguages of a given language, which has the supremal element larger than the supremal normal sublanguage. By using the supremal element, we present an iterative algorithm for computing an L/sub m/(G)-closed, controllable and observable sublanguage of a given marked language, which is larger than the supremal L/sub m/(G)-closed, controllable and normal sublanguage.","PeriodicalId":435263,"journal":{"name":"Sixth International Workshop on Discrete Event Systems, 2002. Proceedings.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129589601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Merseguer, J. Campos, Simona Bernardi, S. Donatelli
{"title":"A compositional semantics for UML state machines aimed at performance evaluation","authors":"J. Merseguer, J. Campos, Simona Bernardi, S. Donatelli","doi":"10.1109/WODES.2002.1167702","DOIUrl":"https://doi.org/10.1109/WODES.2002.1167702","url":null,"abstract":"Unified Modeling Language (UML) is gaining acceptance to describe the behaviour of systems. It has attracted the attention of researchers that are interested in deriving, automatically, performance evaluation models from system's descriptions. A required step to automatically produce a performance model (as any executable model) is that the semantics of the description language is formally defined. Among the UML diagrams, we concentrate on state machines (SMs) and we build a semantics for a significant subset of them in terms of generalized stochastic Petri nets (GSPNs). The paper shows how to derive an executable GSPN model from a description of a system, expressed as a set of SMs. The semantics is compositional since the executable GSPN model is obtained by composing, using standard Petri net operators, the GSPN models of the single SMs, and each GSPN model is obtained by composition of submodels for SM basic features.","PeriodicalId":435263,"journal":{"name":"Sixth International Workshop on Discrete Event Systems, 2002. Proceedings.","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126068723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"About disturbance decoupling of timed event graphs in dioids","authors":"M. Lhommeau, L. Hardouin, Bertrand Cottenceau","doi":"10.1109/WODES.2002.1167689","DOIUrl":"https://doi.org/10.1109/WODES.2002.1167689","url":null,"abstract":"This paper deals with control of timed event graphs (TEG) when a disturbance acts on transitions. We synthesize the greatest feedback controller which allows to match the disturbance action. Formally, this problem is very close of the classical problem of disturbance decoupling for linear systems.","PeriodicalId":435263,"journal":{"name":"Sixth International Workshop on Discrete Event Systems, 2002. Proceedings.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129142547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Algebraic and geometric characterization of Petri net controllers using the theory of regions","authors":"A. Ghaffari, N. Rezg, Xiaolan Xie","doi":"10.1109/WODES.2002.1167691","DOIUrl":"https://doi.org/10.1109/WODES.2002.1167691","url":null,"abstract":"This paper presents a formal treatment of Petri net controller design problems. Two supervisory control problems of plant Petri net models, forbidden state and forbidden state-transition problems, are defined. The theory of regions is used to provide algebraic characterizations of pure and impure control places for both problems. Thanks to Farkas-Minkowski's lemma, the algebraic characterizations lead to nice geometric characterization for the existence of control places for the two supervisory problems.","PeriodicalId":435263,"journal":{"name":"Sixth International Workshop on Discrete Event Systems, 2002. Proceedings.","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114779568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Firing instant approach to control time critical systems in multi-product processing","authors":"P. Bonhomme, P. Aygalinc, S. Calvez","doi":"10.1109/WODES.2002.1167675","DOIUrl":"https://doi.org/10.1109/WODES.2002.1167675","url":null,"abstract":"Time-critical systems are characterized by operation times between a minimum and a maximum value. Any transgression of these specifications acts against production quality. In this paper, we propose to use a firing instant approach to build temporal control when the systems process several kinds of parts. The formalism presented refers to lot switching when the cyclic scheduling is the same whatever the type of part. Under the same assumption, it can be applied to interlaced production leading to a steady state. The P-time Petri net is used as a modeling tool. The method is illustrated for an electroplating line with two types of products.","PeriodicalId":435263,"journal":{"name":"Sixth International Workshop on Discrete Event Systems, 2002. Proceedings.","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130572805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Decentralized failure diagnosis for discrete-event systems with costly communication between diagnosers","authors":"R. Boel, J. van Schuppen","doi":"10.1109/WODES.2002.1167685","DOIUrl":"https://doi.org/10.1109/WODES.2002.1167685","url":null,"abstract":"Reliable supervisory control of engineering systems requires failure diagnosis algorithms for discrete-event systems. For large, modularly designed plants, such as communication networks, robustness considerations and limitations on the communication between local sensors lead to decentralized implementations of failure diagnosis algorithms. A trade-off has to be made between the speed of diagnosis and the cost of communication and computation. An algorithm is proposed for decentralized failure diagnosis with asymmetric communication in which Diagnoser 2 also estimates the observer state of Diagnoser 1 and sends only that subset of failure states which is relevant for the other diagnoser when this is useful for Diagnoser 1's control task of failure detection and diagnosis. This algorithm can help in suggesting practically implementable heuristic algorithms.","PeriodicalId":435263,"journal":{"name":"Sixth International Workshop on Discrete Event Systems, 2002. Proceedings.","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134534913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. D. Febbraro, D. Giglio, R. Minciardi, S. Sacone
{"title":"Optimization of manufacturing systems modelled by timed Petri nets","authors":"A. D. Febbraro, D. Giglio, R. Minciardi, S. Sacone","doi":"10.1109/WODES.2002.1167712","DOIUrl":"https://doi.org/10.1109/WODES.2002.1167712","url":null,"abstract":"Integer timed Petri nets (ITPN) are applied in this work to model automated manufacturing systems, where several products are obtained via sequences of operations executed by different machines. In such a model the system state is represented by the joint information consisting of the net marking and of the residual firing times of timed transitions. On this basis, the state equations representing the system dynamics can be written. With reference to this model, it is possible to build the system state diagram, where two main classes of states can be distinguished, named tangible and vanishing, after the terms introduced for GSPN. Then, a specific performance optimization problem is addressed for which the cost to be optimized can only be associated with the permanence of the system in tangible states.","PeriodicalId":435263,"journal":{"name":"Sixth International Workshop on Discrete Event Systems, 2002. Proceedings.","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128663941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A deadlock avoidance strategy for AGV systems modelled by coloured Petri nets","authors":"M. P. Fanti","doi":"10.1109/WODES.2002.1167670","DOIUrl":"https://doi.org/10.1109/WODES.2002.1167670","url":null,"abstract":"Automated Guided Vehicle Systems (AGVSs) are material handling devices representing an efficient and flexible alternative for material handling. The vehicles follow a guidepath under computer control that assigns route, tasks, velocity, etc. However, the design of AGVSs has to take into account some management problems such as collisions and deadlock. This paper presents a control strategy to avoid deadlock and collisions in zone controlled AGVSs. In particular, the control scheme manages the assignments of new paths and next zone acquisition. Moreover, we propose coloured timed Petri nets to model the AGVS structure and dynamics. The model allows us an easy implementation of the control strategy working on the basis of the knowledge of the system state.","PeriodicalId":435263,"journal":{"name":"Sixth International Workshop on Discrete Event Systems, 2002. Proceedings.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129339786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Supervisory control of dense real-time discrete-event systems with partial observation","authors":"A. Khoumsi","doi":"10.1109/WODES.2002.1167676","DOIUrl":"https://doi.org/10.1109/WODES.2002.1167676","url":null,"abstract":"In supervisory control theory, the basic task of the supervisor is to disable certain events of the plant so that the obtained behaviour lies within a given specification. We propose a method which extends this theory with the following two points. First, the plant and the specification contain temporal constraints and are described by a model called Timed Automata (TA). Second, the supervisor has only a partial observation of the behaviour of the plant. The problem that arises with the TA model is that the state space can be infinite. Recently, we proposed a method to finitely represent the state space which generates less states than the well-known region graph approach. Its principle consists of transforming a TA into a Finite State Automaton (FSA) using two special types of events: Set and Exp. Such a FSA is denoted se-FSA. In this article, we propose a method for the supervisory control of timed discrete event systems that are modelled by TA and partially observable. We use the above-mentioned transformation procedure for representing the plant and the specification by two se-FSAs. Then, we develop a procedure for generating the supervisor from the two se-FSAs that represent the plant and the specification. We also propose a supervisory control architecture.","PeriodicalId":435263,"journal":{"name":"Sixth International Workshop on Discrete Event Systems, 2002. Proceedings.","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121183549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}