Discrete event dynamic systems最新文献

Reducing the computational effort of symbolic supervisor synthesis 减少符号监督合成的计算量

Discrete event dynamic systems Pub Date : 2024-09-12 DOI: 10.1007/s10626-024-00403-4

Sander Thuijsman, Dennis Hendriks, Michel Reniers

{"title":"Reducing the computational effort of symbolic supervisor synthesis","authors":"Sander Thuijsman, Dennis Hendriks, Michel Reniers","doi":"10.1007/s10626-024-00403-4","DOIUrl":"https://doi.org/10.1007/s10626-024-00403-4","url":null,"abstract":"Supervisor synthesis is a means to algorithmically derive a supervisory controller from a discrete-event model of a system and a requirements specification. For large systems, synthesis suffers from state space explosion. To mitigate this, synthesis can be applied to a symbolic representation of the models by using Binary Decision Diagrams (BDDs). Peak used BDD nodes and BDD operation count are introduced as deterministic and platform independent metrics to express the computational effort of a symbolic synthesis. These BDD-based metrics are useful to analyze the efficiency of the synthesis algorithm. From this analysis, modifications can be made to how BDDs are handled during synthesis, improving synthesis efficiency. We demonstrate this approach by introducing and analyzing: DCSH, a variable ordering heuristic; several edge ordering heuristics; and an approach to efficiently enforce state exclusion requirements in synthesis. These methods were recently implemented in our open source supervisory control tool: Eclipse ESCET. The analysis is based on large scale experiments of performing synthesis on a variety of models from literature. We show that: (1) by using DCSH, synthesis with high computational effort can be avoided, and generally low computational effort is required, relative to the variable ordering heuristics that were used prior to this work; (2) applying reverse-model edge order realizes relatively low synthesis effort; and (3) state exclusion requirements can efficiently be enforced by restricting edge guards prior to synthesis. While these methods reduce computational effort in practice, it should be noted that they do not affect the theoretical (worst-case) complexity of synthesis.","PeriodicalId":92890,"journal":{"name":"Discrete event dynamic systems","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142213891","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}

引用次数: 0

An extremum timed extended reachability graph for temporal analysis of time Petri nets 用于时间 Petri 网时序分析的极值定时扩展可达性图

Discrete event dynamic systems Pub Date : 2024-09-05 DOI: 10.1007/s10626-024-00402-5

Jiazhong Zhou, Dimitri Lefebvre, Zhiwu Li

{"title":"An extremum timed extended reachability graph for temporal analysis of time Petri nets","authors":"Jiazhong Zhou, Dimitri Lefebvre, Zhiwu Li","doi":"10.1007/s10626-024-00402-5","DOIUrl":"https://doi.org/10.1007/s10626-024-00402-5","url":null,"abstract":"In this paper, a type of graph, called an extremum timed extended reachability graph, is designed to abstract the temporal specifications and represent the feasible trajectories of time Petri nets. This graph improves the timed extended reachability graph recently proposed for time Petri nets (Lefebvre. Discrete Event Dynamic Systems 29(1):31–56. (2019); Zhou et al. IEEE Trans Autom Control 67(7):3693–3698. (2022)) by replacing the earliest-firing policy with a more general policy. In detail, when a transition is preselected for the next firing, the firing can be delayed for a certain period after its minimal residual time has elapsed, rather than immediately firing once its minimal residual time has elapsed. Then, a sampled timed extended reachability graph is designed, wherein, for a transition preselected to fire next, a finite number of time points within a time interval, starting at minimal residual time and ending at maximal residual time, are selected as the firing time instants for the preselected transition. Furthermore, a special case of the sampled timed extended reachability graph, called an extremum timed extended reachability graph that details only the minimal and maximal residual times of the transitions, is also proposed. For a feasible sequence, the corresponding feasible trajectories with minimal and maximal durations are easy to compute with this graph. Thus, an end-to-end delay of a feasible sequence can be obtained by directly searching the graph. Finally, the scheduling of a typical flexible manufacturing system illustrates the advantages and applications of the proposed approach.","PeriodicalId":92890,"journal":{"name":"Discrete event dynamic systems","volume":"96 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214133","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}

引用次数: 0

Diagnosability and attack detection for discrete event systems under sensor attacks 传感器攻击下离散事件系统的可诊断性和攻击检测

Discrete event dynamic systems Pub Date : 2024-07-12 DOI: 10.1007/s10626-024-00401-6

Feng Lin, Stéphane Lafortune, Caisheng Wang

{"title":"Diagnosability and attack detection for discrete event systems under sensor attacks","authors":"Feng Lin, Stéphane Lafortune, Caisheng Wang","doi":"10.1007/s10626-024-00401-6","DOIUrl":"https://doi.org/10.1007/s10626-024-00401-6","url":null,"abstract":"This paper extends the theory of diagnosability by investigating fault diagnosis in discrete event systems under sensor attacks using finite-state automata as models. It assumes that an attacker has compromised the communication channel between the system’s sensors and the diagnostic engine. While the general attack model utilized by the attacker has been previously studied in the context of supervisory control, its application to fault diagnosis remains unexplored. The attacker possesses the capability to substitute each compromised observable event with a string from an attack language. The attack model incorporates event insertion and deletion, as well as static and dynamic attacks. To formally capture the diagnostic engine’s ability to identify faults in the presence of the attacker, a novel concept called CA-diagnosability is introduced. This extends the existing notions of CA-controllability and CA-observability. A testing procedure for CA-diagnosability is developed, and its correctness is proven. Some sufficient conditions for CA-diagnosability that can be easily checked are also proposed and proved. The paper then investigates conditions under which the role of an attacker can be reverted from malicious to benevolent, that is, to help the diagnoser to diagnose faults. The paper further applies diagnosability theory to investigate conditions under which the presence of the attacker can be detected.","PeriodicalId":92890,"journal":{"name":"Discrete event dynamic systems","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141612728","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}

引用次数: 0

A tropical-algebraic method for the control of timed event graphs with partial synchronization 控制部分同步定时事件图的热带代数方法

Discrete event dynamic systems Pub Date : 2024-07-04 DOI: 10.1007/s10626-024-00400-7

Germano Schafaschek, Laurent Hardouin, Jörg Raisch

{"title":"A tropical-algebraic method for the control of timed event graphs with partial synchronization","authors":"Germano Schafaschek, Laurent Hardouin, Jörg Raisch","doi":"10.1007/s10626-024-00400-7","DOIUrl":"https://doi.org/10.1007/s10626-024-00400-7","url":null,"abstract":"This paper studies a scenario in which the occurrence of one or more events in a discrete event system is subject to external restrictions which may change unexpectedly during run-time. The system is modeled as a timed event graph (TEG) and, in this context, the presence of the aforementioned external restrictions has become known as partial synchronization (PS). This phenomenon arises naturally in several applications, from manufacturing to transportation systems. We develop a formal and systematic method to compute optimal control signals for TEGs in the presence of PS, where the control objective is tracking a given output reference as closely as possible and optimality is understood in the widely-adopted just-in-time sense. The approach is based on the formalism of tropical semirings — in particular, the min-plus algebra and derived semiring of counters. We claim that our method expands modeling and control capabilities with respect to previously existing ones by tackling the case of time-varying PS restrictions, which, to the best of our knowledge, has not been dealt with before in this context.","PeriodicalId":92890,"journal":{"name":"Discrete event dynamic systems","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141547628","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}

引用次数: 0

MGF-based SNC for stationary independent Markovian processes with localized application of martingales 基于 MGF 的静态独立马尔可夫过程 SNC 与马氏体的局部应用

Discrete event dynamic systems Pub Date : 2024-05-08 DOI: 10.1007/s10626-024-00399-x

Anne Bouillard

引用次数: 0

Offline analysis of the relaxed upper boundedness for online estimation ofoptimal event sequences in Partially Observable Petri Nets 部分可观测 Petri 网中最优事件序列在线估计的松弛上界离线分析

Discrete event dynamic systems Pub Date : 2024-04-10 DOI: 10.1007/s10626-024-00396-0

P. Declerck

{"title":"Offline analysis of the relaxed upper boundedness for online estimation ofoptimal event sequences in Partially Observable Petri Nets","authors":"P. Declerck","doi":"10.1007/s10626-024-00396-0","DOIUrl":"https://doi.org/10.1007/s10626-024-00396-0","url":null,"abstract":"The aim of this paper is the analysis of the property of the relaxed structurally boundedness of the unobservable subnet of the Petri net which brings a condition guaranteeing the finitude of all possible sequence lengths in the context of an on-line estimation in Partially Observable Petri Nets relevant to a sliding horizon or a receding horizon starting from the initial marking. Based on specific invariants defined over the real numbers, the approach focuses on an offline structural analysis, that is, the determination of the parts of the unobservable subnet where an online estimation for any criterion can be made. The decomposition-composition technique is based on a block triangular form obtained with any technique. The composition of the substructures leads to a propagation of the relaxed structurally boundedness property through the structure. The study of a large-scale manufacturing system shows that the direct treatment of the large system system can be avoided and that the triangular form brings a sequential treatment allowing a computation based on smaller systems independently of the resolution of the complete system.","PeriodicalId":92890,"journal":{"name":"Discrete event dynamic systems","volume":"46 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140574506","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}

引用次数: 0

An algebraic control method to guarantee generalized marking constraints for partially observable timed event graphs 保证部分可观测定时事件图的广义标记约束的代数控制方法

Discrete event dynamic systems Pub Date : 2024-04-08 DOI: 10.1007/s10626-024-00398-y

Jihene Rajah, Said Amari, Maher Barkallah, Mohamed Haddar

引用次数: 0

Triangulation of diagonally dominant min-plus matrices 对角显性小加矩阵的三角剖分

Discrete event dynamic systems Pub Date : 2024-03-27 DOI: 10.1007/s10626-024-00397-z

Yuki Nishida, Sennosuke Watanabe, Yoshihide Watanabe

引用次数: 0

Simulations and bisimulations for max-plus automata 最大加法自动机的模拟和二模拟

Discrete event dynamic systems Pub Date : 2024-03-02 DOI: 10.1007/s10626-024-00395-1

Miroslav Ćirić, Ivana Micić, Jelena Matejić, Aleksandar Stamenković

{"title":"Simulations and bisimulations for max-plus automata","authors":"Miroslav Ćirić, Ivana Micić, Jelena Matejić, Aleksandar Stamenković","doi":"10.1007/s10626-024-00395-1","DOIUrl":"https://doi.org/10.1007/s10626-024-00395-1","url":null,"abstract":"Two types of simulations and four types of bisimulations for weighted finite automata over the complete max-plus semiring we define as solutions of particular systems of matrix inequations. We provide a procedure that either decides that there is a simulation or bisimulation of a given type between two automata, and outputs the greatest one, or decides that no simulation or bisimulation of that type exists. The procedure is iterative and does not have to end in a finite number of steps. Certain conditions under which this procedure must terminate in a finite number of steps are described in a slightly more general context in Stamenković et al. (Discrete Event Dynamic Systems, 32:1–25, 2022). We also propose a modification of this procedure which, in case there is no simulation or bisimulation of a given type between two max-plus automata, detects this in finitely many steps and faster than the original procedure. In the same case, that modification also finds a natural number such that containment or equivalence is valid for all input words of length less than that number. For max-plus automata with non-negative weights, we point out the differences that occur when the above mentioned procedure is applied over the complete max-plus semiring, and when it is applied over its non-negative part with minus infinity added.","PeriodicalId":92890,"journal":{"name":"Discrete event dynamic systems","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140018715","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}

引用次数: 0

Cycle times in D/D/S series queues with single multi-server bottlenecks 具有单个多服务器瓶颈的 D/D/S 系列队列的周期时间

Discrete event dynamic systems Pub Date : 2024-02-03 DOI: 10.1007/s10626-023-00392-w

Lonnie Turpin, Morgan Turpin

引用次数: 0