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Mengchu Zhou - One of the best experts on this subject based on the ideXlab platform.
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a novel algorithm for wafer sojourn time analysis of single arm cluster tools with wafer residency time constraints and activity time variation
Systems Man and Cybernetics, 2015Co-Authors: Chunrong Pan, Yan Qiao, Mengchu ZhouAbstract:This paper addresses the scheduling problem of single-arm cluster tools with both wafer residency time constraints and activity time variation in semiconductor manufacturing. Based on a Petri Net Model developed in our previous work, polynomial algorithms are proposed to obtain the exact upper bound of the wafer sojourn time delay for the first time. With the obtained results, one can check the feasibility of a given schedule or find a feasible and optimal one if it exists. Illustrative examples are given to show the applications of the proposed method.
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real time scheduling of single arm cluster tools subject to residency time constraints and bounded activity time variation
IEEE Transactions on Automation Science and Engineering, 2012Co-Authors: Yan Qiao, Naiqi Wu, Mengchu ZhouAbstract:It is very challenging to schedule cluster tools subject to wafer residency time constraints and activity time variation. This work develops a Petri Net Model to describe the system and proposes a two-level real-time scheduling architecture. At the lower level, a real-time control policy is used to offset the activity time variation as much as possible. At the upper level, a periodical off-line schedule is derived under the normal condition. This work presents the schedulability conditions and scheduling algorithms for an off-line schedule. The schedulability conditions can be analytically checked. If they are satisfied, an off-line schedule can be analytically found. The off-line schedule together with a real-time control policy forms the real-time schedule for the system. It is optimal in terms of cycle time minimization. Illustrative examples are given to show the application of the proposed approach. Note to Practitioners-This paper discusses the real-time scheduling problem of single-arm cluster tools with wafer residency time constraints and bounded activity time variation. With a Petri Net Model, schedulability is analyzed and schedulability conditions are presented by using analytical expressions. Then, an efficient algorithm is proposed to find a periodical schedule if it is schedulable. Such a schedule is optimal in terms of cycle time and can adapt to bounded activity time variation. Therefore, it is applicable to the scheduling and real-time control of cluster tools in semiconductor manufacturing plants.
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Optimal Petri-Net-Based Polynomial-Complexity Deadlock-Avoidance Policies for Automated Manufacturing Systems
IEEE Transactions on Systems Man and Cybernetics - Part A: Systems and Humans, 2009Co-Authors: Ke Yi Xing, Mengchu Zhou, Feng TianAbstract:Even for a simple automated manufacturing system (AMS), such as a general single-unit resource allocation system, the computation of an optimal or maximally permissive deadlock-avoidance policy (DAP) is NP-hard. Based on its Petri-Net Model, this paper addresses the deadlock-avoidance problem in AMSs, which can be Modeled by systems of simple sequential processes with resources. First, deadlock is characterized as a perfect resource-transition circuit that is saturated at a reachable state. Second, for AMSs that do not have one-unit resources shared by two or more perfect resource-transition circuits that do not contain each other, it is proved that there are only two kinds of reachable states: safe states and deadlock. An algorithm for determining the safety of a new state resulting from a safe one is then presented, which has polynomial complexity. Hence, the optimal DAP with polynomial complexity can be obtained by a one-step look-ahead method, and the deadlock-avoidance problem is polynomially solved with Petri Nets for the first time. Finally, by reducing a Petri-Net Model and applying the design of optimal DAP to the reduced one, a suboptimal DAP for a general AMS is synthesized, and its computation is of polynomial complexity.
Davidrajuh Reggie - One of the best experts on this subject based on the ideXlab platform.
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Single Controller-Based Colored Petri Nets for Deadlock Control in Automated Manufacturing Systems
'MDPI AG', 2020Co-Authors: Kaid Husam, Li Zhiwu, Davidrajuh ReggieAbstract:Deadlock control approaches based on Petri Nets are usually implemented by adding control places and related arcs to the Petri Net Model of a system. The main disadvantage of the existing policies is that many control places and associated arcs are added to the initially constructed Petri Net Model, which significantly increases the complexity of the supervisor of the Petri Net Model. The objective of this study is to develop a two-step robust deadlock control approach. In the first step, we use a method of deadlock prevention based on strict minimal siphons (SMSs) to create a controlled Petri Net Model. In the second step, all control places obtained in the first step are merged into a single control place based on the colored Petri Net to mark all SMSs. Finally, we compare the proposed method with the existing methods from the literature.publishedVersio
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Single Controller-Based Colored Petri Nets for Deadlock Control in Automated Manufacturing Systems
'MDPI AG', 2020Co-Authors: Kaid Husam, Li Zhiwu, Davidrajuh ReggieAbstract:Deadlock control approaches based on Petri Nets are usually implemented by adding control places and related arcs to the Petri Net Model of a system. The main disadvantage of the existing policies is that many control places and associated arcs are added to the initially constructed Petri Net Model, which significantly increases the complexity of the supervisor of the Petri Net Model. The objective of this study is to develop a two-step robust deadlock control approach. In the first step, we use a method of deadlock prevention based on strict minimal siphons (SMSs) to create a controlled Petri Net Model. In the second step, all control places obtained in the first step are merged into a single control place based on the colored Petri Net to mark all SMSs. Finally, we compare the proposed method with the existing methods from the literature
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Automatic Supervisory Controller for Deadlock Control in Reconfigurable Manufacturing Systems with Dynamic Changes
'MDPI AG', 2020Co-Authors: Kaid Husam, Li Zhiwu, Al-ahmari Abdulrahman, Davidrajuh ReggieAbstract:In reconfigurable manufacturing systems (RMSs), the architecture of a system can be modified during its operation. This reconfiguration can be caused by many motivations: processing rework and failures, adding new products, adding new machines, etc. In RMSs, sharing of resources may lead to deadlocks, and some operations can therefore remain incomplete. The objective of this article is to develop a novel two-step solution for quick and accurate reconfiguration of supervisory controllers for deadlock control in RMSs with dynamic changes. In the first step, the Net rewriting system (NRS) is used to design a reconfigurable Petri Net Model under dynamic configurations. The obtained Model guarantees boundedness behavioral property but may lose the other properties of a Petri Net Model (i.e., liveness and reversibility). The second step develops an automatic deadlock prevention policy for the reconfigurable Petri Net using the siphon control method based on a place invariant to solve the deadlock problem with dynamic structure changes in RMSs and achieve liveness and reversibility behavioral properties for the system. The proposed approach is tested using examples in the literature and the results highlight the ability of the automatic deadlock prevention policy to adapt to RMSs configuration changes.publishedVersio
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Automatic Supervisory Controller for Deadlock Control in Reconfigurable Manufacturing Systems with Dynamic Changes
'MDPI AG', 2020Co-Authors: Kaid Husam, Li Zhiwu, Al-ahmari Abdulrahman, Davidrajuh ReggieAbstract:In reconfigurable manufacturing systems (RMSs), the architecture of a system can be modified during its operation. This reconfiguration can be caused by many motivations: processing rework and failures, adding new products, adding new machines, etc. In RMSs, sharing of resources may lead to deadlocks, and some operations can therefore remain incomplete. The objective of this article is to develop a novel two-step solution for quick and accurate reconfiguration of supervisory controllers for deadlock control in RMSs with dynamic changes. In the first step, the Net rewriting system (NRS) is used to design a reconfigurable Petri Net Model under dynamic configurations. The obtained Model guarantees boundedness behavioral property but may lose the other properties of a Petri Net Model (i.e., liveness and reversibility). The second step develops an automatic deadlock prevention policy for the reconfigurable Petri Net using the siphon control method based on a place invariant to solve the deadlock problem with dynamic structure changes in RMSs and achieve liveness and reversibility behavioral properties for the system. The proposed approach is tested using examples in the literature and the results highlight the ability of the automatic deadlock prevention policy to adapt to RMSs configuration changes
Maria Pia Fanti - One of the best experts on this subject based on the ideXlab platform.
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a first order hybrid Petri Net Model for supply chain management
IEEE Transactions on Automation Science and Engineering, 2009Co-Authors: Mariagrazia Dotoli, Maria Pia Fanti, Giorgio Iacobellis, Agostino Marcello ManginiAbstract:A supply chain (SC) is a Network of independent manufacturing and logistics companies that perform the critical functions in the order fulfillment process. This paper proposes an effective and modular Model to describe material, financial and information flow of SCs at the operational level based on first-order hybrid Petri Nets (PNs), i.e., PNs that make use of first-order fluid approximation. The proposed formalism enables the SC designer to choose suitable production rates of facilities in order to optimize the chosen objective function. The optimal mode of operation is performed based on the state knowledge of the obtained linear discrete-time, time-varying state variable Model in order to react to unpredictable events such as the blocking of a supply or an accident in a transportation facility. A case study is Modeled in the proposed framework and is simulated under three different closed-loop control strategies.
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a generalized stochastic Petri Net Model for management of distributed manufacturing systems
Conference on Decision and Control, 2005Co-Authors: Mariagrazia Dotoli, Maria Pia FantiAbstract:A Distributed Manufacturing System (DMS) is a collection of independent companies possessing complementary skills and integrated with transportation and storage systems. This paper deals with the issues of Modeling and managing a DMS. The system is Modeled as a timed discrete event dynamical system by generalized stochastic Petri Nets. Moreover, two well known broad policies are considered to manage the DMS: make-to-stock and make-to-order. In order to compare the two management techniques and to show the effectiveness of each method, a case study is presented.
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coloured timed Petri Net Model for real time control of automated guided vehicle systems
International Journal of Production Research, 2004Co-Authors: Mariagrazia Dotoli, Maria Pia FantiAbstract:Automated guided vehicle systems (AGVS) are material-handling devices representing an efficient and flexible option for products management in automated manufacturing systems. In AGVS, vehicles fol...
Haitham A. Mahmoud - One of the best experts on this subject based on the ideXlab platform.
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Petri Net Model Based on Neural Network for Deadlock Control and Fault Detection and Treatment in Automated Manufacturing Systems
IEEE Access, 2020Co-Authors: Husam Kaid, Abdulrahman Al-ahmari, Emad Abouel Nasr, Adel Al-shayea, Ali K. Kamrani, Mohammed A. Noman, Haitham A. MahmoudAbstract:Previously, different deadlock control strategies for automated manufacturing systems (AMSs) based on Petri Nets with reliable resources have been proposed. However, in real-world applications, resources may be unreliable. Therefore, deadlock control strategies presented in previous research studies are not suitable for such applications. To address this issue, this paper proposes a novel three-step deadlock control strategy for fault detection and treatment of unreliable resource systems. In the first step, a controlled system (deadlock-free) is obtained using the “Maximum Number of Forbidding First met Bad Markings Problem 1” (MFFBMP1), which does not consider resource failures. Subsequently, all obtained monitors are merged into a single monitor based on a colored Petri Net. The second step addresses deadlocks caused by resource failures in the Petri Net Model using a common recovery subNet based on colored Petri Nets. The recovery subNet is applied to the system obtained in the first step to ensure that the system is reliable. The third step proposes a hybrid approach that combines neural Networks with colored Petri Nets obtained from the second step, for the detection and treatment of faults. The proposed approach possesses the advantages of modular integration of Petri Nets and can also learn neurons and reduce knowledge, similar to neural Networks. Therefore, this approach solves the deadlock problem in AMSs and also detects and treats failures. The proposed approach was tested using an example from literature.
Yan Qiao - One of the best experts on this subject based on the ideXlab platform.
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a novel algorithm for wafer sojourn time analysis of single arm cluster tools with wafer residency time constraints and activity time variation
Systems Man and Cybernetics, 2015Co-Authors: Chunrong Pan, Yan Qiao, Mengchu ZhouAbstract:This paper addresses the scheduling problem of single-arm cluster tools with both wafer residency time constraints and activity time variation in semiconductor manufacturing. Based on a Petri Net Model developed in our previous work, polynomial algorithms are proposed to obtain the exact upper bound of the wafer sojourn time delay for the first time. With the obtained results, one can check the feasibility of a given schedule or find a feasible and optimal one if it exists. Illustrative examples are given to show the applications of the proposed method.
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real time scheduling of single arm cluster tools subject to residency time constraints and bounded activity time variation
IEEE Transactions on Automation Science and Engineering, 2012Co-Authors: Yan Qiao, Naiqi Wu, Mengchu ZhouAbstract:It is very challenging to schedule cluster tools subject to wafer residency time constraints and activity time variation. This work develops a Petri Net Model to describe the system and proposes a two-level real-time scheduling architecture. At the lower level, a real-time control policy is used to offset the activity time variation as much as possible. At the upper level, a periodical off-line schedule is derived under the normal condition. This work presents the schedulability conditions and scheduling algorithms for an off-line schedule. The schedulability conditions can be analytically checked. If they are satisfied, an off-line schedule can be analytically found. The off-line schedule together with a real-time control policy forms the real-time schedule for the system. It is optimal in terms of cycle time minimization. Illustrative examples are given to show the application of the proposed approach. Note to Practitioners-This paper discusses the real-time scheduling problem of single-arm cluster tools with wafer residency time constraints and bounded activity time variation. With a Petri Net Model, schedulability is analyzed and schedulability conditions are presented by using analytical expressions. Then, an efficient algorithm is proposed to find a periodical schedule if it is schedulable. Such a schedule is optimal in terms of cycle time and can adapt to bounded activity time variation. Therefore, it is applicable to the scheduling and real-time control of cluster tools in semiconductor manufacturing plants.
