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Altug Iftar - One of the best experts on this subject based on the ideXlab platform.
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Supervisory Controller Design to Enforce Basic Properties in Timed-Place Petri Nets
IFAC Proceedings Volumes, 2013Co-Authors: Aydın Aybar, Altug IftarAbstract:Abstract Supervisory Controller design to enforce boundedness, reversibility, and liveness in discrete-event systems with time-delays is considered. It is assumed that the system is modeled by a timed-place Petri net. The approach of place-stretching, which has been introduced recently, is used for the purpose of designing a Controller. Algorithms are presented to design a Supervisory Controller to enforce boundedness and reversibility simultaneously. This Controller also guarantees T-livenees for the largest possible subset T of the set of transitions. Therefore, boundedness, reversibility, and liveness are enforced simultaneously whenever possible. Furthermore, the designed Controller is also maximally permissive.
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Supervisory Controller design for timed-place Petri nets.
Kybernetika, 2012Co-Authors: Aydın Aybar, Altug IftarAbstract:Supervisory Controller design to avoid deadlock in discrete-event systems modeled by timed-place Petri nets (TPPNs) is considered. The recently introduced approach of place-stretching is utilized for this purpose. In this approach, given an original TPPN (OPN), a new TPPN, called the place-stretched Petri net (PSPN), is obtained. The PSPN has the property that its marking vector is sufficient to represent its state. By using this property, a Supervisory Controller design approach for TPPNs to avoid deadlock is proposed in the present work. An algorithm to determine the set of all the states of the PSPN which lead to deadlock is presented. Using this set, a Controller for the PSPN is defined. Using this Controller, a Controller for the OPN is then obtained. Assuming that the given Petri net is bounded, the proposed approach always finds a Controller in finite time whenever there exists one. Furthermore, this Controller, when exists, is maximally permissive.
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Supervisory Controller design to enforce some basic properties in timed-transition Petri nets using stretching
Nonlinear Analysis: Hybrid Systems, 2012Co-Authors: Aydın Aybar, Altug IftarAbstract:Abstract Supervisory Controller design to enforce boundedness, reversibility, and liveness in timed-transition Petri nets with firing durations is considered. It is assumed that both controllable and uncontrollable transitions may be present and more than one transition may fire simultaneously. The approach of stretching is used to represent the state of the system. Algorithms are presented to design a Supervisory Controller using the forbidden states approach to enforce boundedness and reversibility simultaneously. The designed Controller also guarantees T -liveness for the largest possible subset T of the set of transitions. In particular, boundedness, reversibility, and liveness are simultaneously enforced whenever it is possible. The designed Controller is also the least restrictive Controller which enforces boundedness and reversibility simultaneously.
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Supervisory Controller Design to Enforce Some Basic Properties in Timed Petri Nets
IFAC Proceedings Volumes, 2009Co-Authors: Aydın Aybar, Altug IftarAbstract:Abstract Supervisory Controller design to enforce boundedness, reversibility, and liveness in timed Petri nets with firing durations is considered. It is assumed that both controllable and uncontrollable transitions may be present and more than one transitions may fire simultaneously. The approach of stretching is used to represent the state of the system. Algorithms are presented to design a Controller to enforce boundedness, reversibility, and liveness simultaneously.
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Supervisory Controller design for timed petri nets
International Conference on System of Systems Engineering, 2006Co-Authors: Aydın Aybar, Altug IftarAbstract:A method, called "stretching", is introduced to represent timed Petri nets. Using this method, a new Petri net, called "stretched Petri net", which has only unit delays, is obtained to represent a timed-transition Petri net. Using this net, the state of the original timed Petri net can be represented easily. This representation also makes it easy to design a Supervisory Controller for a timed Petri net for any purpose. In this paper, Supervisory Controller design to avoid deadlock is considered in particular. Using this method, a Controller is first designed for the stretched Petri net. Then, using this Controller, a Controller for the original timed Petri net is obtained. Algorithms to construct the reachability sets of the stretched and original timed Petri nets, as well as algorithms to obtain the Controller for the original timed Petri net are presented. These algorithms are implemented using MATLAB. An example is also presented to illustrate the introduced approach.
Aydın Aybar - One of the best experts on this subject based on the ideXlab platform.
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Supervisory Controller Design to Enforce Basic Properties in Timed-Place Petri Nets
IFAC Proceedings Volumes, 2013Co-Authors: Aydın Aybar, Altug IftarAbstract:Abstract Supervisory Controller design to enforce boundedness, reversibility, and liveness in discrete-event systems with time-delays is considered. It is assumed that the system is modeled by a timed-place Petri net. The approach of place-stretching, which has been introduced recently, is used for the purpose of designing a Controller. Algorithms are presented to design a Supervisory Controller to enforce boundedness and reversibility simultaneously. This Controller also guarantees T-livenees for the largest possible subset T of the set of transitions. Therefore, boundedness, reversibility, and liveness are enforced simultaneously whenever possible. Furthermore, the designed Controller is also maximally permissive.
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Supervisory Controller design for timed-place Petri nets.
Kybernetika, 2012Co-Authors: Aydın Aybar, Altug IftarAbstract:Supervisory Controller design to avoid deadlock in discrete-event systems modeled by timed-place Petri nets (TPPNs) is considered. The recently introduced approach of place-stretching is utilized for this purpose. In this approach, given an original TPPN (OPN), a new TPPN, called the place-stretched Petri net (PSPN), is obtained. The PSPN has the property that its marking vector is sufficient to represent its state. By using this property, a Supervisory Controller design approach for TPPNs to avoid deadlock is proposed in the present work. An algorithm to determine the set of all the states of the PSPN which lead to deadlock is presented. Using this set, a Controller for the PSPN is defined. Using this Controller, a Controller for the OPN is then obtained. Assuming that the given Petri net is bounded, the proposed approach always finds a Controller in finite time whenever there exists one. Furthermore, this Controller, when exists, is maximally permissive.
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Supervisory Controller design to enforce some basic properties in timed-transition Petri nets using stretching
Nonlinear Analysis: Hybrid Systems, 2012Co-Authors: Aydın Aybar, Altug IftarAbstract:Abstract Supervisory Controller design to enforce boundedness, reversibility, and liveness in timed-transition Petri nets with firing durations is considered. It is assumed that both controllable and uncontrollable transitions may be present and more than one transition may fire simultaneously. The approach of stretching is used to represent the state of the system. Algorithms are presented to design a Supervisory Controller using the forbidden states approach to enforce boundedness and reversibility simultaneously. The designed Controller also guarantees T -liveness for the largest possible subset T of the set of transitions. In particular, boundedness, reversibility, and liveness are simultaneously enforced whenever it is possible. The designed Controller is also the least restrictive Controller which enforces boundedness and reversibility simultaneously.
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Supervisory Controller Design to Enforce Some Basic Properties in Timed Petri Nets
IFAC Proceedings Volumes, 2009Co-Authors: Aydın Aybar, Altug IftarAbstract:Abstract Supervisory Controller design to enforce boundedness, reversibility, and liveness in timed Petri nets with firing durations is considered. It is assumed that both controllable and uncontrollable transitions may be present and more than one transitions may fire simultaneously. The approach of stretching is used to represent the state of the system. Algorithms are presented to design a Controller to enforce boundedness, reversibility, and liveness simultaneously.
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Supervisory Controller Design to Enforce Reversibility and Liveness in Colored Petri Nets
International Journal of Control Automation and Systems, 2007Co-Authors: Aydın Aybar, Mustafa ÇimenAbstract:Colored Petri net model which is a model of discrete event systems is considered in this work. A Supervisory Controller which enforces reversibility and liveness simultaneously is presented. Furthermore, the algorithms, written by pseudo-code, are presented for the Supervisory Controller design. A program is developed to implement these algorithms.
Chi-hsu Wang - One of the best experts on this subject based on the ideXlab platform.
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Comments on "Direct adaptive fuzzy-neural control with state observer and Supervisory Controller for unknown nonlinear dynamical systems"
IEEE Transactions on Fuzzy Systems, 2002Co-Authors: Chi-hsu Wang, Han-leih Liu, Tsung-chih LinAbstract:In this paper, an observer-based direct adaptive fuzzy-neural network (FNN) Controller with Supervisory mode for a certain class of high order unknown nonlinear dynamical system is presented. The direct adaptive control (DAC) has the advantage of less design effort by not using FNN to model the plant. By using an observer-based output feedback control law and adaptive law, the free parameters of the adaptive FNN Controller can be tuned on-line based on the Lyapunov synthesis approach. A Supervisory Controller is appended into the FNN Controller to force the state to be within the constraint set. Therefore, if the FNN Controller cannot maintain the stability, the Supervisory Controller starts working to guarantee stability. On the other hand, if the FNN Controller works well, the Supervisory Controller will be de-activated. The overall adaptive scheme guarantees the global stability of the resulting closed-loop system in the sense that all signals involved are uniformly bounded. Simulation results also show that our initial control effort is much less than those in previous works, while preserving the tracking performance.
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Direct adaptive fuzzy-neural control with state observer and Supervisory Controller for unknown nonlinear dynamical systems
10th IEEE International Conference on Fuzzy Systems. (Cat. No.01CH37297), 2001Co-Authors: Chi-hsu WangAbstract:In this paper, an observer-based direct adaptive FNN Controller with Supervisory mode for a certain class of high order unknown nonlinear dynamical system is presented. The direct adaptive control (DAC) has the advantage of less design effort by not using FNN to model the plant. By using an observer-based output feedback control law and adaptive law, the free parameters of the adaptive FNN Controller can be tuned online based on the Lyapunov synthesis approach. A Supervisory Controller is appended into the FNN Controller to force the state to be within the constraint set. Therefore, if the FNN Controller cannot maintain the stability, the Supervisory Controller starts working to guarantee stability. On the other hand, if the FNN Controller works well, the Supervisory Controller will be de-activated. The overall adaptive scheme guarantees the global stability of the resulting closed-loop system in the sense that all signals involved are uniformly bounded.
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FUZZ-IEEE - Direct adaptive fuzzy-neural control with state observer and Supervisory Controller for unknown nonlinear dynamical systems
10th IEEE International Conference on Fuzzy Systems. (Cat. No.01CH37297), 1Co-Authors: Chi-hsu Wang, Han-leih Liu, Tsung-chih LinAbstract:In this paper, an observer-based direct adaptive FNN Controller with Supervisory mode for a certain class of high order unknown nonlinear dynamical system is presented. The direct adaptive control (DAC) has the advantage of less design effort by not using FNN to model the plant. By using an observer-based output feedback control law and adaptive law, the free parameters of the adaptive FNN Controller can be tuned online based on the Lyapunov synthesis approach. A Supervisory Controller is appended into the FNN Controller to force the state to be within the constraint set. Therefore, if the FNN Controller cannot maintain the stability, the Supervisory Controller starts working to guarantee stability. On the other hand, if the FNN Controller works well, the Supervisory Controller will be de-activated. The overall adaptive scheme guarantees the global stability of the resulting closed-loop system in the sense that all signals involved are uniformly bounded.
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Combined direct/indirect adaptive fuzzy-neural networks control with state observer and Supervisory Controller for nonlinear dynamic systems
10th IEEE International Conference on Fuzzy Systems. (Cat. No.01CH37297), 1Co-Authors: Chi-hsu Wang, Tsung-chih Lin, Han-leih LiuAbstract:A state observer-based combined direct/indirect adaptive FNN Controller with Supervisory Controller for a class of uncertain nonlinear dynamic systems is developed in this paper. The combined adaptive FNN Controller, whose free parameters can be tuned online by observer-based output feedback control law and adaptive law, is a combination of direct and indirect adaptive FNN Controllers. A weighting factor, which is adjusted by trade-off between plant knowledge and control knowledge, appended between indirect adaptive FNN control and direct adaptive FNN control. A Supervisory Controller is appended into the FNN Controller to force the state to be within the constraint set.
Ramon Schiffelers - One of the best experts on this subject based on the ideXlab platform.
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Modular model-based Supervisory Controller design for wafer logistics in lithography machines
2015 ACM IEEE 18th International Conference on Model Driven Engineering Languages and Systems (MODELS), 2015Co-Authors: Bram Van Der Sanden, Michel Reniers, Marc Geilen, Twan Basten, Johan Jacobs, Jeroen Voeten, Ramon SchiffelersAbstract:Development of high-level Supervisory Controllers is an important challenge in the design of high-tech systems. It has become a significant issue due to increased complexity, combined with demands for verified quality, time to market, ease of development, and integration of new functionality. To deal with these challenges, model-based engineering approaches are suggested as a cost-effective way to support easy adaptation, validation, synthesis, and verification of Controllers. This paper presents an industrial case study on modular design of a Supervisory Controller for wafer logistics in lithography machines. The uncontrolled system and control requirements are modeled independently in a modular way, using small, loosely coupled and minimally restrictive extended finite automata. The multiparty synchronization mechanism that is part of the specification formalism provides clear advantages in terms of modularity, traceability, and adaptability of the model. We show that being able to refer to variables and states of automata in guard expressions and state-based requirements, enabled by the use of extended finite automata, provides concise models. Additionally, we show how modular synthesis allows construction of local supervisors that ensure safety of parts of the system, since monolithic synthesis is not feasible for our industrial case.
Galperti C. - One of the best experts on this subject based on the ideXlab platform.
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Real-time plasma state monitoring and Supervisory control on TCV
'IOP Publishing', 2019Co-Authors: Blanken T.c., Felici F., Galperti C., Kong M., Vu N.m.t., Jet Contributors, García Muñoz ManuelAbstract:In ITER and DEMO, various control objectives related to plasma control must be simultaneously achieved by the plasma control system (PCS), in both normal operation as well as off-normal conditions. The PCS must act on off-normal events and deviations from the target scenario, since certain sequences (chains) of events can precede disruptions. It is important that these decisions are made while maintaining a coherent prioritization between the real-time control tasks to ensure high-performance operation. In this paper, a generic architecture for task-based integrated plasma control is proposed. The architecture is characterized by the separation of state estimation, event detection, decisions and task execution among different algorithms, with standardized signal interfaces. Central to the architecture are a plasma state monitor and Supervisory Controller. In the plasma state monitor, discrete events in the continuous-valued plasma state are modeled using finite state machines. This provides a high-level representation of the plasma state. The Supervisory Controller coordinates the execution of multiple plasma control tasks by assigning task priorities, based on the finite states of the plasma and the pulse schedule. These algorithms were implemented on the TCV digital control system and integrated with actuator resource management and existing state estimation algorithms and Controllers. The plasma state monitor on TCV can track a multitude of plasma events, related to plasma current, rotating and locked neoclassical tearing modes, and position displacements. In TCV experiments on simultaneous control of plasma pressure, safety factor profile and NTMs using electron cyclotron heating (ECH) and current drive (ECCD), the Supervisory Controller assigns priorities to the relevant control tasks. The tasks are then executed by feedback Controllers and actuator allocation management. This work forms a significant step forward in the ongoing integration of control capabilities in experiments on TCV, in support of tokamak reactor operation.EURATOM 633053Netherlands Organization for Scientific Research 680.47.43
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Real-time plasma state monitoring and Supervisory control on TCV
2019Co-Authors: Blanken T.c., Galperti C., Felici, Federico A.a., Vu, Ngoc Minh Trang, Kong Mengdi, Sauter Olivier, De Baar M.r.Abstract:In ITER and DEMO, various control objectives related to plasma control must be simultaneously achieved by the plasma control system (PCS), in both normal operation as well as off-normal conditions. The PCS must act on off-normal events and deviations from the target scenario, since certain sequences (chains) of events can precede disruptions. It is important that these decisions are made while maintaining a coherent prioritization between the real-time control tasks to ensure high-performance operation. In this paper, a generic architecture for task-based integrated plasma control is proposed. The architecture is characterized by the separation of state estimation, event detection, decisions and task execution among different algorithms, with standardized signal interfaces. Central to the architecture are a plasma state monitor and Supervisory Controller. In the plasma state monitor, discrete events in the continuous-valued plasma state are modeled using finite state machines. This provides a high-level representation of the plasma state. The Supervisory Controller coordinates the execution of multiple plasma control tasks by assigning task priorities, based on the finite states of the plasma and the pulse schedule. These algorithms were implemented on the TCV digital control system and integrated with actuator resource management and existing state estimation algorithms and Controllers. The plasma state monitor on TCV can track a multitude of plasma events, related to plasma current, rotating and locked neoclassical tearing modes, and position displacements. In TCV experiments on simultaneous control of plasma pressure, safety factor profile and NTMs using electron cyclotron heating (ECH) and current drive (ECCD), the Supervisory Controller assigns priorities to the relevant control tasks. The tasks are then executed by feedback Controllers and actuator allocation management. This work forms a significant step forward in the ongoing integration of control capabilities in experiments on TCV, in support of tokamak reactor operation
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Real-time plasma state monitoring and Supervisory control on TCV
'IOP Publishing', 2019Co-Authors: Blanken T. C., Felici F., Galperti C., Kong M., Sauter O., De Baar M. R., Vu N. M. T., Meyer H., Eich T., Beurskens M.Abstract:In ITER and DEMO, various control objectives related to plasma control must be simultaneously achieved by the plasma control system (PCS), in both normal operation as well as off-normal conditions. The PCS must act on off-normal events and deviations from the target scenario, since certain sequences (chains) of events can precede disruptions. It is important that these decisions are made while maintaining a coherent prioritization between the real-time control tasks to ensure high-performance operation. In this paper, a generic architecture for task-based integrated plasma control is proposed. The architecture is characterized by the separation of state estimation, event detection, decisions and task execution among different algorithms, with standardized signal interfaces. Central to the architecture are a plasma state monitor and Supervisory Controller. In the plasma state monitor, discrete events in the continuous-valued plasma state arc modeled using finite state machines. This provides a high-level representation of the plasma state. The Supervisory Controller coordinates the execution of multiple plasma control tasks by assigning task priorities, based on the finite states of the plasma and the pulse schedule. These algorithms were implemented on the TCV digital control system and integrated with actuator resource management and existing state estimation algorithms and Controllers. The plasma state monitor on TCV can track a multitude of plasma events, related to plasma current, rotating and locked neoclassical tearing modes, and position displacements. In TCV experiments on simultaneous control of plasma pressure, safety factor profile and NTMs using electron cyclotron heating (ECI I) and current drive (ECCD), the Supervisory Controller assigns priorities to the relevant control tasks. The tasks are then executed by feedback Controllers and actuator allocation management. This work forms a significant step forward in the ongoing integration of control capabilities in experiments on TCV, in support of tokamak reactor operation
