arXiv subjects

Jan H. van Schuppen

Publications and source records attributed to Jan H. van Schuppen.

27 records · Page 2Linked to original sources

arXiv2015

A Relaxed Framework for Coordination Control of Discrete-Event Systems

In this paper, we simplify the coordination control approach by removing the supervisor for the coordinator from the closed-loop system and relax the restrictions placed on a coordinator. This relaxation results in the simplification of the whole coordination control framework, including the notions of conditional controllability, conditional observability, and conditional normality. Compared to our previous work, the role of the supervisor on a coordinator alphabet is postponed until the final stage of the coordination control synthesis. This completes and clarifies our previous results, while all the fundamental theorems remain valid in the relaxed framework. Unlike previous approaches we can always compute a conditionally controllable sublanguage without any restricting conditions we have used before.

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arXiv2014

On Conditional Decomposability

The requirement of a language to be conditionally decomposable is imposed on a specification language in the coordination supervisory control framework of discrete-event systems. In this paper, we present a polynomial-time algorithm for the verification whether a language is conditionally decomposable with respect to given alphabets. Moreover, we also present a polynomial-time algorithm to extend the common alphabet so that the language becomes conditionally decomposable. A relationship of conditional decomposability to nonblockingness of modular discrete-event systems is also discussed in this paper in the general settings. It is shown that conditional decomposability is a weaker condition than nonblockingness.

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arXiv2014

A Note on Relative Observability in Coordination Control

Relative observability has been introduced and studied in the framework of partially observed discrete-event systems as a condition stronger than observability, but weaker than normality. However, unlike observability, relative observability is closed under language unions, which makes it interesting for practical applications. In this paper, we investigate this notion in the framework of coordination control. We prove that conditional normality is a stronger condition than conditional (strong) relative observability, hence conditional strong relative observability can be used in coordination control instead of conditional normality, and present a distributive procedure for the computation of a conditionally controllable and conditionally observable sublanguage of the specification that contains the supremal conditionally strong relative observable sublanguage.

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arXiv2014

Maximally Permissive Coordination Supervisory Control -- Towards Necessary and Sufficient Conditions

In this paper, we further develop the coordination control framework for discrete-event systems with both complete and partial observation. A new weaker sufficient condition for the computation of the supremal conditionally controllable sublanguage is presented. This result is then used for the computation of the supremal conditionally controllable and conditionally normal sublanguage. The paper further generalizes the previous study by considering general, non-prefix-closed languages.

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arXiv2013

Coordination Control of Discrete-Event Systems Revisited

In this paper, we revise and further investigate the coordination control approach proposed for supervisory control of distributed discrete-event systems with synchronous communication based on the Ramadge-Wonham automata framework. The notions of conditional decomposability, conditional controllability, and conditional closedness ensuring the existence of a solution are carefully revised and simplified. The paper is generalized to non-prefix-closed languages, that is, supremal conditionally controllable sublanguages of not necessary prefix-closed languages are discussed. Non-prefix-closed languages introduce the blocking issue into coordination control, hence a procedure to compute a coordinator for nonblockingness is included. The optimization problem concerning the size of a coordinator is under investigation. We prove that to find the minimal extension of the coordinator event set for which a given specification language is conditionally decomposable is NP-hard. In other words, unless P=NP, it is not possible to find a polynomial algorithm to compute the minimal coordinator with respect to the number of events.

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arXiv2012

On Algorithms and Extensions of Coordination Control of Discrete-Event Systems

In this paper, we further develop the coordination control scheme for discrete-event systems based on the Ramadge-Wonham framework. The notions of conditional decomposability, conditional controllability, and conditional closedness are revised and simplified, supremal conditionally controllable sublanguages of general non-prefix-closed languages are discussed, and a procedure for the computation of a coordinator for nonblockingness is presented.

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arXiv2012

Realization theory of discrete-time linear switched systems

The paper presents realization theory of discrete-time linear switched systems. A discrete-time linear switched system is a hybrid system, such that the continuous sub-system associated with each discrete state is linear. In this paper we present necessary and sufficient conditions for an input-output map to admit a discrete-time linear switched state-space realization. The conditions are formulated as finite rank conditions of a generalized Hankel-matrix. In addition, we present a characterization of minimality of discrete-time linear switched systems in terms of reachability and observable.Further, we prove that minimal realizations are unique up to isomorphism. We also discuss procedures for converting a linear switched system to a minimal one and we present an algorithm for constructing a state-space representation from input-output data.The paper uses the theory rational formal power series in non-commutative variables. The latter theory was successfully applied to bilinear and state-affine systems in the past.

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arXiv2010

Partial-realization theory and algorithms for linear switched systems: A formal power series approach

The paper presents partial-realization theory and realization algorithms for linear switched systems. Linear switched systems are a particular subclass of hybrid systems. We formulate a notion of a partial realization and we present conditions for existence of a minimal partial realization. We propose two partial-realization algorithms and we show that under certain conditions they yield a complete realization. Our main tool is the theory of rational formal power series.

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arXiv2010

Supervisory Control Synthesis of Discrete-Event Systems using Coordination Scheme

Supervisory control of discrete-event systems with a global safety specification and with only local supervisors is a difficult problem. For global specifications the equivalent conditions for local control synthesis to equal global control synthesis may not be met. This paper formulates and solves a control synthesis problem for a generator with a global specification and with a combination of a coordinator and local controllers. Conditional controllability is proven to be an equivalent condition for the existence of such a coordinated controller. A procedure to compute the least restrictive solution is also provided in this paper and conditions are stated under which the result of our procedure coincides with the supremal controllable sublanguage.

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