Hierarchical discrete event systems with inputs and outputs

Perk, Sebastian
Moor, Thomas
Schmidt, Klaus Verner
We propose a framework for the hierarchical design of discrete event systems that addresses both safety and liveness properties. Technically, we build on a notion of inputs and outputs that is closely related to J.C. Willems' behavioural systems theory. We develop a structural admissibility condition that allows for abstraction-based controller synthesis similar to previous work on hybrid control systems. A key feature of our framework is an alternation of subsystem composition and controller synthesis that is expected to be computationally efficient whenever the complexity of the safety specifications is independent of the respective layer in the hierarchy.


Hierarchical multitasking control of discrete event systems: Computation of projections and maximal permissiveness
Schmidt, Klaus Verner; Cury, José E.r. (null; 2010-12-01)
This paper extends previous results on the hierarchical and decentralized control of multitasking discrete event systems (MTDES). Colored observers, a generalization of the observer property, together with local control consistency, allow to derive sufficient conditions for synthesizing modular and hierarchical control that are both strongly nonblocking (SNB) and maximally permissive. A polynomial procedure to verify if a projection fulfills the above properties is proposed and in the case they fail for a g...
Hierarchical and decentralized multitasking control of discrete event systems
Schmidt, Klaus Verner; Cury, José E. R. (2007-12-01)
In this paper, a hierarchical and decentralized approach for composite discrete-event systems (DES) that have to fulfill multiple tasks is elaborated. Colored marking generators that can distinguish classes of tasks are used as the system model, and a colored abstraction procedure as well as sufficient conditions for nonblocking and hierarchically consistent control are developed. It is shown that the computational complexity for supervisor computation is reduced. A flexible manufacturing system example dem...
Marked-string accepting observers for the hierarchical and decentralized control of discrete event systems
Schmidt, Klaus Verner (2006-12-01)
The paper extends previous work, where we develop a control theory for nonblocking hierarchical control of decentralized discrete event systems (DES). The results are based on two technical conditions for the hierarchical abstraction: it has to be (i) locally nonblocking and (ii) marked string accepting. In this paper, we investigate the systematic construction of the hierarchical abstraction. Starting from an initial natural projection which need not fulfill (i) and (ii), we provide an algorithm to compute...
Multi-objective decision making using fuzzy discrete event systems: A mobile robot example
Boutalis, Yiannis; Schmidt, Klaus Verner (2010-09-29)
In this paper, we propose an approach for the multi-objective control of sampled data systems that can be modeled as fuzzy discrete event systems (FDES). In our work, the choice of a fuzzy system representation is justified by the assumption of a controller realization that depends on various potentially imprecise sensor measurements. Our approach consists of three basic steps that are performed in each sampling instant. First, the current fuzzy state of the system is determined by a sensor evaluation. Seco...
Mobile robot navigation based on fuzzy discrete event systems
Tampakis, Georgios; Schmidt, Klaus Verner; Boutalis, Yiannis (2009-12-01)
Recently, several approaches for the control of fuzzy discrete event systems (FDES) have been proposed. First results towards the use of FDES in mobile robot navigation have also been presented, which however mainly build on sensory information processing. In this paper, we develop a methodology to compute control actions for the navigation of a mobile robot based on distributed FDES. The FDES description permits to take into account possible uncertainties in sensory information and enables a prediction of ...
Citation Formats
S. Perk, T. Moor, and K. V. Schmidt, “Hierarchical discrete event systems with inputs and outputs,” presented at the Hierarchical discrete event systems with inputs and outputs, 8th International Workshop on Discrete Event Systems, WODES 2006, Ann Arbor, MI, Amerika Birleşik Devletleri, 10 - 12 Temmuz 2006, Ann Arbor, MI, Amerika Birleşik Devletleri, 2006, Accessed: 00, 2021. [Online]. Available: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=34250636226&origin=inward.