We consider a generalized form of the conventional decentralized control architecture for discrete-event systems where the control actions of a set of supervisors can bè`fused'' using both union and intersection of enabled events. Namely, the supervisors agree a priori on choosing``fusion by union'' for certain controllable events and``fusion by… (More)
—Most of the results on decentralized supervisory control are based on supervisors that make unconditional decisions: " enable " and " disable. " In this paper, we introduce and study the properties of decentralized supervisory control architectures where supervisors are allowed to make conditional decisions in addition to unconditional decisions. The… (More)
— We investigate diagnosability of stochastic discrete-event systems where the observation of certain events is unreliable, that is, there are non-zero probabilities of the misdetection and misclassification of events based on faulty sensor readings. Such sensor unreliability is unavoidable in applications such as nuclear energy generation. We propose the… (More)
Decentralized diagnosis of discrete event systems has received a lot of attention to deal with distributed systems or with systems that may be too large to be diagnosed by one centralized site. This paper casts the problem of decentralized diagnosis in a new hierarchical framework. A key feature is the exploitation of different local decisions together with… (More)
— Various notions of diagnosability reported in literature deal with uniformly bounded finite detection or counting delays. The uniformity of delays can be relaxed while delays remain finite. We introduce various notions of diagnosability allowing nonuniformly bounded finite delays. A polynomial-time verification algorithm for diagnosability with… (More)
The problem of verifying the properties of diagnosability and I-diagnosability is considered. We present new polynomial-time algorithms for deciding diagnosability and I-diagnosability. These algorithms are based on the construction of a nondeterministic automaton called a veriier.
A theoretical framework and its practical implications for formulating and implementing model-based monitoring of discrete flow networks are discussed. Possible flows of items are described as discrete-event (DE) traces. Each trace defines the DE sequence(s) that are triggered when an entity follows a given flow-path, visiting tracking locations within the… (More)
The past decade has witnessed the development of a body of theory, with associated applications, for fault diagnosis of dynamic systems that can be modeled in a discrete event systems framework. This paper presents several new notions of diagnosability, together with on-line diagnosis decision rules, in the context of a general decentralized architecture… (More)