Learn More
In the first part of this paper, we generalize a notion of robust supervisory control to deal with marked languages. We show how to synthesize a supervisor to control a family of plant models, each with its own specification. The solution we obtain is the most general in that it provides the closest approximation to the supremal controllable sublanguage for(More)
In this paper we present a hierarchical method that decomposes a discrete-event system (DES) into a high level subsystem which communicates with ¢ ¡ ¤ £ parallel low level subsystems through separate interfaces, which restrict the interaction of the subsystems. We first review the setting for the serial case (¦ ¥ § £) [1], and then generalize it for¨¡ © £.(More)
—In this paper, we present a hierarchical method that decomposes a system into two subsystems, and restricts the interaction of the subsystems by means of an interface. We present definitions for two types of interfaces [represented as discrete-event systems (DESs)], and define a set of interface consistency properties that can be used to verify if a DES is(More)
This paper considers supervisory control of probabilistic discrete event systems (PDES). PDESs are modeled as generators of probabilistic languages. The supervisory control problem considered is to find, if possible, a supervisor under whose control the behaviour of a plant is identical to a given probabilistic specification. The probabilistic supervisors(More)
—Flexible manufacturing systems have long been touted as an application area for supervisory control theory. Unfortunately, due to the typical exponential growth of state space with the number of interacting subsystems, concurrent systems such as manufacturing applications have, for the most part, remained beyond the reach of existing supervisory control(More)
Safety cases have become popular, even mandated, in a number of jurisdictions that develop products that have to be safe. Prior to their use in software certification, safety cases were already in use in domains like aviation, military applications, and the nuclear industry. Argument based methodologies/approaches have recently become the cornerstone for(More)
This paper describes the lessons we learned over a thirteen year period while helping to develop the shutdown systems for the nuclear generating station at Darlington, Ontario, Canada. We begin with a brief description of the project and then show how we modified processes and notations developed in the academic community so that they are acceptable for use(More)