Showing papers by "W. M. Wonham published in 2008"
TL;DR: A flexible decentralized and hierarchical architecture is presented to reduce computational effort in designing optimal nonblocking supervisors for discrete-event systems (DES) and proves the computational effectiveness of this approach.
Abstract: A flexible decentralized and hierarchical architecture is presented to reduce computational effort in designing optimal nonblocking supervisors for discrete-event systems (DES). We organize a DES into modular subsystems that embody internal interacting dependencies. Verification of, and coordination among modular subsystems are achieved through their model abstractions. Sufficient conditions are presented to guarantee that coordinators and modular supervisors result in maximally permissive and nonblocking control. A medium-sized example demonstrates the computational effectiveness of our approach.
152 citations
28 May 2008
TL;DR: It is demonstrated that STSLib can design optimal nonblocking supervisors for systems of state size up to 10626, and the resulting controllers are tractable and readily comprehensible.
Abstract: State tree structures (STS) are an adaptation of statecharts to supervisory control theory. STSLib is a C++ library that we have developed to support the symbolic analysis and synthesis of STS. This paper presents a short introduction to the library, and then applies the library to two benchmarks: (1) cat and mouse tower (CMT), (2) dining philosophers (DP). We demonstrate that STSLib can design optimal nonblocking supervisors for systems of state size up to 10626, and the resulting controllers are tractable and readily comprehensible.
34 citations
TL;DR: In this paper, the voltage control problem in ULTC is solved in different modes of operation, using discrete-event systems (DES) based solutions. And the specifications are controllable and the closed-loop control system is nonblocking.
22 citations
11 Jun 2008
TL;DR: Based on TSTS, an efficient recursive algorithm is presented that can perform nonblocking supervisory control design (in reasonable time and memory) for systems of state size 1012 and higher.
Abstract: It is well known that the nonblocking supervisory control problem is NP-hard, subject in particular to state space explosion that is exponential in the number of system components. The problem of state explosion is more challenging in Timed DES than in untimed DES. In this paper we propose to manage complexity by organizing the system as a Timed State Tree Structure (TSTS). Based on TSTS we present an efficient recursive algorithm that can perform nonblocking supervisory control design (in reasonable time and memory) for systems of state size 1012 and higher.
11 citations