Think Globally, Act Locally: Decentralized Supervisory Control

Incremental model evolution and reusability of supervisors for discrete event systems

“…It is worth noting that the problem of reusing supervisors in the case of horizontal growth is much di!erent from previous work on decentralized supervisory control and supervisory control with partial observation (Cieslak, Desclaux, Fawaz & Varaiya, 1988;Lin & Wonham, 1988a,b,1990Rudie & Wonham, 1992). We are mainly concerned about how to reuse a given supervisor when the underlying system model evolves while previous work focused on how to design a (decentralized or partialobservation) supervisor to control a given and static (i.e., unchanged) system model.…”

“…To compare horizontal growth with decentralized supervision (Lin & Wonham, 1988bRudie & Wonham, 1992), we can view as a local supervisor for G""G . In decentralized supervision, the question is how to design a local supervisor that is as a global supervisor, while in horizontal growth, the local supervisor is given.…”

Application of supervisory control theory to theme park vehicles

“…The projections are used to model local observation channels for the corresponding local supervisors. The local control commands issued by S 1 and S 2 will be put together according to a certain fusion rule, e.g., the conjunctive rule which defines the global control command as the intersection of all local commands (Rudie and Wonham 1992), or the disjunctive rule which defines the global control command as the union of local commands (Yoo and Lafortune 2002), or the combination of both conjunctive and disjunctive rules (Yoo and Lafortune 2002). To make control more effective, communication may be allowed among local supervisors (see e.g., Rudie et al 2003), and to reduce potential costs of maintaining sensor readings in a partially observed system sensors may be activated only when necessary (see e.g., Wang et al 2010).…”

Distributed Control Synthesis

“…This (finite state) automaton observes the controlled system, progresses according to the transitions it observes, and blocks some of the enabled transitions, depending on its current state. In a similar way, in distributed control [34,26,25], for each process we assign such a supervisor, which changes its states each time the process it supervises makes a transition, or when a visible transition of another process (e.g., through the change of shared variables) is executed. Based on its states, the supervisor allows (supports) transitions of the controlled process.…”

“…A related problem, which we address in this paper, is to automatically design control to distributed systems [25,26,34]. Synthesis is achieved in an incremental way: an already existing distributed system is modified to satisfy an additional property.…”