A new framework for supervisory control

Proposes a new framework for supervisory control design for discrete event systems. Both plants and supervisors are represented by process objects which encapsulate control and observation interfaces with the process dynamics. The process dynamics are modeled by nondeterministic state machines (NSMs), while the interfaces are modeled by equivalence relations (arbitrary masks) on the set of event labels (including ε). Process objects are interconnected by a single operator called masked composition. This framework permits combined open-loop/closed-loop control as well as nondeterministic plants and nondeterministic supervision. By encapsulating control and observation masks with process dynamics and using the operator of masked composition to build complex objects out of simpler ones, it provides a foundation for an object-oriented approach to discrete event control