Optimal non‐blocking decentralized supervisory control with unobservable controllable events

Abstract

Paranormality is an observation property of a language, in which the occurrence of unobservable events never exits the closure of the language. In this paper, a synthesis method is proposed to construct a paranormal supervisor. We propose a method to construct a controllable language such that the occurrence of unobservable events does not exit the closure of the controllable language. Moreover, a new observation property, that is, Quasi Output Control Consistency (QOCC) is defined to construct the optimal (least restrictive) non-blocking decentralized supervisory control in the presence of unobservable controllable events. Using QOCC and natural observer properties, we propose a method to construct a normal supervisor such that an arbitrary pair of lookalike strings are initiated and terminated with identical observable and uncontrollable events. It is assumed that one of these strings has unobservable controllable events. An OCC property is defined in the literature as a special case of QOCC property, where none of the lookalike strings has unobservable controllable events.

On coparanormality in distributed supervisory control of discrete‐event systems

“…Paranormality is another property of a language, that is, the occurrence of unobservable events in the plant never causes an exit from the closure of the language. We employ this property and quasi output control consistency (QOCC) property to construct an optimal non‐blocking decentralized supervisory control with unobservable controllable events [21].…”

Masked observation for majority‐based control of a democratic progress model in the framework of discrete event systems

“…However, the objective of our work is not to achieve a common objective but to increase or decrease the number of agents satisfying private objectives, which will be termed progress or regression. In this respect, our approach is also dissimilar to conventional decentralized control (e.g., [24,25]) in which the control goal is the realization of a global objective and all agents (called local supervisors) are designed solely with respect to the global objective.…”