Max Hering de Queiroz

Learn More
The Supervisory Control Theory is applied to a manufacturing cell commanded by a programmable logic controller (PLC). By means of local modular approach a methodology that exploits modularity of the plant and of the behavioral specifications models optimal supervisors are obtained without state-space explosion. For the purpose of simplifying the ladder(More)
This paper presents an approach for reducing computational efforts in the synthesis of modular supervisors for discrete event systems. Most of large scale systems are represented by the composition of several smaller subsystems. To avoid the design on a single, often large plant, modular supervisors are synthesized on local models, which are constructed(More)
This paper presents an approach for functionally dealing with multiple tasks in the supervisory control of discrete-event systems (DES). The colored marking generator (CMG), a special type of Moore automaton, is introduced as a model that distinguishes classes of tasks in DES. The main results of supervisory control theory are extended to this model,(More)
This paper deals with the implementation of supervisory control of discrete events systems in programmable logic controllers. A modular approach of the supervisory control theory is applied for performing the formal synthesis of supervisors. Some problems that arise in the implementation of supervisory control are reviewed from the literature. The main(More)
In this paper, a hierarchical and decentralized approach for composite discrete-event systems (DES) that have to fulfill multiple tasks is elaborated. Colored marking generators that can distinguish classes of tasks are used as the system model, and a colored abstraction procedure as well as sufficient conditions for nonblocking and hierarchically(More)
Hierarchical Interface-Based Supervisory Control employs interfaces that allow properties of a monolithic system to be verified through local analysis. By avoiding the need to verify properties globally, significant computational savings can be achieved. In this paper we provide local requirements for a multi-level architecture employing command-pair type(More)
This paper presents a model-driven engineering approach to model and verify PLC programs written in Ladder Diagram. PLC and plant are modeled in FIACRE language according to transformation models. A verification toolchain is built around FIACRE, in order to guarantee the satisfaction of generic and application-oriented properties. The potential of this(More)
This paper proposes a method to simplify Extended Finite-state Automata (EFA) in such a way the least restrictive controllable supervisor is preserved. The method is based on variable abstraction, which involves the identification and removal of irrelevant variables from a model. Variable abstraction preserves controllability, and the paper shows how(More)
A modular approach for efficiently dealing with multiple tasks and multiple specifications in the supervisory control of composite discrete-event systems (DES) is presented. Colored marking generators are used to distinguish classes of tasks in supervisory control of DES, which allows the synthesis of optimal supervisors that are nonblocking with respect to(More)