A general technique for the PLC-Based implementation of RW supervisors with time delay functions

Uzam, Murat

doi:10.1007/s00170-011-3817-1

Cited by 13 publications

(2 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In order to perform the simulation and formal verification it was followed the approach proposed in for the translation of SFC to Timed Automata (TA) [33], for obtaining the timed automata model. Also, it has been considered the modeling of the comportment of the controller.…”

Section: Simulation and Formal Verification Of The Specificationmentioning

confidence: 99%

Simulation and Formal Verification for Improving Safety of PLC Programs

Galvão¹,

Machado²

2016

RIiM

View full text Add to dashboard Cite

The use of analysis techniques for improving quality of software for industrial controllers is widely used. Mainly Simulation and Formal Verification can be used as complementary techniques improving dependability of mechatronic systems behavior. In this paper there are used Simulation and Formal Verification for guaranteeing safe software for Programmable Logic Controllers, mainly related with using Function blocks of IEC 61131-3 standard. For studying, simulating and verifying behavior of those blocks are used timed automata, as modeling formalism, and UPPAAL, as tool for simulation and Formal Verification purposes.

show abstract

Section: Simulation and Formal Verification Of The Specificationmentioning

confidence: 99%

Simulation and Formal Verification for Improving Safety of PLC Programs

Galvão¹,

Machado²

2016

RIiM

View full text Add to dashboard Cite

show abstract

“…In [27], the implementation on PLCs of Ramadge-Wonham (RW) supervisors [28] with time delay functions is considered and a method, based on the TPL technique, is proposed for obtaining a ladder diagram from the supervisor. The avalanche effect and other problems associated with the implementation of supervisors on PLC have not been addressed.…”

mentioning

confidence: 99%

Bridging the Gap Between Design and Implementation of Discrete-Event Controllers

Moreira

Basilio

2014

IEEE Trans. Automat. Sci. Eng.

View full text Add to dashboard Cite

Extended labeled Petri nets (ELPNs), i.e., labeled Petri nets with inhibitor arcs, are usually used to model the desired closed-loop behavior of a controlled discrete-event system, and, as such, their states are formed with both the controller and the plant states. However, the control logic is based on the controller states only and the interaction between controller and plant is carried out through sensor readings from the plant and control actions (forced events) from the controller. This makes ELPN not suitable for modeling the controller. Control interpreted Petri nets (CIPNs), on the other hand, include control actions in the places and sensor readings in the transitions as part of their formal structure, and so provide a better formalism for controller modeling. In this paper, we propose a two-step approach to discrete-event controller implementation, as follows: (i) we first propose a set of transformation rules to convert the initial ELPN to an equivalent CIPN, therefore extracting the control logic from the desired closed-loop behavior and (ii) we present a straightforward systematic way to translate the CIPN into a ladder diagram. We apply the results presented here to the implementation of the automation system of a plastic molding machine.Note to Practitioners-The usual approach to the design of manufacturing systems is to model the desired closed-loop system behavior using, for example, Petri nets, and in the sequel to extract the discrete-event controller from this model with the view to implementing the control logic on a Programmable Logic Controller (PLC). So far, the controller extraction is carried out in an ad hoc and intuitive way. In order to overcome the lack of formal methods to deal with controller extraction and implementation, we propose here a set of rules to construct, in a systematic way, the ladder diagram that implements the discrete-event controller. We illustrate the conversion technique proposed here by applying it to the implementation of the automation system of a plastic molding machine.Index Terms-Discrete-event systems (DESs), ladder diagram, manufacturing systems, Petri nets, programmable logic controller (PLC).

show abstract