MSc dissertation proposal 2013/2014

Networked Supervisory Control

Introduction:

Industrial installations require using reliable control and monitoring devices. Programmable Logic Controllers (PLCs) are a component of choice for this purpose. PLCs are modular digital computers that allow using a large variety, and number, of electrical input and/or output interfaces [PLC_intro]. In addition, current PLCs are equipped with Ethernet like devices, which allow building large scale processes that can include multiple sites, and large distances.

This work is focused in an industrial pipeline for transporting natural gas. In particular, is considered a Pressure Reduction Station (PRS). A PRS, as the name indicates, takes natural gas from a higher to a lower pressure pipeline. Being a critical process, standard PRS designs always incorporate some redundancy, namely two parallel output pipelines having each three alternative valves place in series.

The main goal of this project is to control and monitor a PRS.

Objectives:

The main objective of this work is the design of a remote monitoring and operation interface for a PRS based on a PLC.

Detailed description:

Networked PLCs are a must nowadays. Electrical and natural gas distribution grids benefit of SCADA systems monitoring substations built upon PLC components. Typical PLC devices implement Ethernet / IP communications through the Modbus protocol [Modbus]. The objective of this MSc project is remotely monitoring and operating a physical system, namely a natural gas pipeline Pressure Reduction Station (PRS), using PLCs.

The work is therefore organized in the following main steps:

- Describing the interface to the physical system as a collection of sensors and actuators

- Designing a Petri Net to represent the system, including some system failures

- Designing a supervisor for the system

- Converting the supervisor to PLC code and testing it using a simulation environment as Codesys [Codesys-www]

- Designing communications with the PLC in order to remotely monitor and configure the process

In this end of this project one will have established of a toolchain to develop and test supervisory logic controllers involving the conversion of Petri nets to PLC code and the remote process monitoring and supervision.

References:

[PLC_intro] "What is a PLC?", in Machine Information Systems website, http://www.machine-information-systems.com/PLC.html

[ModBus] http://www.modbus.org/

[Schneider_Premium] "Schneider PAC, PLC & other Controllers" http://www2.schneider-electric.com/corporate/en/products-services/products-services-intermediate.page?f=NNM1:PAC%2C+PLC+%26+other+Controllers&p_function_id=2

[Codesys-www] http://www.codesys.com/

Requirements (grades, required courses, etc):

-

Expected results:

At the end of the work, the students will have enriched their experience in creating system based on a PLC using off-the-shelve components.

Place for conducting the work-proposal:

ISR / IST

More MSc dissertation proposals on Computer and Robot Vision in:

http://omni.isr.ist.utl.pt/~jag