DIS 2006 15.6.2006 Helsinki University of Technology

Multi-Agent System Enhanced Supervision of Process Automation

Teppo Pirttioja1, Antti Pakonen2, Ilkka Seilonen3, Aarne Halme1, Kari Koskinen3

Helsinki University of Technology, Finland1Automation Technology Laboratory3Information and Computer Systems in Automation

2VTT Technical Research Centre of Finland

DIS 2006

IEEE 2006 Workshop on Distributed Intelligent SystemsJune 15 -16, Diplomat Hotel Prague, Czech Republic

DIS 2006 15.6.2006 Helsinki University of Technology

Agenda

Background and motivation Process automation and user needs Available technologies

Architecture Multi agent system based architecture Roles of agents Internals of an agent

Test scenario Conclusions and future work

DIS 2006 15.6.2006 Helsinki University of Technology

Background and Motivation:process automation Process Automation

Factories are running 24/7 and as effectively as possible General trend: Less personnel and bigger and more complex

factories, so there is more to supervise Ordinary IT solutions are used, because its cheap and it works

Results often data systems with mixed user interfaces Information is measured and gathered but not easily available

to users

User need easy and efficient access to all data Users need right information, in the right place, in right time,

and in right level of abstraction and easily! It’s not about tools and technology, it’s also the way people

are used to operate

DIS 2006 15.6.2006 Helsinki University of Technology

Background and Motivation: user needs within process automation

System within process automation is running mainly on it’s own User intervention mainly needed when there are problems in the system Users need to get information when critical changes happen Changes may result from input material variations, devices malfunctions, etc...

Various user profiles of supervision Process operators; physical process, measurements, ... Servicemen; device conditions for drives, valves, ... System developers; performance issues, control optimization, ... Business managers; orders, financial aspects, ...

What kind of concrete supervision tools are needed? Easy browsing and navigating trough all process related data Search engine to access data in separate and heterogeneous systems Find situations and data combinations that are interested by the user Easy setup for monitoring a combination of various measured variables

DIS 2006 15.6.2006 Helsinki University of Technology

Background and Motivation:What technologies might be useful?

Integration problem Semantic Web tools makes more and more information available

in machine understandable form May make the integration of separate systems easier There are no ontologies about factories available yet and there is no ready and standardized solution of how to

combine number of services to build up more complicated services (orchestration)

Supervision problem Automate routine supervision as much as possible Let people be just decision-makers for real problems that are not

possible to automate Proactive agents are argued to be suitable for active supervision

DIS 2006 15.6.2006 Helsinki University of Technology

Architecture: agents as information mediators in Semantic Automation

Proactive operation of agents

System integration with semantic web tools

DIS 2006 15.6.2006 Helsinki University of Technology

Architecture: agents operating in various roles

IA

PA

DF

CA

PA

PA

FA

AA

CA

DA

IA

CA CA

Continuous data analyzing

Various events from wrapper agents

CA = Client Agent, DA = Diary AgentIA = Information Agent, FA = Fault AgentAA = Alarm Agent, DF = Directory Facilitator

IAIA

Information processing

User Interface

DIS 2006 15.6.2006 Helsinki University of Technology

Architecture: internal structure of an agent

User configurable manager module Uses data processing modules for actual information processing Adapts to changing situations with context depended operation

(Belief-Desires-Intentions)

Data processing modules Communication with other agents Data I/O connections

Connecion directly to process automation measurements

Connection to other databases Data processing

Reasoning and logic Mathematic processing

Data storage modules Temporal storage of data

DIS 2006 15.6.2006 Helsinki University of Technology

User configurability supervision of process

How human users could define these tasks? Should be easy to desing, configure and maintain Framework, architecture etc. is needed

This solution should be as flexible as SQL servers are in data management area

But SQL servers as such can’t be used because Monitoring in automation is a task or a process, it’s not just QUERY ! Some information is ready to be access directly, but quite often we

need to wait for triggering events Data is stored in mixed formats (semantics)

What if we use the previously presented agent architecture? Let see how it could work in typical process related monitoring task

DIS 2006 15.6.2006 Helsinki University of Technology

Temporal monitoring scenarioProcess related problem explained

Problem: There are slowly drifting measurements in the processes Sensors that become dirty, etc.

Alarms provided by process automation system are not helping, because Limits are often set too wide to minimize false alarms Limits are set normally to check just one value at the time Control loops are compensating the error

User need a tool to monitor a combination of process quantities This kind of monitoring would be especially useful temporally e.g., startups and shutdowns of a process, or when there is a change in product

”for next 15 minutes make sure that pump is running and level in the tank is rising”

Solution proposal: fault may be found by gross checking process quantities User defines a set of constraints that agents are then set to monitor e.g., check that Measurement1 is always more than Measurement2

DIS 2006 15.6.2006 Helsinki University of Technology

Temporal monitoring scenarioOperation of agents

CA = Clint Agent Provides user interface and lets

user define constraints IA = Information Agent

Performs the monitoring task Divides the set of constraints

based on the initial values Delegates monitoring to peers Reports to the user when

needed PA1 = Process Agent 1

Knows Meas1 value PA2 = Process Agent 2

Knows Meas2 value DF = Directory Facilitator

Yellow page services Knows what agent is providing

what information

DIS 2006 15.6.2006 Helsinki University of Technology

Temporal monitoring scenarioActive monitoring of agents

Normally the situation is OK in the beginning so changes in measured values need to be monitored

Process agents monitor their own values and report when their partial constraints are broken

When partial constraints are broken the Information agent tests the set of constraints again

If constraints are ok the monitoring continues with updated values

If some constraint of the overall set of constraints is broken, then the user is informed

DIS 2006 15.6.2006 Helsinki University of Technology

Conclusions and Future Work Users within process automation need powerful tools to search, access,

and supervise information produced in all around the factory And this system should be easy to setup, configure, and maintain

Enabling technologies seems to be available Ontologies and semantic web tools “solves” interoperability issues Agents for proactive operation - monitoring on behalf of human user

Combining architecture - Semantic Automation

Future Work Testing on more complex monitoring tasks Test Scenarios motivated by real life problems and situated in real factories Use semantic web tools to provide user configurability

e.g., SPARQL (Query language for RDF/OWL from W3C) OWL for plant models, etc.

Internal operational principles are still much open

Consentrating more on the user viewpoint What services are really needed by the user? How user would like to configure and use various services?

DIS 2006 15.6.2006 Helsinki University of Technology

That’s it

Questions

Thanks to Project group: www.automation.hut.fi/projects/proage/

Funding: National Technology Agency of Finland, Metso Automation, UPM Kymmene, Teleca