Development of an Intelligent Agent based Manufacturing System
Hong-Seok Park
1
and Ngoc-Hien Tran
2
1
School of Mechanical and Automotive Engineering, University of Ulsan, Ulsan 680-749, South Korea
2
University of Transport and Communications, Lang Thuong Ward, Dong Da District, Hanoi, Vietnam
Keywords: Cognitive Agent, Modern Manufacturing, Self-optimization.
Abstract: The new trend of the manufacturing system development is to apply autonomous behaviours inspired from
biology for the manufacturing systems. In which, the resources of the manufacturing system are considered
as biological organisms, which are autonomous entities so that the manufacturing system has the advanced
characteristics inspired from biology such as self-adaptation, self-diagnosis, and self-optimization. To carry
out these characteristics, the paper presents a paradigm about intelligent agent, called the cognitive agent
and using cognitive agents for adapting to disturbances such as tool wear, machine breakdown that have
happened on the shop floor. Modern manufacturing systems having the distributed control need autonomy
and cooperation in solving problems of agents from agent technology, and cognitive capabilities for agents
from cognitive technology. Cognitive agents combined from these two technologies are necessary for future
manufacturing systems.
1 INTRODUCTION
The human beings can adapt to the environmental
changes by the cognitive capabilities such as
perception and intellectual functions as shown in
Figure 1 in which the learning capability allows the
human being to improve the knowledge and skill to
adapt to the changes. Currently, human workers with
their skills and knowledge adapt to changes of
almost activities from design to manufacturing
process. The new trend is to apply the decision
capability, knowledge, and human being capabilities
into the manufacturing system that shows the
combination of cognitive science, automation
technology, and computer science as shown in
Figure 1: Cognitive capabilities of human beings.
Figure 2. Intelligence in manufacturing systems is
shown by the self-learning, self-adaptation, self-
diagnosis, and self-optimization capability. These
characteristics allow the system to improve the
current capability, to diagnose the status. The
cognitive models have been studied to apply into
manufacturing systems to equip the system with the
cognitive capability.
Figure 2: Cognition for realizing intelligence in
manufacturing (Tobias, 2009).
The cognitive factory was proposed by Zaeh
(2009) in which the advantages of both of automated
systems and cognitive capabilities of human were
inherited. The cognitive architecture namely Beliefs-
Desires-Intentions (BDI) proposed by Zhao and Son
Park H. and Tran N.
Development of an Intelligent Agent based Manufacturing System.
DOI: 10.5220/0006136704450450
In Proceedings of the 9th International Conference on Agents and Artificial Intelligence (ICAART 2017), pages 445-450
ISBN: 978-989-758-220-2
Copyright
c
2017 by SCITEPRESS Science and Technology Publications, Lda. All rights reserved
445
(2008) was applied for the cognitive factory.
Machines and their process are equipped with
cognitive capabilities to enable the machines for
reacting flexibly to the manufacturing changes.
Figure 3: A cognitive machining system (Zaeh, 2009).
The BDI architecture was based on a decision
making model of human comprising the knowledge
models, perception and control methods, planning
mechanism, and a cognitive perception-action loop.
The information about status of machines and
processes are got from the beliefs module. The states
of tasks that the system will carry out are defined as
desires. The task’s states that the system will work
towards are defined as intentions. Figure 3 illustrates
a vision of a cognitive machining system. The
machines equipped the cognitive abilities can
communicate, cooperate, and negotiate to get the
optimal manufacturing process.
2 LITERATURE REVIEW
The new trend in manufacturing filed is to apply the
bio-inspired technologies to equip the machines and
processes with autonomous behaviours as shown in
Figure 4. The new concepts in manufacturing have
been proposed such as Genetic Manufacturing
System (GMS) (Christo, 2007), Biological
Manufacturing System (BMS) (Ueda, 2006),
Holonic Manufacturing System (HMS) (Leitao,
2002), and Intelligent Manufacturing System with
Biological Principles (IMS-BP) (Park, 2010).
Autonomy allows the system to recover
autonomously without either upper level aids such as
the Enterprise Resource Planning (ERP), and the
Manufacturing Execution System (MES) or the
operator intervention. In these manufacturing
system, each entity in the manufacturing system is
an autonomous entity so that it can overcome the
disturbances by itself or communicate with the
others to overcome the disturbances.
Figure 4: Evolution of manufacturing systems toward the
autonomous manufacturing.
On the machine level, the evolution of control
techniques toward future machines with intelligent
control is summarized in Figure 5. Technical
innovations in the hardware and software of machine
tools have improved their efficiency, allowing the
application of CNC machine tools in machining
automation that is both highly accurate and
productive (Nakamoto, 2004, Shirase, 2009).
Figure 5: Trend of intelligent control techniques.
3 CORE TECHNOLOGIES
Figure 6 shows the classification of agents including
biological, robotic, and software agents. In this
research, the agents for controlling the
manufacturing system are software agents which are
computer programs. The agents have the advanced
characteristics as autonomy, social ability, reactivity,
and pro-activeness (Monostori, 2006, Leitao, 2009).
Autonomy is the ability of agent for achieving its
ICAART 2017 - 9th International Conference on Agents and Artificial Intelligence
446
Figure 6: Agent classification.
goals without any support from the other agents.
Agent cooperation for getting the global goal of the
system is called the agent’s social ability. The
reactivity is the ability of agents to respond to the
manufacturing changes basing on the relation
between perception and action. The agent’s pro-
activeness is the ability to express the goal-directed
behaviours.
Figure 7: Architecture of cognitive agent.
The cognitive agent is a computer program
which uses the BDI architecture inspired from the
human decision-making model to arm an agent with
artificial cognitive capabilities as shown in Figure 7.
The agent performs cognitive activities such as
perception, reasoning, and execution (Zhao, 2008)
that emulate the human cognitive behaviours. The
cognitive agent inherits all characteristics from the
traditional agent, including the autonomy, social
ability, reactivity and pro-activeness. The different
feature in comparison with the conventional agent,
which is shown by the improvement of the pro-
activeness characteristic, is the intelligence of the
cognitive agent. Intelligence is the ability of the
agent to use its knowledge and reasoning
mechanisms for making a suitable decision with
respect to the environmental changes.
4 COGNITIVE AGENTS BASED
MANUFACTURING SYSTEM
With the traditional manufacturing system, the
information systems such as manufacturing
execution system (MES) keep the main role for
operating the manufacturing system. In the
intelligent agent based manufacturing system, at
normal status, the shop floor is controlled by the
MES. In case the disturbance happen such as tool
wear, machine breakdown and so on, the agent
system controls the operation by agent cooperation.
Figure 8 shows the information model of the
intelligent agent based machining system.
Figure 8: Architecture of cognitive agent based
manufacturing system.
The .NET platform and C# were used for
programming intelligent agents. Figure 9 show he
system architecture with information flow of the
intelligent based machining system. For carrying out
the system, three kernel issues such as the
interaction protocol, agent behaviours, and database
(DB) must be focused on. The extensible markup
language (XML) messages are used for interacting
between agent with MES as well as with other
Development of an Intelligent Agent based Manufacturing System
447
agents. Communication among agents with the
programmable logic controllers (PLC) is established
using the process control protocol (OPC) for linking
and embedding objects. The physical devices on the
machining system such as sensors, alarm device, and
the controlled machine connect to PLCs. SQL
Server
TM
2005 was used for programming database
(DB).
Figure 9: System architecture of the autonomous
machining shop.
The functionality of the developed agent system
was tested successfully on the test-bed. Model of the
test-bed is shown in Figure 10. The working method
of the test-bed is explained as follows:
- RFID Reader sends the work-piece ID to PLC
(denoted by 1).
- Work-piece agent gets the work-piece ID from
PLC and sends to the machine agent (denoted by
2).
- The machine agent requires the task from MES
(denoted by 3).
- The machine agent sends the task to PLC
(denoted by 4).
- PLC turns on the green light (denoted by 5).
- After finishing the task, PLC turns off the light
(denoted by 6).
- PLC sends the signal to the transporter agent to
transfer the work-piece to the next machine
(denoted by 7).
- Inputted disturbance (denoted by 8).
- PLC sends the signal to the machine agent
(denoted by 9).
- Agent overcomes the disturbance by itself or
cooperation with the other machine agents.
Figure 10: System architecture of the machining shop.
Figure 11: Reaction of the agent in the case of tool wear.
ICAART 2017 - 9th International Conference on Agents and Artificial Intelligence
448
The reaction of the developed system in the case
of tool wear is shown in Figure 11. Steps of this case
are explained as follows:
- Input disturbance shown by turning on the red
light (alarm) at PLC 1.
- PLC 1 sends the signal to agent.
- OPC protocol is used for communicating
between PLC and agent.
- Agent diagnoses the disturbance type.
- If the disturbance belongs to the non-negotiation
type, agent generates a new plan and sends the
command to PLC.
- The system overcomes the disturbance shown by
turning on the green light at PLC 1.
The reaction of the developed system in the case
of machine breakdown is shown in Figure 12. Steps
of this case are explained as follows:
- Input disturbance shown by turning on the red
light (alarm) at PLC 1.
- PLC 1 sends the signal to agent.
- Collecting data.
- Agent diagnoses the disturbance belonging to the
negotiation type.
- Agents establish the wireless network to server
- Agent negotiation as shown in Figure 13.
- An appropriate agent is selected for carrying out
the job of the failure machine.
- The system overcomes the disturbance shown by
turning on the green light at PLC 2.
Figure 12: Reaction of the agents in the case of machine
breakdown.
5 CONCLUSIONS
Cognitive agents enable the manufacturing system to
adapt flexibility to changes and disturbances without
upper level aids or a total planning modification. In
the cognitive agent based manufacturing, the
cognitive capabilities such as perception, reasoning,
and cooperation are equipped for resources on the
shop floor. In order to prove the efficiency of the
proposed cognitive agent concept, the test-bed was
implemented and focused on the self-adjustment
mechanism in the case of the disturbances. The
experimental results show that the mechanism of the
proposed system enables the system to adapt to the
disturbances successfully.
Figure 13: Agent negotiation process.
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