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wilamowski-b-m-irwin-j-d-industrial-communication-systems-2011

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16-10 Industrial Communication Systems<br />

• Data interoperability: In PROSA, one has to deal with implementation specific data that may<br />

cause difficulties during system installation. In PABADIS, data virtually does not have an established<br />

connection to the ERP system. In PABADIS’PROMISE, the ontology is spread throughout<br />

the entire automation pyramid linking all three layers (ERP–MES–field control) together.<br />

• Control flow: PROSA has a strict vertical control flow that lacks feedback to the upper layer of<br />

the ERP. PABADIS has a limited feedback to the ERP. It actually approaches it only at the end<br />

of the production cycle. PABADIS’PROMISE supports permanent connection with the ERP via<br />

planned, periodic, or event-based reports during the production order life cycle.<br />

16.4.4 Challenges of Industrial Agents’ Usage<br />

All above-mentioned architectures approach the manufacturing automation from the conceptual point<br />

of view and often overlook the application-related aspects that are implied by the distributed nature of<br />

the concepts. In particular, security, product identification, and data interoperability are vital aspects<br />

for practical implementations.<br />

Distributed <strong>systems</strong> lack a single point of control with decision-making being spread over multiple entities<br />

that communicate with each other. This causes higher security risks, due to the intensive <strong>communication</strong><br />

that such architectures require and the fact that there is no single entity that controls the system.<br />

Another challenge for distributed <strong>systems</strong> is to provide a general overview of the processes and components<br />

on the shop floor. It is difficult to keep track of the products, work-in-progress, and materials in the<br />

plant, which implies that tracking the exact location of pieces is a huge challenge. Therefore, more advanced<br />

identification of the work pieces is required in order to guarantee the efficient operation of the system.<br />

Last but not least, distribution of decision-making functionality requires interoperability of information<br />

flow over all three layers of the automation pyramid as well as mechanisms of distributed databases.<br />

Therefore, a common ontology with mechanisms of data abstraction for different control entities is<br />

required to guarantee the coordination within the system.<br />

16.4.5 Other Application Areas in Brief<br />

While agent-based applications have not yet achieved a noteworthy penetration in industry they nevertheless<br />

are heavily knocking at the door of several <strong>industrial</strong> application areas, including manufacturing<br />

and supply chain management, logistics, process control, tele<strong>communication</strong>, (air) traffic and transportation,<br />

or defense (cf., e.g., [7]). In the center of many of those agent-based <strong>industrial</strong> <strong>systems</strong> stand<br />

aspects like coordination, cooperation, self-organization, timely and reasonable/intelligent reactions to<br />

unforeseen developments, planning and decision-making, especially also under real-time constraints<br />

and mainly in distributed areas where the individual units are supposed to be autonomous, and in intelligent<br />

behavior in general.<br />

The aviation and space control industry is another frontrunner of agent technology. Especially,<br />

Âautonomous missions, such as collision control <strong>systems</strong> for unmanned, often also referred to as “uninhabited”<br />

or “remotely piloted” aerial vehicles (UAV) have attracted a lot of (<strong>industrial</strong>) research (cf. e.g.,<br />

Â[10–13,15,17,18]). In the AGENTFLY project (cf. [15]) developed in the Gerstner Laboratory, Czech Technical<br />

University (CTU) in Prague has been working with the Air Force Research Laboratory, New York, on<br />

a software prototype supporting the planning and execution of aerial missions of UAVs that includes the<br />

free-flight-based collision avoidance of UAVs with other aerial vehicles. Here, UAVs are truly autonomous<br />

entities whose autonomy is realized by its own set of intelligent software agents. Each flight mission is tentatively<br />

planned before take-off, obviously without being able to consider already likely collisions. During<br />

a flight, the agents detect possible collisions and engage in peer-to-peer negotiations aimed at sophisticated<br />

replanning in order to avoid any collisions. Ref. [10] describes a similar project, in which two different<br />

approaches for adding autonomous control to an existing UAV are explored, tested, and evaluated. The<br />

AERIAL project (cf. [13]) is a distributed system that is able to ensure coordination and control of a fleet<br />

© <strong>2011</strong> by Taylor and Francis Group, LLC

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