HFW

[ Paulo Sousa | Nuno Silva | Fabricare ]

The CIM Laboratory of Instituto Superior de Engenharia do Porto (Portugal), identified the following minimum set of features for an holon:

unique identification;
communication;
directory knowledge base (i.e. what other's do and where they are); and
capabilities knowledge base (i.e. what can it do).

A holon has autonomy, social ability, reactivity, etc. A framework providing these, and possibly other, characteristics greatly reduces implementation time and errors. The developed infrastructure [Silva et al. (1998)], HFW - Holonic Framework (Figure 1), addresses this issues and, being an in-house product, allows them to modify it as needed.

Figure 1 – HFW’s basic structure

The framework provides asynchronous communications, directory services and support for several protocols. A protocol is a set of messages and rules (defining which messages make sense at any given time), that allows two holons to communicate with each other. The use of object oriented mechanisms allows communication messages to be perfectly routed and processed.

Each specific Holon is responsible for defining its protocol(s) and sensor/actuator procedures.

References

Silva, N.; Sousa, P. and Ramos, C. (1998) A Holonic Manufacturing System Implementation. Proceedings of the Advanced Summer Institute (ASI'98). Bremen, Germany, 14-17 July.