Evolvable assembly systems environment
Article Type: News From: Assembly Automation, Volume 29, Issue 3
According to the results attained by many roadmaps, one of the most important objectives to be met by European industry is sustainability, which is multi-faceted: including economical, social and ecological aspects. The obvious conclusion to this holistic problem is that future manufacturing solutions will have to deal with very complex scenarios.
Evolvable assembly systems (EAS) represents one of the paradigms proposed as an opportunity to solve such threats.
Evolvable systems have characteristically distributed control, are composed of intelligent modules and are open in architecture. The technical and architectural aspects of the evolvable system development are supported by a comprehensive methodological framework. Evolvability being a system concept, it is envisaged to address every aspect of an assembly system throughout its life cycle, i.e. design and development, operation and evolution. The work has been and being implemented through large European research projects. Furthermore,integration of legacy subsystems and modules have been addressed in the methodology.
The main difference in the EAS paradigm is that it was created from a more dynamic, industrially relevant perspective (trigger issue): EAS is mainly concerned with what occurs in a production system when a production change-over is called for; that is, whenever the current production system needs to undergo some change in its physical, control, or productivity layout. Such changes occur at ramp-up, product change-over, or demand surges. This is where the biological inspiration to EAS first makes itself apparent: it is change that drives the adaptability/evolution of the EAS systems, not the current or known scenarios.
Furthermore, the adaptability is dictated by real evolvability principles such as “survival-of-the-fittest” at algorithm level. This biological approach becomes even more evident when one studies the way modularity is achieved within EAS. In most approaches, modularity is set by either known mechanical subdivisions, or by taking the classical subdivisions that exist within manufacturing; for example, in reconfigurable assembly, the modules are most often set by the transport/handling/joining/placing/packaging processes. There is no biological link and the RMS and HMS paradigms tend to try to achieve a general, top-level solution. EAS is radically different in this respect as it will focus on the predicted and unpredictable changes that may occur within a very limited product range (genus). The first solution will be limited and specific, and may, if successful, gradually be applied to the associated product family (species). Hence, EAS is not a generic solution but a specific approach that may be adopted by other “species” if its evolutionary capabilities denote a high rate of success.
Furthermore, EAS takes a hybrid and not top-down approach to the definition of its modules. The EAS modules are defined by precise sub-processes that have been identified for a given product range: the taxonomy of the sub-processes is very detailed and therefore results in fine granularity. This is a low-level approach, and gives modules with very optimised performance characteristics:process-oriented modules. Note that since it is specific, and focuses on the given evolutionary demands of a product range and its exact sub-processes, it may also be closely linked to product design issues. This is unique among current paradigms.
It has, to date, resulted in several demonstrators and offered methodologies and architectures in support. This web site presents current developments and applications.
The EUPASS project has now launched a collaborative web site: www.eas-env.org/. This site is open for all people interested in developing adaptive/evolvable systems, and allows members to collaborate in the development of standards,architectures, module specifications and so forth.
