HYBRID FMS CONTROL ARCHITECTURES BASED ON HOLONIC PRINCIPLES

The escalation in processor technologies and the corresponding reducti on in costs have enabled alternative FMS control architectures to be d eveloped without the restrictions of ''fixed machine controller bounda ries.'' These new architectures can be based upon the use of intellige nt servo axes, which are desccribed in this article, as flexible numer ical control (FNC). In current parlance, the FNC is a ''part movement holon'' within a manufacturing cell. The control architectures that ca n be derived from the FNC concept are referred to as hybrid architectu res and share the emerging attributes of holonics. This article detail s the problems that arise in the scheduling and control of FMSs in the light of hybrid control architectures. A number of traditional schedu ling approaches have been devised to cope with the scheduling of parts to discrete machines, but the problem here is to ascribe the processi ng (machining) of part features to axis groups. This article documents how two research programs, undertaken at the CIM Centre at Swinburne University of Technology in Hawthorn, Victoria, Australia, have endeav ored to address the problem of hybrid architectures and their associat ed scheduling.