Integration of the real time levels of a multilevel hierarchical control; application to a flexible assembly cell

The authors present a conception approach for distributed control of flexible manufacturing system (FMS). This control is based on five levels, with specific attributes: the long term planning level; the forecast scheduling level; the supervision level; the sub-sets coordination level; and the local control level. By nature, the two first ones are nonreal-time control levels. Conversely, the other levels are heavily constrained by manufacturing real time events. The specific competences of each level are defined, but the integration method to obtain the best cooperation between these specialities has to be described: this last point composes the main aim of this paper.