Verification of functional constraints for safe product driven control

Abstract

This paper deals with dynamic reconfiguration of DES control within the context of manufacturing system to answer product variability or production resources availability. More precisely, it focuses on product-driven control (PDC) that embeds decisional and adaptation capabilities within the product. PDC can be defined in a static or dynamic way: in the first case, all switchable manufacturing trajectories are predefined and implemented in the product control while, in the second case, PDC can be seen as a non-deterministic and “on the fly” choice among control trajectories to fit with the manufacturing system availability and the product state. In this last case, PDC safety is ensured thanks to a filtering approach that enables to maintain PDC within a state space that satisfy functional and safety constraints whatever the control generated by the reconfiguration process is. This paper focuses on the definition and verification of a minimal set of constraints that ensure the sufficiency and the non blocking properties of the constraints. A case study illustrates the approach.