Hybrid modelling and optimal control of a multi product batch plant

This paper addresses the problem of optimally selecting the production plan for a Multiproduct Batch Plant. The proposed approach can also be applied to a broader class of optimal control problems for systems with discrete inputs. The plant is modelled as a Discrete Hybrid Automaton (DHA) using the high level modelling language, HYbrid System DEscription Language (HYSDEL), which allows conversion of the DHA model into an Mixed Logical Dynamical (MLD) model. The solution algorithm, which takes into account a model of a hybrid system described as an MLD system, is based on reachability analysis ideas. The algorithm abstracts the behaviour of the hybrid system into a “tree of evolution”, where nodes of the tree represent reachable states of the system, and branches connect two nodes if a transition exists between the corresponding states. To each node a cost function value is associated and, based on this value, the tree exploration is driven, searching for the optimal control profile