| A unique systematic design methodology is developed for achieving efficiency in solving some useful control problems of real-time discrete-event systems. To achieve this, an extended modelling formalism, which allows the incorporation of data variables, is proposed for describing real-time discrete-event systems. Based on this formalism, a new state-feedback control framework which can exercise two types of control mechanisms: enabling/disabling and forcing is established.;Two important control problems are handled in this thesis. The first problem involves finding solutions which ensure that predicate-based constraints are satisfied invariantly in a closed-loop real-time discrete-event system. To tackle this problem leads to the development of a self-contained theory based on an innovative analysis of event trajectories of a system and a strategy for manipulating control mechanisms. A novel decision algorithm, employing a hybrid dynamic programming/constrained-search method, offers a baseline for handling forcing and thereby plays a key role in the derivation of sufficient conditions which guarantee this control problem is solvable. Furthermore, a procedure for controller synthesis is obtained based on a crucial connection between solvability conditions of this problem in this theory and an adapted notion of control-invariance in Ramadge-Wonham theory.;The second control problem is how to find solutions which ensure that the first control problem is solvable and deadlock-freedom is achievable. Sufficient conditions are presented for the existence of solutions to this problem.;For both control problems, synthesis procedures in pseudocode are provided. As application examples, some control problems are examined: a traffic-light in a subway system, a transfer line in manufacturing system, and two rods in a nuclear power plant. The feasibility of this systematic design approach is effectively demonstrated by these examples in terms of computational effort and explicit representations of control policies.;As a whole, this thesis combines mathematical theory and quasi real-world applications. |
