A MATHEMATICAL APPROACH TO DISCRETE-EVENT DYNAMIC MODELING OF HYBRID SYSTEMS

Presently, design of supervisory control systems is based on ad hoc de sign methods. This project attempts to approach the design of supervis ory controllers using the structure of continuous and sampled systems. The approach builds on process models, incorporates performance speci fications and constraints imposed by the plant and otherwise and synth esises the controller by partial inversion of the process model. This paper describes a modelling technology derived for hybrid systems. The hybrid system consists of a continuous plant forced by commands from the supervisory control system and observed through event detectors. T he event detectors generate the ''measurements'' used as inputs to the supervisory control system. The modelling technology quantises the st ate space systematically and leads to discrete-event dynamic process m odels that depend on the discrete inputs and the effects of the enviro nments of the plant. Modelling and control of a simple plant is discus sed. The resulting controlled systems are analysed for undesirable eff ects.