Object-oriented modeling of hybrid systems

Abstract

A new methodology for the object--oriented description of models consisting of a mixture of continuous and discrete components is presented. The object--oriented paradigm enables the user to describe such models in a modular fashion that permits the reuse of these models independently of the environment in which they are to be embedded. The paper explains the basic mechanisms needed for object--oriented modeling of hybrid systems by means of language constructs available in the object--oriented modeling language Dymola. It then addresses more advanced concepts such as variable structure models containing e.g. ideal electrical switches, ideal diodes and dry friction. INTRODUCTION Hybrid models contain both continuous and discrete parts. In simulation programs, the continuous parts are described by sets of differential equations and algebraic equations in either explicit form (ODE) or implicit form (DAE). Traditionally, the discrete parts are expressed with event descriptions. A numeric...