Abstract

Introduction The paper presents a model for hybrid systems, that is, systems that combine discrete and continuous components. Such systems are usually reactive real-time systems used to control an environment evolving over time. A main assumption is that a run of a hybrid system is a sequence of two-phase steps. The first phase of a step corresponds to a continuous state transformation usually described in terms of some parameter representing the time elapsed during this phase. In the second phase the state is submitted to a discrete change taking zero time. To illustrate this assumption, consider a temperature regulator commanding a heater so as to maintain the temperature ` of a room between two given bounds ` min and ` max . A run of such a system is a sequence of steps determined by the alternating state changes of the heater from ON to OFF<F26.

Citations