Comments on Clock Models in Hybrid Automata and Hybrid Control Systems

Hybrid systems have received a lot of attention in the past decade and a number of different models have been proposed in order to establish mathematical framework that is able to handle both continuous and discrete aspects. This contribution is focused on two models: hybrid automata and hybrid control systems with continuousdiscrete interface and the importance of clock models is emphasized. Simple and relevant examples, some taken from the literature, accompany the presentation.