Early Behaviour Modelling for Control Systems

When developing embedded control software, control systems engineers model both the control algorithm and the system to be controlled, the so called plant, together. The models realised with tools such as Matlab/Simulink or Dymola are based on the systems´ physical properties and provide an accurate view of the behaviour with regard to time and value. Nowadays control functionality is implemented in software, methods and models used in software engineering become more important. Alas, the abstraction level of control engineering models and software engineering models does not correspond. In early development phases software functionality is often modeled in an abstract way. In order to enable the developers to model a plant´s behaviour at early development stages abstractly, we introduce behavioural models for continuous systems and a hierarchy thereof that allows coarse descriptions and stepwise refinements. With means of an example we show how this hierarchy can support the development process.