Languages and applications in hybrid modelling : positioning of Chi

A widely used classification of modelling languages distinguishes the categories continuous-time (CT), discrete-event (DE), discrete-time (DT), and hybrid. For a better insight into the many different hybrid languages, a classification of five categories (CT, CT+, DE, DE+, and CT/DE) is proposed. Each category is explained, together with many of the included languages, simulators, and the associated application fields. Special interest is given to the Chi language used for specification, simulation and real-time control of industrial systems. Its CT part is based on (conditional) DAEs, its DE part on Communicating Sequential Processes. The suitability of the language for DE, CT, and CT/DE modelling is illustrated by two cases.