A Combined Continuous-Time / Discrete-Event Approach to Modelling and Simulation of Manufacturing Machines

Using simulation models for the development and testing of control systems can have significant advantages over using real machines. This paper demonstrates the suitability of the language χ for machine modelling. The language integrates a small number of powerful orthogonal continuous-time and discrete-event concepts. The discrete-event part of χ is based on a CSP-like concurrent programming language; the continuous-time part is based on DAEs. Models are specified in a symbolic mathematical notation. A case study is presented of a transport system consisting of conveyor belts. The model of the system illustrates how the combined continuous-time/discrete-event approach simplifies accurate modelling of manufacturing machines. 1