Jan-Erik Stromberg

Abstract. This article presents an approach to simulating hybrid sys-tems. We show how a discrete controller that controls a continuous envi-ronment can be co-simulated with the environment (plant) using C-code generated automatically from mathematical models. This approach uses Signal with Simulink to model complex hybrid systems. The choices are motivated by the fact that Signal is a powerful tool for modelling complex discrete behaviours and Simulink is well-suited to deal with continuous dynamics. In particular, progress in formal analysis of Sig-nal programs and the common availability of the Simulink tool makes these an interesting choice for combination. We present various alter-natives for implementing communication between the underlying sub-models. Finally, we present interesting scenarios in the co-simulation of a discrete controller with its environment: a non-linear siphon pump originally designed by the Swedish engineer Christofer Polhem in 1697.