A hybrid system is defined as the mixture of continuous systems and discrete event systems. Researchers in this field have proposed modeling methods for such systems, but were not dealed with simulation environments for analyzing them. This paper proposes a formal modeling and simulation framework for such hybrid systems.
A Hybrid Discrete Event System Specification (HDEVS) formalism is proposed to represent the dynamics of such systems. The HDEVS formalism supports information conversion between continuous and discrete event systems. A/E (Analog-to-Event) and E/A (Event-to-Analog) converters perform such conversion by mapping segments to events and events to segments, respectively.
The proposed formalism is implemented as two types of simulation envirionments: HDEVSim++ and HDEVSimHLA. HDEVSim++ is a centralized simulation environment for simulation of such systems modeled by the HDEVS formalism. HDEVSimHLA is a distributed simulation environment based on HLA (High Level Architecture) which is a common technical framework for distributed simulation.
To demonstrate effectiveness of the proposed modeling framework and the associated simulation environment, modeling and simulation of a mobile robot system, consisting of eight continuous systems and two discrete event systems, is exemplified.
