UML-based modeling and multi-threaded simulation for hybrid dynamic systems

Recently, modeling and simulation for the hybrid dynamic systems (HDS) have attracted much attention for manufacturing systems. However, most available HDS modeling approaches usually result in unnatural and complex models as both discrete logic and continuous behavior are involved. In this paper, we extend the statechart of the standard unified modeling language (UML) to model HDS with a natural representation and show that the proposed extended UML modeling approach provides more compact and clearer specifications for complex interdependencies between discrete and continuous behavior. Furthermore, a Java-based real-time kernel is developed to implement the simulation of the extended UML models. In the proposed approach, Java provides an implementation path and the extended UML provides a reverse engineering path for the HDS. Finally, an application of a three-axis motion control system is provided to illustrate the overall modeling and simulation approach.