Graphical Modeling of Hybrid Dynamics with Simulink and Stateflow

Simulink and Stateflow are tools for Model-Based Design that support a variety of mechanisms for modeling hybrid dynamics. Each of these tools has different strengths. In this paper, a new modeling construct is presented that combines these strengths to enable graphical modeling of hybrid dynamics within a single Stateflow chart. A new type of Stateflow state that acts as a Simulink subsystem is developed to facilitate graphical modeling of continuous dynamics using Simulink blocks inside Stateflow. Remote textual and graphical state access using new state-accessor blocks enables continuous states to be used in transition guards and reset actions. Key features of this new formalism are illustrated using various examples with hybrid dynamics.