Comodeling Revisited: Execution of Behavior Trees in Modelica

Large-scale systems increasingly consist of a mixture of co-dependent software and hardware. The differing nature of software and hardware means that they are often modeled separately and with different approaches. Comodeling is a design strategy that allows hardware/software integration issues to be identified, investigated and resolved in the early stages of development. Previous work described a comodeling approach that integrates Behavior Engineering with Modelica. This paper revisits this approach and introduces a new means of integration that natively executes Behavior Trees in Modelica rather than utilizing external functions. This enhanced integration has several benefits. Firstly, it makes comodeling easier to apply as the comodel is captured solely in Modelica. Secondly, it makes the ability to execute Behavior Trees widely available. Finally, it opens the possibility to use comodeling with other complementary approaches such as the virtual verification of system designs against system requirements.