2110 Computer Aided Early Design based on Integration of Modelica and SysML

For purpose of supporting initial early design stage, a physical modelling language named Modelica is proposed. The Modelica is used in the multi-domain simulation from the conceptual and functional design stage. On the other hand, for the purpose of designing complex systems such as like automobile or medical equipment which have large software and much behaviour, a System Modelling Language SysML is proposed in order to capture the customer requirement and reduce the behavioural and software development time. One of the weak points of Modelica is poor description ability for requirement analysis approach because of lack of representing complex combination of states actions such as like complex software. Also, SysML has some weak point that it is hard to understand for physical engineer because lack of representation ability of differential equation and algebraic equation. A parametric diagram, which is newly added when SysML is proposed from UML (Unified Modelling Language), is only able to describe such physical phenomena. This weak point of SysML can be recognized as the strong point of Modelica. Hence, this paper proposes an integrated design support system which includes SysML and Modelica via proposing integrated modelling methodology. The requirement definition is developed using component behaviour and actions in SysML, and the physical modelling is developed by physical properties on component attribute in Modelica. By this integration, the physical and software simulation can be done from early design stage.