Exploiting Causality for Structured Models Using Bond Graphs

In order to understand, design, and control physical engineering systems, it is often necessary to construct mathematical models which can predict system behaviour. Bond graphs provide a structured approach to carrying out the modeling process for all types of interacting, energetic systems, including nolinear systems. And bond graphs provide a structured approach to assessing input/output causality which dictates, prior to deriving any equations, the manner in which equations must be put together if a computable model is to result. This paper deals with using the causal structure to construct complex nonlinear, overall system models by "fitting together" models of subsystems and components.