Alternative Bond Graph Causal Patterns and Equation Formulations for Dynamic Systems

Abstract

Given mathematical models of components of a system, the equations for the system can be formulated in a number of distinct ways. Bond graphs provide a convenient explicit way to study the interactions among component models and the system equation formulations which follow from the various ways in which input-output causality can be assigned. Three means of causality assignment are compared: an all-integral method, an all derivative method, and a Lagrange-equation procedure. Some interesting differences among the procedures occur when fields (dependent state variables) or nonlinear junction structures (geometric nonlinearities) are present in the system model.