Duality in system analysis for bond graph models

Duality as a general notion has been discussed previously in multiple domains. The field of system modeling, analysis and control has used it for quite some time. The duality between the controllability and the observability is well known, especially in the case of the linear time-invariant systems. But when it comes to the linear systems in general, time-invariant or otherwise, the definitions become ambiguous. Even though there have been papers which use the state space representation or the module theoretical approach, a unified description has not been found yet. This paper is meant to fill in this gap, by using the bond graph representation. The bond graph perspective offers a global overview because the bond graph is a graphical tool which can be seen both as a state space representation and as a module.