Furthermore, the new technique is quite systematic an amenable for symbolic computations. For electro-mechanical systems there is a lot of additional structure, which should be exploited for simulation and control purposes. This suggests that the interconnected system described by differential and algebraic equations is also Hamiltonian in some generalized sense. Crucial concept in this formulation of implicit Hamiltonian systems is a mathematical geometric structure, called Dirac structure, which can be regarded as an abstract formulation of Tellegen's theorem. The Dirac structure of an interconnected system is determined by the Dirac structures of the sub-systems, together with the interconnection constraints.
Dissipation is included by terminating some of the system ports by dissipative elements.
The proposed Hamiltonian modelling of physical systems emphasizes modularity, yields proper tools for structural and stability analysis, and forms a natural starting point for the design of passive controllers with inherent robustness properties.