Time and spatial discretization methods that preserve passivity properties for systems described by partial differential equations

Deals with systems described by partial differential equations with focus on mechanical systems with elasticity. It is investigated how to make a finite dimensional approximation of the partial differential equation so that certain physical properties still hold. In particular, Galerkin models related to finite element models are studied. Also time discretization that ensures that internal conservation laws still hold for the discrete-time models is discussed. Another topic that is discussed is the use of exponentially stable observers based on contraction properties of the system. It is shown that Galerkin models can be used to construct exponentially stable observers of finite dimension for certain systems described by partial differential equations.