Energy shaping revisited

Energy shaping is the essence of passivity based control (PBC), a controller design technique that is very well-known in mechanical systems. Our objectives in the article are threefold. First, to call attention to the fact that PBC does not rely on some particular structural properties of mechanical systems, but hinges on the more fundamental (and universal) property of energy balancing. Second, to identify the physical obstacles that hamper the use of “standard” PBC in applications other than mechanical systems. In particular, we show that “standard"” PBC is stymied by the presence of unbounded energy dissipation, hence it is applicable only to systems that are stabilizable with passive controllers. Third, to revisit a PBC theory that has been developed to overcome the dissipation obstacle, as well as to make the incorporation of process prior knowledge more systematic. These two important features allow us to design energy based controllers for a wide range of physical systems