Hybrid and Discrete Systems

The reason why the term physical modeling has been coined is the need to distinguish between two extreme approaches to physical systems modeling. On the one extreme we have so called ’black-box modeling’ where a mathematical model is fitted to measurements. On the other extreme we have physical modeling in which case we only use insight into the system structure combined with known physical laws to derive an appropriate mathematical model. In practice though, none of the two extreme approaches are particularly fruitful in isolation. In order to model any non-trivial system, the two approaches will have to be combined. However, depending on the character of the system, one of the two modeling activities, i.e., physical modeling or parameter estimation, may dominate the overall modeling effort. In this section we focus on the physical modeling process.