Conference paper

Ettler P., Kárný M., Nedoma Petr.

Proceedings of the 6th EUROSIM Congress on Modelling and Simulation

ARGESIM-ARGE Simulation News,Vienna University of Technology

Ljubljana, Slovenia

2007

978-3-901608-32-2

Dr. Ing. Pavel Ettler (COMPUREG Plzeň, s. r. o.)

Simulation, modelling, estimation, multiple models

Reliable extrapolation - simulation or prediction - of system output is an invaluable departure point for the control system design. For application of model-based techniques, the knowledge of the model structure is essential. It can be based purely on the physical point of view or estimated from process data while the system is considered as a "black box". Mixing of both methods results in "grey box" modelling. Often, modelled systems are governed by several known physical laws and each of these laws implies a model, which should match the data. Nevertheless inevitable uncertainties often make simulated outputs of respective models unreliable. The problem is especially pronounced for systems with a significant time delay. This motivates search for methods, which utilize all available models at once and mix their outputs with the aim to get better results. In the paper, four variants of mixing are considered, discussed and their performance compared on industrial data. Seeming alternative -- a simple complex model is discussed as well. Data for experiments came from a cold rolling mill.