Integration of different approaches to simulate active structures for automotive applications

To solve a wide range of vibration problems with the active structures technology, different simulation approaches for several models (depending on frequenzy range, modal density and control target) are needed. These simulation approaches can be different for each individual part of the active system: the mechanical structure, the active components (sensors, actuators), and for the controller. To ensure a highly efficient and accurate simulation of the active system, the submodels must harmonize. For this purpose, structural models considered in this article are modal state space formulations and transfer based or impedance based models. Consequently, the impedance based models are derived directly from the measured transfer functions. The modal state space formulation are derived from finite element models and/or experimental modal analysis. To couple mechanical and electrical systems with active materials, the concepts of impedance models was succesfully tested. The impedance models are enhanced by adapting them to the measured electrical impedance. The controller design depends strongly on the frequency range and the number of modes to be controlled. To control systems with a small number of modes, techniques such as active damping or integral force feedback may be used, whereas in the case of systems with a large number of modes or with modes that are not well separated, other control concepts (e.g. adaptive controllers) are more convenient. The approaches introduced here will be verified by simulating academic test examples.