The test rig has three bearing levels of which two are active bearings supported by piezo actuators. This way a real-world system with two resonances in the operating range can be modelled, as it is found in an engine. The control of the actuators can lead to tensions in the shaft, which would not occur for a bearing configuration with two bearings. The modelling is also more difficult due to the over-determined bearing configuration, which means that the bearing forces are dependent on the material properties, for example. Due to the uncertainties in the modelling, the test rig therefore offers ideal conditions for testing and evaluating the robustness of control approaches.

In the past, most common control approaches such as LQR/LQG, Integral Force Feedback, FxLMS, µ-Synthesis and Gain-Scheduled H_∞ have been implemented. For future research, the test bench will be used to validate control approaches that are either model-free or self-adjusting. The aim is to identify controls that can be applied to a real system without modelling the system beforehand.