Auto-tuning of a tunable structural insert

This paper considers the auto-tuning of structural inserts, placed into part of a structure to affect the transmission of bending vibrations there. Auto-tuning has the potential to optimise the vibration reduction produced by the insert even in the face of time-varying changes in the dynamic properties of the structure or of the disturbance signal. A particular type of tunable insert is considered, namely one which comprises two elastic face plates and a central core of tunable fluid such as an electro-rheological (ER) or magneto-rheological (MR) fluid. By adjusting the applied electric or magnetic field the visco-elastic properties of the fluid can be controlled and hence so, too, can the vibration transmission properties of the insert. The auto-tuning scheme itself utilises a downstream sensor, which provides a measure of the vibration energy after the insert, and an adaptive algorithm in the feedback loop. The adaptive algorithm determines the optimal field applied to the tunable insert.