Active vibration μ-synthesis-control of a hydrostatically supported flexible beam

This paper presents active vibration control of a hydrostatically supported, flexible beam. The objective is to show the capability of active hydrostatic bearings, where the flow rate is controlled with a fast dynamic servo valve. Consequently the damping as well as the stiffness behaviour of the supported structure should be improved. First the damping behaviour is increased by using acceleration feedback in combination with the modem, robust control concept t-synthesis. It enables to overcome undesirable properties of the mechatronic system as, weakly damped, low frequency flexible modes, phase lag, slight nonlinearities or non-col location. To increase the stiffness of the bearings the oil gap is used as control variable and controlled to constant with PI-control. Finally, the obtained results are compared with the state-of-the-art technology of hydrostatic bearings.