An active tuned vibration absorber

An active tuned vibration absorber 800 is disclosed for reducing vibrations in a structure 802, the structure 802 being perturbed by a vibration source that generates vibrations having a frequency varying over time within a set of characteristic frequencies. The vibration absorber 800 comprises: a mount 804 for attachment to the structure; a moveable mass 806; a spring arrangement 808, 812 connected between the mass and the mount; at least one sensor 818, 820 providing a measurement of a perturbation associated with the vibration source; an actuator arrangement 816, 1318 for applying a force between the mass and the mount; and a control system 822, 1300 for generating an actuator driving signal for driving the actuator 816 using the or each measurement, comprising: a plurality of control subsystems 1302, 1304, 1306 taking the or each measurement 1308, 1310, 1312, 1314 as an input, each control subsystem being tuned to a respective one of the set of characteristic frequencies; and a processing unit 1316 for combining the output of the subsystems to generate the actuator driving signal.