A New Approach to Active Vibration Suppression

Active Vibration Suppression is the area of research at the intersection of two mostly independent disciplines, Structural Mechanics and Active Control. The dynamic behaviour of large flexible systems such as bridges, buildings and aerospace structures generally involves many natural frequencies and modes; in theory an infinite number in continuous structures. In two important respects the available structural-dynamics (finite element) models are unsuitable for use with conventional active control (state-space) methods; they are too large and do not represent damping accurately enough. This problem is addressed by a new approach to active vibration suppression using measured receptances. The method, which may be cast an inverse problem, offers a completely fresh theoretical viewpoint, with attendant new understanding. The theory has its origins in structural dynamics, whereas generally in active vibration suppression, theory developed by the active control community is applied to structural vibration problems. The method developed is generic, having wide applications and not limited to particular types of structures. It addresses a problem that is presently very difficult to tackle with existing methods. It is not limited by physical size or complexity, and does not rely on (possibly inaccurate) mathematical models. The research will include not only the theoretical development of a completely new approach but also the demonstatation of practical usefulness of the theory in laboratory tests, rotor simulations and helicopter ground vibration tests. The research will be carried out in close collaboration with engineering scientists from Westland Helicopters Ltd.