Structural vibration control.

Undesirable time-variable motions of dynamical structures (e.g. scales. bal ances. vibratory platforms, bridges and buildings) are mainly caused by unk nown or uncertain excitations. In a variety of applications it is desirable or even necessary to attenuate these disturbances in an effective way and with moderate effort. Hence, several passive as well as active methods and techniques have been developed in order to treat there problems. However, e mployment of active techniques often fails because of their considerable fi nancial costs. We propose an affordable control scheme which accounts for t he above-mentioned deficiencies. In addition. we allow constraints on contr ol actions. Furthermore, the number of control inputs (actuators) may be ar bitrary, i.e., tilt system mag; be mismatched. The scheme is based on Lyapu nov stability theory and, provided that the bounds of the uncertainties ars a priori known, a stable attractor (ball of ultimate boundedness) of the s tructure can be computed. In case measurement errors or uncertainties, resp ectively, are significant, it is shown how the Lyapunov-based control schem e may be combined with a fuzz control concept. The effectiveness and behavi or of the control scheme is demonstrated on two simplified models of elasti c structures such as a two story building and a bridge subjected to a movin g truck. (C) 2001 The Franklin Institute. Published by Elsevier Science Ltd . All rights reserved.