VARIABLE GAIN FEEDBACK-CONTROL TECHNIQUE OF ACTIVE MASS DAMPER AND ITS APPLICATION TO HYBRID STRUCTURAL CONTROL

A systematic design procedure and an algorithm are devised for variabl e gain feedback (VGF) control of buildings with active mass damper (AM D) systems. The limit of the stroke length of the auxiliary mass, whic h is considered to be one of the most important physical constraints f or application of AMD systems to actual structures, is studied. A set of variable feedback gains is designed as a function of a single varia ble that indicates a trade-off between the reduction of the building r esponse and the amplitude of the auxiliary mass stroke, and this varia ble is on-line controlled to keep the amplitude of the auxiliary mass stroke constant, and within its limits. A design method of static outp ut feedback controller for modal control of buildings with non-classic al damping is also presented. Next, an efficient control method for hy brid structural control is developed, with combined use of the VGF con trol and the static output feedback control. It is shown through numer ical examples that the proposed control method effectively adapts the control performance according to the variation in the intensity level of the external excitations in such a manner that the amplitude of the auxiliary mass stroke is kept within its limits and the control power is restrained as well. The application range of the AMD systems is th ereby improved significantly. (C) 1997 by John Wiley & Sons, Ltd.