In a previous paper, the identification algorithm is presented for feedback active controlled systems to identify the excitation from the structural response measured. The aim of this paper is to propose a feedback-feedfonvard control algorithm using the identified excitation to improve the classical LQR control. A numerical simulation is applied to an eight story building subjected to base acceleration and controlled by active mass damper system. | Vietnam Journal of Mechanics, VAST , Vol. 29, No. 4 (2007) , pp. 507 - 516 ON A FEEDBACK-FEEDFORWARD IDENTIFICATION CONTROL ALGORITHM FOR FEEDBACK ACTIVE CONTROLLED STRUCTURES LA Due VIET , NGUYEN DONG ANH Institute of Mechanics Abstract . Linear quadratic regulator (LQR) is an effective method of feedback active control theory. However, the LQR control is not truly optimal because it is only a feedback algorithm, . the external excitation term is ignored in the optimal equation. In a previous paper [1] , the identification algorithm is presented for feedback active controlled systems to identify the excitation from the structural response measured. The aim of this paper is to propose a feedback-feedfonvard control algorithm using the identified excitation to improve the classical LQR control. A numerical simulation is applied to an eight story building subjected to base acceleration and controlled by active mass damper system. 1. INTRODUCTION In recent years, much progress and new concepts have been achieved in reducing the structure response due to environmental and man-made loading . Among those innovative means, passive damping and active control systems represent fundamental approaches for response reduction in structures . Passive damping systems encompass a range of devices, which are characterized by a capability to enhance energy dissipation in the structure . This effect may be achieved by using devices which operate by conversion of kinetic energy to heat such as friction dampers, viscous dampers . . . or by transferring of energy among vibrating modes such as tuned mass dampers or tuned liquid dampers. Passive devices, however, have inherent limitations which can be solved by active control systems. For example, the passive tuned mass damper is often tuned to the first natural frequency of the structure, means that it is designed to reduce only the first mode vibration. An active mass damper, on the other hand , can be effective over a much wider
