Seismic structural control using an electric servomotor active mass driver system

Abstract

This Study investigates an electric-type active mass driver (AMD) system for structural vibration control. Composed primarily of an electric servomotor and a ball screw, the electrical AMD system is free from noise problems, oil leakage, and labor-intensive maintenance that commonly are associated with hydraulic AMD systems. The desired stroke amplification of the mass and the power demand of the servomotor can be adjusted via the ball screw pitch, which in turn affects the effectiveness and efficiency of the system. Meanwhile, an instantaneous optimal direct Output feedback control algorithm is adopted. Numerical simulation is performed using a five-story steel frame as the object structure under the conditions of the 1940 El Centro earthquake. The AMD system proves to be effective and efficient within a certain range of the ball screw pitch. The reductions of the peak responses can reach as high as 70% if properly designed. Requiring only the velocity measurement of the top floor for on-line feedback control. the proposed control algorithm is recommended for practical implementation. Copyright (C) 2004 John Wiley Sons, Ltd.