Direct Adaptive Neurocontrol of Structures under Earth Vibration

Abstract

A direct adaptive neurocontroller is proposed to reduce structure response to earth vibrations by actively creating an equal but opposite force to that of the first mode force of the structure. While earthquake forces are generally considered to be unpredictable, the short-term predictions by the proposed neurocontrol architecture significantly reduce structure vibrations. To demonstrate its general applicability and utility to future earthquakes, the proposed adaptation algorithm is also shown to be asymptotically convergent. The approach is validated by several simulations in which actual time series from the Hachino, Northridge, Kobe, and Bam earthquakes are applied against structures of various heights, three-, five-, and seven-story structures. The simulation results are then compared with those of a conventional linear quadratic regulator. Results indicate a significant and consistent improvement in minimal structure displacement.