Sampled-data H2 optimal output feedback control for civil structures

An optimal control method involving sampled data is considered for use in earthquake and wind engineering applications. The structure is modelled as a continuous system attached to a discrete-time controller using zero order sample-and-hold devices. Examples of two buildings with active base isolators and a 163 m tall planar frame with an active mass damper are considered. The buildings with the base isolators are subjected to excitation input using the 1940 El Centro earthquake (NS component) as an example, while the planar frame is subjected to assumed sinusoidal gusts with a period close to that of the frame. The controlled responses (with and without time delays) are studied. To further analyze the features of the control designs, the building examples with base isolators are subjected to five other different earthquake excitation records. Trends in control performance and effectiveness are presented and discussed. The results suggest that such systems are potentially suited for implementation in the vibration control of civil infrastructures; such potentiality becomes more realistic with the current trends in software development and the increased use of digital computers. Copyright (C) 1999 John Wiley & Sons, Ltd.