Robust Active Optimal Control Scheme Including Soil-Structure Interaction

• Published in: Journal of structural engineering (New York, N.Y.) N.Y.), 1993-09, Vol.119 (9), p.2533-2551
• Main Authors: Alam, S. M. Shahid, Baba, Shunsuke
• Format: Article
• Language: English
• Subjects: Applied sciences; Buildings. Public works; Exact sciences and technology; Geotechnics; Structure-soil interaction; TECHNICAL PAPERS
• ISSN: 0733-9445; 1943-541X
• DOI: 10.1061/(ASCE)0733-9445(1993)119:9(2533)

A robust active optimal-control scheme is presented for the vibration control of a seismically excited structure. The conventional optimal-regulator-control scheme for civil engineering structures with fixed-base assumption and without an observer is found to be quite ineffective for soft soils, where the effect of soil-structure interaction is prominent. A new algorithm is developed including the effect of soil-structure interaction in which soil is represented by the frequency-independent springs and dampers. The effect of the variation of soil parameters on the control scheme is taken into account by the introduction of an observer. An acceleration-type observer is used, which minimizes the difference of accelerations between the real structure and the mathematical model. The scheme is found to be robust for a considerable range of variation in the soil stiffness. The system involves an inherent instability due to the effect of observation spillover, which is corrected by prefiltering the sensor data. On the other hand, no control spillover is observed.