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Modified Optimal Algorithm for Active Structural Control.

pdf icon Modified Optimal Algorithm for Active Structural Control. (918 K)
Sadek, F.; Mohraz, B.

NISTIR 5782; 29 p. January 1996.

Available from:

National Technical Information Service
Order number: PB96-165949


building technology; active control; control algorithms; optical control; structural dynamics


This study presents a modification to two linear optimal control algorithms, namely classical and instantaneous, to achieve a greater reduction in structural displacements and control forces. The modification consists of building a library of gain matrices and selecting the gain matrix that would result in the maximum control force without exceeding the control system capacity. The modification was used to compute the response of several single-degree-of-freedom (SDOF) systems, a multi-degree-of-freedom (MDOF) system, and a base isolated structure. Based on the examples considered, the modification results in a reduction of up to 45% in the peak control forces and structural displacements as compared to existing algorithms. The study shows that the external excitation influences the selection of the control system parameters such as controller capacity and gain matrices. These parameters, therefore, should be determined according to the seismic excitation intensity expected at the site.