Robust active control against wind-induced structural vibrations

Slender flexible structures are vulnerable to vibrations under wind loads. The dynamic model of a frame-like structure is obtained by finite element approximation in this paper and used further for the design of an active control mechanism. The behavior of the structure is described by simplified linear equations. A linear quadratic regulator and an H2 optimal control method are used for the suppression of the extended vibration effects. Structured uncertainties are considered to reflect the errors between the model and the reality. To accommodate directly the plant uncertainties and to obtain a best possible performance in the face of uncertainties a robust H∞ optimal control for active control structure is used. The two latter robust controllers take into account as well incompleteness of the measured information, a fact that cannot be neglected in civil engineering, and lead to applicable designs of smart structures. The numerical simulation shows that vibrations can be suppressed by means of the proposed methods.