Optimal hybrid control of structures under earthquake excitation

Optimal control of base‐isolated and non‐base‐isolated buildings subjected to earthquake excitation is considered. The control force at any instant is determined on‐line through minimizing a quadratic time‐dependent performance index based on the total energy imparted to the structure and the control effect. This control algorithm is based upon the use of discrete actuators and sensors that exert the control force and monitor the response of the building. Having constant gain matrices makes this algorithm efficient and easy to implement. The effect of time delay on the efficiency of the algorithm is investigated. Comparisons have been made to demonstrate the effectiveness of the proposed method.