Independent modal space fuzzy control of earthquake-excited structures

An independent modal space fuzzy control technique for vibration control of earthquake-excited structures is presented. The proposed technique is a hybrid control method, which adopts a two-step design procedure consisting of designing an optimal controller in modal space and fuzzy tuning of the pre-designed modal control gains. The state space equation is transformed into modal coordinates and modal feedback gains are obtained by application of the optimal control theory. For an improved seismic performance of the vibration control system, a rule-based fuzzy tuner is introduced. The tuner modulates appropriately the modal gains according to the contribution of the modal responses to the structural response. The validity and effectiveness of the proposed control scheme is shown numerically on an earthquake-excited six-story building structure.