Developement of fuzzy logic-based control systems for structural vibration reduction

Abstract

This dissertation proposes effective, reliable and simple active, semiactive, and hybrid control algorithms based on fuzzy theory using active hydraulic actuators and semiactive MR dampers to reduce structural responses due to seismic and wind loads. Moreover, the simple semiactive fuzzy control system using a MR damper for vibration suppression of the building structure subjected to ground accelerations has been experimentally investigated by a shaking table test. A simple and efficient semiactive fuzzy control method using an MR damper is presented for seismic response reduction. Only one controller compared with a semiactive clipped-optimal controller which is very efficient controller to reduce seismic response using MR damper produces directly the desired command voltage using fuzzy rule inference as the desired force demanded is varied so that the actuator can produce forces as close as possible to the desirable forces. This type controller has all advantages of the fuzzy control algorithm in previous studies. The hybrid control systems combining active fuzzy controller using hydraulic actuators and semiactive fuzzy controller using MR dampers are implemented for bench-mark problem with linear elastomeric isolation system and nonlinear frictional isolation system, respectively. When a control method based on fuzzy algorithm to a structure is used for vibration reduction, it is inherent robust, easy to treat the uncertainties of input data from the ground motion and structural vibration sensors and able to handle the non-linear behavior of the structure because of no need of exact mathematical model of the structure easily. Therefore, the fuzzy algorithm could be applied simply to linear and nonlinear base isolated systems. An active/semiactive modal-fuzzy control method is presented for seismic response reduction. The major issue in this study is based on the fuzzy algorithm adding modal approach for seismic response reduction. In the case of combination ...