Structural Vibration Reduction Using Fuzzy Control of

Control devices can be used in civil structures to dissipate energy from earthquakes, reduce structural damage and prevent failure. Semi-active control devices have been shown to be more energy-efficient than active devices and more effective in reducing seismic structural vibrations than passive devices. A type of semi-active control device, the magnetorheological (MR) damper, consists of a hydraulic cylinder containing micron-sized, magnetically polarizable particles suspended in a liquid such as water, glycol, mineral or synthetic oil. The damping capabilities of this device can be quickly varied by changing the viscosity of the MR fluid from viscous to semi-solid through the introduction of a magnetic field. The objective of this research is to develop a fuzzy controller to regulate the damping properties of the MR damper. Because fuzzy control uses expert knowledge instead of differential equations, it allows for the development of simple algorithms. It does not require accurate information on structural and vibration characteristics of the system and is therefore an attractive alternative for complex and/or nonlinear systems