Adaptive vibration control by a variable-damping dynamic absorber using ERfluid

This paper describes a variable-damping dynamic absorber applying Electrorh eological (ER) fluid to the damping element of a conventional-type dynamic absorber. A prototype of variable-damping dynamic absorber was constructed and its performance was verified with a three-story structural model. The s pecial ability of the present dynamic absorber is to reduce the vibration a mplitude at several frequencies by a single dynamic absorber. ER fluid is f unctional fluid whose yield shear stress can be changed by the applied elec tric field strength. Because of its peculiar property, ER fluid has been ap plied to various mechanical components such as shock absorbers and engine m ounts for vehicles, clutches, valves, etc. One of the practical ways in app lying ER fluid to mechanical components may be to expand the performance of conventional mechanical components by combining ER fluid effectively with them. In this sense, this paper shows a successful application of ER fluid to a conventional-type dynamic absorber. An adaptive neural network control system composed of a forward model network for system identification and a controller network was introduced to control the variable-damping element of the dynamic absorber. The numerical simulations show good agreements wit h the experimental results.