Variable viscous control of a homogeneous ER fluid device considering its dynamic characteristics

Abstract

Homogeneous electro-rheological (ER) fluid is one of the intelligent fluids, having properties by which their apparent viscosity coefficient can be controlled according to the strength of an electric field applied to them. However, the ER effect of the fluid is easily changed by shear rate variation or temperature variation. Therefore, it is desirable for this fluid to be compensated by a feedback controller considering its dynamic characteristic. In this study, a continuous and accurate viscous control method is proposed, in order to enable a more effective use of the ER fluid, and demonstrate the application of the control method to a developed homogeneous ER clutch using a personal computer. The results of our experiment clearly show that the viscous coefficient of the clutch has been accurately and speedily controlled to the desirable viscous coefficient by the proposed control method. Therefore, by applying the proposed control method, it is possible to obtain a reliable ER device without being influenced by variations of this fluid property.