The purpose of this study is to apply the variable damping impedance control to semi-active system using the homogeneous ER (Electro-rheorogical) fluid. A homogeneous ER fluid is constituted by liquid crystal or polymer liquid crystal, and it can change the apparent viscosity under a Newtonian fluid by applying the electric field. Then, when the fluid is applied for device of the machine system, the system can be used as a variable viscous damper. However, these systems have a lot of parameter variations or nonlinear elements. Therefore, some feedback compensations are necessary for these systems to keep up more precisely viscosity.
In this paper, we apply the force-based damping control to the homogeneous ER clutch in order to use the characteristics of the fluid enough. We apply the damping control based on the force control to keep up more precisely viscosity. The result of our experiment clearly has shown that the viscosity of the clutch is more certainly controlled by the force-based impedance control.