Torque control of electrorheological fluidic actuators

In this paper, the experimental closed loop torque control of electro-rheological fluids (ERF) based actuators for haptic applications is performed. ERFs are liquids that respond mechanically to electric fields by changing their properties, such as viscosity and shear stress, electroactively. Using the electrically controlled rheological properties of ERFs, we developed actuators for haptic devices that can resist human operator forces in a controlled and tunable fashion. In this study, the ERF actuator analytical model is derived and experimentally verified and accurate closed loop torque control is experimentally achieved using a non-linear proportional integral controller with a feed-forward loop.