Development of High-Performance Actuators Using ER Fluids

We developed ER actuators with high performance. An ER actuator consists of ER clutch, reduction gear unit and electric motor. The electrodes of the output-shaft side in the developed ER actuators are made of light material such as CFRP, and the moment of inertia of the ER actuators with respect to the output-shaft becomes very small. As a result, the large torque/inertia ratio can be obtained, compared with conventional actuators. When comparing with powder clutches in which the torque/inertia ratio is considered to be extremely high, the torque/inertia ratio of small-size ER actuators is not inferior. Considering the slow response property of powders in powder clutches, it can be stated that ER actuators are devices with extremely high response characteristics. Firstly we discuss the design and structure of ER actuators. Secondly the experimental results are presented. Then, the control experiments are executed. The developed ER actuators are used in order to develop the new force display system which has high-fidelity force-presentation ability.