Recently, a common area between robots and humans tends to increase, in the fields of welfare and the medical treatment. It is necessary to consider frequent interference of the human and the robot in these areas. However, many of joints of the robot have the actuator with high-gear-ratio gear trains. Therefore, when the robot comes in contact with man, the robot has the possibility to give man the pain. In this study, a human interactive robot manipulator with elastic joint that composed of an ER fluid is developed. Further, a torque controller considering human pain tolerance is applied to the manipulator. The simulation and experimental results are also given to show the effectiveness of the manipulator.
