Development of a soft manipulator using a smart flexible joint for safe contact with humans

Recently, as robots and humans increasingly share common spaces especially in the fields of the medicine and home automation, it has become necessary to consider the frequent physical contact of robots and humans. However, many robot joints have actuators with high-ratio gear trains. Therefore, when the robot comes into human contact, the robot may cause pain. This study describes the development of a soft manipulator using a smart flexible joint composed of an ER fluid. Further, a torque controller designed in light of human pain tolerance is applied to the soft manipulator. Experimental results demonstrate the effectiveness of the manipulator.