Robust Control of 2-DOF Dielectric Elastomer Actuator

In optical systems, reflectors are commonly used to direct light beams to desired directions. Recently, due to external disturbances, it has been a great challenge to put such precise optical manipulation systems to special environments with high disturbances, such as outer space optical communication or magnetic resonance imaging rooms. These circumstances require the equipment robust to high vibration or strong magnetic field. Traditional optical systems which contain electrical motors and gear sets may not suit these special working conditions. In this paper, a dielectric elastomer based optical manipulator with 2-degree-of-freedom (2-DOF) is developed. Its soft and gear-less moving structure makes it lightweight and naturally resistant to vibrations. Moreover, its non-electromagnetic moving mechanism allows it to work under a strong magnetic field environment. A dual-H-infinity control is developed to track two independent tilting angles along two axes. Experimental result showed this manipulator is able to track 2-DOF reference signals with 0.03 degree tracking accuracy.