Control Concepts for Dielectric Elastomer Actuators

When using smart actuators, an appropriate power electronics and a well designed force control are necessary in order to established a common force interface. Driving the actuators at high voltages and typically low currents requires special topologies, which have to meet the necessity of a bidirectional energy flow, a high efficiency and bandwidth. An inverter topology is presented, which is modeled afterwards in order to design a high dynamic voltage controller. For the force control of Dielectric Elastomer Actuators, the nonlinear relations between voltage and Maxwell stress as well as the mechanical hysteresis have to be compensated. The resulting open-loop force control can be used for superimposed motion controls, such as position, vibration and impedance controls.