Sliding-Mode Control of a Dielectric Elastomer Actuator Featuring Non-Invertible Dynamics

Dielectric elastomers are highly nonlinear actuators with complex dynamic behaviour. As a consequence they are modeled using both viscoelastic and geometric nonlinear elements. Their control is especially challenging due to the dominant hysteresis and creep behavior they exhibit. These nonlinearities also deem their dynamics non-invertible and consequently, their effective control is nontrivial. A novel sliding-mode scheme that approximates the system dynamics locally for small time steps is designed herewith. Simulated closed-loop results are presented to demonstrate the efficacy of the proposed control technique.