Modeling, Identification, and Control of a Dielectric Electro-Active Polymer Positioning System

This paper deals with a positioning system based on a dielectric electro-active polymer membrane. The motion is generated by the deformation of the membrane caused by the electrostatic compressive force between two compliant electrodes applied on the surface of the polymer. This paper proposes a detailed electro-mechanical nonlinear model of the system, which is subsequently used to develop (in both time and frequency domains) various model-based feedback control laws. Accurate modeling is useful to compensate the nonlinear behavior of the actuator (caused by the material characteristics and geometry) and obtain PID controllers providing precise tracking of steps or sinusoidal reference signals. The various design strategies are compared on various experimental tests.