Linear control of multi-electrode dielectric elastomer actuator with a finite element model

Abstract

Soft robots have shown overwhelming performance compared to the hard ones in many fields. Autonomous movement of soft robots requires compatible actuators with good controllability. Although dielectric elastomer actuator (DEA) has the attributes of fast response and low density, the intrinsic nonlinear behavior encumbers its application in position control, especially for multiple degree of freedom (DOF). Here, we present a multi-electrode DEA based positioning system with linear output controller. Selectively actuating the isolated electrodes with a compact multi-channel power supply, translation and rotation can be achieved. Considering that the voltage-induced deformation of DEA is rather complex, numerical analysis using commercial finite-element package is proposed to investigate the influence of configuration and actuation manner on the output. Four-quadrant DEA is employed to build the positioning system for its optimal performance. According to the calculated voltage-displacement relationship, a linear controller is established and experiments are performed. Coexisting-electrode DEA with linear output has the potential in multi-DOF positioning system, such as antenna adjustment for soft robots with remote telecontrol. The proposed finite element method is very convenient and user-friendly, especially for the users without computation background.