Open-Loop Control of Creep and Vibration in Dielectric Elastomer Actuators With Phenomenological Models

Dielectric elastomer actuators (DEAs) have shown great potentials for biomimetic soft robots. The inherent viscoelastic nonlinearities (such as creep and hysteresis) and the vibration dynamics of the DEAs may limit their motion accuracy in practical applications. However, few control efforts are made to handle these problems. In this paper, we propose a feedforward control approach for creep and vibration compensation of a dielectric elastomer actuator. To this end, a relative creep model of the DEA is first established, and a creep compensator based on the relative creep model is designed to eliminate the creep. Then, a vibration compensator based on a zero vibration input-shaping (ZVIS) technique is developed to suppress the vibrational dynamics of the creep-compensated DEA. The experimental results with the proposed control approach demonstrate that the creep of the DEA is reduced from 20% to less than 7%, and the overshoot of initially about 38.72% is almost completely removed.