Simple Controller Design Based on Internal Model Control for Twisted and Coiled Polymer Actuator

Abstract

A twisted and coiled polymer actuator (TCPA) is a novel soft actuator. TCPA is fabricated by twisting nylon fibers. The TCPA extends and contracts by heating and cooling. By applying conductive nylon fibers to the actuator, the electroactive TCPA can be driven by the Joule heating of the applied voltage. It has noteworthy properties such as a high power/mass ratio, large deformation, and low hysteresis. By applying conductive nylon fibers to the actuator, it can be driven by the electrical input. From these properties, many soft robots using the electroactive TCPA have been demonstrated, such as robotic hands, locomotion robots, robot skins, biomimetic robots, and so on. In this paper, to realize a simple controller design, an internal model control based on the identified model is applied. The applied controller can be designed easily without experience in parameter-tuning based on controls theory. The validity of the applied method is investigated through experiments.