Modelling & Control of Conjugated Polymer Actuators Using Robust control QFT

Abstract

Conjugated polymer actuators can be employed to achieve micro and nano scale precision, and have wide range of application including biomimetic robots, and biomedical devices. In comparison to robotic joints, they do not have friction or backlash, but on the other hand, they have complicated electro-chemo-mechanical dynamics which makes accurate and robust control of the actuator really difficult. This paper consists of two major parts. In the first part the infinite-dimensional physical model of actuator will be replaced with a family of linear uncertain transfer functions based on Golubev Method. Further model development will take into account the influence of reduction/oxidation level on the variation of the actuator resistance and the evaporation of the solvent. In the second part the robust control QFT will be applied to control the highly uncertain dynamics of the conjugated polymer actuators. The main steps involved in the design of a QFT controller are template generation, loop shaping, and pre-filter design. Finally the analysis of design shows that QFT controller has consistent and robust tracking performance.