Affiliations: [a] Department of Mechanical Engineering, Ferdowsi
University of Mashhad, Mashhad, Iran | [b] Department of Mechanical Engineering, University of
Kashan, Kashan, Iran
Abstract: Conjugated polymer actuators can be employed to achieve micro scale
precision positioning, having a wide range of application including biomimetic
robots, and biomedical devices. They can operate with low voltage while
producing large displacement, 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 difficult. There has been extensive research on modeling the
electrochemical dynamics of polypyrrole bending actuators. However the
mechanical dynamics modeling of actuator remains to be unexplored. In this
paper finite element modeling and robust control of fast trilayer polypyrrole
bending actuators is proposed. In the modeling part the infinite-dimensional
admittance 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 proper mechanical dynamics, which is essential, when using
fast conducting polymer actuators. The purposed modeling approach will be
validated based on the existing experimental data. In the controlling part the
robust control QFT will be applied to control the highly uncertain dynamics of
the conjugated polymer actuators while the actuator carrying variable tip
loadings. Finally the analysis of design shows that QFT controller has
consistent and robust tracking performance.
Keywords: Fast conjugated polymer actuators, Polypyrrole, FEM, Uncertainty, QFT, Active vibration control
