Position control of fishing line artificial muscles (coiled polymer actuators) from nylon thread

Takeshi Arakawa, Kentaro Takagi, Kenji Tahara, Kinji Asaka

Research output: Chapter in Book/Report/Conference proceedingConference contribution

64 Citations (Scopus)


Recently, fishing line artificial muscle has been developed and is paid much attention due to the properties such as large contraction, light weight and extremely low cost. Typical fishing line artificial muscle is made from Nylon thread and made by just twisting the polymer. In this paper, because of the structure of the actuator, such actuators may be named as coiled polymer actuators (CPAs). In this paper, a CPA is fabricated from commercial Nylon fishing line and Ni-Cr alloy (Nichrome) wire is wound around it. The CPA contracts by the Joule heat generated by applied voltage to the Nichrome wire. For designing the control system, a simple model is proposed. According to the physical principle of the actuator, two first-order transfer functions are introduced to represent the actuator model. One is a system from the input power to the temperature and the other is a system from the temperature to the deformation. From the system identification result, it is shown that the dominant dynamics is the system from the input power to the temperature. Using the developed model, position control of the voltage-driven CPA is discussed. Firstly, the static nonlinearity from the voltage to the power is eliminated. Then, a 2-DOF PID controller which includes an inversion-based feed forward controller and a PID controller are designed. In order to demonstrate the proposed controller, experimental verification is shown.

Original languageEnglish
Title of host publicationElectroactive Polymer Actuators and Devices (EAPAD) 2016
EditorsFrederic Vidal, Yoseph Bar-Cohen
ISBN (Electronic)9781510600393
Publication statusPublished - 2016
EventElectroactive Polymer Actuators and Devices (EAPAD) 2016 - Las Vegas, United States
Duration: Mar 21 2016Mar 24 2016

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


OtherElectroactive Polymer Actuators and Devices (EAPAD) 2016
Country/TerritoryUnited States
CityLas Vegas

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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