Feedforward control of twisted and coiled polymer actuator based on a macroscopic nonlinear model focusing on energy

Ken Masuya, Shu Ono, Kentaro Takagi, Kenji Tahara

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

This letter proposes a feedforward (FF) controller for the twisted and coiled polymer actuator (TCPA), the so-called fishing line/sewing thread artificial muscle, based on its macroscopic nonlinear model. TCPA is an artificial muscle, and it contracts up to 50% in response to heating. Although several methods considering Joule heating as the input have been proposed to control the TCPA displacement, the FF controller based on the linear model shows the nonnegligible offset error. Therefore, the FF controller should be designed based on a nonlinear model, e.g., the model constructed by the authors. However, computing the inverse of the nonlinear model for the FF controller is difficult. Even if the inverse can be computed under static conditions, the problem of how to compensate the dynamics still remains. For this problem, we compensate the dynamics based on the idea of the Hammerstein model, namely we divide the inverse dynamics into the nonlinear transformation part and linear dynamics part. The former part consists of a converter from the displacement to temperature and a ratio adjuster for the squared voltage. Meanwhile, the latter is represented by the linear model of TCPA temperature. Through experiments, it is verified that the proposed FF controller can reduce the offset error of the displacement compared with the linear controller.

Original languageEnglish
Pages (from-to)1824-1831
Number of pages8
JournalIEEE Robotics and Automation Letters
Volume3
Issue number3
DOIs
Publication statusPublished - Jul 1 2018

Fingerprint

Feedforward Control
Feedforward control
Nonlinear Model
Feedforward
Actuator
Actuators
Polymers
Controller
Controllers
Energy
Artificial muscle
Linear Model
Muscle
Hammerstein Model
Joule Heating
Inverse Dynamics
Nonlinear Transformation
Joule heating
Converter
Thread

All Science Journal Classification (ASJC) codes

  • Control and Systems Engineering
  • Human-Computer Interaction
  • Biomedical Engineering
  • Mechanical Engineering
  • Control and Optimization
  • Artificial Intelligence
  • Computer Science Applications
  • Computer Vision and Pattern Recognition

Cite this

Feedforward control of twisted and coiled polymer actuator based on a macroscopic nonlinear model focusing on energy. / Masuya, Ken; Ono, Shu; Takagi, Kentaro; Tahara, Kenji.

In: IEEE Robotics and Automation Letters, Vol. 3, No. 3, 01.07.2018, p. 1824-1831.

Research output: Contribution to journalArticle

@article{26132f89249648198a9b4b31000fa3ae,
title = "Feedforward control of twisted and coiled polymer actuator based on a macroscopic nonlinear model focusing on energy",
abstract = "This letter proposes a feedforward (FF) controller for the twisted and coiled polymer actuator (TCPA), the so-called fishing line/sewing thread artificial muscle, based on its macroscopic nonlinear model. TCPA is an artificial muscle, and it contracts up to 50{\%} in response to heating. Although several methods considering Joule heating as the input have been proposed to control the TCPA displacement, the FF controller based on the linear model shows the nonnegligible offset error. Therefore, the FF controller should be designed based on a nonlinear model, e.g., the model constructed by the authors. However, computing the inverse of the nonlinear model for the FF controller is difficult. Even if the inverse can be computed under static conditions, the problem of how to compensate the dynamics still remains. For this problem, we compensate the dynamics based on the idea of the Hammerstein model, namely we divide the inverse dynamics into the nonlinear transformation part and linear dynamics part. The former part consists of a converter from the displacement to temperature and a ratio adjuster for the squared voltage. Meanwhile, the latter is represented by the linear model of TCPA temperature. Through experiments, it is verified that the proposed FF controller can reduce the offset error of the displacement compared with the linear controller.",
author = "Ken Masuya and Shu Ono and Kentaro Takagi and Kenji Tahara",
year = "2018",
month = "7",
day = "1",
doi = "10.1109/LRA.2018.2801884",
language = "English",
volume = "3",
pages = "1824--1831",
journal = "IEEE Robotics and Automation Letters",
issn = "2377-3766",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
number = "3",

}

TY - JOUR

T1 - Feedforward control of twisted and coiled polymer actuator based on a macroscopic nonlinear model focusing on energy

AU - Masuya, Ken

AU - Ono, Shu

AU - Takagi, Kentaro

AU - Tahara, Kenji

PY - 2018/7/1

Y1 - 2018/7/1

N2 - This letter proposes a feedforward (FF) controller for the twisted and coiled polymer actuator (TCPA), the so-called fishing line/sewing thread artificial muscle, based on its macroscopic nonlinear model. TCPA is an artificial muscle, and it contracts up to 50% in response to heating. Although several methods considering Joule heating as the input have been proposed to control the TCPA displacement, the FF controller based on the linear model shows the nonnegligible offset error. Therefore, the FF controller should be designed based on a nonlinear model, e.g., the model constructed by the authors. However, computing the inverse of the nonlinear model for the FF controller is difficult. Even if the inverse can be computed under static conditions, the problem of how to compensate the dynamics still remains. For this problem, we compensate the dynamics based on the idea of the Hammerstein model, namely we divide the inverse dynamics into the nonlinear transformation part and linear dynamics part. The former part consists of a converter from the displacement to temperature and a ratio adjuster for the squared voltage. Meanwhile, the latter is represented by the linear model of TCPA temperature. Through experiments, it is verified that the proposed FF controller can reduce the offset error of the displacement compared with the linear controller.

AB - This letter proposes a feedforward (FF) controller for the twisted and coiled polymer actuator (TCPA), the so-called fishing line/sewing thread artificial muscle, based on its macroscopic nonlinear model. TCPA is an artificial muscle, and it contracts up to 50% in response to heating. Although several methods considering Joule heating as the input have been proposed to control the TCPA displacement, the FF controller based on the linear model shows the nonnegligible offset error. Therefore, the FF controller should be designed based on a nonlinear model, e.g., the model constructed by the authors. However, computing the inverse of the nonlinear model for the FF controller is difficult. Even if the inverse can be computed under static conditions, the problem of how to compensate the dynamics still remains. For this problem, we compensate the dynamics based on the idea of the Hammerstein model, namely we divide the inverse dynamics into the nonlinear transformation part and linear dynamics part. The former part consists of a converter from the displacement to temperature and a ratio adjuster for the squared voltage. Meanwhile, the latter is represented by the linear model of TCPA temperature. Through experiments, it is verified that the proposed FF controller can reduce the offset error of the displacement compared with the linear controller.

UR - http://www.scopus.com/inward/record.url?scp=85050652067&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85050652067&partnerID=8YFLogxK

U2 - 10.1109/LRA.2018.2801884

DO - 10.1109/LRA.2018.2801884

M3 - Article

AN - SCOPUS:85050652067

VL - 3

SP - 1824

EP - 1831

JO - IEEE Robotics and Automation Letters

JF - IEEE Robotics and Automation Letters

SN - 2377-3766

IS - 3

ER -