Position and Force Control of a Twisted and Coiled Polymeric Actuator

Chunbing Wu,Wen Zheng

doi:10.1109/access.2020.3011731

Chunbing Wu, Wen Zheng

Open Access

https://doi.org/10.1109/access.2020.3011731

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Abstract

Twisted and coiled polymer (TCP) actuator has many advantages such as high contraction capability, high work density, low cost materials, and easiness of fabrication, making it promising for applications in biomedical devices, soft robotic, and energy-harvesting equipment. However, convenient and effective control of TCP actuators still remain some challenges. In this paper, we use an accurate strain-temperature and force-temperature model of TCP actuators to design a simple and efficient closed-loop PID control system. The validity of the proposed controllers is investigated through numerical simulations and experiments. The results show good control performance with minimum tracking errors which is less than 3% in our work. Such accuracy is ideal for many engineering fields and robotic designs.

Highlights

Inspired by biological system and thanks to the development of smart materials, a new robotics paradigm which is called ‘‘soft robotics’’ based on soft materials and deformable structures is towarding to more practical applications [1]–[5]
We propose a control method based on a multi-mechanisms model for electrical driving twisted and coiled polymer (TCP) actuator utilizing commercial silver-plated Nylon fiber
It might because we limited the maximum heating power to avoid overheating of TCP actuators

Summary

INTRODUCTION

Inspired by biological system and thanks to the development of smart materials, a new robotics paradigm which is called ‘‘soft robotics’’ based on soft materials and deformable structures is towarding to more practical applications [1]–[5]. Other researchers measured the temperature of TCP actuators via resistance change of metal wire twisted with precursor fibers during actuation process [20]–[22]. Such method avoided the use of added sensors and provided an excellent muscle structure for both actuation and temperature feedback. We propose a control method based on a multi-mechanisms model for electrical driving TCP actuator utilizing commercial silver-plated Nylon fiber. Silver coating means those fibers can be heated up . The rise and fall response of the TCP actuators help to calculate Cth

THERMO-MECHANICAL MODEL

FABRICATION PROCESS

TEMPERATURE MEASUREMENT

RESULTS AND DISCUSSION

CONCLUSION