TY - JOUR
T1 - Acoustic Length Sensor for Soft Extensible Pneumatic Actuators with a Frequency Characteristics Model
AU - Takaki, Ken
AU - Taguchi, Yoshitaka
AU - Nishikawa, Satoshi
AU - Niiyama, Ryuma
AU - Kawahara, Yoshihiro
N1 - Funding Information:
Manuscript received February 24, 2019; accepted July 1, 2019. Date of publication July 25, 2019; date of current version August 15, 2019. This letter was recommended for publication by Associate Editor L. Wen and Editor K.-J. Cho upon evaluation of the reviewers’ comments. This work was supported by JST ERATO Grant Number JPMJER1501, Japan. (Corresponding author: Ken Takaki.) K. Takaki, Y. Taguchi, and Y. Kawahara are with the School of Engineering, The University of Tokyo, Tokyo 113-8654, Japan (e-mail: takaki@akg.t.u-tokyo.ac.jp; ytaguchi@ginjo.t.u-tokyo.ac.jp; kawahara@akg.t.u-tokyo.ac.jp).
Publisher Copyright:
© 2016 IEEE.
PY - 2019/10
Y1 - 2019/10
N2 - In this study, we present a length sensor that can be used for extensible soft pneumatic actuators. Conventional length sensors detect the changes in electrical resistance and capacitance owing to the deformation of the actuator; hence, deterioration and destruction occur when they are used with an actuator that has a large expansion ratio. In addition, their low resolution and linearity makes them unsuitable for use in actuator control. Our proposed sensor comprises only a speaker and a microphone installed at one end of the actuator. We propose a method to deterministically measure the length of a tube by generating a broadband acoustic signal in a tube and measuring the resonance characteristics determined by the shape of the tube. Our experimental results demonstrate that the error in the measurement with our sensor is not more than 4% with a strain up to 200%. Unlike conventional acoustic sensing methods that measure the time of flight by using ultrasound, our proposed method yields accurate results even when the tube is bent. Therefore, the proposed method can be applied to various types of pneumatic actuators.
AB - In this study, we present a length sensor that can be used for extensible soft pneumatic actuators. Conventional length sensors detect the changes in electrical resistance and capacitance owing to the deformation of the actuator; hence, deterioration and destruction occur when they are used with an actuator that has a large expansion ratio. In addition, their low resolution and linearity makes them unsuitable for use in actuator control. Our proposed sensor comprises only a speaker and a microphone installed at one end of the actuator. We propose a method to deterministically measure the length of a tube by generating a broadband acoustic signal in a tube and measuring the resonance characteristics determined by the shape of the tube. Our experimental results demonstrate that the error in the measurement with our sensor is not more than 4% with a strain up to 200%. Unlike conventional acoustic sensing methods that measure the time of flight by using ultrasound, our proposed method yields accurate results even when the tube is bent. Therefore, the proposed method can be applied to various types of pneumatic actuators.
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U2 - 10.1109/LRA.2019.2931273
DO - 10.1109/LRA.2019.2931273
M3 - Article
AN - SCOPUS:85071007304
SN - 2377-3766
VL - 4
SP - 4292
EP - 4297
JO - IEEE Robotics and Automation Letters
JF - IEEE Robotics and Automation Letters
IS - 4
M1 - 8772162
ER -