Discrimination of Object Curvature Based on a Sparse Tactile Sensor Array

Object curvature plays an important role in grasping and manipulation. To be more exact, local curvature is a more useful information for grasping practically. Vision and touch are the two main methods to extract surface curvature of an object, but vision is often limited since the complete contact...

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Main Authors: Weiting Liu, Binpeng Zhan, Chunxin Gu, Ping Yu, Guoshi Zhang, Xin Fu, Christian Cipriani, Liang Hu
Format: Article
Language:English
Published: MDPI AG 2020-06-01
Series:Micromachines
Subjects:
Online Access:https://www.mdpi.com/2072-666X/11/6/583
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author Weiting Liu
Binpeng Zhan
Chunxin Gu
Ping Yu
Guoshi Zhang
Xin Fu
Christian Cipriani
Liang Hu
author_facet Weiting Liu
Binpeng Zhan
Chunxin Gu
Ping Yu
Guoshi Zhang
Xin Fu
Christian Cipriani
Liang Hu
author_sort Weiting Liu
collection DOAJ
description Object curvature plays an important role in grasping and manipulation. To be more exact, local curvature is a more useful information for grasping practically. Vision and touch are the two main methods to extract surface curvature of an object, but vision is often limited since the complete contact area is invisible during manipulation. In this paper, the authors propose an object curvature estimation method based on an artificial neural network algorithm through a lab-developed sparse tactile sensor array. The compliant layer covering on the sensor is indispensable for fitting the curved surface. Three types (plane, convex sphere, and convex cylinder) of sample and each type of sample including 30 different radiuses (1 mm to 30 mm) were used in the experiment. The overall classification accuracy was 93.1%. The average curvature radius estimating error based on an artificial neural network (ANN) algorithm was 1.87 mm. When the radius of curvature was bigger than 5 mm, the average relative error was smaller than 20%. As a comparison, the sensor array density we used in this paper was less than 9/cm<sup>2</sup>, which was smaller than the density of human SAII receptors, but the discrimination result was close to the SAII receptors. Comparison with the curvature discrimination ability of the human body showed that this method has a promising application prospect.
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spelling doaj.art-6d2986400ee042caa285aa1b9209e3de2023-11-20T03:28:45ZengMDPI AGMicromachines2072-666X2020-06-0111658310.3390/mi11060583Discrimination of Object Curvature Based on a Sparse Tactile Sensor ArrayWeiting Liu0Binpeng Zhan1Chunxin Gu2Ping Yu3Guoshi Zhang4Xin Fu5Christian Cipriani6Liang Hu7State Key Laboratory of Fluid Power and Mechatronic Systems, School of Mechanical Engineering, Zhejiang University, Hangzhou 310007, ChinaState Key Laboratory of Fluid Power and Mechatronic Systems, School of Mechanical Engineering, Zhejiang University, Hangzhou 310007, ChinaState Key Laboratory of Fluid Power and Mechatronic Systems, School of Mechanical Engineering, Zhejiang University, Hangzhou 310007, ChinaCollege of Mechanical and Electrical Engineering, Wenzhou University, Wenzhou 325035, ChinaState Key Laboratory of Fluid Power and Mechatronic Systems, School of Mechanical Engineering, Zhejiang University, Hangzhou 310007, ChinaState Key Laboratory of Fluid Power and Mechatronic Systems, School of Mechanical Engineering, Zhejiang University, Hangzhou 310007, ChinaThe Biorobotic Institute, Scuola Universitaria Superiore Pisa, 56025 Pisa, ItalyState Key Laboratory of Fluid Power and Mechatronic Systems, School of Mechanical Engineering, Zhejiang University, Hangzhou 310007, ChinaObject curvature plays an important role in grasping and manipulation. To be more exact, local curvature is a more useful information for grasping practically. Vision and touch are the two main methods to extract surface curvature of an object, but vision is often limited since the complete contact area is invisible during manipulation. In this paper, the authors propose an object curvature estimation method based on an artificial neural network algorithm through a lab-developed sparse tactile sensor array. The compliant layer covering on the sensor is indispensable for fitting the curved surface. Three types (plane, convex sphere, and convex cylinder) of sample and each type of sample including 30 different radiuses (1 mm to 30 mm) were used in the experiment. The overall classification accuracy was 93.1%. The average curvature radius estimating error based on an artificial neural network (ANN) algorithm was 1.87 mm. When the radius of curvature was bigger than 5 mm, the average relative error was smaller than 20%. As a comparison, the sensor array density we used in this paper was less than 9/cm<sup>2</sup>, which was smaller than the density of human SAII receptors, but the discrimination result was close to the SAII receptors. Comparison with the curvature discrimination ability of the human body showed that this method has a promising application prospect.https://www.mdpi.com/2072-666X/11/6/583sparse tactile sensor arraymachine learningneural networkdiscrimination of curvaturecompliant contact
spellingShingle Weiting Liu
Binpeng Zhan
Chunxin Gu
Ping Yu
Guoshi Zhang
Xin Fu
Christian Cipriani
Liang Hu
Discrimination of Object Curvature Based on a Sparse Tactile Sensor Array
Micromachines
sparse tactile sensor array
machine learning
neural network
discrimination of curvature
compliant contact
title Discrimination of Object Curvature Based on a Sparse Tactile Sensor Array
title_full Discrimination of Object Curvature Based on a Sparse Tactile Sensor Array
title_fullStr Discrimination of Object Curvature Based on a Sparse Tactile Sensor Array
title_full_unstemmed Discrimination of Object Curvature Based on a Sparse Tactile Sensor Array
title_short Discrimination of Object Curvature Based on a Sparse Tactile Sensor Array
title_sort discrimination of object curvature based on a sparse tactile sensor array
topic sparse tactile sensor array
machine learning
neural network
discrimination of curvature
compliant contact
url https://www.mdpi.com/2072-666X/11/6/583
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