scholarly journals A MEMS Tactile Sensor with Fingerprint-Like Array of Contactors for High Resolution Visualization of Surface Distribution of Tactile Information

2020 ◽  
Vol 32 (2) ◽  
pp. 305-314
Author(s):  
Kazuki Watatani ◽  
◽  
Kyohei Terao ◽  
Fusao Shimokawa ◽  
Hidekuni Takao
Keyword(s):  
High Resolution ◽  
Frictional Force ◽  
Present Report ◽  
Tactile Sensor ◽  
Mechanical Analysis ◽  
Surface Shape ◽  
Woven Fabric ◽  
Surface Distribution ◽  
Tactile Information ◽  
Fabric Surface

In the present report, we have developed a tactile sensor with fingerprint-like array of contactors for obtaining the surface distribution of tactile information in high spatial resolutions. Six high resolution sensing modules of contactors with biaxial detectors were integrated in line at a pitch of 500 μm, the typical pitch of fingerprint ridges. Each sensing module independently detected the micro surface shape and locally generated frictional force on the object surfaces. Mechanical analysis of the fabricated sensors showed good sensitivities and highly linear responses. Consequently, the measured detection resolutions of surface shape and frictional force were 0.17 μm and 9.9 μN, respectively. The experimental performance evaluation of fabricated sensor was measured in the distribution of tactile information by sweeping the sensor with a yaw angle. Additionally, the 3D surface shape of weave structure and surface distribution of frictional force in a woven fabric with 0.4 mm pitch of threads in high spatial resolution was clearly visualized/observed. Moreover, the directionality of tactile information of the fabric surface distribution was successfully realized using the tactile sensor with the array of contactors by sweeping in different directions.

scholarly journals High-Speed Tactile Sensing for Array-Type Tactile Sensor and Object Manipulation Based on Tactile Information

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Wataru Fukui ◽  
Futoshi Kobayashi ◽  
Fumio Kojima ◽  
Hiroyuki Nakamoto ◽  
Nobuaki Imamura ◽  
...  
Keyword(s):  
High Resolution ◽  
High Speed ◽  
Tactile Sensor ◽  
Robotic Hand ◽  
Robot Hand ◽  
Dexterous Manipulation ◽  
Tactile Information ◽  
Array Type ◽  
Measurement Cycle ◽  
Very High

We have developed a universal robot hand with tactile and other sensors. An array-type tactile sensor is crucial for dexterous manipulation of objects using a robotic hand, since this sensor can measure the pressure distribution on finger pads. The sensor has a very high resolution, and the shape of a grasped object can be classified by using this sensor. The more the number of measurement points provided, the higher the accuracy of the classification, but with a corresponding lengthening of the measurement cycle. In this paper, the problem of slow response time is resolved by using software for an array-type tactile sensor with high resolution that emulates the human sensor system. The validity of the proposed method is demonstrated through experiments.

The study of needle type influence on woven fabric surface area during the sewing process

2021 ◽  
pp. 004051752110191
Author(s):  
Beti Rogina-Car ◽  
Stana Kovačević
Keyword(s):  
Computer Program ◽  
Tensile Properties ◽  
Surface Area ◽  
Cotton Fabrics ◽  
Woven Fabric ◽  
Microscopic Images ◽  
Needle Type ◽  
Fabric Surface ◽  
Needle Point

The aim of this study was to investigate the damage to cotton fabrics (ticking and damask) caused by stitching with three types of needle point shapes (R, SES and SUK) and four needle sizes (70, 80, 90 and 100 Nm). Damage to the yarn and the surface area of the hole were investigated. Based on the results, it can be concluded that two types of damage occur during sewing: the needle passes through the warp/weft (it displaces the yarn) and the needle damages the warp/weft. An analysis and comparison of the surface area of the holes was carried out, obtained by a computer program based on microscopic images. The results show greater damage to the yarn at the needle piercing point in the ticking due to higher density, friction and low yarn migration. The largest surface area of the holes was produced when sewing with SUK-designated needles on ticking and damask. When sewing damask, R-designated needles cause the least damage to the piercing point, whereas SES-designated needles give the best results when sewing the ticking. Thread damage was further confirmed by testing the tensile properties of the yarn at the needle piercing points.

scholarly journals Hi-Speed Tactile Sensing for Array-type Tactile Sensor and Object Manipulation based on Tactile Information

2012 ◽  
Vol 25 (5) ◽  
pp. 117-125
Author(s):  
Wataru Fukui ◽  
Futoshi Kobayashi ◽  
Fumio Kojima ◽  
Hiroyuki Nakamoto ◽  
Tadashi Maeda ◽  
...  
Keyword(s):  
Tactile Sensor ◽  
Object Manipulation ◽  
Tactile Sensing ◽  
Tactile Information ◽  
Array Type

scholarly journals A low-cost, human-like, high-resolution, tactile sensor based on optical fibers and an image sensor

2018 ◽  
Vol 15 (4) ◽  
pp. 172988141878363 ◽  
Author(s):  
Utku Büyükşahin ◽  
Ahmet Kırlı
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Fiber Optic ◽  
Low Cost ◽  
Experimental Studies ◽  
Main Idea ◽  
Tactile Sensor ◽  
Image Sensor ◽  
Sensor Design ◽  
Tactile Sensors

Tactile sensors are commonly a coordinated group of receptors forming a matrix array meant to measure force or pressure similar to the human skin. Optic-based tactile sensors are flexible, sensitive, and fast; however, the human fingertip’s spatial resolution, which can be regarded as the desired spatial resolution, still could not be reached because of their bulky nature. This article proposes a novel and patented optic-based tactile sensor design, in which fiber optic cables are used to increase the number of sensory receptors per square centimeter. The proposed human-like high-resolution tactile sensor design is based on simple optics and image processing techniques, and it enables high spatial resolution and easy data acquisition at low cost. This design proposes using the change in the intesity of the light occured due to the deformation on contact/measurement surface. The main idea is using fiber optic cables as the afferents of the human physiology which can have 9 µm diameters for both delivering and receiving light beams. The variation of the light intensity enters sequent mathematical models as the input, then, the displacement, the force, and the pressure data are evaluated as the outputs. A prototype tactile sensor is manufactured with 1-mm spatial and 0.61-kPa pressure measurement resolution with 0–15.6 N/cm2 at 30 Hz sampling frequency. Experimental studies with different scenarios are conducted to demonstrate how this state-of-the-art design worked and to evaluate its performance. The overall accuracy of the first prototype, based on different scenarios, is calculated as 93%. This performance is regarded as promising for further developments and applications such as grasp control or haptics.

Characterization of the effect of fabric structure on the optical properties of woven fabrics

2019 ◽  
Vol 23 (1) ◽  
pp. 58-70
Author(s):  
Paniz Khosravani ◽  
Nazanin Ezazshahabi ◽  
Masoud Latifi
Keyword(s):  
Optical Properties ◽  
Structural Parameters ◽  
Human Perception ◽  
Comparative Judgment ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Content Type ◽  
Weave Structure ◽  
The Aesthetic ◽  
Fabric Surface

Purpose This paper aims to study the optical properties of woven fabrics. Design/methodology/approach The current study was carried out to objectively evaluate the luster of a group of woven fabrics with different weave structures and weft densities, with the aid of a goniophotometer. The results obtained from the objective luster measurement were validated by a set of pair comparison subjective tests using Thurstone’s law of comparative judgment. Findings The proper correlation with the R2 value of more than 0.96, between subjective and objective tests, confirmed the reliability and accordance of objective results with the human perception of luster. Statistical analysis of the luster results clarified that the effect of fabric structural parameters such as weave structure and weft density are significant at the confidence range of 95 per cent. The highest luster index was achieved for the twill 3/1 weave structure and the lowest luster belonged to the plain pattern. In addition, an increase in the density of the fabric leads to better luster. Moreover, it was concluded that the surface roughness affects the luster. A rise in the roughness value of the woven fabric causes reduction in its luster property. Originality/value Optical properties of woven fabrics, which are mainly attributed through the measurement of luster, are important for qualifying the aesthetic characteristics of the fabrics with various weave structures. Bearing in mind the influence of fabric surface properties on the aesthetic features of cloths, obtaining information in this field is a guide for selecting the suitable fabric for various end uses.

scholarly journals Magnetostrictive tactile sensor of detecting friction and normal force for object recognition

2020 ◽  
Vol 17 (4) ◽  
pp. 172988142093232
Author(s):  
Bing Zhang ◽  
Bowen Wang ◽  
Yunkai Li ◽  
Shaowei Jin
Keyword(s):  
Recognition Rate ◽  
Tactile Sensor ◽  
Tactile Sensing ◽  
Dynamic Force ◽  
Force Output ◽  
Tactile Sensors ◽  
Tactile Information ◽  
Normal Contact ◽  
New Type ◽  
Learning Machine

Tactile information is valuable in determining properties of objects that are inaccessible from visual perception. A new type of tangential friction and normal contact force magnetostrictive tactile sensor was developed based on the inverse magnetostrictive effect, and the force output model has been established. It can measure the exerted force in the range of 0–4 N, and it has a good response to the dynamic force in cycles of 0.25–0.5 s. We present a tactile perception strategy that a manipulator with tactile sensors in its grippers manipulates an object to measure a set of tactile features. It shows that tactile sensing system can use these features and the extreme learning machine algorithm to recognize household objects—purely from tactile sensing—from a small training set. The complex matrixes show the recognition rate is up to 83%.

scholarly journals Design, Motivation and Evaluation of a Full-Resolution Optical Tactile Sensor

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 928 ◽  
Author(s):  
Carmelo Sferrazza ◽  
Raffaello D’Andrea
Keyword(s):  
High Resolution ◽  
Deep Neural Network ◽  
Normal Force ◽  
Tactile Sensor ◽  
High Accuracy ◽  
Image Sensors ◽  
Random Pattern ◽  
Full Resolution ◽  
Sense Of Touch ◽  
Modern Image

Human skin is capable of sensing various types of forces with high resolution and accuracy. The development of an artificial sense of touch needs to address these properties, while retaining scalability to large surfaces with arbitrary shapes. The vision-based tactile sensor proposed in this article exploits the extremely high resolution of modern image sensors to reconstruct the normal force distribution applied to a soft material, whose deformation is observed on the camera images. By embedding a random pattern within the material, the full resolution of the camera can be exploited. The design and the motivation of the proposed approach are discussed with respect to a simplified elasticity model. An artificial deep neural network is trained on experimental data to perform the tactile sensing task with high accuracy for a specific indenter, and with a spatial resolution and a sensing range comparable to the human fingertip.

Detecting Feature of Haptic Interaction Based on Distributed Tactile Sensor Network on Whole Body

2007 ◽  
Vol 19 (1) ◽  
pp. 42-51 ◽  
Author(s):  
Tomoyuki Noda ◽  
◽  
Takahiro Miyashita ◽  
Hiroshi Ishiguro ◽  
Kiyoshi Kogure ◽  
...  
Keyword(s):  
Sensor Network ◽  
Tactile Sensor ◽  
The Self ◽  
Whole Body ◽  
Transmission Protocol ◽  
Processing Unit ◽  
Haptic Interaction ◽  
Tactile Information ◽  
Self Organized ◽  
Basic Experiments

To extract information about users contacting robots physically, the distribution density of tactile sensor elements, the sampling rate, and the resolution all must be high, increasing the volume of tactile information. In the self-organized skin sensor network we propose for dealing with a large number of tactile sensors embedded throughout a humanoid robot, each network node having a processing unit is connected to tactile sensor elements and other nodes. By processing tactile information in the network based on the situation, individual nodes process and reduce information rapidly in high sampling. They also secure information transmission routes to the host PC using a data transmission protocol for self-organizing sensor networks. In this paper, we verify effectiveness of our proposal through sensor network emulation and basic experiments in spatiotemporal calculation of tactile information using prototype hardware. As an emulation result of the self-organized sensor network, routes to the host PC are secured at each node, and a tree-like network is constructed recursively with the node as a root. As the basic experiments, we describe an edge detection as data processing and extraction for haptic interaction. In conclusion, local information processing is effective for detecting features of haptic interaction.

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