scholarly journals Modeling Analysis and 3D Force Prediction of a Novel Piezoelectric Tactile Sensor

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Feilu Wang ◽  
Rungen Ye ◽  
Yang Song ◽  
Yufeng Chen ◽  
Yanan Jiang ◽  
...  
Keyword(s):  
Polyvinylidene Fluoride ◽  
Three Dimensional ◽  
Tactile Sensor ◽  
Good Prediction ◽  
Tactile Sensors ◽  
Force Prediction ◽  
Sensor Model ◽  
Modeling Analysis ◽  
Efficient Performance ◽  
Perception Model

To measure three-dimensional (3D) forces efficiently and improve the sensitivity of tactile sensors, a novel piezoelectric tactile sensor with a “sandwich” structure is proposed in this paper. An array of circular truncated cone-shaped sensitive units made of polyvinylidene fluoride (PVDF) is sandwiched between two flexible substrates of polydimethylsiloxane (PDMS). Based on the piezoelectric properties of the PVD F sensitive units, finite element modelling and analysis are carried out for the sensor. The relation between the force and the voltage of the sensitive unit is obtained, and a tactile perception model is established. The model can distinguish the sliding direction and identify the material of the slider loaded on the sensor. A backpropagation neural network (BPNN) algorithm is built to predict the 3D forces applied on the tactile sensor model, and the 3D forces are decoupled from the voltages of the sensitive units. The BPNN is further optimized by a genetic algorithm (GA) to improve the accuracy of the 3D force prediction, and fairly good prediction results are obtained. The experimental results show that the novel tactile sensor model can effectively predict the 3D forces, and the BPNN model optimized by the GA can predict the 3D forces with much higher precision, which also improves the intelligence of the sensor. All the prediction results indicate that the BPNN algorithm has very efficient performance in 3D force prediction for the piezoelectric tactile sensor.

An Endoscopic Grasper Tool With Integrated Tactile Sensors for Use in Minimally Invasive Surgery

Volume 3 ◽  
2004 ◽  
Author(s):  
Javad Dargahi ◽  
Siamak Najarian
Keyword(s):  
Dynamic Range ◽  
Light Emitting Diode ◽  
Three Dimensional ◽  
Tactile Sensor ◽  
Tactile Sensors ◽  
Light Emitting ◽  
Force Magnitude ◽  
Dimensional Finite Element ◽  
Amplification System ◽  
Three Dimensional Finite Element

In this paper, we report on the design, testing, fabrication, and modeling of a semiconductor-based microstrain gauge endoscopic tactile sensor. This sensor is capable of measuring both the magnitude and the position of an applied load on a commercial endoscopic grasper tool. It consists of two microstrain gauge sensors, placed on the prototype endoscopic grasper. A light emitting diode device is used to visually see the intensity of the applied force. In total, 20 different force magnitudes for 7 different locations on the endoscopic grasper are tested experimentally. The range of force magnitude changes in the domain of 0.5 N to 10 N. The in-house electrical amplification system for the microstrain gauges is also designed, fabricated, and tested. The sensor is insulated and can operate safely in wet environments. The designed sensor assembly exhibits high force sensitivity, good linearity, and large dynamic range. A three-dimensional finite element modeling (FEM) is employed to predict the behavior of the designed system. Based on FEM results, there is a good agreement between these data the results obtained experimentally.

Coated Tactile Sensor Using Signal Time Delay Phenomenon

Impact ◽  
2019 ◽  
Vol 2019 (10) ◽  
pp. 79-81
Author(s):  
Takayuki Takahashi
Keyword(s):  
Time Delay ◽  
Three Dimensional ◽  
Tactile Sensor ◽  
Systems Science ◽  
Physical Interaction ◽  
Tactile Sensors ◽  
Different Types ◽  
Delay Phenomenon ◽  
Signal Time

Tactile sensors measure information arising from the sensor's physical interaction with its environment. There are different types, including force/torque, dynamic and thermal. Many devices require sensors to detect contact with the outside world, much like robots. Dr Takayuki Takahashi is a researcher based in the Department of Symbiotic Systems Science, Fukushima University, Japan. He and his team have developed a tactile sensor that can be sprayed over three-dimensional shapes, called the Spray Coated Tactile Sensor (ScoTacS).

Develop Flexible Piezoelectric PVDF Nano-Fibrous Membrane

2011 ◽  
Vol 675-677 ◽  
pp. 465-468 ◽  
Author(s):  
Yong Rong Wang ◽  
Pei Hua Zhang ◽  
Chun Ye Xu
Keyword(s):  
Polyvinylidene Fluoride ◽  
Ferroelectric Properties ◽  
Tactile Sensor ◽  
Fibrous Membrane ◽  
Diameter Distribution ◽  
Pvdf Film ◽  
Tactile Sensors ◽  
Electrospinning Technique ◽  
External Impact ◽  
Fibrous Membranes

Piezoelectric polymer, polyvinylidene fluoride (PVDF) film, has been widely investigated as sensor and transducer material due to its high piezo-, pyro-, and ferroelectric properties. However, there are many limitations for PVDF film as human-related tactile sensor, such as non-breathability, stretching, requirement of additional process like poling, etc. In this paper, PVDF nano-fibrous membrane which is light, flexible, and wearable was prepared by electrospinning technique. The electrospinning parameters such as the voltage, feeding rate, tip-tocollector distance, etc, were well controlled. More than 4 hours electrospinning time was needed for a certain thickness of PVDF nano-fibrous membrane. The morphology of PVDF nanofiber was determined by scanning electron microscopy (SEM), the diameter distribution was calculated and crystal structure was evaluated by FTIR spectroscopy. We found the feasibility of developing piezoelectric PVDF fibrous membranes through electrospinning technology, which is a good candidate for flexible human-related tactile sensors to sense garment pressure, blood pressure, heartbeat rate, accidental external impact on human body, etc.

scholarly journals Structure Analysis and Decoupling Research of a Novel Flexible Tactile Sensor Array

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Feilu Wang ◽  
Yang Song ◽  
Zhenya Zhang ◽  
Wanli Chen
Keyword(s):  
Sensor Array ◽  
Back Propagation ◽  
Three Dimensional ◽  
Structural Complexity ◽  
Tactile Sensor ◽  
Back Propagation Neural Network ◽  
Sensor Model ◽  
Sensor Structure ◽  
Hidden Layer ◽  
Decoupling Algorithm

This paper presents a novel flexible tactile sensor structure and proposes an efficient decoupling algorithm for the tactile sensor. Firstly, structure of the sensor model is introduced, and the sensing mechanism of the sensor array based on force-sensitive conductive rubber is analyzed. Then the mapping relation between the resistances of conductive pillars and the three-dimensional force is deduced. After that, the force applied on the tactile sensor is decoupled from the resistance information by the improved Back Propagation Neural Network (BPNN) algorithm with the number of hidden layer nodes optimized. The flexible tactile sensor model achieves the decomposition of the three-dimensional information from the structure with its unique design, avoids the direct interference between electrodes of the sensor array, reduces the structural complexity and the nonlinear degree, improves the decoupling accuracy, and accelerates the decoupling rate.

scholarly journals Three-dimensional printing of tactile sensors for soft robotics

MRS Bulletin ◽  
2021 ◽  
Author(s):  
Xinran Zhou ◽  
Pooi See Lee
Keyword(s):  
3D Printing ◽  
Three Dimensional ◽  
Tactile Sensor ◽  
Soft Robotics ◽  
Fabrication Method ◽  
Tactile Sensors ◽  
Three Dimensional Printing ◽  
Future Potential ◽  
Dimensional Printing ◽  
Printing Techniques

AbstractThree-dimensional (3D) printing has become an important fabrication method for soft robotics, due to its ability to make complex 3D structures from computer designs in simple steps and multimaterial co-deposition ability. In this article, the application of 3D printing techniques in the fabrication of four types of tactile sensors commonly used in soft robotics, including the piezoresistive tactile sensor, capacitive tactile sensor, piezoelectric tactile sensor, and triboelectric tactile sensor, will be discussed. The 3D printing mechanism, material, and structure for each type of sensor will be introduced, and the perspectives on the future potential of 3D printable tactile sensors will be discussed.

Multilayered and Arrayed Flexible Tactile Sensor Using PVDF

2007 ◽  
Vol 120 ◽  
pp. 229-234
Author(s):  
Byung June Choi ◽  
Kwang Mok Jung ◽  
Jae Do Nam ◽  
Sang Moo Lee ◽  
Yasu Yoshi Yokokohji ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Polyvinylidene Fluoride ◽  
High Spatial Resolution ◽  
Three Dimensional ◽  
Tactile Sensor ◽  
Processing Technique ◽  
Normal Forces ◽  
Characteristic Features ◽  
Electronic Hardware ◽  
Contact Sensors

In this paper, we present a multilayered and arrayed flexible sensor made of Polyvinylidene Fluoride (PVDF), which can detect contact normal forces as well as positions. Since the sensor is flexible enough to be adapted to arbitrarily curved three-dimensional surfaces, it can be employed as the fingertip sensor of the robot hand, contact sensors for robot manipulators etc. The sensor displays enhanced characteristic features in terms of ease of fabrication, high spatial resolution and cost-effectiveness. We propose a new design of the sensor that can be fabricated without adopting sophisticated processing technique as well as with improved spatial resolution. In addition, an electronic hardware for signal processing using a DSP chip has been proposed and, its effectiveness is validated experimentally.

scholarly journals Three-Dimensional Force Prediction of a Flexible Tactile Sensor Based on Radial Basis Function Neural Networks

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Feilu Wang ◽  
Yang Song
Keyword(s):  
Radial Basis Function ◽  
Basis Function ◽  
Nonlinear Approximation ◽  
Three Dimensional ◽  
Sliding Window ◽  
Tactile Sensor ◽  
Least Square ◽  
Force Prediction ◽  
Conductive Rubber ◽  
Radial Basis

A flexible tactile sensor array with 6 × 6 N-type sensitive elements made of conductive rubber is presented in this paper. The property and principle of the tactile sensor are analyzed in detail. Based on the piezoresistivity of conductive rubber, this paper takes full advantage of the nonlinear approximation ability of the radial basis function neural network (RBFNN) method to approach the high-dimensional mapping relation between the resistance values of the N-type sensitive element and the three-dimensional (3D) force and to accomplish the accurate prediction of the magnitude of 3D force loaded on the sensor. In the prediction process, the k -means algorithm and recursive least square (RLS) method are used to optimize the RBFNN, and the k -fold cross-validation method is conducted to build the training set and testing set to improve the prediction precision of the 3D force. The optimized RBFNN with different spreads is used to verify its influence on the performance of 3D force prediction, and the results indicate that the spread value plays a very important role in the prediction process. Then, sliding window technology is introduced to build the RBFNN model. Experimental results show that setting the size of the sliding window appropriately can effectively reduce the prediction error of the 3D force exerted on the sensor and improve the performance of the RBFNN predictor, which means that the sliding window technology is very feasible and valid in 3D force prediction for the flexible tactile sensor. All of the results indicate that the optimized RBFNN with high robustness can be well applied to the 3D force prediction research of the flexible tactile sensor.

scholarly journals Evaluation of Circle Diameter by Distributed Tactile Information in Active Tracing

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Hiroyuki Nakamoto ◽  
Futoshi Kobayashi ◽  
Fumio Kojima
Keyword(s):  
Voluntary Movement ◽  
Synthesis Method ◽  
Tactile Sensor ◽  
Active Touch ◽  
Robotic Hand ◽  
Tactile Sensors ◽  
Robotic Hands ◽  
Tactile Information ◽  
Sensor Model ◽  
Circle Diameter

Active touch with voluntary movement on the surface of an object is important for human to obtain the local and detailed features on it. In addition, the active touch is considered to enhance the human spatial resolution. In order to improve dexterity performance of multifinger robotic hands, it is necessary to study an active touch method for robotic hands. In this paper, first, we define four requirements of a tactile sensor for active touch and design a distributed tactile sensor model, which can measure a distribution of compressive deformation. Second, we suggest a measurement process with the sensor model, a synthesis method of distributed deformations. In the experiments, a five-finger robotic hand with tactile sensors traces on the surface of cylindrical objects and evaluates the diameters. We confirm that the hand can obtain more information of the diameters by tracing the finger.

A Mechatronic Platform for Calibration and Performance Test of Extrinsic Tactile Sensor on Prosthesis Hand

2015 ◽  
Vol 12 (02) ◽  
pp. 1550005
Author(s):  
Xiaoying Cheng ◽  
Chunxin Gu ◽  
Weiting Liu ◽  
Xin Fu
Keyword(s):  
Polyvinylidene Fluoride ◽  
Performance Test ◽  
Tactile Sensor ◽  
Curved Surface ◽  
Prosthetic Hand ◽  
Surface Load ◽  
Tactile Sensors ◽  
Measurement Sensor ◽  
Rigid Rod ◽  
And Performance

This paper presents a mechatronic platform consists of a stimulator and a prosthesis hand holder, which aims at extrinsic flexible tactile sensor calibration and performance test for prosthesis hand application. The former is driven by a linear motor and the latter is driven by the combination of one 3 dimensions of freedom (DoF) motion stage and two rotation stages. A procedure is developed to calibrate flexible tactile sensors attached on the anthropomorphic prosthetic hand, whose surface is curved. Although the flexible tactile sensors can be easily integrated on to the mentioned curved surface due to its flexibility and compliance, they are usually flat fabricated and characterized under the working of flat situation. Curved surface sensor characterization is not directly available from the manufacturer. Furthermore, when tactile sensors are applied, there would be an elastic layer covered on top for protection and improvement of grasping ability. This elastic material essentially deteriorates the characteristics of the sensor under it, which is another important reason for establishing a platform to re-calibrate tactile sensor mounted on prosthetic hand. In this paper, two kinds of commercial tactile sensors are involved which are force sensing resistor (FSR) representing static measurement sensor and polyvinylidene fluoride (PVDF) sensor representing dynamic measurement sensor where a rigid rod with polydimethylsiloxane (PDMS) covered imitates prosthetic finger. The methodology of calibration compares the measured data obtained from tactile sensor with the one from a load cell fixed on the stimulator. The procedure of receptive-field measurement for tactile sensor on the prosthetic hand is shown and the equation for estimating the position and amplitude of surface load on top of elastic cover is established. Different combinations of tactile sensors are implemented on the rigid substance and two motion patterns of stimulator are performed on them, which are indentation and sliding. The performance of developed platform is also analyzed and it shows the ability of testing flexible tactile sensor for prosthesis hand.

scholarly journals A Vibrissa-Inspired Highly Flexible Tactile Sensor: Scanning 3D Object Surfaces Providing Tactile Images

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1572
Author(s):  
Lukas Merker ◽  
Joachim Steigenberger ◽  
Rafael Marangoni ◽  
Carsten Behn
Keyword(s):  
Steel Wire ◽  
Sense Organ ◽  
Tactile Sensor ◽  
Tactile Sensors ◽  
Measuring Device ◽  
3D Object ◽  
Torque Transducer ◽  
Sense Of Touch ◽  
Important Basis ◽  
Support Reactions

Just as the sense of touch complements vision in various species, several robots could benefit from advanced tactile sensors, in particular when operating under poor visibility. A prominent tactile sense organ, frequently serving as a natural paragon for developing tactile sensors, is the vibrissae of, e.g., rats. Within this study, we present a vibrissa-inspired sensor concept for 3D object scanning and reconstruction to be exemplarily used in mobile robots. The setup consists of a highly flexible rod attached to a 3D force-torque transducer (measuring device). The scanning process is realized by translationally shifting the base of the rod relative to the object. Consequently, the rod sweeps over the object’s surface, undergoing large bending deflections. Then, the support reactions at the base of the rod are evaluated for contact localization. Presenting a method of theoretically generating these support reactions, we provide an important basis for future parameter studies. During scanning, lateral slip of the rod is not actively prevented, in contrast to literature. In this way, we demonstrate the suitability of the sensor for passively dragging it on a mobile robot. Experimental scanning sweeps using an artificial vibrissa (steel wire) of length 50 mm and a glass sphere as a test object with a diameter of 60 mm verify the theoretical results and serve as a proof of concept.

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