Flexible Pneumatic Bending Actuator for a Robotic Tongue

2020 ◽  
Vol 32 (5) ◽  
pp. 894-902
Author(s):  
Nobutsuna Endo ◽  
◽  
Yuta Kizaki ◽  
Norihiro Kamamichi
Keyword(s):  
Control Method ◽  
Tensile Tests ◽  
Physical Models ◽  
Silicone Resin ◽  
Deformation Model ◽  
Soft Body ◽  
Human Tongue ◽  
Simultaneous Control ◽  
Bending Actuator ◽  
Computer Simulators

There are not many physical models of oral and laryngeal systems for human speech movement in both computer simulators and mechanical simulators. In particular, there is no robot tongue mechanism that completely reproduces the deformation motion of the human tongue. The human tongue is an aggregate of muscles devoid of a skeleton. It only possesses a small hyoid. The purpose of this study is to develop a flexible actuator without a rigid link, aiming at the development of a tongue mechanism for a mechanical speech robot. We propose a flexible pneumatic bending actuator using thin McKibben muscles and a soft body formed by a silicone resin. We have verified its mechanical characteristics and described a control method for displacement and curvature. The elasticity/compliance of the silicone resin forming the soft body of this actuator was quantified by tensile tests. The oscillation parameters were identified, and it is suggested that the dynamic model can be described by a spring-mass-damper system. Assuming an arc-shaped deformation model, a simultaneous control system for the arc length and curvature was constructed and its effectiveness was confirmed.

scholarly journals Deformation model and experimental evaluation of a contractable and bendable wire-pulling mechanism with embedded soft tubes for a robotic tongue

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Nobutsuna Endo
Keyword(s):  
Degrees Of Freedom ◽  
Physical Models ◽  
Deformation Model ◽  
Soft Body ◽  
Piecewise Constant ◽  
Multiple Degrees Of Freedom ◽  
Human Tongue ◽  
Drive And Control ◽  
Deformation Tests ◽  
And Control

AbstractFew physical models of oral and laryngeal systems for human speech movement exist for computer or mechanical simulators. In particular, a robot tongue mechanism that fully reproduces the deformation motion of the human tongue is lacking. The human tongue is an aggregate of muscles that is devoid of a skeleton. It possesses only a small hyoid. A mechanism that can drive and control the deformation of a soft body, such as the human tongue, along multiple degrees of freedom has not been realized to date. To solve this problem, a wire-pulling mechanism with embedded soft tubes is proposed. Using this mechanism, a flexible tongue that can be deformed along multiple degrees of freedom without breaking the wire is achieved. A prototype planar mechanism with two degrees of freedom that is capable of contraction and bending was fabricated. A deformation model that assumes a piecewise constant curvature (PCC) was formulated. Deformation tests confirmed that the prototype is capable of contraction and bending movements that are consistent with those of the model. Variations in the error with respect to the hardness of the deformable part are discussed, and the limits of the deformation model based on the PCC assumption are presented.

Influence of Early-Stage Hydrolysis on Tensile Fracture Behavior of HAp/PLA Composites Interface-Controlled by Reaction Control Utilizing Photodissociable Protecting Groups

2017 ◽  
Vol 11 (6) ◽  
pp. 932-940 ◽  
Author(s):  
Mototsugu Tanaka ◽  
Tomoyuki Takahashi ◽  
Isao Kimpara ◽  
◽  
◽  
...  
Keyword(s):  
Fracture Behavior ◽  
Control Method ◽  
Early Stage ◽  
Tensile Tests ◽  
Immersion Test ◽  
Interfacial Bonding ◽  
Tensile Fracture ◽  
Interface Control ◽  
Nitrobenzyl Alcohol ◽  
Biological Environment

In this study, the change in the tensile fracture behavior of HAp/PLA composites, interface-controlled using pectin and chitosan, was evaluated for the case of the early-stage hydrolysis. Here, the reaction between the HAp particles and modification polymers was controlled using o-nitrobenzyl alcohol. Tensile tests after immersion in a pseudo biological environment indicated that the interface-control method employed in this study improved the fracture properties of HAp/PLA composites significantly, inducing the large plastic deformation. In addition, the effects of early-stage hydrolysis on fracture behavior and mechanism are discussed from the viewpoint of interfacial structures for the interface-controlled HAp/PLA composites. Observations of fracture morphologies and surfaces suggest that the interface-control employed in this study successfully improved interfacial bonding, enabling the effective usage of the deformability of the PLA matrix. The interface-control method employed in this study also maximized the fracture strain through the combination of improved interfacial bonding and an increase in the ductility of the PLA matrix after a 2-week immersion. Test results also suggest that the cancelation induced by the degradation of chitosan accelerated the degradation of the PLA matrix after a longer immersion.

scholarly journals Use of Electric Discharge for Simultaneous Control of Weeds and Houseflies Emerging from Soil

Insects ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 861
Author(s):  
Yoshinori Matsuda ◽  
Kunihiko Shimizu ◽  
Takahiro Sonoda ◽  
Yoshihiro Takikawa
Keyword(s):  
Weed Control ◽  
Pest Control ◽  
Electric Discharge ◽  
Control Method ◽  
Arc Discharge ◽  
Electrically Conductive ◽  
Iron Plate ◽  
Simultaneous Control ◽  
Fly Control ◽  
Plant Shoots

An electrostatic apparatus was developed to control weeds and houseflies emerging from ground soil in a greenhouse simultaneously. Identical iron plates were placed in parallel at a defined interval and fixed in an iron frame. Two sets of fixed iron plates were used, one for weed control and one for fly control. For weed control, all of the iron plates were negatively charged, and negative charges accumulated on the plates were released to weed shoots through arc discharge. Houseflies were introduced into the space between the negatively charged and grounded plates, then subjected to arc discharge from the charged plates. Both plant shoots and adult houseflies are electrically conductive; thus, they were killed by discharge-exposure in the electric field between the charged iron plate and the ground soil, and between the charged and grounded plates, respectively. In practical use, these two devices were assembled as a two-level apparatus for simultaneous control of both targets. Several apparatuses were linked together, which increased the total electricity charge on the plates and produced a stronger discharge force sufficient to kill all targets. Thus, this study provides an electrostatics-based pest-control method for pesticide-independent greenhouse farming.

A NOVEL PROPORTIONAL AND SIMULTANEOUS CONTROL METHOD FOR PROSTHETIC HAND

2017 ◽  
Vol 17 (08) ◽  
pp. 1750120 ◽  
Author(s):  
XIN LI ◽  
QIANG HUANG ◽  
JINYING ZHU ◽  
WENTAO SUN ◽  
HAOTIAN SHE
Keyword(s):  
Time Delay ◽  
Control Method ◽  
Prosthetic Hand ◽  
Wrist Flexion ◽  
Simultaneous Control ◽  
Flexion Extension ◽  
Hand Control ◽  
System Input ◽  
And Performance ◽  
Semg Signals

This paper proposes a novel control method of using the surface electromyogram (sEMG) signals to predict the kinematics of hand and wrist, which will be applied in the prosthetic hand control. Prediction of movement in 3 degree-of-freedoms’ (DoFs’) (wrist flexion/extension (WFE), lateral abduction/adduction (LAA), and hand open/close (HOC)) is investigated in this paper. The proposed control method contains a time-delay recurrent neural network (TDRNN), adopting the previous prediction of the joint angles and the time-delay sEMG signals as the system input. This proposed method uses a batch training based on Levenberg–Marquardt (LM) algorithm to learn the weights of the TDRNN. The trained TDRNN is aimed to achieve simultaneous and proportional regression from human movements of the 3 DoFs to those of the prosthetic hand. Three able-bodied subjects are chosen to participate in the test and demonstrate its feasibility and performance. The offline test result R2 ranges between 0.81 and 0.94. The online test results show that TDRNN reacts faster, which verifies that the method proposed in this paper will be feasible and effective in prosthetic hand control.

Position-Force Control for a Six Coordinate Industrial Robot when Performing Complicated Surface Treatment

2019 ◽  
Vol 20 (1) ◽  
pp. 34-43
Author(s):  
V. L. Afonin ◽  
L. V. Gavrilina ◽  
A. N. Smolentsev
Keyword(s):  
Surface Treatment ◽  
Control Method ◽  
Industrial Robot ◽  
Complex Surface ◽  
Industrial Robots ◽  
Complex Surfaces ◽  
Simultaneous Control ◽  
Cutting Surface ◽  
Assembly Operations ◽  
Executive Body

When performing certain technological operations, multi-coordinate industrial robots require simultaneous control of the movement of the executive body and the developed effort. When performing assembly operations (for example, a shaft with a bush), it is necessary to perform a free movement of the shaft along the bore of the bushing and to ensure minimum pressure on the bore walls. When performing operations to handle complex surfaces of parts, it is simultaneously required to move the tool over the surface at a specified speed and to perform a metered pressure on the surface. Since it is impossible to control the force and motion simultaneously at the same coordinate, it is necessary either to switch from one control method to another, or to control various actuators and different controllable coordinates of the actuator. In multi-coordinate robots, this task is complicated by the fact that to control the movement of one of the Cartesian coordinates of the executive body, and by another force, it is simultaneously necessary to control the interrelated generalized coordinates of the robot’s mechanism. In the work presented, the solution of the problem of control of a six-coordinate industrial robot is described, in which the separation of the degrees of mobility into power control and positional control of trajectory motion is carried out. In order to accomplish the task, additional variable parameters are introduced for the treatment of complex surfaces, which determine the position of the cutting edge on the cutting surface, which makes it possible to expand the service area of the robot during selection, for example, one of the coordinates for controlling the pressure force. This task is considered using the example of a six-coordinate industrial robot when performing a complex surface treatment operation, when it is required to program the tool at a specified speed along a path on the surface and at the same time carry out the controlled pressure of the tool on the surface.

The Mechanical Characteristics of 3D Printed Parts According to the Build Orientation

2014 ◽  
Vol 474 ◽  
pp. 381-386 ◽  
Author(s):  
Petr Zelený ◽  
Jiří Šafka ◽  
Irina Elkina
Keyword(s):  
Rapid Prototyping ◽  
Fused Deposition Modeling ◽  
Mechanical Characteristics ◽  
Tensile Tests ◽  
Physical Models ◽  
Build Orientation ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
Component Element ◽  
3D Printed

This article is focused on a production of mechanically resistant physical models using Rapid Prototyping technology. There are two tested materials, ABS is the first build material and ABS-like is the second build material with similar properties. The article describes the production of a testing component - element for tensile tests by two RP technologies. The first technology is FDM (Fused Deposition Modeling) and the second PolyJet Matrix. Further the article describes the description and evaluation of the tensile tests.

An Inelastic Constitutive Model for Monotonic, Cyclic, and Creep Deformation: Part II—Application to Type 304 Stainless Steel

1976 ◽  
Vol 98 (2) ◽  
pp. 106-112 ◽  
Author(s):  
A. Miller
Keyword(s):  
Stainless Steel ◽  
Rate Sensitivity ◽  
Tensile Tests ◽  
Standard Test ◽  
304 Stainless Steel ◽  
Deformation Model ◽  
Creep Tests ◽  
Creep Fatigue ◽  
Type 304 ◽  
Type 304 Stainless Steel

For the deformation model developed in Part I, material constants are calculated from standard test data on type 304 stainless steel. With them, simulations are made of various types of tests, including tensile tests, strain-rate sensitivity, creep tests with stress drops, strain-controlled cycling, and creep-fatigue interaction. The simulations show general agreement with the corresponding experimental data for type 304, but in a few respects, quantitative improvements are required. Implications of the strengths and weaknesses of the new model are discussed.

scholarly journals Underwater Bending Actuator Based on Integrated Anisotropic Textile Materials and a Conductive Hydrogel Electrode

Actuators ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 270
Author(s):  
Sascha Pfeil ◽  
Alice Mieting ◽  
Rebecca Grün ◽  
Konrad Katzer ◽  
Johannes Mersch ◽  
...  
Keyword(s):  
Functional Materials ◽  
Tensile Tests ◽  
Image Correlation ◽  
Surrounding Water ◽  
Textile Materials ◽  
Dielectric Elastomer Actuators ◽  
Conductive Hydrogel ◽  
Bending Actuator ◽  
Bending Behavior ◽  
Carbon Based

Electroactive polymers (EAPs), especially dielectric elastomer actuators (DEAs), belong to a very promising and emerging class of functional materials. While DEAs are mostly utilized to rely on carbon-based electrodes, there are certain shortcomings of the use of carbon electrodes in the field of soft robotics. In this work we present a fish-like bending structure to serve as possible propulsion element, completely avoiding carbon-based electrodes. The presented robot is moving under water, using a particularly tailored conductive hydrogel as inner electrode and a highly anisotropic textile material to manipulate the bending behavior of the robot. The charge separation to drive two DEAs on the outsides of the robot is provided by the conductive hydrogel while the surrounding water serves as counter electrode. To characterize the hydrogel, tensile tests and impedance spectroscopy are used as measurement methods of choice. The performance of the robot was evaluated using a digital image correlation (DIC) measurement for its bending deflections under water. The developed fish-like robot was able to perform a dynamic bending movement, based on a tri-stable actuator setup. The performed measurements underpin the sufficient characteristics for an underwater application of conductive hydrogel electrodes as well as the applicability of the robotic concept for under water actuations.

scholarly journals Numerical Studies of Deformations and Crack Propagation in Reinforced Concrete Annular Sections Under Thermopower Loads

2021 ◽  
Vol 10 (3) ◽  
Author(s):  
Ihor Karkhut ◽  
◽  
Josyp Luchko ◽  
Vladyslav Kirichok
Keyword(s):  
Reinforced Concrete ◽  
Cross Sections ◽  
Computer Calculation ◽  
Field Tests ◽  
Physical Models ◽  
Deformation Model ◽  
Numerical Studies ◽  
Current State ◽  
Modern Level

The article describes the current state and the level of research of annular cross-sections of structures of energy facilities operating under conditions of thermal and force effects. The results of a numerical experiment to study the deformability and crack resistance of annular сross-sections and their comparison with the results of testing physical models of fragments of reinforced concrete chimneys are presented. It is shown that at the modern level of development of the mathematical apparatus and computer calculation programs, using the deformation model, the deviation does not exceed 20%. The described research results of other authors and this work confirm the possibility of replacing cost and long-term field tests with numerical experiments.

Recent Radiative and Collisional Atomic Data of Astrophysical Interest

1988 ◽  
Vol 102 ◽  
pp. 129-132
Author(s):  
K.L. Baluja ◽  
K. Butler ◽  
J. Le Bourlot ◽  
C.J. Zeippen
Keyword(s):  
Mass Production ◽  
Bound States ◽  
Physical Models ◽  
Impact Excitation ◽  
Electron Impact Excitation ◽  
Atomic Data ◽  
Isoelectronic Sequence ◽  
Astrophysical Interest ◽  
Radiative Transitions ◽  
Forbidden Transitions

SummaryUsing sophisticated computer programs and elaborate physical models, accurate radiative and collisional atomic data of astrophysical interest have been or are being calculated. The cases treated include radiative transitions between bound states in the 2p4and 2s2p5configurations of many ions in the oxygen isoelectronic sequence, the photoionisation of the ground state of neutral iron, the electron impact excitation of the fine-structure forbidden transitions within the 3p3ground configuration of CℓIII, Ar IV and K V, and the mass-production of radiative data for ions in the oxygen and fluorine isoelectronic sequences, as part of the international Opacity Project.

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