Design of the Bionic Rehabilitative Leg Based on the Passive Gait Biped

2013 ◽  
Vol 461 ◽  
pp. 597-607
Author(s):  
Zhen Ze Liu ◽  
De Jun Liu ◽  
Lei Zhang ◽  
Yan Tao Tian
Keyword(s):  
Lower Extremity ◽  
Dimensional Space ◽  
Lagrange Function ◽  
Three Dimensional ◽  
Biped Robot ◽  
Muscle System ◽  
Energy Shaping ◽  
Walking Gait ◽  
Zero Dynamic ◽  
Movement Function

The wearable assistive and rehabilitative leg is a complex mechanical device mounted with the underactuated joints based on the bionic mechanism. This device can ameliorate the movement function of the nerve and muscle system of the lower extremity. By applying the bionic control strategy and exerting force on the lower extremity of patients, the walking gait of normal human being can be simulated. The patients with leg deformity who need to be remedied can benefit from this method. The expense on medical treatment can be considerably reduced by this kind of device, which alleviates the burden on family and society economically. The walking stability controller is designed for researching the biped robots in 3D ( three-dimensional) space. By constructing the almost-cyclic Lagrange function, the biped robot dynamic system is decoupled into sagittal and lateral portions. Then the potential energy shaping and kinetic energy shaping controller is designed for the sagittal portion of under-actuated robot in 2D space , so that the stable walking gait and bionic characteristic gait can be obtained; the output zero dynamic controller is applied to control the lateral counterpart, which satisfies the dynamic decoupling conditions of the system. The simulation results show that the proposed method is effective.

STABLE PERIODIC GAITS OF N-LINK BIPED ROBOT IN THREE DIMENSIONAL SPACE

2006 ◽  
Vol 39 (15) ◽  
pp. 689-694
Author(s):  
Oumnia Licer ◽  
Nacer K. M'Sirdi ◽  
Noureddine Manamanni ◽  
Noureddine El Alami
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Biped Robot ◽  
Stable Periodic ◽  
Three Dimensional Space

Modeling and Simulation of Lower Extremity Exoskeleton

2014 ◽  
Vol 487 ◽  
pp. 504-508 ◽  
Author(s):  
Yu Zhang ◽  
Xiao Bo Wu ◽  
Hui Fang Liu
Keyword(s):  
Lower Extremity ◽  
Degrees Of Freedom ◽  
Inverted Pendulum ◽  
Three Dimensional ◽  
Human Walking ◽  
Auxiliary Equipment ◽  
Walking Gait ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling ◽  
Physical Prototype

In order to make the paralyzed live on their own and return to the society to the most degree, mechanical exoskeleton technology is tried to applied in the field of auxiliary equipment. First, degrees of freedom and mechanical structure at the each joint of lower extremity exoskeleton was ascertained.Then a three dimensional modeling design for the lower extremity exoskeleton was carried out with SIEMENS NX8.0 and a walking gait on a flat for it was planned on MATLAB basing on inverted pendulum model.Finally the legs model was simulated on ADAMS.The result of the simulation was basically the same as planned gait which can better satisfy the requirement of human walking and can be used as reference for developping the physical prototype of lower extremity exoskeleton.

From a 3D Passive Biped Walker to a 3D Passivity-Based Controlled Robot

2018 ◽  
Vol 15 (04) ◽  
pp. 1850009 ◽  
Author(s):  
Borhan Beigzadeh ◽  
Mohammad Reza Sabaapour ◽  
Mohammad Reza Hairi Yazdi ◽  
Kaamran Raahemifar
Keyword(s):  
Three Dimensional ◽  
Biped Robot ◽  
Asymptotically Stable ◽  
Periodic Motions ◽  
Biped Robots ◽  
Energy Shaping ◽  
Flat Feet ◽  
Passivity Based Control ◽  
Stable Passive ◽  
Stable Control

Asymptotically stable control of biped robots, especially based on reproducing passive periodic motions, have become of interest nowadays. In this paper, firstly, a three-dimensional (3D) stable passive biped walker which is a compass gait one with flat feet, compliant ankles and particular arrangement of moments of inertia has been presented. Then, a passivity-based control of the related biped robot based on elaborating 3D form of potential energy shaping method has been applied. In other words, by adding minimal actuations to the aforementioned passive walker, its passive periodic gait that belongs to a particular slope has been reproduced on any arbitrary surface such as the level ground. Simulation results support the effectiveness of the proposed approach.

Fall Initiation Criteria for Three-Dimensional Multi-Segmental Model of Biped Robot

2014 ◽  
Author(s):  
Chang B. Joo ◽  
Joo H. Kim
Keyword(s):  
Optimization Problems ◽  
Center Of Pressure ◽  
Dimensional Space ◽  
Center Of Mass ◽  
Reaction Force ◽  
Three Dimensional ◽  
Biped Robot ◽  
3D Space ◽  
Force Direction ◽  
Balancing Conditions

A biped mechanism can maintain its balance by redirecting the ground reaction force direction and changing the center of pressure location. In this paper, how the variable inertia in a multibody dynamic model is related to those efforts is investigated and fall initiation criteria in three dimensional space, a balanced state manifold is constructed by using a 3D multi-segmental model. The balanced state domain is constructed by iteratively solving nonlinear constrained optimization problems and finding the velocity extrema at given center of mass positions subjected to certain balancing conditions. The constructed balanced state domain of a multi-segmental model can be used as fall initiation criteria in 3D space and it demonstrates the better balancing maintenance capability of 3D multi-segmental model than the 3D linear inverted pendulum mode.

Three Dimensional structure and organization of diploid chromosomes by optical section microscopy

1987 ◽  
Vol 45 ◽  
pp. 633-635
Author(s):  
David A. Agard ◽  
Yasushi Hiraoka ◽  
John W. Sedat
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Developmental State ◽  
Mitotic Cell ◽  
Biological Properties ◽  
Dimensional Structure ◽  
Specific Gene ◽  
Three Dimensional Structure ◽  
Complementary Techniques ◽  
Dynamic Structures

In an effort to understand the complex relationship between structure and biological function within the nucleus, we have embarked on a program to examine the three-dimensional structure and organization of Drosophila melanogaster embryonic chromosomes. Our overall goal is to determine how DNA and proteins are organized into complex and highly dynamic structures (chromosomes) and how these chromosomes are arranged in three dimensional space within the cell nucleus. Futher, we hope to be able to correlate structual data with such fundamental biological properties as stage in the mitotic cell cycle, developmental state and transcription at specific gene loci.Towards this end, we have been developing methodologies for the three-dimensional analysis of non-crystalline biological specimens using optical and electron microscopy. We feel that the combination of these two complementary techniques allows an unprecedented look at the structural organization of cellular components ranging in size from 100A to 100 microns.

Diffraction contrast of dislocations in icosahedral quasicrystals

1990 ◽  
Vol 48 (4) ◽  
pp. 454-455
Author(s):  
K. Urban ◽  
Z. Zhang ◽  
M. Wollgarten ◽  
D. Gratias
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Complete Characterization ◽  
Extinction Condition ◽  
Burgers Vector ◽  
Diffraction Contrast ◽  
Lattice Geometry ◽  
Reference Space ◽  
Icosahedral Quasicrystals ◽  
The One

Recently dislocations have been observed by electron microscopy in the icosahedral quasicrystalline (IQ) phase of Al65Cu20Fe15. These dislocations exhibit diffraction contrast similar to that known for dislocations in conventional crystals. The contrast becomes extinct for certain diffraction vectors g. In the following the basis of electron diffraction contrast of dislocations in the IQ phase is described. Taking account of the six-dimensional nature of the Burgers vector a “strong” and a “weak” extinction condition are found.Dislocations in quasicrystals canot be described on the basis of simple shear or insertion of a lattice plane only. In order to achieve a complete characterization of these dislocations it is advantageous to make use of the one to one correspondence of the lattice geometry in our three-dimensional space (R3) and that in the six-dimensional reference space (R6) where full periodicity is recovered . Therefore the contrast extinction condition has to be written as gpbp + gobo = 0 (1). The diffraction vector g and the Burgers vector b decompose into two vectors gp, bp and go, bo in, respectively, the physical and the orthogonal three-dimensional sub-spaces of R6.

Flavin radicals, conformational sampling and robust design principles in interprotein electron transfer: the trimethylamine dehydrogenase-electron-transferring flavoprotein complex

2004 ◽  
Vol 71 ◽  
pp. 1-14
Author(s):  
David Leys ◽  
Jaswir Basran ◽  
François Talfournier ◽  
Kamaldeep K. Chohan ◽  
Andrew W. Munro ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Kinetic Studies ◽  
Molecular Assembly ◽  
Conformational Sampling ◽  
Trimethylamine Dehydrogenase ◽  
Key Residues ◽  
Electron Transferring Flavoprotein ◽  
Electron Transfer Complex

TMADH (trimethylamine dehydrogenase) is a complex iron-sulphur flavoprotein that forms a soluble electron-transfer complex with ETF (electron-transferring flavoprotein). The mechanism of electron transfer between TMADH and ETF has been studied using stopped-flow kinetic and mutagenesis methods, and more recently by X-ray crystallography. Potentiometric methods have also been used to identify key residues involved in the stabilization of the flavin radical semiquinone species in ETF. These studies have demonstrated a key role for 'conformational sampling' in the electron-transfer complex, facilitated by two-site contact of ETF with TMADH. Exploration of three-dimensional space in the complex allows the FAD of ETF to find conformations compatible with enhanced electronic coupling with the 4Fe-4S centre of TMADH. This mechanism of electron transfer provides for a more robust and accessible design principle for interprotein electron transfer compared with simpler models that invoke the collision of redox partners followed by electron transfer. The structure of the TMADH-ETF complex confirms the role of key residues in electron transfer and molecular assembly, originally suggested from detailed kinetic studies in wild-type and mutant complexes, and from molecular modelling.

Topics in Quaternion Linear Algebra

2014 ◽  
Author(s):  
Leiba Rodman
Keyword(s):  
Linear Algebra ◽  
Complex Analysis ◽  
Dimensional Space ◽  
Applied Mathematics ◽  
Three Dimensional ◽  
Number System ◽  
Graduate Course ◽  
Open Problems ◽  
Unpublished Research ◽  
Reference Tool

Quaternions are a number system that has become increasingly useful for representing the rotations of objects in three-dimensional space and has important applications in theoretical and applied mathematics, physics, computer science, and engineering. This is the first book to provide a systematic, accessible, and self-contained exposition of quaternion linear algebra. It features previously unpublished research results with complete proofs and many open problems at various levels, as well as more than 200 exercises to facilitate use by students and instructors. Applications presented in the book include numerical ranges, invariant semidefinite subspaces, differential equations with symmetries, and matrix equations. Designed for researchers and students across a variety of disciplines, the book can be read by anyone with a background in linear algebra, rudimentary complex analysis, and some multivariable calculus. Instructors will find it useful as a complementary text for undergraduate linear algebra courses or as a basis for a graduate course in linear algebra. The open problems can serve as research projects for undergraduates, topics for graduate students, or problems to be tackled by professional research mathematicians. The book is also an invaluable reference tool for researchers in fields where techniques based on quaternion analysis are used.

Extension of the Spatial PDI Model to Three Dimensions

1997 ◽  
Vol 84 (1) ◽  
pp. 176-178
Author(s):  
Frank O'Brien
Keyword(s):  
Population Density ◽  
Dimensional Space ◽  
Finite Lattice ◽  
Three Dimensional ◽  
Upper Bounds ◽  
Three Dimensions ◽  
Lower And Upper Bounds ◽  
Density Index ◽  
Three Dimensional Space

The author's population density index ( PDI) model is extended to three-dimensional distributions. A derived formula is presented that allows for the calculation of the lower and upper bounds of density in three-dimensional space for any finite lattice.

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