Kinematic Synthesis of Gait Correction for a Rehabilitation Machine

2021 ◽  
Author(s):  
Zvonimir Pusnik ◽  
Carl A. Nelson ◽  
Judith M. Burnfield ◽  
Thad W. Buster
Keyword(s):  
Movement Patterns ◽  
Synthesis Process ◽  
Kinematic Synthesis ◽  
Normal Gait ◽  
Foot Motion ◽  
Angle Difference

Abstract This paper outlines the synthesis process for a redesign of the intelligently controlled assistive rehabilitation elliptical’s (ICARE) pedal system to enhance replication of gait-like movement patterns while training. The synthesized mechanism overcomes some limitations identified in certain ellipticals, specifically generation of taller, more rounded foot paths compared to over-ground gait. The proposed solution minimizes the position and angle difference curves between the ICARE foot motion and normal gait.

OPTIMIZATION OF MODIFIED WATT’S LINKAGE FOR AN APPROXIMATELY LONG STRAIGHT PATH WITHIN LIMITED DIMENSION

2016 ◽  
Vol 40 (3) ◽  
pp. 399-417
Author(s):  
Jun Wu ◽  
Shaowei Fan ◽  
Minghe Jin ◽  
Hong Liu
Keyword(s):  
Genetic Algorithm ◽  
Constrained Optimization ◽  
Synthesis Process ◽  
Path Generation ◽  
Practical Application ◽  
Optimal Method ◽  
Kinematic Synthesis ◽  
Straight Path ◽  
Limited Dimension

This paper presents an optimal method of aiming for an approximately straight path of the Modified Watt’s Linkage (MWL) within limited dimension. A modification to the Watt’s linkage and the corresponding condition are introduced, followed by the kinematic synthesis. The path generation based on the modification considering constraints from practical application is provided. Genetic algorithm is utilized to perform the constrained optimization. The centrosymmetric property of the MWL is considered in the synthesis process. Ideal parameters of the mechanism are achieved to demonstrate the effectiveness of the proposed method.

Vision-Based Kinematic Synthesis of Hand Motion

2006 ◽  
Author(s):  
Karthikeyan Duraisamy ◽  
Alba Perez-Gracia ◽  
Marco P. Schoen
Keyword(s):  
Complex Dynamics ◽  
Synthesis Process ◽  
Forward Kinematics ◽  
Variable Cost ◽  
Human Hand ◽  
Myoelectric Signals ◽  
Kinematic Synthesis ◽  
Hand Motion ◽  
Hand Model ◽  
Time Motion

The purpose of this work is to develop a human hand model that will work in conjunction with the myoelectric signals from the arm muscles, for those people who have lost their upper extremity. Though there are many prostheses available on the market with variable cost and functional accuracy, it is hard to find a prosthesis that mimics the complete functionality of the human hand, due to the complex hand motion, the complex dynamics of the myoelectric signals, and the difficulty involved in the acquisition of these signals, which complicates the implementation. In order to overcome some of these problems, the proposed hand model mimics most of the hand movements and it is used together with a kinematic synthesis process to identify the motion of the hand, obtained from visual data. In this paper, the human hand is modeled as a collection of five serial chains. For each movement performed by the joints in the finger/wrist, revolute joints are considered in different configurations, which yield movements similar to those of the human hand. The forward kinematics in matrix form is formulated using Denavit-Hartenberg parameters and expressed using Clifford Algebra exponentials. Kinematic synthesis is used to adjust the dimensions of the proposed model to the hand of the subject, and to identify the angles at each joint for a given hand motion. In the kinematic synthesis process, the forward kinematics equations of the hand are solved for both the angles of the joints and the dimensions of the hand. The synthesis equations obtained from the kinematic synthesis process are solved using a Levenberg-Marquardt nonlinear least-squares algorithm. The experimental setup for the real-time motion capturing consists of three camerasand is to be used in future work to relate the joint motion to the myoelectric signals acquired from the subject's arm.

A Novel Paradigm for the Qualitative Synthesis of Simple Kinematic Chains Based on Complexity Measures

2011 ◽  
Vol 3 (3) ◽  
Author(s):  
Waseem A. Khan ◽  
Jorge Angeles
Keyword(s):  
Complexity Analysis ◽  
Vertical Axis ◽  
Synthesis Process ◽  
Geometric Complexity ◽  
Qualitative Synthesis ◽  
Complexity Measures ◽  
Kinematic Synthesis ◽  
Kinematic Chains ◽  
Loss Of Regularity ◽  
Four Bar Linkage

Proposed in this paper is a paradigm for the qualitative synthesis of simple kinematic chains that is based on the concept of complexity. Qualitative synthesis is understood here as the number and the type stages of the kinematic-synthesis process. The formulation hinges on the geometric complexity of the surface associated with lower kinematic pairs. First, the geometric complexity of curves and surfaces is recalled, as defined via the loss of regularity (LOR). The LOR, based in turn on the concept of diversity, measures the spectral richness of the curvature of either the curve or the surface under study. The paper closes with a complexity analysis of all six lower kinematic pairs, as a means to guide the mechanical designer into the conceptual stage of the design process. The paradigm is illustrated with the computation of the complexity of the four-bar linkage in all its versions, planar, spherical, and spatial, as well as that of a transmission for the conversion of a rotation about a vertical axis into one about a horizontal axis.

A unified approach to the kinematic synthesis of five-link, four-link, and double-wishbone suspension mechanisms with rack-and-pinion steering control

2016 ◽  
Vol 231 (10) ◽  
pp. 1374-1387 ◽  
Author(s):  
P A Simionescu
Keyword(s):  
Synthesis Process ◽  
Dimensional Synthesis ◽  
Steering Control ◽  
Unified Approach ◽  
Kinematic Synthesis ◽  
Simplified Approach ◽  
Camber Angle ◽  
Toe Angle ◽  
Ball Joints ◽  
Wheel Track

This paper presents a unified approach to the problem of dimensional synthesis of the five-link, four-link, and three-link (double-wishbone) suspension mechanisms with a rack-and-pinion steering input. In a simplified approach, the guiding links are assumed to be removed from their joints, allowing the wheel to be exactly driven through a number of prescribed jounce–rebound and steering positions during the kinematic synthesis process. Alternatively, the tie rod is maintained in place, and the rack length and the lengths of the remaining four guiding links are allowed to vary. An optimization problem based on the aggregated change in distance between the released ball joints evaluated in the aforementioned positions is then defined. By prescribing to the wheel a jounce–rebound motion only, rear-suspension mechanisms of the five-link, four-link, and three-link types can be conveniently synthesized by following the same procedure. Several solutions obtained through synthesis are then analyzed for their changes in steering error, recessional wheel motion, wheel track, toe angle and camber angle, showing very promising results. Additionally, a comprehensive review of nearly 150 publications relevant to the suspension design of automobiles is provided in the paper.

Characterization of a monolayer graphitic structure

1994 ◽  
Vol 52 ◽  
pp. 760-761
Author(s):  
X. Lin ◽  
X. K. Wang ◽  
V. P. Dravid ◽  
J. B. Ketterson ◽  
R. P. H. Chang
Keyword(s):  
Three Dimensional ◽  
Single Layer ◽  
Synthesis Process ◽  
Graphitic Structure ◽  
Positive Gaussian Curvature ◽  
Graphitic Sheet ◽  
Structural And Electronic Properties ◽  
New Material ◽  
Hexagonal Network

For small curvatures of a graphitic sheet, carbon atoms can maintain their preferred sp2 bonding while allowing the sheet to have various three-dimensional geometries, which may have exotic structural and electronic properties. In addition the fivefold rings will lead to a positive Gaussian curvature in the hexagonal network, and the sevenfold rings cause a negative one. By combining these sevenfold and fivefold rings with sixfold rings, it is possible to construct complicated carbon sp2 networks. Because it is much easier to introduce pentagons and heptagons into the single-layer hexagonal network than into the multilayer network, the complicated morphologies would be more common in the single-layer graphite structures. In this contribution, we report the observation and characterization of a new material of monolayer graphitic structure by electron diffraction, HREM, EELS.The synthesis process used in this study is reported early. We utilized a composite anode of graphite and copper for arc evaporation in helium.

Effect of temperature during the synthesis process of CdSe nanoparticles using the colloidal technique

MRS Advances ◽  
2020 ◽  
Vol 5 (63) ◽  
pp. 3389-3395
Author(s):  
R. González-Díaz ◽  
D. Fernández-Sánchez ◽  
P. Rosendo-Francisco ◽  
G. Sánchez-Legorreta
Keyword(s):  
Scanning Tunneling Microscope ◽  
Electron Cloud ◽  
Cdse Nanoparticles ◽  
Effect Of Temperature ◽  
Synthesis Process ◽  
Scanning Tunneling ◽  
Tunneling Microscope ◽  
First Results ◽  
Effects Of Temperature ◽  
Scanning Electron

AbstractIn this work, the first results of the effects of temperature during the production of Se2- ions and the effect during the interaction of Cd2+ and Se2- ions in the synthesis process of CdSe nanoparticles are presented. The synthesis of CdSe was carried out by the colloidal technique, in the first one we used a temperature of 63 °C to produce Se2- ions and in the second one an interaction temperature of 49 °C. The samples were characterized using a Scanning Electron Microscope (SEM) and a Scanning Tunneling Microscope (STM). From the SEM micrographs it was possible to identify the thorns formation and irregular islands. STM micrographs reveal elliptical shapes with a regular electron cloud profile.

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