scholarly journals A Modified Kinematic Model of Shoulder Complex Based on Vicon Motion Capturing System: Generalized GH Joint with Floating Centre

Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3713
Author(s):  
Chunzhao Zhang ◽  
Mingjie Dong ◽  
Jianfeng Li ◽  
Qiang Cao
Keyword(s):  
Kinematic Model ◽  
Elevation Angle ◽  
Quantitative Information ◽  
Upper Limb Rehabilitation ◽  
Mechanism Model ◽  
Shoulder Complex ◽  
Coupling Characteristics ◽  
Motion Characteristics ◽  
Joint Center ◽  
Motion Capturing

Due to the complex coupling motion of shoulder mechanism, only a small amount of quantitative information is available in the existing literature, although various kinematic models of the shoulder complex have been proposed. This study focused on the specific motion coupling relationship between glenohumeral (GH) joint center displacement variable quantity relative to the thorax coordinate system and humeral elevation angle to describe the shoulder complex. The mechanism model of shoulder complex was proposed with an algorithm designed. Subsequently, twelve healthy subjects performed right arm raising, lowering, as well as raising and lowering (RAL) movements in sixteen elevation planes, and the motion information of the markers attached to the thorax, scapula, and humerus was captured by using Vicon motion capturing system. Then, experimental data was processed and the generalized GH joint with floating center was quantized. Simultaneously, different coupling characteristics were detected during humerus raising as well as lowering movements. The motion coupling relationships in different phases were acquired, and a modified kinematic model was established, with the description of overall motion characteristics of shoulder complex validated by comparing the results with a prior kinematic model from literature, showing enough accuracy for the design of upper limb rehabilitation robots.

scholarly journals A Kinematic Model of the Shoulder Complex Obtained from a Wearable Detection System

2020 ◽  
Vol 10 (11) ◽  
pp. 3696
Author(s):  
Jianfeng Li ◽  
Chunzhao Zhang ◽  
Mingjie Dong ◽  
Qiang Cao
Keyword(s):  
Detection System ◽  
Kinematic Model ◽  
Elevation Angle ◽  
Rehabilitation Robots ◽  
Variable Quantity ◽  
Analytical Formulas ◽  
Shoulder Complex ◽  
Arm Elevation ◽  
Joint Center ◽  
Movement Rules

Due to the complex coupled motion of the shoulder mechanism, the design of the guiding movement rules of rehabilitation robots generally lacks specific motion coupling information between the glenohumeral (GH) joint center and humeral elevation angle. This study focuses on establishing a kinematic model of the shoulder complex obtained from a wearable detection system, which can describe the specific motion coupling relationship between the GH joint center displacement variable quantity relative to the thorax coordinate system and the humeral elevation angle. A kinematic model, which is a generalized GH joint with a floating center, was proposed to describe the coupling motion. Twelve healthy subjects wearing the designed detection system performed a right-arm elevation in the sagittal and coronal planes respectively, and the motion information of the GH joint during humeral elevation in the sagittal and coronal planes was detected and quantized, with the analytical formulas acquired based on the experimental data. The differences in GH joint motion during humeral elevation in the sagittal and coronal planes were also evaluated respectively, which also verified the effectiveness of the proposed kinematic model.

Helical Kirigami-Enabled Centimeter-Scale Worm Robot With Shape-Memory-Alloy Linear Actuators

2015 ◽  
Vol 7 (2) ◽  
Author(s):  
Ketao Zhang ◽  
Chen Qiu ◽  
Jian S. Dai
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Degrees Of Freedom ◽  
Screw Theory ◽  
Kinematic Model ◽  
Parallel Structure ◽  
Geometrical Parameters ◽  
Parallel Structures ◽  
Complete Procedure ◽  
Motion Characteristics

The wormlike robots are capable of imitating amazing locomotion of slim creatures. This paper presents a novel centimeter-scale worm robot inspired by a kirigami parallel structure with helical motion. The motion characteristics of the kirigami structure are unravelled by analyzing the equivalent kinematic model in terms of screw theory. This reveals that the kirigami parallel structure with three degrees-of-freedom (DOF) motion is capable of implementing both peristalsis and inchworm-type motion. In light of the revealed motion characteristics, a segmented worm robot which is able to imitate contracting motion, bending motion of omega shape and twisting motion in nature is proposed by integrating kirigami parallel structures successively. Following the kinematic and static characteristics of the kirigami structure, actuation models are explored by employing the linear shape-memory-alloy (SMA) coil springs and the complete procedure for determining the geometrical parameters of the SMA coil springs. Actuation phases for the actuation model with two SMA springs are enumerated and with four SMA springs are calculated based on the Burnside's lemma. In this paper, a prototype of the worm robot with three segments is presented together with a paper-made body structure and integrated SMA coil springs. This centimeter-scale prototype of the worm robot is lightweight and can be used in confined environments for detection and inspection. The study presents an interesting approach of integrating SMA actuators in kirigami-enabled parallel structures for the development of compliant and miniaturized robots.

Three-Dimensional Kinematic Modelling of the Human Shoulder Complex—Part II: Mathematical Modelling and Solution Via Optimization

1989 ◽  
Vol 111 (2) ◽  
pp. 113-121 ◽  
Author(s):  
S. T. Tu¨mer ◽  
A. E. Engin
Keyword(s):  
Optimization Problem ◽  
Kinematic Model ◽  
Three Dimensional ◽  
Joint Motion ◽  
Upper Arm ◽  
Complex Part ◽  
Kinematic Modelling ◽  
Shoulder Complex ◽  
The Individual

In this paper, individual joint sinus cones associated with the sternoclavicular, claviscapular, and glenohumeral joints of the three-dimensional kinematic model introduced in Part I for the human shoulder complex are quantitatively determined. First, mathematical description of the humerus orientation with respect to torso is given in terms of eight joint variables. Since the system is a kinematically redundant one, solution for the joint variables satisfying a prescribed humerus orientation is possible only if additional requirements are imposed; and the “minimum joint motion” criterion is introduced for this purpose. Two methods, namely the Lagrange multipliers and flexible tolerance methods, are formulated and tested for the optimization problem. The statistical in-vivo data base for the circumductory motion of the upper arm is employed to determine a set of joint variables via optimization, which are then utilized to establish the sizes and orientations of the elliptical cones for the individual joint sinuses. The results are discussed and compared with those given on the basis of measurements made on cadaveric specimens.

The Research on Characteristics of Movement Coupling in Forging Manipulator

2012 ◽  
Vol 591-593 ◽  
pp. 648-652
Author(s):  
Jing Fei He ◽  
Chao Xu ◽  
Hua Deng ◽  
Long Han
Keyword(s):  
Experimental Verification ◽  
Control Strategy ◽  
Kinematic Model ◽  
Input Output ◽  
Heavy Duty ◽  
Theory Analysis ◽  
Movement Path ◽  
Forging Manipulator ◽  
Coupling Characteristics

Heavy-duty forging manipulators play an important role in extreme manufacturing. Based on the kinematic model of DDS forcing manipulator, the input- output relation equations in terms of position are derived. According to the actually movement path of output mechanism, a new decoupling concept is defined as to forcing manipulator. The input-output relation matrices in terms of velocity are established at three major motions, and the coupling characteristics of mechanism are analyzed. At last, the theory analysis is proved correct by experimental verification. The results show that three major motion mechanisms of DDS forcing manipulator are partially decoupled under the new decoupling concept compared with the conventional one, which helps to simplify the control strategy of DDS forcing manipulator.

Design and human–machine compatibility analysis of Co-Exos II for upper-limb rehabilitation

2019 ◽  
Vol 39 (4) ◽  
pp. 715-726
Author(s):  
Leiyu Zhang ◽  
Jianfeng Li ◽  
Shuting Ji ◽  
Peng Su ◽  
Chunjing Tao ◽  
...  
Keyword(s):  
Upper Limb ◽  
Degrees Of Freedom ◽  
Kinematic Model ◽  
Compact Structure ◽  
Vertical Movements ◽  
Content Type ◽  
Upper Limb Rehabilitation ◽  
Compatibility Analysis ◽  
Configuration Synthesis ◽  
Limb Rehabilitation

Purpose Upper-limb joint kinematics are highly complex and the kinematics of rehabilitation exoskeletons fail to reproduce them, resulting in hyperstaticity and human–machine incompatibility. The purpose of this paper is to design and develop a compatible exoskeleton robot (Co-Exos II) to address these problems. Design/methodology/approach The configuration synthesis of Co-Exos II is completed using advanced mechanism theory. A compatible configuration is selected and four passive joints are introduced into the connecting interfaces based on optimal configuration principles. A Co-Exos II prototype with nine degrees of freedom (DOFs) is developed and still owns a compact structure and volume. A new approach is presented to compensate the vertical glenohumeral (GH) movements. Co-Exos II and the upper arm are simplified as a guide-bar mechanism at the elevating plane. The theoretical displacements of passive joints are calculated by the kinematic model of the shoulder loop. The compatible experiments are completed to measure the kinematics of passive joints. Findings The compatible configuration of the passive joints can effectively reduce the gravity influences of the exoskeleton device and the upper extremities. The passive joints exhibit excellent compensation effect for the GH joint movements by comparing the theoretical and measured results. Passive joints can compensate for most GH movements, especially vertical movements. Originality/value Co-Exos II possesses good human–machine compatibility and wearable comfort for the affected upper limbs. The proposed compensation method is convenient to therapists and stroke patients during the rehabilitation trainings.

scholarly journals Extensible-Link Kinematic Model for Determining Motion Characteristics of Compliant Mechanisms

2013 ◽  
Author(s):  
Justin Beroz ◽  
Shorya Awtar ◽  
A. John Hart
Keyword(s):  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Kinematic Model ◽  
Taylor Series Expansion ◽  
Motion Trajectory ◽  
Model Framework ◽  
Error Components ◽  
Straight Line Parallel ◽  
Line Parallel ◽  
Motion Characteristics

We present an extensible-link kinematic model for characterizing the motion trajectory of an arbitrary planar compliant mechanism. This is accomplished by creating an analogous kinematic model consisting of links that change length over the course of actuation to represent elastic deformation of the compliant mechanism. Within the model, the motion trajectory is represented as an analytical function. By Taylor series expansion, the trajectory is expressed in a parametric formulation composed of load-independent and load-dependent terms. Here, the load-independent terms are entirely defined by the shape of the undeformed compliant mechanism topology, and all load-geometry interdependencies are captured by the load-dependent terms. This formulation adds insight to the process for designing compliant mechanisms for high accuracy motion applications because: (1) inspection of the load-independent terms enables determination of specific topology modifications for improving the accuracy of the motion trajectory; and (2) the load-dependent terms reveal the polynomial orders of principally uncorrectable error components of the motion trajectory. The error components in the trajectory simply represent the deviation of the actual motion trajectory provided by the compliant mechanism compared to the ideally desired one. We develop the generalized model framework, and then demonstrate its utility by designing a compliant micro-gripper with straight-line parallel jaw motion. We use the model to analytically determine all topology modifications for optimizing the jaw trajectory, and to predict the polynomial order of the uncorrectable trajectory components. The jaw trajectory is then optimized by iterative finite elements (FE) simulation until the polynomial order of the uncorrectable trajectory component becomes apparent.

scholarly journals The Mechanical Origin of the Radial Shape in Distichous Phyllotaxy Grass Plants

2021 ◽  
Author(s):  
Yoshiki Tokuyama ◽  
Yohei Koide ◽  
Kazumitsu Onishi ◽  
Kiwamu Hikichi ◽  
Miku Omachi ◽  
...  
Keyword(s):  
Time Course ◽  
Computational Models ◽  
Shape Change ◽  
Kinematic Model ◽  
Elevation Angle ◽  
Three Dimensional ◽  
Oryza Rufipogon ◽  
Model Parameters ◽  
Isogenic Line ◽  
Wild Rice Species

Abstract Three-dimensional plant shapes are influenced by their phyllotaxy, which plays a significant role in their environmental adaptation. Grasses with distichous phyllotaxy have linearly aligned culms and usually have vertical fan-like shapes. Counterintuitively, some distichous phyllotaxy grasses have radial shapes. Here, we investigate the organ-level mechanism underlying radial shape development in the distichous phyllotactic wild rice species (Oryza rufipogon). Detailed time-course phenotyping and three-dimensional micro-computed tomography showed that changes in the elevation angle in the main culm and azimuth angle in the primary tillers contribute to radial shape development. To infer the mechanical basis of the shape change, we simulated the movements of culms controlled by different kinematic factors. The computational models predicted that the combination of movements, including that controlled by negative gravitropism, produces the overall radial shape. This prediction was experimentally assessed. The analysis using a near-isogenic line of the gene, PROG1 for prostrate growth and the gravitropic mutant (lazy1) showed an association between genes and our model parameters. Our findings provide a simple, yet substantial, kinematic model for how the shape in distichous phyllotaxy plants changes as part of their adaptation to the surrounding environment.

An Origami Parallel Structure Integrated Deployable Continuum Robot

2015 ◽  
Author(s):  
Ketao Zhang ◽  
Chen Qiu ◽  
Jian S. Dai
Keyword(s):  
Translational Motion ◽  
Kinematic Model ◽  
Parallel Structure ◽  
Continuum Robots ◽  
Helical Springs ◽  
Parallel Structures ◽  
Driven System ◽  
Continuum Robot ◽  
Motion Characteristics ◽  
Novel Design

This paper presents a novel design for continuum robots in light of origami inspired folding techniques. The work of the present paper starts from design of a crease pattern, which consists of two triangular bases and three waterbomb bases, and folding process for creating an origami parallel structure in 3D from the crease pattern in 2D. Mapping the origami parallel structure to an equivalent kinematic model, the motion characteristics of the origami structure are unraveled in terms of kinematic principles. The analysis reveals that mixed rotational and translational motion of the origami parallel structure enables both axial contraction and bending motion. A novel multi-section continuum robot with integrated origami parallel structures and bias elements is then proposed to imitate not only bending motion but also contraction of continuum apparatus in nature. According to kinematics of the proposed continuum robot and features of the embedded helical spring in each module, three actuation schemes and their enabled two typical working phases with a tendon driven system are presented. A prototype of the continuum robot with six modules connected in serial is produced and tested. The functionality of the proposed continuum robot by integrating the origami parallel structure as its skeleton and helical springs as the compliant backbone is validated by the preliminary experimental results.

Sign in / Sign up

Export Citation Format

Share Document