Singularity Analysis on Constrained Bifurcations

2007 ◽  
pp. 157-165
Author(s):  
Z. Q. Wu ◽  
Y. S. Chen
Keyword(s):  
Singularity Analysis

scholarly journals Singularity analysis and analytic solutions for the Benney–Gjevik equations

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Andronikos Paliathanasis ◽  
Genly Leon ◽  
P. G. L. Leach
Keyword(s):  
Evolution Equations ◽  
Singularity Analysis ◽  
Analytic Solutions ◽  
Travelling Wave ◽  
Travelling Wave Solutions ◽  
Painlevé Test ◽  
Wave Solutions ◽  
Algebraic Solutions

Abstract We apply the Painlevé test for the Benney and the Benney–Gjevik equations, which describe waves in falling liquids. We prove that these two nonlinear 1 + 1 evolution equations pass the singularity test for the travelling-wave solutions. The algebraic solutions in terms of Laurent expansions are presented.

scholarly journals A System of Four ODEs: The Singularity Analysis

2001 ◽  
Vol 8 (2) ◽  
pp. 217-219 ◽  
Author(s):  
S Yu Sakovich
Keyword(s):  
Singularity Analysis

Singularity Analysis and Representation of the General Gough-Stewart Platform

2000 ◽  
Vol 19 (3) ◽  
pp. 271-288 ◽  
Author(s):  
Boris Mayer St-Onge ◽  
Clément M. Gosselin
Keyword(s):  
Singularity Analysis ◽  
Stewart Platform

scholarly journals Bifurcation and Singularity Analysis of a Molecular Network for the Induction of Long-Term Memory

2006 ◽  
Vol 90 (7) ◽  
pp. 2309-2325 ◽  
Author(s):  
Hao Song ◽  
Paul Smolen ◽  
Evyatar Av-Ron ◽  
Douglas A. Baxter ◽  
John H. Byrne
Keyword(s):  
Singularity Analysis ◽  
Molecular Network ◽  
Long Term Memory ◽  
Term Memory

scholarly journals Singularity analysis of quasi-linear DAEs

2005 ◽  
Vol 303 (1) ◽  
pp. 135-149
Author(s):  
Zhihui Yang ◽  
Yun Tang ◽  
Bing Li
Keyword(s):  
Singularity Analysis

Optimal Design of a 4-DOF SCARA Type Parallel Robot Using Dynamic Performance Indices and Angular Constraints

2012 ◽  
Vol 4 (3) ◽  
Author(s):  
Songtao Liu ◽  
Tian Huang ◽  
Jiangping Mei ◽  
Xueman Zhao ◽  
Panfeng Wang ◽  
...  
Keyword(s):  
Optimal Design ◽  
Dynamic Performance ◽  
Parallel Robot ◽  
Singularity Analysis ◽  
Rigid Body Dynamics ◽  
Performance Indices ◽  
Global Dynamic ◽  
Transmission Angle ◽  
Body Dynamics ◽  
Rigid Design

This paper deals with the optimal design of a 4-DOF SCARA type (three translations and one rotation) parallel robot using dynamic performance indices and angular constraints within and amongst limbs. The architecture of the robot is briefly addressed with emphasis on the mechanical realization of the articulated traveling plate for achieving a lightweight yet rigid design. On the basis of the kinematic singularity analysis, two types of transmission angle constraints are considered to ensure the kinematic performance. A simplified model of rigid body dynamics is then formulated, with which two global dynamic performance indices are proposed for minimization by taking into account both inertial and centrifugal/Coriolis effects. In addition, the servomotor specifications are estimated using the Extended Adept Cycle. The proposed approach has successfully been employed to develop a prototype machine.

Abstract 1357: Mobility of Epicardial Rotors During Human Ventricular Fibrillation

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Martyn P Nash ◽  
Ayman Mourad ◽  
Chris P Bradley ◽  
David J Paterson ◽  
Peter M Sutton ◽  
...  
Keyword(s):  
Coronary Artery Disease ◽  
Cardiac Surgery ◽  
Aortic Valve Disease ◽  
Singularity Analysis ◽  
Epicardial Mapping ◽  
Voltage Versus ◽  
Phase Singularity ◽  
The Mean ◽  
Artery Disease ◽  
Contact Electrodes

Introduction: Stability of reentry during VF may depend on the dynamics of rotor cores. We determined the mobility of rotors during human VF using global epicardial mapping and phase singularity analysis. Methods: In 10 patients undergoing cardiac surgery (6 with coronary artery disease; 4 with aortic valve disease), VF was induced by burst pacing prior to (n=7) or immediately following (n=3) the onset of cardiopulmonary bypass. For each subject, a 20 – 40 s episode of fibrillatory activity was sampled at 1 kHz using an epicardial sock containing 256 unipolar contact electrodes connected to a UnEmap system. Trajectories of persistent epicardial rotors (singularities of phase maps, based on de-trended voltage versus its Hilbert transform, lasting for > 1000 ms) were tracked. The mean core location was determined across the lifetime of each persistent rotor. The rotor was classified as stationary if its core remained within 15 mm of the mean location for more than 90% of its duration. Results: Using the above criteria, the numbers of mobile and stationary rotors varied from patient-to-patient (see figure ). In all but one patient, there were more mobile than stationary rotors. Over all patients, the mean ± SD number of mobile rotors (32 ± 21) was significantly greater than stationary rotors (7 ± 6, P<0.01). Conclusions: At least one stationary rotor was always present during human VF, but it is predominantly characterised by a small number of persistent mobile rotors.

scholarly journals A Novel Kinematically Redundant Planar Parallel Robot Manipulator With Full Rotatability

2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Nicholas Baron ◽  
Andrew Philippides ◽  
Nicolas Rojas
Keyword(s):  
Potential Application ◽  
Robot Manipulator ◽  
Video Recording ◽  
Parallel Robot ◽  
Singularity Analysis ◽  
Geometric Method ◽  
Forward Kinematics ◽  
Online Video ◽  
End Effector ◽  
Moving Platform

This paper presents a novel kinematically redundant planar parallel robot manipulator, which has full rotatability. The proposed robot manipulator has an architecture that corresponds to a fundamental truss, meaning that it does not contain internal rigid structures when the actuators are locked. This also implies that its rigidity is not inherited from more general architectures or resulting from the combination of other fundamental structures. The introduced topology is a departure from the standard 3-RPR (or 3-RRR) mechanism on which most kinematically redundant planar parallel robot manipulators are based. The robot manipulator consists of a moving platform that is connected to the base via two RRR legs and connected to a ternary link, which is joined to the base by a passive revolute joint, via two other RRR legs. The resulting robot mechanism is kinematically redundant, being able to avoid the production of singularities and having unlimited rotational capability. The inverse and forward kinematics analyses of this novel robot manipulator are derived using distance-based techniques, and the singularity analysis is performed using a geometric method based on the properties of instantaneous centers of rotation. An example robot mechanism is analyzed numerically and physically tested; and a test trajectory where the end effector completes a full cycle rotation is reported. A link to an online video recording of such a capability, along with the avoidance of singularities and a potential application, is also provided.

Modelling and Simulation of a Robotic System for Lower Limb Rehabilitation

2018 ◽  
Author(s):  
Bogdan Gherman ◽  
Iosif Birlescu ◽  
Paul Tucan ◽  
Calin Vaida ◽  
Adrian Pisla ◽  
...  
Keyword(s):  
Lower Limb ◽  
Parallel Robot ◽  
Gait Training ◽  
Singularity Analysis ◽  
Robotic System ◽  
Upper Limb Rehabilitation ◽  
Post Stroke ◽  
Kinematic Modelling ◽  
Limb Rehabilitation ◽  
Lower Limb Rehabilitation

As the life span increases and the availability of physicians becomes more and more scarce, robotic rehabilitation for post-stroke patients becomes more and more demanding, especially due to the repeatability character of the rehabilitation exercises. Both lower and upper limb rehabilitation using robotic systems have proved to be very successful in different stages of the rehabilitation process, but only a few address the immediate (critical) post-stroke phase, especially when the patient is hemiplegic and is unable to stand. The paper presents the kinematic modelling, singularity analysis and gait simulation for a new 4-DOF parallel robot named RECOVER used for lower limb rehabilitation for bedridden patients. The robotic system has been designed for the mobilization of the lower limb, namely the following motions: the hip and knee flexion and the plantar adduction/abduction and flexion/dorsiflexion. The kinematics has been studied and the singularity configurations have been determined to achieve a failsafe rehabilitation robot. Numerical simulations prove that the system can be used for gait training exercises in safe conditions.

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