High-Fidelity Rendering of Contact With Virtual Objects

2015 ◽  
Vol 137 (7) ◽  
Author(s):  
Arash Mohtat ◽  
József Kövecses
Keyword(s):  
Contact Force ◽  
Constitutive Relations ◽  
Sampling Rate ◽  
Smooth Transition ◽  
Virtual Object ◽  
High Fidelity ◽  
Unified Approach ◽  
One Dimensional ◽  
The Core ◽  
The One

When interacting with a virtual object (VO) through a haptic device, it is crucial to feedback a contact force to the human operator (HO) that displays the VO physical properties with high fidelity. The core challenge, here, is to expand the renderable range of these properties, including larger stiffness and smaller inertia, at the available sampling rate. To address this challenge, a framework entitled high-fidelity contact rendering (HFCR) has been developed in this paper. The framework consists of three main strategies: an energy-based rendering of the contact force, smooth transition (ST) between contact modes, and remaining leak dissipation (LD). The essence of these strategies is to make the VO emulate its continuous-time counterpart. This is achieved via physically meaningful modifications in the constitutive relations to suppress artificial energy leaks. The strategies are first developed for the one-dimensional (1D) canonical VO; then, generalization to the multivariable case is discussed. Renderability has been analyzed exploring different stability criteria within a unified approach. This leads to stability charts and identification of renderable range of properties in the presence and absence of the HO. The framework has been validated through simulation and various experiments. Results verify its promising aspects for various scenarios including sustained contact and sudden collision events with or without the HO.

Design of Shape Memory Alloy Actuators

1992 ◽  
Vol 114 (2) ◽  
pp. 223-230 ◽  
Author(s):  
C. Liang ◽  
C. A. Rogers
Keyword(s):  
Thermal Analysis ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Constitutive Relations ◽  
Design Approach ◽  
One Dimensional ◽  
Design Case ◽  
The One ◽  
Transient Thermal ◽  
Capacitance Transient

This paper describes the design of shape memory alloy force and displacement actuators based upon the thermomechanical constitutive relations previously developed by the authors. Numerical simulations and design case studies are presented which show the utility and advantages of this method over design methods currently being used. The types of actuators described and analyzed include bias spring actuators, differential force actuators, and their hybrid systems. The design approach includes coupling between the one-dimensional thermomechanical constitutive relations and a lumped capacitance transient thermal analysis. The design approach described herein will provide a practical and convenient method for use in the design of shape memory alloy actuators.

A New Theory of Elastic Sandwich Plates—One-Dimensional Case

1959 ◽  
Vol 26 (3) ◽  
pp. 415-421
Author(s):  
Yi-Yuan Yu
Keyword(s):  
Infinite Plate ◽  
Theory Of Elasticity ◽  
Dimensional Case ◽  
Transverse Shear Deformation ◽  
Sandwich Plates ◽  
Rotatory Inertia ◽  
One Dimensional ◽  
The Core ◽  
The One ◽  
Final Equation

Abstract A new flexural theory of isotropic elastic sandwich plates is deduced from the theory of elasticity. The one-dimensional case is presented in this paper. The theory includes the effects of transverse-shear deformation and rotatory inertia in both the core and faces of the sandwich, and no limitation is imposed upon the magnitudes of the ratios between the thicknesses, material densities, and elastic constants of the core and faces of the sandwich. The method used is an extension of one due to Mindlin [1], and the results reduce to those of his for the corresponding homogeneous plates as special limiting cases. A final equation also may be simplified and reduced to the corresponding results of Reissner [2], Hoff [3], and Eringen [4] for the bending of ordinary sandwich plates that have thin faces. Results of the theory are applied to the problem of bending of a cantilever plate subjected to load at the unsupported end and to the problem of propagation of straight-crested waves in an infinite plate.

scholarly journals Compound viscous thread with electrostatic and electrokinetic effects

2012 ◽  
Vol 701 ◽  
pp. 171-200 ◽  
Author(s):  
D. T. Conroy ◽  
O. K. Matar ◽  
R. V. Craster ◽  
D. T. Papageorgiou
Keyword(s):  
Electric Field ◽  
Fluid Viscosity ◽  
One Dimensional ◽  
The Core ◽  
Jet Breakup ◽  
Voltage Potential ◽  
Leaky Dielectric Model ◽  
Model Equations ◽  
The One ◽  
Wave Limit

AbstractBreakup of an electrified viscous compound jet, surrounded by a dielectric gas, is investigated theoretically. The fluids are considered to be electrolytes and the core fluid viscosity is assumed to be much larger than that of the annular fluid. Axisymmetric configurations are considered with the three fluids bound by a cylindrical electrode that is held at a constant voltage potential. The model equations are investigated asymptotically in the long-wave limit, yielding two cases corresponding to a negligible surface charge with electrokinetic effects and a leaky dielectric model. A linear stability analysis for both cases is performed and the electrical effects are found to have a stabilizing effect, which is consistent with previous investigations of single electrified jet breakup at small wavenumbers. The one-dimensional equations are also solved numerically. The electric field is found to cause satellite formation in the core fluid, which does not occur in the purely hydrodynamic case, with the satellite size increasing with the strength of the electric field.

Structure of the Bloch wall in multilayers

2005 ◽  
Vol 461 (2058) ◽  
pp. 1911-1926 ◽  
Author(s):  
Carlos J García-Cervera
Keyword(s):  
Film Thickness ◽  
Magnetic Materials ◽  
Double Layer ◽  
Dimensional Reduction ◽  
Interlayer Spacing ◽  
Optimal Shape ◽  
Bloch Wall ◽  
One Dimensional ◽  
The Core ◽  
The One

We present an analysis of the structure of Bloch walls in layered magnetic materials in the context of micromagnetics. We have obtained the Γ -limit of a one-dimensional reduction of the Landau–Lifshitz energy for a double layer in several asymptotic regimes. As a result, the optimal energy, the core length and the optimal shape of the Bloch wall have been determined. The effects of the interlayer spacing and the film thickness are studied. A comparison between the structure of the Bloch and Néel walls in multilayers is carried out. We illustrate all our findings by numerically minimizing the one-dimensional energy.

scholarly journals From Simmel to Relational Sociology

2020 ◽  
Author(s):  
Sophie Mützel ◽  
Lisa Kressin
Keyword(s):  
Social Network ◽  
The Other ◽  
Georg Simmel ◽  
Relational Sociology ◽  
Sociology Of Culture ◽  
Cultural Issues ◽  
One Dimensional ◽  
The Core ◽  
The Past ◽  
The One

Georg Simmel (1858-1918), who is widely regarded as one of the classics and intellectual grandfathers of sociology, has written on a variety of topics from several disciplinary perspectives. Yet despite the breadth and richness of his work, current sociology typically focuses only on individual dimensions. On the one hand, Simmel’s work is seen as foundational to a formal sociology, which is at the core of social network analysis. On the other hand, Simmel’s works on cultural issues yield astute analyses of modernity, which is why they are classics in the sociology of culture. However, such one-dimensional interpretations of Simmel’s work appear limited and in turn do not sufficiently capture his influence on the field of sociology. This chapter claims that the separated readings of the “two Simmels” need to be brought together to make full analytical use of Simmel’s most important heuristic distinction: form and content. Moreover, we will show that relational sociology of the past four decades has moved in that direction by taking the interrelation of structure and meaning seriously.

A Unified Approach to the One-Dimensional Analysis and Design of Radial and Mixed Flow Turbines

1976 ◽  
Author(s):  
F. J. Wallace ◽  
N. C. Baines ◽  
A. Whitfield
Keyword(s):  
Dimensional Analysis ◽  
Design Procedure ◽  
Unified Approach ◽  
Mixed Flow ◽  
Loss Mechanism ◽  
One Dimensional ◽  
Analysis And Design ◽  
Disk Friction ◽  
Loss Models ◽  
The One

A unified one-dimensional analysis and design procedure for radial and mixed flow turbines is presented. This procedure considers the flow in all of the turbine components, including the inlet volute, nozzled or nozzleless inlet duct, rotor and exit duct. Losses are included for each component; in the stationary ducts, friction is the main loss mechanism, and in the rotor skin friction, clearance and disk friction are considered separately. Incidence losses at entry to both nozzle and rotor are calculated using one of two loss models. For each component, the procedure is to combine the equations of continuity, momentum, energy, and entropy into a single dimensionless expression for the Mach number at exit. This approach has proved possible under a wide variety of circumstances, and with its flexibility and ease of programming for solution by computer would seem to have many applications in one-dimensional ducted flow. The predicted performance of a radial inflow nozzleless turbine is compared with experimental results. The comparison is considered to be sufficiently good to confirm the validity of this approach. The results obtained with each of the two incidence loss models are compared. Each model is found to have its own advantages and fields of application.

scholarly journals A thermoelastoplastic theory for special Cosserat rods

2018 ◽  
Vol 24 (3) ◽  
pp. 686-700
Author(s):  
Smriti ◽  
Ajeet Kumar ◽  
Alexander Großmann ◽  
Paul Steinmann
Keyword(s):  
Yield Criterion ◽  
Constitutive Relations ◽  
Transversely Isotropic ◽  
Field Variable ◽  
Theory Reduction ◽  
One Dimensional ◽  
Cosserat Rods ◽  
The One ◽  
Strain Measures ◽  
Additional Equation

A general framework is presented to model coupled thermoelastoplastic deformations in the theory of special Cosserat rods. The use of the one-dimensional form of the energy balance in conjunction with the one-dimensional entropy balance allows us to obtain an additional equation for the evolution of a temperature-like one-dimensional field variable, together with constitutive relations for this theory. Reduction to the case of thermoelasticity leads us to the well-known nonlinear theory of thermoelasticity for special Cosserat rods. Later on, additive decomposition is used to separate the thermoelastic part of the strain measures of the rod from their plastic counterparts. We then present the most general quadratic form of the Helmholtz energy per unit undeformed length for both hemitropic and transversely isotropic rods. We also propose a prototype yield criterion in terms of forces, moments, and hardening stress resultants, as well as associative flow rules for the evolution of plastic strain measures and hardening variables.

scholarly journals A Bargaining Model of Collective Choice

2000 ◽  
Vol 94 (1) ◽  
pp. 73-88 ◽  
Author(s):  
Jeffrey s. Banks ◽  
John Duggan
Keyword(s):  
Spatial Model ◽  
Collective Choice ◽  
Collective Decision Making ◽  
Bargaining Model ◽  
One Dimensional ◽  
The Core ◽  
Strategic Incentives ◽  
The One ◽  
Upper Hemicontinuity ◽  
Parliamentary Politics

We provide a general theory of collective decision making, one that relates social choices to the strategic incentives of individuals, by generalizing the Baron-Ferejohn (1989) model of bargaining to the multidimensional spatial model. We prove existence of stationary equilibria, upper hemicontinuity of equilibrium outcomes in structural and preference parameters, and equivalence of equilibrium outcomes and the core in certain environments, including the one-dimensional case. The model generates equilibrium predictions even when the core is empty, and it yields a “continuous” generalization of the core in some familiar environments in which the core is nonempty. As the description of institutional detail in the model is sparse, it applies to collective choice in relatively unstructured settings and provides a benchmark for the general analysis of legislative and parliamentary politics.

Structured Rank-(r1, . . . , rd) Decomposition of Function-related Tensors in R_D

2006 ◽  
Vol 6 (2) ◽  
pp. 194-220 ◽  
Author(s):  
B.N. Khoromskij
Keyword(s):  
Complexity Analysis ◽  
Type Model ◽  
Problem Size ◽  
Nonlocal Operators ◽  
One Dimensional ◽  
The Core ◽  
Tensor Product Approximation ◽  
Higher Order Tensors ◽  
The One ◽  
Linear Cost

AbstractThe structured tensor-product approximation of multidimensional nonlocal operators by a two-level rank-(r1, . . . , rd) decomposition of related higher-order tensors is proposed and analysed. In this approach, the construction of the desired approximant to a target tensor is a reminiscence of the Tucker-type model, where the canonical components are represented in a fixed (uniform) basis, while the core tensor is given in the canonical format. As an alternative, the multilevel nested canonical decomposition is presented. The complexity analysis of the corresponding multilinear algebra shows an almost linear cost in the one-dimensional problem size. The existence of a low Kronecker rank two-level representation is proven for a class of function-related tensors.

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