SuP‐Ring: A pneumatic tactile display with substitutional representation of contact force components using normal indentation

2021 ◽  
Author(s):  
Hoang Hiep Ly ◽  
Yoshihiro Tanaka ◽  
Michitaka Fujiwara
Keyword(s):  
Contact Force ◽  
Tactile Display ◽  
Force Components

An Extension of CEB Elastic-Plastic Contact Model

2007 ◽  
Author(s):  
A. Sepehri ◽  
K. Farhang
Keyword(s):  
Contact Force ◽  
Tangential Force ◽  
Three Dimensional ◽  
Tangential Direction ◽  
Asperity Contact ◽  
Force Component ◽  
Normal Contact ◽  
Elastic Plastic ◽  
Force Components ◽  
Plastic Parts

Three dimensional elastic-plastic contact of two nominally flat rough surfaces is by developing the equations governing the shoulder-shoulder contact of asperities based on the Chang, Etsion and Bogy (CEB) model of contact in which volume conservation is assumed in the plastic flow regime. Shoulder-shoulder asperity contact yields a slanted contact force consisting of both tangential (parallel to mean plane) and normal components. Each force component comprises elastic and elastic-plastic parts. Statistical summation of normal force components leads to the derivation of the normal contact force for the elastic-plastic contact akin to the CEB model. Half-plane tangential force due to elastic-plastic contact is derived through the statistical summation of tangential force component along an arbitrary tangential direction.

scholarly journals A Finite Element-Based Elastic-Plastic Model for the Contact of Rough Surfaces

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Ali Sepehri ◽  
Kambiz Farhang
Keyword(s):  
Finite Element ◽  
Contact Force ◽  
Contact Area ◽  
Rough Surfaces ◽  
Constitutive Relations ◽  
Element Model ◽  
Tangential Component ◽  
Asperity Contact ◽  
Elastic Plastic ◽  
Force Components

Three-dimensional elastic-plastic contact of two nominally flat rough surfaces is considered. Equations governing the shoulder-shoulder contact of asperities are derived based on the asperity constitutive relations from a finite element model of the elastic-plastic interaction proposed by Kogut and Etsion (2002), in which asperity scale constitutive relations are derived using piecewise approximate functions. An analytical fusion technique is developed to combine the piecewise asperity level constitutive relations. Shoulder-shoulder asperity contact yields a slanted contact force consisting of two components, one in the normal direction and a half-plane tangential component. Statistical summation of the asperity level contact force components and asperity level contact area results in the total contact force and total contact area formulae between two rough surfaces. Approximate equations are developed in closed form for contact force components and contact area.

Analysis and Visualization of the Contact Force Solution Space for Multi-Limbed Mobile Robots With Three Feet Contact

2003 ◽  
Author(s):  
Dennis W. Hong ◽  
Raymond J. Cipra
Keyword(s):  
Contact Force ◽  
Dimensional Space ◽  
Contact Point ◽  
Solution Process ◽  
Solution Space ◽  
Contact Forces ◽  
Static Equilibrium ◽  
Equilibrium Equations ◽  
Force Components ◽  
The Relationship

A new analytical method for determining, describing, and visualizing the solution space for the contact force distribution of multi-limbed robots with three feet in contact with the environment in three-dimensional space is presented. The foot contact forces are first resolved into strategically defined foot contact force components to decouple them for simplifying the solution process, and then the static equilibrium equations are applied to find certain contact force components and the relationship between the others. Using the friction cone equation at each foot contact point and the known contact force components, the problem is transformed into a geometrical one to find the ranges of contact forces and the relationship between them that satisfy the friction constraint. Using geometric properties of the friction cones and by simple manipulation of their conic sections, the whole solution space which satisfies the static equilibrium and friction constraints at each contact point can be found. Two representation schemes, the “force space graph” and the “solution volume representation,” are developed for describing and visualizing the solution space which gives an intuitive visual map of how well the solution space is formed for the given conditions of the system.

scholarly journals Heel effects on joint contact force components in the equine digit: a sensitivity analysis

2010 ◽  
Vol 42 ◽  
pp. 475-481 ◽  
Author(s):  
P. NOBLE ◽  
J.-P. LEJEUNE ◽  
I. CAUDRON ◽  
P. LEJEUNE ◽  
B. COLLIN ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Contact Force ◽  
Joint Contact Force ◽  
Joint Contact ◽  
Force Components

Viscoelastic Contact of Rough Surfaces in Relative Normal and Sliding Motion

2008 ◽  
Author(s):  
Ali Sepehri ◽  
Kambiz Farhang
Keyword(s):  
Contact Force ◽  
Tangential Force ◽  
Three Dimensional ◽  
Tangential Velocity ◽  
Asperity Contact ◽  
Sliding Motion ◽  
Force Velocity ◽  
Force Components ◽  
Viscoelastic Contact ◽  
Approximate Equations

Mathematical formulae are derived for normal and tangential components of the contact force that depend not only on the proximity of the two surfaces but also the rate of approach and relative sliding. The development of the contact model is based on the asperity shoulder-shoulder contact leading to slanted asperity contact force. Thus an asperity force contains both normal and tangential components. Three dimensional consideration of asperity contact force yields directionally dependence of both the normal and tangential force components. A previously reported statistical approach is employed in which the dependence of the asperity normal and tangential contact force components on relative tangential velocity of two asperities are cast as corrective factors in the mathematical description of normal and tangential force components. The two corrective coefficients are the force directionality corrective coefficient and the force-velocity directionality corrective coefficient. Approximate equations are found for each of the normal and half-plane tangential force components that achieve accuracy within five (5) percent error.

Visualization of the Contact Force Solution Space for Multi-Limbed Robots

2005 ◽  
Vol 128 (1) ◽  
pp. 295-302 ◽  
Author(s):  
Dennis W. Hong ◽  
Raymond J. Cipra
Keyword(s):  
Contact Force ◽  
Dimensional Space ◽  
Contact Point ◽  
Three Dimensional ◽  
Solution Space ◽  
Entire Solution ◽  
Contact Forces ◽  
Static Equilibrium ◽  
Equilibrium Equations ◽  
Force Components

A new analytical method for determining, describing, and visualizing the solution space for the contact force distribution of multi-limbed robots with three feet in contact with the environment in three-dimensional space is presented. The foot contact forces are first resolved into strategically defined foot contact force components to decouple them, and then the static equilibrium equations are applied. Using the friction cone equation at each foot contact point, the problem is then transformed into a geometrical one. Using geometric properties of the friction cones and by simple manipulation of their conic sections, the entire solution space which satisfies the static equilibrium and friction constraints at each contact point can be found. Two representation schemes, the “force space graph” and the “solution volume representation,” are developed for describing and visualizing the solution space which gives an intuitive visual map of how well the solution space is formed for the given conditions of the system.

Contact of Rough Surfaces: Combined Elastic and Rate-Dependent Effects

2008 ◽  
Author(s):  
Ali Sepehri ◽  
Kambiz Farhang
Keyword(s):  
Half Plane ◽  
Contact Force ◽  
Rough Surfaces ◽  
Tangential Force ◽  
Approximation Error ◽  
Tangential Velocity ◽  
Contact Forces ◽  
Tangential Contact ◽  
Force Components ◽  
Approximate Equations

Approximate closed form equations are found for normal and tangential contact forces of rough surfaces in dry friction. Using a viscoelastic asperity behavior, mathematical formulae are derived for normal and tangential components of the contact force that depend not only on the separation of the two surfaces but also the rate of approach and relative sliding. The tangential force over a half-plane, corresponding to the moving direction, is found accounting for the directionality of the tangential component of asperity forces. A statistical approach is forwarded in which dependence of the asperity normal and tangential contact force on relative tangential velocity of two asperities can presented as corrective factors in the mathematical description of normal and tangential force components. These are force directionality corrective coefficient and force-velocity directionality corrective coefficient. Two sets of approximate equations are found for each of the normal and half-plane tangential force components. The simplest forms of the approximate equations achieve accuracy to within five (5) percent error, while other forms yield approximation error within 0.2 percent.

Loading and Unloading Processes in Elastic-Plastic Contact of a Rough Surface With a Flat

2008 ◽  
Author(s):  
Ali Sepehri ◽  
Kambiz Farhang
Keyword(s):  
Contact Force ◽  
Tangential Force ◽  
Three Dimensional ◽  
Tangential Direction ◽  
Asperity Contact ◽  
Force Component ◽  
Normal Contact ◽  
Elastic Plastic ◽  
Force Components ◽  
Plastic Parts

Three dimensional elastic-plastic contact of two nominally flat rough surfaces is considered. Equations governing the shoulder-shoulder contact of asperities are derived based on the Chang, Etsion and Bogy (CEB) model of contact in which volume conservation is assumed in the plastic flow regime. Shoulder-shoulder asperity contact yields a slanted contact force consisting of both tangential (parallel to mean plane) and normal components. Each force component comprises elastic and elastic-plastic parts. Statistical summation of normal force components leads to the derivation of the normal contact force for the elastic-plastic contact akin to the CEB model. Half-plane tangential force due to elastic-plastic contact is derived through the statistical summation of tangential force component along an arbitrary tangential direction.

Partial Contact Force Controllability in Active Wheeled Vehicles

1998 ◽  
Vol 123 (2) ◽  
pp. 169-175 ◽  
Author(s):  
B. J. Choi ◽  
S. V. Sreenivasan
Keyword(s):  
Contact Force ◽  
Geometric Approach ◽  
Contact Forces ◽  
Force Distribution ◽  
Distribution Problem ◽  
Passive Components ◽  
Uneven Terrain ◽  
Partial Contact ◽  
Force Components ◽  
Wheeled Vehicles

This paper presents a geometric approach for solving the force distribution problem in active wheeled vehicles (AWVs) moving on uneven surfaces. Here an active vehicle is defined as a system that includes independent actuators for all its internal joints. In general, AWVs do not possess omni-directional mobility, and they possess fewer actuators than the number of wheel-ground contact force components. This article presents an approach for separating the contact force vectors into active and passive components such that there exists an invertible square matrix that maps the active contact forces to the actuator efforts. An appropriate force allocation algorithm can then be developed for these systems. The concepts introduced in this article are demonstrated via an example of AWVs on uneven terrain. An example of force distribution in active legged vehicles (ALVs) that possess the same number of actuators as contact forces is also provided for comparison.

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