LuGre model has been widely used in dynamic friction modeling and compensation. However, there are some practical difficulties when applying it to systems experiencing large range of motion speeds such as, the linear motor drive system studied in the ∧ article. This article first details the digital implementation problems of the LuGre model based dynamic friction compensation. A modified model...

Friction exists in all machines having relative motion, and plays an important role in many servo mechanisms and simple pneumatic or hydraulic systems. In order to achieve high precision motion control, accurate friction modeling and effective compensation techniques have to be investigated. In this chapter, we shall present a systematic treatment of adaptive friction compensation techniques fr...

A model that predicts the static friction for elastic-plastic contact of rough surfaces is presented. The model incorporates the results of accurate finite element analyses for the elastic-plastic contact, adhesion and sliding inception of a single asperity in a statistical representation of surface roughness. The model shows strong effect of the external force and nominal contact area on the s...

An artificial neural network (ANN) model was employed to predict the soil cohesion and soil internal friction angle. The soil samples were collected from different cultivated sites in seven regions in Saudi Arabia. Direct shear box method was used to determine soil cohesion and soil internal friction angle. The input factors to ANN model were soil dry density, soil moisture content and soil tex...

In the computational fluid dynamics (CFD) modeling of gas-solids two phase flow, the effect of boundary conditions play an important role in predicting the hydrodynamic characteristics of fluidized beds. In this work, the hydrodynamics of conical fluidized bed containing dried TiO2 nano-agglomerates were studied both experimentally and computationally. The pressure drop ...

I. Preliminary Remarks A. Introduction B. Some Fundamental Definitions and Questions C. Basic Scenarios for Friction D. Phenomenology of Static and Low-Velocity Kinetic Friction II. Rigid Walls A. Geometric Interlocking B. Thermal Effects C. Applications 1. Nanotubes 2. Curved, Nanoscale Contacts III. Dry, Elastic Friction A. Properties of the Prandtl–Tomlinson Model 1. Definition of the Model ...

Distributions of contact stresses at the neutral point in metal forming are very hard to be properly predicted due to the complex interface situation and lack of suitable friction models. In this paper, the dynamic friction model in which the friction depends on both time rate of strain and normal pressure has been applied to predict contact stresses in cylinder upsetting. Case studies have sho...

Friction is the result of complex interactions between contacting surfaces in a nanoscale perspective. Depending on the application, the di erent models available are more or less suitable. Available static friction models are typically considered to be dependent only on relative speed of interacting surfaces. However, it is known that friction can be a ected by other factors than speed. In thi...

Friction accounts for more than 60% of the motor torque, and hard nonlinearities due to Coulomb friction and stiction severely degrade control performances as they account for nearly 30% of the industrial robot motor torque. Although many friction compensation methods are available (Armstrong-Helouvry et al., 1994; Lischinsky et al., 1999; Bona & Indri, 2005;), here we only introduce relatively...

Multiple physical variables potentially affect the friction coefficient of Asymmetric Friction Connections (AFC). This paper discusses cyclic response a class AFC subjected to repeated load protocols. Two phenomena are observed. First, coefficient, initially higher due wear and moment-axial force-shear force interaction, stabilizes after multiple cycles. Second, test repetitions on same specime...