With nanotextured surfaces and interfaces increasingly being encountered in technological and biomedical applications, there is a need for a better understanding of frictional properties involving such surfaces. Here we report friction measurements of several nanostructured surfaces using an Atomic Force Microscope (AFM). These nanostructured surfaces provide well defined model systems on which...

Abstract We consider an experimental system consisting of a pendulum, which is free to rotate 360 degrees, attached to a cart. The cart can move in one dimension. We study the effect of friction on the design and performance of a feedback controller, a linear quadratic regulator, that aim to stabilize the pendulum in the upright position. We show that a controller designed using a simple viscou...

During the last decades, under the increasing demand for more accurate high-performance motion systems, various friction models appropriate for control purpose of mechanical systems have been proposed. Most of these friction models formulate a heuristic dynamical model based on a few observed typical friction properties (e.g. a Stribeck curve for constant velocities and a hysteresis behaviour i...

This paper presents a thorough literature review of the size effects of friction in microforming. During miniaturization, the size effects of friction occur clearly. The paper first introduces experimental research progress on size effects of friction in both micro bulk and sheet forming. The effects of several parameters are discussed. Based on the experimental results, several approaches have...

Rolling friction has been explained in terms of crack propagation through an adhesive joint. The contact between a smooth cylinder and flat has been regarded as an adhesive junction bounded by two cracks moving in the same direction at the same speed, one crack continually opening and one closing. Propagation of these cracks requires a force which is calculated from crack theory and shown to be...

We study the noncontact friction between an atomic force microscope tip and a metal substrate in the presence of bias voltage. The friction is due to energy losses in the sample created by the electromagnetic field from the oscillating charges induced on the tip surface by the bias voltage. We show that the friction can be enhanced by many orders of magnitude if the adsorbate layer can support ...

In this paper, the effects of friction compensation, including exact compensation, undercompensation and overcompensation, in PD controlled 1DOF mechanical systems are investigated. The friction force that is acting on the mechanical system and the friction compensation term in the feedback loop are described by a class of discontinuous friction models consisting of static, Coulomb and viscous ...

The van der Waals friction between two semi-infinite solids, a small neutral particle and semi-infinite solid is reconsidered on the basis of thermal quantum field theory in Matsubara formulation. The friction calculated in this approach is in agreement with the friction calculated in the framework of dynamical modification of the Lifshitz theory with use of the fluctuation-dissipation theorem....

This article describes the detailed friction modeling of the Genera1 Electric GP132 industrial robot. Friction is an area whose importance is often discounted in the development of control systems because it is thought to be insignificant or unmodelable. This work demonstrates that friction does have a predictable structure, and that significant performance improvement can be realized through i...

During high-temperature ball-on-disc tests of aluminium against steel, hot aluminium deformsand wear track evolves. The individual contributions of ploughing and shearing to theapparent friction and the contact pressure are unknown. The aim of this chapter was todevelop a model capable of determining these parameters. It was found that during high-temperature ball-on-disc tests,...