Abstract In order to fulfill the requirement that electric linear load simulator needs improve loading accuracy by compensation method based on friction model in active situation with small load, considering influence of coulomb and maximum static friction, an improved LuGre is proposed. At same time, since effect highly nonlinear determined numerous parameters, differential evolution algorithm...

We show that in slowly generated two-dimensional packings of frictional spheres, a significant fraction of the friction forces lie at the Coulomb threshold-for small pressure p and friction coefficient mu , about half of the contacts. Interpreting these contacts as constrained leads to a generalized concept of isostaticity, which relates the maximal fraction of fully mobilized contacts and cont...

This study makes use of an energy balance to identify damping parameters in mechanical vibration systems. By balancing the energy input as registered in the force-displacement relationship of the real system against the energy lost theoretically in a damping model with unknown parameters, the identification algorithms are developed. We apply the estimation equations to both numerical and experi...

We propose a simple continuum model to interpret the shearing motion of dense, dry and cohesion-less granular media. Compressibility, dilatancy and Coulomb-like friction are the three basic ingredients. The granular stress is split into a rate-dependent part representing the rebound-less impacts between grains and a rate-independent part associated with long-lived contacts. Because we consider ...

In comparison to classical cascade control architecture of DC motors, the state feedback control offers advantages in terms of design complexity, hardware realization and adaptivity. This paper presents a methodic approach to state space control of a DC motor. The state space model identified from experimental data provides the basis for a linear quadratic regulator (LQR) design. The state feed...

This paper presents a new tool which makes it possible to find the spatial configuration of a system featuring elastic fibres interacting with each other and/or with rigid bodies. The configuration is determined by means of the principle of the minimum elastic potential energy of the system, ignoring Coulomb friction at the contacts. In particular, the paper reports both the elastic fiber model...

A mixed formulation for a Tresca frictional contact problem in linear elasticity is considered in the context of boundary integral equations, which is later extended to Coulomb friction . The discrete Lagrange multiplier, an approximation of the surface traction on the contact boundary part, is a linear combination of biorthogonal basis functions. In case of curved elements, these are the solut...

Contact problems of elasticity are used in many fields of science and engineering, especially in structural mechanics, geology and biomecanics. Many numerical procedures solving contact problems have been proposed in the engineering literature. They are based on standard discretization techniques for partial differential equations in combination with a special implementation of non-linear conta...

Friction appears in all mechanical systems and has a significant impact on control. Successful design of mechatronic systems requires an understanding of the effects of friction as well as techniques to compensation. Friction phenomena are complicated because they are caused by many different physical mechanisms. Friction can cause a substantial deterioration of the performance of a control sys...

Contact modelling, simulation, and analysis of mechanical systems with friction need proper treatments due to the non-smooth nature of the contact phenomenon. Two main approaches to deal with the contact problems are constraint and compliant based formulations [3]. In constraint based approaches, the problem is formulated by imposing the kinematic unilateral constraints between bodies in contac...