The use of Coulomb’s friction law with the principles of classical rigid-body dynamics introduces mathematical inconsistencies. Specifically, the forward dynamics problem can have no solutions or multiple solutions. In these situations, compliant contact models, while increasing the dimensionality of the state vector, can resolve these problems. The simplicity and efficiency of rigid-body model...

We present a unified treatment for modeling Coulomb and viscous friction within multi-rigid body simulation using the principle of maximum dissipation. This principle is used to build two different methods—an event-driven impulse-based method and a time stepping method—for modeling contact. The same principle is used to effect joint friction in articulated mechanisms. Experiments show that the ...

Friction is present in all mechanical systems and causes a wide range of problems for control. The development of friction models and methods to account for friction in control has been an active research area for many years. A promising friction model that is capable of describing a wide array of observed friction phenomena is the LuGre model. This thesis deals with the application of friction...

We propose a Langevin model with Coulomb friction. Through the analysis of the corresponding Fokker-Planck equation, we have obtained the steady velocity distribution function under the influence of the external field.

We study the discretized problem of the shape optimization of three-dimensional elastic bodies in unilateral contact. The aim is to extend existing results to the case of contact problems obeying the Coulomb friction law. Mathematical modelling of the Coulomb friction problem leads to an implicit variational inequality. It is shown that for small coefficients of friction the discretized problem...

The design of a controller for a flexible system under the influence of friction is presented. A linear programming technique for finding an optimal control of linear flexible systems is extended to frictional systems. A floating oscillator is used in the development, where friction and control input forces are acting on the first mass. The result of the linear programming is a control profile ...

This paper focuses on the state-periodic adaptive compensation of cogging and Coulomb friction for permanent magnet linear motors (PMLM) executing a task repeatedly. The cogging force is considered as a position dependent disturbance and the considered Coulomb friction is non-Lipschitz at zero velocity. The key idea of our disturbance compensation method is to use one trajectory-period past inf...

Friction characterization is a prerequisite for an accurate control of electromechanical systems. This paper considers the identification and control of friction in a high load torque DC motor to the end of achieving accurate tracking. In the first place, model-based feedforward controllers for friction compensation are considered. For this purpose, friction model structures ranging from the cl...

Being a complex nonlinear phenomenon, friction is a difficult part to characterize and identify in a mechanical system. Friction is the result of interaction between one body over or along another and is dependent on many parameters, such as contact geometry, topography, surface materials, presence and type of lubrication and relative motion. The classical Coulomb friction has been widely used ...