We study the effects of temperature and sliding velocity on superlubricity in numerical simulations of the Frenkel-Kontorova model. We show that resonant excitations of the phonons in an incommensurate sliding body lead to an effective friction and to thermal equilibrium with energy distributed over the internal degrees of freedom. For finite temperature, the effective friction can be described...

A robust consensus controller is proposed for heterogeneous higher order nonlinear multi-agent systems (MAS), when the agent dynamics are involved with mismatched uncertainties. A distributed consensus protocol based on a time varying nonhomogeneous finite time disturbance observer (FTDO) and sliding mode control is designed to realize the network consensus of higher order MAS. The time varying...

We study the presence and effect of subglacial water on the motion of inland ice in western Dronning Maud Land, Antarctica. A full-Stokes model including three routing schemes for a thin film of subglacial water and a modification of a Weertman-type sliding relation, to account for higher sliding velocities under wet basal conditions, were used to perform 200 ka spin-up simulations on a 2.5 km ...

Durability of engineering workpieces surfaces is well-known to be strongly related to the microstructural evolutions induced by machining processes. One current challenge is to choose the right process parameters, such as the sliding speed, in order to optimize both the subsurface microstructure and the surface properties. In this paper, a special tribometer, able to simulate contact pressures ...

In this paper, by applying analytical method and using experimental method data, the effect of sliding velocity on friction coefficient for contact of copper with copper is investigated. Some equations for obtaining friction coefficient as a function of sliding velocity for contact of copper with copper by applying second analytical method and using experimental method data are achieved. The re...

This paper presents the design and analysis of a high performance robust controller for the Stewart platform manipulator. The controller is a variable structure controller that uses a linear sliding surface which is designed to drive both tracking and synchronization errors to zero. In the controller the model based equivalent control part of the sliding mode controller is computed in task spac...

Fuel cell powered systems have low voltage and high current output characteristics. Therefore, the output voltage of the fuel cell must be stepped up by DC-DC converter. In this paper an integrated mathematical model for proton exchange membrane fuel cell power system with DC-DC converter is described by analyzing the working mechanism of the proton exchange membrane fuel cell and the boost DC-...

The plane strain problem of a curved elastic body pressed against an elastic half-space is considered. The effect of adhesion is included through the use of surface energy in a manner similar to the well-known JKR theory for spherical contacts. The compressive normal force is held constant while a tangential force is gradually increased from zero. The contact is characterized by complete stick ...

Functional Electrical Stimulation can restore movement in certain paralyzed individuals. Electric current pulses excite the intact peripheral nerves, cause the muscles to contract and generate joint movements. Since this physiological and biomechanical system is highly nonlinear and time-varying, feedback control is necessary for satisfactory FES control of the joint angles. In this study, a co...

Control of an industrial robot consist of nonlinear terms that causes the uncertainty and external turmoil and must be considered in control law designing. In this study, a control strategy will be presented for the robot arms, based on fuzzy logic control connection and sliding mode control (SMC). The using motivation of SMC in robotic is mainly the admirable features of it such as design simp...