Electromechanical System with a Stochastic Friction Field

Abstract

This work analyzes the stochastic nonlinear dynamics of an electromechanical system with dry-friction. The system has a mechanical part and an electromagnetic part. It is composed of a cart, whose motion is excited by a DC motor. The coupling between the motor and the cart is made by a mechanism called scotch yoke, so that the motor rotational motion is transformed in horizontal cart motion over a rail. It is considered the existence of random dry-friction between the cart and the rail. The friction coefficient is modeled as a stochastic Poisson field over the rail. Due to the friction, the resulting motion of the motor can be characterized by two qualitatively different modes, the stick- and slip-modes, with a non-smooth transition between them. The focus of the work is finding, from a stochastic point of view, the stick- and slip-mode parts of the trajectory, i.e., to compute the uncertainty propagation in the system response.