We consider the rate-independent problem of a particle moving in a three dimensional half space subject to a time-dependent nonlinear restoring force having a convex potential and to Coulomb friction along the flat boundary of the half space, where the friction coefficient may vary along the boundary. Our existence result allows for solutions that may switch arbitrarily often between unconstrai...

The purpose of the paper is to give a pedagogical introduction to the multiple time-scale technique, on the example of the high friction limit of the Kramers equation. We begin with a discussion of the standard perturbation technique as presented in van Kampen’s reference book V K , which will be shown to fail in the long-time limit. Application of the multiple time-scale technique avoids these...

The physics describing ultrasonic wire bonding is only partly known. A better understanding how bond strength depends on process parameters could increase productivity by speeding up process ramp-up and increasing process reliability. In this work, the influence of normal force and ultrasonic amplitude on the ball bond quality is investigated. The determination of the ultrasonic friction energy...

Predictive control employs future and past information to maintain servo performance and stability in uncertain environment. Nevertheless, nonlinear friction and unknown disturbances still challenge application of predictive control to precision positioning in typical electromechanical transmission systems due to strict demands on accuracy and control performance. In this paper, a modified pred...

Since there are backlash friction and time-varying stiffness, the characteristics of gear pair has strong nonlinearity. When a gear has faults such as pitting, spalling and tooth breakage, there are often some nonlinear characteristics as super-harmonics or sub-harmonics along with vibration signal. These characteristics will cause some difficulty for fault diagnostics, so it is necessary to st...

In bilateral telemanipulation algorithms based on enforcing time-domain passivity, internal friction in the devices poses an additional energy drain. This can severely decrease the obtainable transparency of these algorithms when high amounts of friction are present in the slave device. Based on a model of the friction, the dissipated energy can be estimated and reclaimed inside the energy bala...