The pivot friction of voice-coil-motor (VCM) actuator is measured for a 1.8-inch small disk drive with disk rotating and slider flying. The measurement is carried out under the conditions that the actuator is controlled and the head movement amplitude is growing by changing the references. The hysteresis of friction versus head position is then obtained. An operator based modeling approach is a...

This paper concerns the problem of dynamic parameter identification of robot manipulators and proposes a closed‐loop identification procedure using modified Fourier series (MFS) as exciting trajectories. First, a static continuous friction model is involved to model joint friction for realizable friction compensation in controller design. Second, MFS satisfying the bo...

In this paper, we investigate the planar dynamic pivoting problem, in which a pinched object is reoriented to a desired pose through wrist swing motion and grip force regulation. Traditional approaches based on friction compensation do not work well for this problem, as we observe the torsional friction at the contact has large uncertainties during pivoting. In addition, the discontinuities of ...

This paper presents a new dynamical friction model structure which allows accurate modeling both in the sliding and the presliding regimes. Transition between these two regimes is accomplished without a switching function. The model incorporates a hysteresis function with nonlocal memory and arbitrary transition curves. These last aspects prove essential for modeling presliding friction that is...

In this paper we present an energy-based algorithm to minimize limit cycles in dynamically balancing wheeled inverted pendulum (IP) machines. Because the algorithm is not based on absolute values of parameters, the performance is robust and accounts for mechanical reconfiguration and wear. The effects of phenomena such as drive-train friction, rolling friction, backlash and sensor bandwidth are...

This paper presents a novel modeling and compensation approach for the angular transmission error in harmonic drive gearings. In the modeling, physical phenomena of the transmission error due to nonlinear elastic deformations in micro-displacement region are especially dealt with, as well as the synchronous component which has been discussed in a variety of conventional studies. Based on the an...

In this paper, we propose a feedforward compensation method to enhance the performance of the lateral guidance system of heavy vehicles on automated highway systems (AHS). The feedforward controller blends well with the linear robust feedback controller. The proposed feedforward compensation is motivated by the analogy between a vehicle lateral control system on curved roads and a mechanical sy...

Stick-slip phenomenon is often associated with the control of low velocity motion because of the positional dependancy of friction and negative damping friction that decreases as the motion speed increases. In this paper, smooth low velocity tracking control of a commercial robot joint is demonstrated experimentally using a combination of high gain PID control, fast sampling rate and high posit...