A dynamics inversion compensation scheme is designed for control of nonlinear discretetime systems with input backlash. The compensator uses the dynamic inversion technique, with a neural network (NN) for inverting the backlash nonlinearity in the feedforward path. The technique provides a general procedure for using NN to determine the dynamics preinverse of an invertible discrete time dynamic...

As one of the core components, the joint plays an important role during the movement of space manipulator, and its performance will be influenced by the existence of the backlash, which can severely sacrifice the quality of the manipulator to perform a task. In order to have a comprehensive understanding of the influence of the backlash to the gear transmission joints, a dynamic model of planet...

Many of the physical phenomena, like friction, backlash, drag, and etc., which appear in mechanical systems are inherently nonlinear and have destructive effects on the control systems behavior. Generally, they are modeled by hard nonlinearities. In this paper, two different methods are proposed to cope with the effects of hard nonlinearities which exist in friction various models. Simple inver...

An optimization model is constructed to select the optimum reduction ratios that minimize the total angular backlash of a gear train, under constraints on the total reduction ratio and available space. It is found that a proper layout of reduction ratios has a major eVect on the total angular backlash of a gear train.

The behavior of robotic manipulators with backlash is analyzed. Based on the pseudo-phase plane two indices are proposed to evaluate the backlash effect upon the robotic system: the root mean square error and the fractal dimension. For the dynamical analysis the noisy signals captured from the system are filtered through wavelets. Several tests are developed that demonstrate the coherence of th...

The advantages of miniaturisation, e.g. low masses, low power consumption and small dimensions open new fields of applications for powerful micro actuators in areas dealing with particular environmental conditions like ultra high vacuum or wide temperature ranges. In fact these kinds of applications are mostly challenging positioning tasks, such as the sensitive movement or exact adjustment of ...

We have performed first-order reversal-curve measurements of the temperature-driven metal-insulator transition in VO2 thin films, which enable quantitative analysis of the hysteresis behavior. An unexpected tail-like feature in the contour plot of the reversal-curve distribution indicates the existence of metallic domains, even at temperatures below the closing of the hysteresis. These domains ...

Planetary gear trains can be more compact and efficient as power transmissions than fixed axis gear trains but are also more complicated and less understood in terms of vibration health monitoring. A practical differential planetary gear train, which combines two inputs and one output, is studied using multi-body dynamics software. Backlash between the sun gear and planet gears are precisely sp...