In this paper feedforward controller is designed to eliminate nonlinear hysteresis behaviors of a piezoelectric stack actuator (PSA) driven system. The control design is based on inverse Prandtl-Ishlinskii (P-I) hysteresis model identified using particle swarm optimization (PSO) technique. Based on the identified P-I model, both the inverse P-I hysteresis model and feedforward controller can be...

Control of nonlinear systems preceded by unknown hysteresis nonlinearities is a challenging task. In the literature, many mathematical models have been proposed to describe the hysteresis. The challenge addressed here is how to fuse those hysteresis models with available robust control techniques to have the basic requirement of stability of the system. The purpose of the paper is to show such ...

This paper presents the development and initial results of a controller based on a novel rate-dependent hysteresis model. The controller has been developed for “Micron,” a microsurgical instrument designed to sense and actively cancel tremor and other undesired motion during vitreoretinal intervention. To accomplish this, Micron uses a three-degree-of-freedom parallel manipulator with piezoelec...

For cosmetic reasons, hand prostheses are provided with cosmetic gloves. Their pleasing appearance, however, is accompanied by poor mechanical behavior, resulting in a negative influence on prosthesis operation. Glove stiffness is high and nonlinear, and internal friction in the glove material causes energy dissipation (hysteresis). In this article, two methods for reducing hysteresis in cosmet...

We test the predictive power of first-order reversal curve (FORC) diagrams using simulations of random magnets. In particular, we compute a histogram of the switching fields of the underlying microscopic switching units along the major hysteresis loop, and compare to the corresponding FORC diagram. We find qualitative agreement between the switching-field histogram and the FORC diagram, yet dif...

Birefringent strands are key to understanding polymeric non-Newtonian flows, especially in extension. Utilising microfluidic extensional flow oscillatory rheometry coupled with microvelocimetry (μ-PIV), we report experiments on the genesis, steady state and decay of such strands, together with rheological consequences. For closely monodisperse atactic polystyrene, we report massive effects of t...

In this paper, modelling and identification of a hydraulic servoactuator system is presented. The importance of such a model is evident in further understanding the system and in order to develop a robust force controller. The model accounts for line losses, nonlinear orifice areas, hysteresis, friction, leakage, and load dynamics. System parameters are identified based on a high-performance hy...

This paper studies, from a modelling point of view, the influence of randomly distributed lattice defects (non-patterned areas and variable hole size) on the ferromagnetic resonance behaviour and spin wave mode profiles of 2D magnonic crystals based on Ni80Fe20 antidot arrays with hexagonal lattice. A reference sample is first defined via the comparison of experimental and simulated hysteresis ...

The Preisach formalism is used to model magnetic hysteresis loops in soft magnetic materials subject to tensile stress. The model uses the Stoner-Wohlfarth mechanism of coherent rotation and dispersion of easy axes to capture the vector response of the magnetization. The Preisach density is constructed as the weighed sum of normal probability density functions (pdf) for the regions of high and ...

The paper presents fuzzy logic based direct torque control (DTC) scheme of an induction motor (IM) and its comparative study using intelligent techniques under varying dynamic conditions are discussed. Direct torque control (DTC) of an induction motor fed by a voltage source inverter is a modest scheme that does not need lengthy computation time and can be implemented without pulse encoders but...