This paper considers the evolution of smooth, two-dimensional vortices subject to a rotating external strain field, which generates regions of recirculating, cat’s eye stream line topology within a vortex. When the external strain field is smoothly switched off, the cat’s eyes may persist, or they may disappear as the vortex relaxes back to axisymmetry. A numerical study obtains criteria for th...

In this paper we study the response to external disturbances of a double integrator with saturating feedback. For a class of disturbances that have bounded integrals over all intervals, we show that a linear static feedback law can always be designed to ensure boundedness of the states. Moreover, boundedness can be preserved if the disturbance is biased by a small DC signal. In the special case...

In this work, a second-order sliding mode control algorithm is proposed for variable speed laboratory size DC generator wind turbine experiment system in order to track a speed profile and operate the wind turbine at maximum power extraction. The turbine torque, which varies with the wind speed, is considered as an unknown disturbance and rejected by the sliding mode strategy. The sliding mode ...

In this paper, a control scheme based on state prediction is proposed for class of nonlinear systems subject to input delay and external disturbance. Firstly, as constant delay, an improved that combining with dynamic surface (DSC) technique proposed, which can compensate the completely. Secondly, by considering disturbance, effective controller prediction, DSC disturbance observer presented ta...

To improve the dynamic performances of the permanent magnet synchronous motor (PMSM) drive, a novel implementation of speed controller based on adaptive fuzzy logic is presented in this paper. Using the output of the fuzzy speed controller (FC), the quadrature axis current reference value can be obtained. At the same time, the outputs of the current controller can be corrected by the disturbanc...