Home About us Contact | |||
Adaptive Stabilization (adaptive + stabilization)
Selected AbstractsDirect adaptive control for non-linear uncertain systems with exogenous disturbancesINTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 2 2002Wassim M. Haddad Abstract A direct adaptive non-linear control framework for multivariable non-linear uncertain systems with exogenous bounded disturbances is developed. The adaptive non-linear controller addresses adaptive stabilization, disturbance rejection and adaptive tracking. The proposed framework is Lyapunov-based and guarantees partial asymptotic stability of the closed-loop system; that is, asymptotic stability with respect to part of the closed-loop system states associated with the plant. In the case of bounded energy L2 disturbances the proposed approach guarantees a non-expansivity constraint on the closed-loop input,output map. Finally, several illustrative numerical examples are provided to demonstrate the efficacy of the proposed approach. Copyright © 2002 John Wiley & Sons, Ltd. [source] Nonuniform video coding by means of multifoveal geometriesINTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 1 2002J.A. Rodríguez This paper presents a control mechanism for video transmission that relies on transmitting nonuniform resolution images depending on the delay of the communication channel. These images are built in an active way to keep the areas of interest of the image at the highest resolution available. In order to shift the areas of high resolution over the image and to achieve a data structure that is easy to process by using conventional algorithms, a shifted foveal multiresolution geometry of adaptive size is used. If delays are too high, the resolution areas of the image can be transmitted at different rates. A functional system has been developed for corridor surveillance with static cameras. Tests with real video images have proven that the method allows an almost constant rate of images per second as long as the channel is not collapsed. A new method for determining the areas of interest is also proposed, based on hierarchical object tracking by means of adaptive stabilization of pyramidal structures. © 2002 John Wiley & Sons, Inc. Int J Imaging Syst Technol 12, 27,34, 2002 [source] Low-gain adaptive stabilization of semilinear second-order hyperbolic systemsMATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 18 2004Toshihiro Kobayashi Abstract In this paper low-gain adaptive stabilization of undamped semilinear second-order hyperbolic systems is considered in the case where the input and output operators are collocated. The linearized systems have an infinite number of poles and zeros on the imaginary axis. The adaptive stabilizer is constructed by a low-gain adaptive velocity feedback. The closed-loop system is governed by a non-linear evolution equation. First, the well-posedness of the closed-loop system is shown. Next, an energy-like function and a multiplier function are introduced and the exponential stability of the closed-loop system is analysed. Some examples are given to illustrate the theory. Copyright © 2004 John Wiley & Sons, Ltd. [source] Adaptive output feedback control for a class of planar nonlinear systems,ASIAN JOURNAL OF CONTROL, Issue 5 2009Fang Shang Abstract This paper is concerned with the problem of global adaptive stabilization by output feedback for a class of planar nonlinear systems with uncertain control coefficient and unknown growth rate. The control coefficient is not supposed to have known upper bound, and this relaxes the corresponding requirement in the existing literature (see e.g. 1, 2. First, by the universal control method, an observer is constructed based on the dynamic high-gain K-filters. Then, the control design procedure is developed to obtain the stabilizing controller and dynamic compensator for the uncertainties in the control coefficient. It is shown that the global stability of the closed-loop system can be guaranteed by the appropriate choice of the design parameters. A simulation example is also provided to illustrate the correctness of the theoretical results. © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society. [source] |