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Abdel Latif Elshafei

Bio: Abdel Latif Elshafei is an academic researcher from Cairo University. The author has contributed to research in topics: Control theory & Fuzzy control system. The author has an hindex of 19, co-authored 69 publications receiving 1011 citations. Previous affiliations of Abdel Latif Elshafei include Qassim University & United Arab Emirates University.


Papers
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Journal ArticleDOI
TL;DR: The paradigm presented is also based on a feedback linearizing (FBL) scheme, yet it ensures system stabilization, and experimental results illustrate the success of the proposed controller in stabilization and cart-position tracking of a reference trajectory.
Abstract: In this brief, we address adaptive fuzzy control of the inverted-pendulum on a cart problem as an underactuated mechanical system. Many of the schemes presented in the adaptive fuzzy control literature tackle the problem as a second-order system based on feedback linearization. Such schemes render unstable zero dynamics for the cart-pole systems which hinders experimental implementation. The paradigm presented is also based on a feedback linearizing (FBL) scheme, yet it ensures system stabilization. A damping term and an adaptive fuzzy control term are added to guarantee asymptotic stability and to account for disturbances. Experimental results illustrate the success of the proposed controller in stabilization and cart-position tracking of a reference trajectory

100 citations

Journal ArticleDOI
01 Sep 2000
TL;DR: In this paper, a robust power system stabiliser is designed that can properly function over a wide range of operating conditions and extend the machine loadability by drawing the root loci for a finite number of extreme characteristic polynomials.
Abstract: Power system stabilisers (PSS) are usually implemented by feeding a speed signal through a supplementary loop that comprises a proper phase lead. The design parameters of this loop are load dependent. Thus, they have to be adjusted at each operating condition. A simple robust PSS is designed that can properly function over a wide range of operating conditions and extend the machine loadability. The lead compensator design is achieved by drawing the root loci for a finite number of extreme characteristic polynomials. Such polynomials are obtained, using the Kharitonov theorem, to reflect wide loading conditions on characteristic equation coefficients. For this purpose the explicit analytical forms for the coefficients of the system transfer functions are derived. Simulation results illustrate the effectiveness of the proposed stabiliser as it is applied to the original nonlinear differential equations describing system dynamics under wide loading conditions at lagging and leading power factors.

74 citations

Journal ArticleDOI
TL;DR: Simulation results demonstrate the superiority of the proposed fuzzy-predictive controller compared to a gain schedule PI controller and a mixed H2/H∞ controller.

73 citations

Journal ArticleDOI
TL;DR: In this paper, an indirect adaptive fuzzy controller is proposed as a power system stabilizer to damp inter-area modes of oscillation following disturbances in power systems, which can cope with oscillations at different operating points.

71 citations

Journal ArticleDOI
TL;DR: The adaptive nature of the new controller significantly reduces the rule base size and improves its performance and is confirmed by simulation results of a single-machine infinite-bus system under different operating points and exposed to both small and large disturbances.

70 citations


Cited by
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Journal Article
TL;DR: In this paper, two major figures in adaptive control provide a wealth of material for researchers, practitioners, and students to enhance their work through the information on many new theoretical developments, and can be used by mathematical control theory specialists to adapt their research to practical needs.
Abstract: This book, written by two major figures in adaptive control, provides a wealth of material for researchers, practitioners, and students. While some researchers in adaptive control may note the absence of a particular topic, the book‘s scope represents a high-gain instrument. It can be used by designers of control systems to enhance their work through the information on many new theoretical developments, and can be used by mathematical control theory specialists to adapt their research to practical needs. The book is strongly recommended to anyone interested in adaptive control.

1,814 citations

Journal ArticleDOI
TL;DR: A survey on recent developments (or state of the art) of analysis and design of model based fuzzy control systems based on the so-called Takagi-Sugeno fuzzy models or fuzzy dynamic models.
Abstract: Fuzzy logic control was originally introduced and developed as a model free control design approach. However, it unfortunately suffers from criticism of lacking of systematic stability analysis and controller design though it has a great success in industry applications. In the past ten years or so, prevailing research efforts on fuzzy logic control have been devoted to model-based fuzzy control systems that guarantee not only stability but also performance of closed-loop fuzzy control systems. This paper presents a survey on recent developments (or state of the art) of analysis and design of model based fuzzy control systems. Attention will be focused on stability analysis and controller design based on the so-called Takagi-Sugeno fuzzy models or fuzzy dynamic models. Perspectives of model based fuzzy control in future are also discussed

1,575 citations

Book
01 Aug 1996
TL;DR: Fuzzy sets as mentioned in this paper are a class of classes in which there may be grades of membership intermediate between full membership and non-membership, i.e., a fuzzy set is characterized by a membership function which assigns to each object its grade of membership.
Abstract: The notion of fuzziness as defined in this paper relates to situations in which the source of imprecision is not a random variable or a stochastic process, but rather a class or classes which do not possess sharply defined boundaries, e.g., the “class of bald men,” or the “class of numbers which are much greater than 10,” or the “class of adaptive systems,” etc. A basic concept which makes it possible to treat fuzziness in a quantitative manner is that of a fuzzy set, that is, a class in which there may be grades of membership intermediate between full membership and non-membership. Thus, a fuzzy set is characterized by a membership function which assigns to each object its grade of membership (a number lying between 0 and 1) in the fuzzy set. After a review of some of the relevant properties of fuzzy sets, the notions of a fuzzy system and a fuzzy class of systems are introduced and briefly analyzed. The paper closes with a section dealing with optimization under fuzzy constraints in which an approach to...

885 citations

Journal ArticleDOI
TL;DR: A review of the current status in control performance assessment (CPA) technology and industrial applications is presented in this paper, where the authors highlight the benefits and drawbacks of each CPA method.

490 citations

Reference BookDOI
01 Jan 1999
TL;DR: 1. Control Methodology 2. Dynamical Systems 3. Applications to Social and Environmental Problems 4.
Abstract: 1. Control Methodology 2. Dynamical Systems 3. Applications to Social and Environmental Problems

325 citations