Asad Azemi

Sliding-Mode Adaptive Observer Approach to Chaotic Synchronization

Extensions of sliding-mode adaptive observer are presented for state reconstruct nonlinear systems with uncertainty having unknown bounds. The observer uses non gains that are smoothened versions of classical sliding-mode gains and they are co ously updated to guarantee a globally stable observation error. This observer is ap to Chua’s circuit in a chaotic synchronization scheme. A generalization to known w form type disturbances and measurement uncertainties is pointed out. @S0022-0434 ~00!02304-2#

Actuator fault detection and isolation in nonlinear systems using LMIs and LMEs

An actuator fault detection and isolation scheme for a class of continuous-time nonlinear systems is presented. A bank of unknown-input observers is used for this purpose. Only linear matrix equations and inequalities are used in the design which makes it particularly attractive from a computational viewpoint.

PSpice and MATLAB in undergraduate and graduate electrical engineering courses

Popular educational software packages such as PSpice and MATLAB are rapidly becoming an essential part of many undergraduate and graduate electrical engineering courses. This paper presents experience at the Delaware County Campus of the Pennsylvania State University and the University of Arkansas at Fayetteville, with the incorporation of these packages into undergraduate and graduate level course. Specifically, the use of PSpice in circuits and signals course and circuits laboratory, and MATLAB in control systems, and optimal control courses. These packages have been found to greatly enhance student understanding of the course material.

Intelligent arrhythmia detection and classification using ICA.

In this paper a novel approach for cardiac arrhythmias detection is proposed. The proposed method is based on using independent component analysis (ICA) and wavelet transform to extract important features. Using the extracted features different machine learning classification schemas, MLP and RBF neural networks and K-nearest neighbor, are used to classify 274 instance signals from the MIT-BIH database. Simulations show that multilayer neural networks with Levenberg-Marquardt (LM) back propagation algorithm provide the optimal learning system. We were able to obtain 98.5% accuracy, which is an improvement in comparison with the similar works

Using AVK method to solve nonlinear problems with uncertain parameters

Although we usually would like to work with exact systems, most of the real world systems are nonlinear with uncertain parameters. In this paper, we propose AVK (A.V. Kamyad) approach to solve nonlinear problems with uncertain parameters (NPUP). This approach substitutes the original nonlinear system with an equivalent nonlinear programming (NLP) problem. Using this approach, we found an optimal solution of NLP problem and a new approximate solution for the original NPUP in Lp space.

Teaching the introductory computer programming course for engineers using Matlab

The introductory computer programming course for engineers is usually taught using the C++ programming language. This work describes our efforts during the past four years, as a pilot project, which can be used in an evaluation process by those departments that would like to substitute Matlab for C++. Those who would like to continue the current practice, but are looking for more challenging problems or projects involving Matlab can also use the project outcome. In order to increase student involvement in the learning process and further improve learning outcomes, the implementation plan included various hardware and software projects, not all at the same time. Robotics projects were added to illustrate an application of programming; which students can relate to and enjoy, as well as helping them improve their software and algorithm design skills for real-time applications. Software projects included the design of simple games and applications using Matlabpsilas graphical user interface (GUI) tool. A discussion of the advantages and disadvantages of conducting a computer programming course in this format, including four different course formats that we have used are included.

Full and reduced-order-robust adaptive observers for chaotic synchronization

Full- and reduced-order adaptive observers are presented for state reconstruction of nonlinear systems with uncertainty having unknown bounds. The observers use nonlinear gains that are smoothened versions of classical sliding-mode gains and they are continuously updated to guarantee a globally stable observation error. These observers are applied to Chuas circuit in a chaotic synchronization scheme with possible application to secure communications. A performance comparison of full- and reduced-order observers is also included.

Comparative study of several nonlinear stochastic estimators

In this paper we investigate the relative performance and design procedures of several nonlinear stochastic estimators. The filters that we are comparing are: Lyapunov-based, covariance assignment, extended Kalman filter, and state-dependent Riccati equation estimator. First we provide an overview of these estimators and then we will compare their performance using first- and second-order nonlinear stochastic systems. The discussion will include convergence property, difficulty level of the design, computational time, and overall performance, based on absolute error and mean square error of the estimation.

Phase synchronization and synchronization frequency of two-coupled van der Pol oscillators with delayed coupling

In this paper, phase synchronization and the frequency of two synchronized van der Pol oscillators with delay coupling are studied. The dynamics of such a system are obtained using the describing function method, and the necessary conditions for phase synchronization are also achieved. Finding the vicinity of the synchronization frequency is the major advantage of the describing function method over other traditional methods. The equations obtained based on this method justify the phenomenon of the synchronization of coupled oscillators on a frequency either higher, between, or lower than the highest, in between, or lowest natural frequency of the aggregate oscillators. Several numerical examples simulate the different cases versus the various synchronization frequency delays.

Using MATLAB in a graduate electrical engineering optimal control course

Control system design packages like MATLAB, MATRIX/sub x/, Control C, SIMNON, etc. have become essential ingredients of both undergraduate and graduate courses in the systems and controls area. This work describes our experience, at the Great Valley Campus of the Pennsylvania State University and the University of Arkansas, with the use of one of these packages, namely MATLAB with its Control Systems, Robust Control and LMI toolboxes in an optimal control course. In this paper we describe those standard functions of MATLAB and Control Systems Toolbox that are most appropriate for use in an optimal control course. Next, we focus on some special features of MATLAB that can be used to produce interactive simulations, using user interface controls. With the help of interactive simulations, instructors can effectively illustrate the change in system response due to parameter variations. Examples illustrating these features are included. A discussion of how MATLAB helps in reducing the amount of time spent in performing computational homework assignments and the advantages of using graphics user interface control is given. Finally, the general positive student reaction is reported.