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International Review of Automatic Control - Papers
A
Fuzzy Lyapunov Gain Scheduling Control for a Class of Nonlinear Systems
Based on Zubov’s Method
by K. Jouili, H.
Jerbi, N. Benhadj Braiek
Vol. 2. n. 3, pp. 235-248
Abstract - The present research work investigates a new nonlinear controller synthesis approach that is based on the methodological theory of Lyapunov. In particular, it relies on the determination of a Lyapunov function which is computed by solving Zubov’s partial differential equation of the studied controlled system. A nonlinear control law with adjustable parameters of attraction domains is derived. A Gain Scheduling Lyapunov-based control synthesis is implanted to construct an input control that guarantees stability and high precision along a desired trajectory. The characterization of parameters of attraction regions can causes serious practical problems as saturation behaviour. A fuzzy logic system is constructed and implemented in the Lyapunov Gain Scheduling to solve such problems and to permit online implementation of the proposed approach. The design is based on heuristic fuzzy rules such that each rule in the fuzzy logic system refers to a stable closed-loop subsystem. The explored control methodology is evaluated to a non-trivial temperature tracking in a CSTR. The simulation results demonstrate the efficiency and the high performance of the developed technique.
Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Control Lyapunov function, Zubov’s method, Stability domain, Gain Scheduling, Input saturation, Fuzzy logic system.
Model Predictive Control of Continuous Nonlinear Systems Using Series
Approximations
by Chrystine Gorman, Nathan Slegers
Vol. 2. n. 3, pp. 249-257
Abstract - This work develops a non-linear model predictive control method using series approximations. The method extends previous methods to include control effort and terminal control conditions in the penalty function while still resulting in an analytic approximate solution to the optimal control. It is shown that addition of control penalties provide a more intuitive method for shaping control when compared to extension of the prediction horizon required in previous methods. In addition, accuracy of the approximate solution is improved by directly penalizing control and maintaining a short prediction horizon.
Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Nonlinear Control, Optimal Control, Optimization Methods, Predictive Control.
Local
Stability Study of Mamdani Fuzzy PI Control Systems Determination of an
Attraction Domain
by B. Zahra, A.
Sakly, M. Benrejeb
Vol. 2. n. 3, pp. 258-267
Abstract - The determination of an attraction domain of an equilibrium point for fuzzy PI control systems in the case of particular partition of fuzzy input subsets is developed in this paper. To search local asymptotic stability for the fuzzy system, homogeneous overvaluing systems and the arrow form of the characteristic matrix are used in this study.
Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Local asymptotic stability, Mamdani fuzzy PI controller, Vector norms, Homogeneous overvaluing systems, Attraction domain.
Holonomic
Stratified Motion Planning along Decomposed Trajectory
by
István Harmati, Dániel A. Drexler
Vol. 2. n. 3, pp. 268-285
Abstract - This paper presents a new stratified motion planning which is accomplished along decomposed trajectory of a special class of system including walking robots, multiple fingers and similar reconfigurable multi-agent systems. The method assumes that the vector fields of a fictitious system called bottom stratified system span its entire configuration space. The concept establishes a method which is able to solve the motion planning problem (MPP) with a greater degree of freedom than previous stratified motion planning algorithms (MPA). The greater degree of freedom appears in the trajectory which is prescribed to the system. More exactly, while the previous approaches could reach only a final point, one may prescribe a special trajectory to the system if the new method is used. In order to use an efficient structure for motion and trajectory planning, an appropriate solution is to be chosen from the more than one existing representations. The paper presents a methodology to select the most suitable solution which satisfies the motion planning constraints. The results are demonstrated on an illustrative example of the new stratified motion planning for a hexapod robot.
Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Motion planning, Stratified system, Differential geometry.
Boundary Control of Nonlinear Distributed Parameters Port-Hamiltonian
Models for the Shallow Water Dynamics
by Alexandru
Dimofte, Boussad Hamroun, Laurent Lefèvre, Eduardo Mendes
Vol. 2. n. 3, pp. 286-299
Abstract - The port-controlled Hamiltonian formulation for classical hyperbolic systems is first recalled. It is applied to the classical Shallow Water equations used to model the free-surface water dynamics in open-air channels or rivers. Then an “energy shaping” control law suggested by a geometrically reduced mixed finite elements model is derived. It is shown how this control law is independent from the order of the reduced model. A Casimir invariant based energy shaping method for distributed parameter port Hamiltonian systems is developed and used to prove the stability of the desired equilibrium water flow and water levels profiles when the suggested boundary control law is applied directly to the infinite dimensional system.
Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Distributed Parameters Systems, Port-Controlled Hamiltonian Systems, Boundary Control Systems, Energy Shaping, Shallow Water Equations.
Real Power Transfer Allocation Method with the Application of
Radial Basis Function Network
by S. N. Khalid,
M. W. Mustafa, H. Shareef, A. Khairuddin, S. S Abdulah, A. Kalam
Vol. 2. n. 3, pp. 300-308
Abstract - This paper proposes a new method to identify the real power transfer between generators and load using modified nodal equations. It further focuses on creating an appropriate Radial Basis Function Network (RBFN) to solve the problem in a simpler and faster manner. For this purpose, two separate stages training algorithm have been chosen for the proposed RBFN power transfer allocation technique. Almost all system variables obtained from load flow solutions are utilised as input to the neural network. The validation of the proposed methodology is demonstrated by using the actual 25-bus equivalent power system of south Malaysia, to illustrate the effectiveness of the RBFN technique compared to that of the modified nodal equations method.
Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Load flow, Modified nodal equations method, Radial basis function network and real power.
Genetic Design of a Fuzzy Logic Controller for a Photovoltaic Grid Connected
System
by N. Tkouti, A.
Moussi
Vol. 2. n. 3, pp. 309-313
Abstract - This paper presents implementation of a fuzzy logic controller for the control of a line commutated inverter in a photovoltaic grid connected system, in which the design is performed automatically by means of genetic algorithm. The control system has the objective of extracting the maximum available solar power from the photovoltaic energy system and transferring this power to utility. Simulation results verify the superior performance of genetic fuzzy controller and its robustness in variant climatic conditions.
Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Fuzzy Controller, Genetic Algorithm, Grid Connection, Maximum Power Point Tracking, Photovoltaic Energy.
An
Observer-Based Approach for Induction Machine Faults Diagnosis
by M.
N. Saadi, H. Kherfane, B. Bensaker
Vol. 2. n. 3, pp. 314-319
Abstract - Induction machine faults diagnosis approaches such as motor current signature analysis (MCSA), extended Park’s vector approach (EPVA) and electric power spectral analysis (EPSA) consider the machine as a black-box system. Spectral analysis as a key tool is used for processing the available stator current signal to diagnose the machine faults. However, it is well known that different types of faults influence the stator current spectrum and it is very difficult to discriminate them. In order to overcome the inherent spectrum analysis difficulties an observer-based approach for induction machine faults diagnosis is investigate and discussed in this paper. A model of the machine is considered. A state observer is designed to estimate unmeasured state variables of the machine that contain more information about fault occurrence and its isolation. A simulation example for stator and rotor faults diagnosis is presented to point out the merits of the proposed approach.
Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Induction machine, Fault diagnosis, State observer, State estimator.
High
Performance Speed Tracking of Induction Motor Drives Using an Adaptive
Fuzzy-Neural Network Control
by Mokhtar Zerikat,
Soufyane Chekroun
Vol. 2. n. 3, pp. 320-326
Abstract - This paper relates an adaptive speed control of hybrid fuzzy-neural network for a high-performance induction motor drives. Speed control performance of induction motors is affected by parameter variations and non linearities in the induction motor. The aim of the proposed control scheme is to improve the performance and robustness of the induction motor drives under non linear loads and parameter variations. Both the design of the fuzzy controller and its integration with neural network in a global control system are discussed.. Simulation results shown excellent tracking performance of the proposed control system, and have convincingly demonstrated the usefulness of the hybrid fuzzy-neural controller in high-performance drives with uncertainly.
Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Induction motor, Hybrid fuzzy-neural network control, Adaptive control, Robustness.
Comfort
Improvement in Vehicles Using Electrorheological Dampers and Fuzzy Logic
Control
by J.
Rezaeepazhand, L. Pahlevan
Vol. 2. n. 3, pp. 327-335
Abstract - In the present study, two passive and a semi-active suspension systems with squeeze-mode electro-rheological (ER) dampers are presented to reduce the transmitted forces to the driver. Since the rigid connection of the driver’s seat to the cabin with ER damper imposed undesirable values of acceleration to the driver, an independent ER-based suspension for the seat is applied to the assembly. A 2-DOF model of the system is constructed and a modified direct integration algorithm is used to simulate the transient behavior of the system. Further, to maintain the acceleration of the driver’s seat in its allowable limit a fuzzy logic control system (FLC) is applied. As the results present, the designed controller was found very effective in reduction of the transmitted force to the driver.
Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Fuzzy logic, ER dampers, Vibration control, Cabin suspension, Transient analysis.
An
Assistive Guidance System for Disabled People
by Abdelghani
Redjati, Mounir Bousbia-Salah
Vol. 2. n. 3, pp. 336-340
Abstract - The aim of this paper is to develop a voice control system for disabled people. It is based on a speech recognition development kit ‘VD364’ and is intended to control a wheelchair as well as a manipulator arm for people with severe disabilities. The objective is then to put forward a vocal command system that allows the arm to move in a well determined area to accomplish tasks that must be given by the user as well as the displacement of the wheelchair. In addition, an ultrasonic system is considered to detect obstacles faced by the user. Experimental results of the proposed system are presented and discussed.
Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Obstacle detection, Robotic assistance, Speech, Vocal command.
Intelligent
Control of Quasi Resonant Buck Converter
by A. Rameshkumar,
Dr. S. Arumugam
Vol. 2. n. 3, pp. 341-348
Abstract - A controller based on Fuzzy logic is implemented and its application to the regulation of power converter is investigated. Being free of complex equations and heavy computation, it achieves fast dynamic response and adapts to varying conditions of operation. The topology is modelled using MATLAB software and operated at finite higher switching frequency to evaluate its closed-loop performance in respect of line and load regulation. It is verified by transient characteristics that due to quasi-resonance there is a drastic change in peak overshoot and settling time and the proposed strategy has good rejection ability for supply and load disturbances.
Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Quasi Resonant Buck Converter, GSSA, Fuzzy Logic, Line regulation and load regulation.
A
Dual Action Multi-loop Error-Driven Control Strategy for Speed Control
of Switched Reluctance Motors
by Nirod C. Sahoo,
Adel M. Sharaf
Vol. 2. n. 3, pp. 349-358
Abstract - This paper presents the design of a novel dual action multi-loop error-driven nonlinear control strategy for closed-loop speed control of switched reluctance motor (SRM) drive under dynamic conditions. The proposed control system consists of cascade connections of a desired torque controller, a reference current generator and voltage controller (one for each phase of SRM). The desired torque controller takes reference speed, actual motor speed and average motor current as inputs to generate a modulated error signal and outputs the desired torque. The reference current generator outputs phase reference currents assuming two-phase-on scheme. The phase voltage controller, using a tan-sigmoid activation function, computes the voltages to be applied to the phase windings to regulate the desired currents using reference and actual currents and motor speed. A supplementary speed signal assists in better current regulating action under dynamic conditions. The tan-sigmoid activation block inside voltage controller helps to compensate for the nonlinearities of the electrical circuit of phase windings. The complete control algorithm is tested, by simulations, under transient conditions on the nonlinear dynamic model of SRM. The responses are compared with those of conventional controllers, i.e., proportional-integral (PI) type controllers, for various operating conditions. The results demonstrate the efficacy of the speed control scheme.
Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Switched reluctance motor, Speed control, Multi-loop nonlinear control.
Automatic
Segmentation of Handwritten Arabic Documents
by F. Bouafif
Samoud, S. Snoussi Maddouri, N. Ellouze
Vol. 2. n. 3, pp. 359-365
Abstract - This paper presents an automatic extraction of handwritten components. In the first hand we present two more used methods in the literature. The first method is based on the MM. The second method is based on HT. In the second hand we propose a hybrid method based on the combination between the HT and the MM. These methods are evaluated on CENPARMI-Arabic Checks Database, in order to extract the handwritten components existing in the check (numerical amount, literal amount and date zone). We present a concept for automatic evaluation of the results, based on a label tools for the different part of the used documents. We achieve a correct extraction rate of 96.5% for the proposed method.
Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Document processing, Extraction methods, MM, HT, CENPARM-data base.
