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Home>Products>Journal and Reviews>I.RE.A.CO.>Latest issue International Review of Automatic Control (Theory and Applications) - November 2008 - Papers
International Review of Automatic Control - Papers
Vol. 1. n. 4, pp. 407-412
Abstract - This paper presents a study on adaptive stabilization of continuous nonlinear systems with unknown terms. These systems are represented by Takagi-Sugeno (TS) fuzzy models using the sector nonlinearity concept. The stabilization of this class of systems and the determination of the estimated vector are made by an approach using a polyquadratic Lyapunov function. The development of the new obtained conditions of stability is given in terms of Linear Matrix Inequalities (LMI). The case of an unstable continuous nonlinear system of third order is considered to illustrate the proposed approach. Copyright © 2008 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Adaptive stabilization, Takagi-Sugeno (TS) fuzzy model, Linear Matrix Inequality (LMI), polyquadratic Lyapunov function.
by H. Boubertakh, M. Tadjine, P.-Y. Glorennec, S. Labiod Vol. 1. n. 4, pp. 413-421
Abstract - This paper shows analytically and clearly that typical zero-order Takagi–Sugeno (TS) PI , PD and PID fuzzy controllers with symmetric triangular membership functions for premise variables, symmetric singleton membership functions for the output variable, Larsen’s product for the fuzzy implication and the average sum for the defuzzification operator, are exactly equivalent to their counterpart classical PI, PD and PID controllers. These controllers cumulate the advantages of the classical and fuzzy controllers, namely, the simplicity and interpretability which makes the parameters tuning an easier task. The nonlinear behavior of these fuzzy controllers suitable for complex systems can be obtained easily by moving their quantities from their “linear” positions. That can be done manually or by using an optimization method. Copyright © 2008 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Fuzzy PID controllers, Classical PID controllers, Takagi-Sugeno fuzzy systems.
Vol. 1. n. 4, pp. 422-434
Abstract - This paper is reserved for the description and the parametric estimation of the non-linear stochastic systems. We consider the class of the non-linear stochastic systems, which can be described by input-output non-linear mathematical models with unknown, but constant, or time-varying parameters. The formulation of the parametric estimation problem of the considered non-linear stochastic systems is made, by using the prediction error method and the least squares techniques. In this context, two types of recursive parametric estimation methods are envisaged, namely the recursive instrumental variable (RIV) method and the recursive extended least squares (RELS) method. Recursive algorithms corresponding of the two recursive parametric estimation methods are developed. The parametric estimation of non-linear stochastic systems with unknown time-varying parameter is treated, while including a forgetting factor in the recursive parametric estimation algorithms. A numerical example, which is relating to the parametric estimation of a non-linear stochastic system, is treated in order to validate the developed analytical results. Copyright © 2008 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Non-linear stochastic systems, Input-output non-linear mathematical models, Parametric estimation, RIV parametric estimation method, RELS parametric estimation method.
Vol. 1. n. 4, pp. 435-440
Abstract - This paper addresses the synthesis of a fuzzy Model predictive control (FMPC) for nonlinear process based on fuzzy model of the Takagi-Sugeno (T-S) type, resulting in a stable closed-loop control system. Therefore the fuzzy model is viewed as a linear time varying system rather than a nonlinear one. Our strategy reduced the original and complex nonlinear quadratic optimization problem into a minimizing a convex function under constraints LMI. The method is applied to an industrial continuous stirred tank reactor (CSTR) problem with explicit and the simulation results demonstrate the effectiveness of the FMPC. Copyright © 2008 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Model Based predictive control (MBPC), non-linear system, Takagi−Sugeno (T−S) fuzzy models, LMI-Based design.
Vol. 1. n. 4, pp. 441-445
Abstract - In this work a solution set of synthesis problem for the family of nonlinear systems is constructed, i.e., we find a set of positional bounded controls, and the trajectory of the system , starting at the initial position terminates at the origin in finite some time . The method of the controllability function is used. Copyright © 2008 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Controllability function method, Synthesis problem, Nonlinear control system.
Vol. 1. n. 4, pp. 446-457
Abstract - In this paper a stable adaptive fuzzy control of permanent magnet synchronous motor (PMSM) is developed. The possibilities offered by the fuzzy systems Takagi-Sugeno type are invested, in terms of continuous nonlinear functions approximation capacity, and Lyapunov theory is exploited to establish a parametric adaptation law ensuring the total system stability. The fuzzy adaptive law incorporates a compensatory robust term, which has as a role to compensate the reconstruction errors effects. The simulation results of permanent magnet synchronous motor speed tracking show the proposed method validity in the presence of strong parametric perturbations. Copyright © 2008 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Fuzzy systems, Fuzzy adaptive law, Robust term, Reconstruction errors, Permanent magnet synchronous machine, Inverter.
Vol. 1. n. 4, pp. 458-465
Abstract - To reach the maximum wind power extraction, wind turbine has to reduce their disconnection. For this reason grid operators impose, by theirs grid connection requirements, to wind turbine producer to support some grid disturbance. This paper deals with the behavior of wind turbine equipped with a Doubly Fed Induction Generator (DFIG) under voltage dip. A control strategy of the Unified Power Flow Control (UPFC) using PI controller is presented. And finally fuzzy logic controller is illustrated and compared to PI controller. Simulation results have shown that the proposed control strategy is more effective, and the fluctuation of the active and reactive power may be successfully limited in a small range under a serious grid voltage dip. In addition, the effectiveness of the proposed control strategy is demonstrated by the reduction of the time of transient mode caused by the grid voltage dip. Copyright © 2008 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Wind energy, Doubly Fed Induction Generator, voltage dips, fault, fuzzy logic controller.
Vol. 1. n. 4, pp. 466-473
Abstract - This paper demonstrates that invariant regulator and superior servo performance can be obtained, compared to fixed gain controllers, through sliding mode speed control of a decoupled induction machine. The speed control scheme consists of a standard indirect vector control implementation for torque control, with a sliding mode speed controller. Assuming the bounds on the parameter variations are known, the control law is derived. The chattering of single component sliding mode controller, is eliminated by introducing a boundary layer. The performance of single component sliding mode controller with boundary layer is further improved by dual component sliding mode controller. Robustness to variation of parameters, like rotor resistance and moment of inertia are demonstrated through simulation. Results are compared with fixed gain controllers. A speed estimation algorithm is implemented and used in the sliding mode control scheme. Sensorless sliding mode control is found to be superior to fixed gain control. Further, it is established through tests that, dual component sliding mode control performs better than single component sliding mode control. Copyright © 2008 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Field Orientation, Sliding Mode Control, Speed Estimation Schemes, Observer based Estimation.
Vol. 1. n. 4, pp. 474-485
Abstract - This paper gives an overview on control and management strategies for energy systems in hybrid electric vehicles. This paper formulates energy management as an optimization problem, provides an overview on optimization techniques and stability analysis. Being first of its own kind in providing the basic mathematical formulations, this paper will be beneficial for the young researchers in this area. Copyright © 2008 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Hybrid Electric vehicle, Energy management and control, Optimization techniques, stability analysis.
Vol. 1. n. 4, pp. 486-493
Abstract - TA variable speed wind energy conversion system, with squirrel cage induction generator, is reported in this paper. The induction generator is driven by a vertical axis wind turbine and feeds power to utility grid through two double side pulse width modulated converters connected between stator and grid. Fuzzy logic control is used to increase the energy captured from wind, and to increase efficiency by reducing core loss. Transient performance of speed control system is also improved. The generator control system uses three fuzzy controllers. The first fuzzy controller tracks the generator speed with the wind velocity to extract maximum power. The second fuzzy controller programs machine flux for light load efficiency improvement. The third fuzzy controller provides robust speed control against wind vortex and turbine oscillatory torque. The performance of the fuzzy controlled variable speed wind energy conversion system is evaluated through simulation study in MATLAB. Simulation results prove that wind power system with fuzzy control captures more power, has more efficiency and less core loss. Closed loop speed response of the generator with fuzzy controller, shows that fast speed response can be obtained with well designed fuzzy controller. Copyright © 2008 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Decoupling control, fuzzy logic controller, induction generator, vector control, wind power generator.
Vol. 1. n. 4, pp. 494-499
Abstract - Metal oxide arresters have dynamic characteristics that are significant for overvoltage coordination studies involving fast front surges. This dynamic responses are frequency-dependent and can not be represented with the conventional non-linear V-I characteristics. Several models have been proposed to simulate this frequency-dependent behavior. But their accuracy are not acceptable in some cases. In this paper a new technique based on the genetic algorithm is proposed to obtain the best possible parameter values of the metal oxide arrester model. The existing GA method is developed by adding a weight term in the objective function which is related to the magnitude of input impulse current in time domain.The proposed method is applied on recommended surge arrester dynamic model from the IEEE W.G. 3.4.11 and results are obtained. The simulations were performed with the SIMULINK/MATLAB and the results were compared with the experimental data reported on the manufacturer’s catalogue available in the literature.The main innovation introduced by the paper lies in the implicitly of the criteria proposed for the parameter identification of the dynamic model of arresters. Effectiveness and simplicity of use make the proposed method a useful tool for insulation coordination studies involving steep front transients. Copyright © 2008 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Metal Oxide Surge Arrester, Frequency-Dependent Model, Genetic Algorithm.
Vol. 1. n. 4, pp. 500-506
Abstract - In this paper, a control scheme for a robust compensation of friction in a servomechanism is proposed. The advantage of this method is based on active disturbance rejection added to the action of the high stiff gain provided by the nonlinear controller. The designed controller uses the estimated system states (position, velocity) to enhance tracking performance of the servomechanism while the estimated disturbance is rejected for the compensation of the effects of nonlinear friction. The validity of the proposed control strategy is demonstrated under simulations and the robustness of the observer/controller is verified. Copyright © 2008 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Disturbance Observer, Active Disturbance Rejection, Stiffness Control, Servomechanism with friction.
Vol. 1. n. 4, pp. 507-514
Abstract - In this paper we are concerned with the automatic control of a two axis sun tracking system with a PIC microcontroller (16F84A) in order to evaluate the gain in term of collected solar energy between fixed system and two axis sun tracking system. In this we start with an introduction that include a survey exhaustive bibliography of relevant work on the field of the sun tracking systems in the last ten years, where we present their control systems and the experimental results followed by a description of the mechanical parts of each system and we give the incentives behind the present work and the approach used as to provide a consistent alternative namely mechanical solution for the vertical and horizontal movements of the supporting structure in order to ensure the energy autonomy for the entrainment of the system. Then we present a control approach based on the programmable electronics with closed loop system where we have used a new low cost optical sensor realized with simple photodiodes. Finally, we give the results of in-situ experimentation for two systems: A fixed system tilled at 45° and oriented to the south and the two sun tracking system that led to have a gain in the collected solar energy (51.29%) between the two systems. Copyright © 2008 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Photovoltaic generators; Sun tracking system; PIC microcontroller; collected solar energy.
Vol. 1. n. 4, pp. 515-522
Abstract -
This paper tackles the subject of the motion command of a wheeled mobile
robot. A fuzzy logic controller (FLC) has been developed and implemented
for the motion of the robot from an initial position towards another
desired position, taking into account the Kinematic constraints. Copyright © 2008 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Fuzzy controller, Optimization, Gradient Method, Autonomous Mobile Robot.
by L. Yu, G. Yan, L. Yu, G. Liu Vol. 1. n. 4, pp. 523-527
Abstract - This paper described the structure of a flexible miniature robotic system which can move in human cavities, it makes inchworm-like movement driven by a 3-DOF pneumatic rubber actuator and holds its positions by air chambers. The driving characteristics in axial and bending directions of the actuator were analyzed and the robot control system was designed. The five-layer neural network controller was proposed to estimate the straight movement and the bending movement of the actuator respectively. The control response of the system by fuzzy neural network, wavelet neural network and fuzzy wavelet basis neural network were studied. Results prove that good static and dynamic control effect of the robotic system can be obtained by the proposed fuzzy wavelet basis neural network. Copyright © 2008 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Intelligent Control, fuzzy wavelet neural network, Robot Actuator.
by S. W. Nawawi, M. N. Ahmad, J. H. S. Osman Vol. 1. n. 4, pp. 528-542
Abstract - TIn this paper the modeling and control for class of mobile robot using feedback linearization method is discussed. The dynamic model of a TWIP mobile robot is derived based on Lagrange method. The condition of the model then has been checked for strong accessibility and maximum relative degree for the purpose of state-feedback linearization controller design. Based on these result it is known that the partial feedback linearization controller can be formulated which forms as main contribution of this work. The controller can perform the tracking of TWIP orientation and heading speed, while maintaining the pitch angle within specified range. The verification of the performance of the controller under various system conditions is done through simulation work. Copyright © 2008 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Velocity control, Input-output state-feedback linearization, Wheeled mobile robot, Nonlinear system.
by M. Siahi, M. A. Sadrnia , A. Darabi Vol. 1. n. 4, pp. 543-548
Abstract - In this paper the design of an observer for MIMO systems using eigenstructure assignment and the employment of this observer for fault diagnosis are investigated. Moreover, the designed observer will be implemented in a model of unmanned aircraft. Furthermore, the state feedback design with eigenstructure assignment has been accomplished on the aircraft. The design aim is to obtain suitable gains for the observer and the state feedback, as well. Using this method, a complete parametric expression for the observer gains and the state feedback gains are established in terms of a set of parametric vectors and closed loop poles. The existence of a set of parametric vectors and closed loop poles represents some degrees of freedom in the design. The simulation results corroborate the effectiveness and simplicity of the proposed method. Copyright © 2008 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Eigenstructure Assignment, State Observer, State Feedback, Fault Detection and isolation.
by M. R. Bonyadi, H. Shah-Hosseini Vol. 1. n. 4, pp. 549-559
Abstract - Numerical Computation is widely used in engineering problems. In this paper, it is shown that many Numerical Computation problems can be expressed by one or few artificial neurons. Then, the task of solving each of the problems is converted to the task of training the neurons in order to find the weights of the neurons. The weights of the neurons contain the solution to the problem at hand. As a result, to solve a Numerical Computation problem, there is no need to develop special algorithms for the problem. Experimental results demonstrate that this novel approach is successful in solving several different Numerical Computation problems and may pave the way to tackle other Numerical Computation problems by using only neural networks without developing specific algorithms. Copyright © 2008 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Neural Networks, Numerical Computation, Gradient Descent, Levenberg-Marquardt.
by L. Nabli, K. Ouni Vol. 1. n. 4, pp. 560-566
Abstract - In this paper we present an approach of detection and localization of the defects, based on a indirect supervision using principal component analysis (PCA) and the Average Dynamics of the Metrics (ADM). In a unity of textile spinning, we define some indicators of quality of the product. ADM permits the valuation of the quality of the produced to different levels of the proceeding of manufacture. Like this, an indication of calculated detection from the last principal components is used to the detection of the defects. Once a default is detected, the calculation by contribution of the variables is used to localize the variable tally to the default. Copyright © 2008 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Indirect supervision, Principal components analysis, Average dynamics of the metrics, Diagnosis, Detection of the defects of quality indicators, Calculation of the contributions.
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