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Home>Products>Journal and Reviews>I.RE.A.CO.>Latest issue International Review of Automatic Control (Theory and Applications) - January 2010 - Papers
International Review of Automatic Control - Papers
Vol. 3. n. 1, pp. 1-10
Abstract - The use of efficient methods to handle uncertainty in type-2 fuzzy controllers (FCs) is of fundamental importance for real world applications, since the success of this kind of controllers will depend on finding the appropriated parameters of the type-2 controller, being this task highly computational expensive thus time demanding. Therefore, the use of new methods to achieve the aforementioned tasks is still under study. In this paper we used a novel optimization method called the Human Evolutionary Model (HEM) to optimize the parameters of two implementations of interval type-2 FCs, one using the Matlab Mendel’s software; the second using an interval type-2 implementation referred in literature as Average method since uncertainty is modeled using two type-1 FC. Some experiments are presented where system uncertainty was simulated, for both controllers the fuzziness of MFs was optimized using the HEM. Some bench marks were established in order to know the proposed system performance. In this work, the experimental results showed that both controllers perform very similar and they are consistent with previous results, so the HEM demonstrated to be a suitable method to optimize type-2 MFs. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: T2 Fuzzy Controller, HEM, Global Optimization.
Vol. 3. n. 1, pp. 11-23
Abstract - The problem of fault and abrupt disturbance detection and isolation (FDI) for discrete linear systems is analyzed in this paper. The parity space approach to robust fault detection is an elegant and a general tool for additive faults in stochastic linear systems. Algorithms for detecting and isolating faults on-line and analyzing the probability for correct and incorrect decisions off-line are provided. The basic idea behind the model-based FDI approach is to take advantage of the nominal model of the system to generate residue that contains information about the faults. Evidently, the quality of the model is of fundamental importance for both fault detectability and isolability. Therefore, we design a detection system to be able to minimize the error risks, the false alarms probability (PF) and the non detection failures probability (PND). The establishment of a system model is often sullied with uncertainties such as, dynamic rapids neglected, non measured disturbances, neglected delays and unknown parametric variations. The aim is to design residual generators, which deliver a residual signal fully decoupled from unknown disturbances. First, an approximate disturbance decoupling in fault detection is established. The objective of work is to conceive a robust system FDI with respect to uncertainties and to improve the performances of decision-making on the state of a given system. Among the required performances are the detection of incipient faults, the speed of detection, the insulation and the characterization of the detected faults, the minimization of the number of false alarm and the minimization of the non detection failures probability. In this paper we focus our attention on the evaluation of the residuals with Bayes test and GLR test of binary hypothesis test for fault detection and isolation to adaptive threshold compared with a fixed threshold. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Approach decoupling, FDI, decision-making, fixed threshold, adaptive threshold, Bayes test, GLR test, test performances, false alarm, miss detection, most stringent test.
by N. Majdoub, A. Sakly, M. Sakly, M. Benrejeb Vol. 3. n. 1, pp. 24-31
Abstract - In this paper, Ant Colony Optimization (ACO) algorithm is used to computation of the optimal switching instants for autonomous switched systems. We seek to minimize the performance index, depends on these instants, over a finite time horizon. The proposed algorithm is validated through numerical examples, where the obtained results are compared to gradient method ones. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Autonomous Switched Systems, Switching Instants Optimization, Ant Colony Optimization (ACO).
Vol. 3. n. 1, pp. 32-37
Abstract - The establishment of planning and management staff represents a major problem facing most organizations. This task is based on finding solutions to combinatorial nature, responding to multiple constraints. In this paper we describe an advanced method for finding a solution very close to the mathematical model of type CSOP that we selected for the preparation of schedules of nurses. This method combines the technique of column generation dynamic changed with the procedure of branch and bound which allows it to be done at each node of the tree search. Our results show that the tool developed is very effective in terms memory usage, decision support based on the preferences and wishes of assignment. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: planning, decision support, optimization, branch and bound, column generation.
Vol. 3. n. 1, pp. 38-44
Abstract - Negative and positive feedback regulation are ubiquitous in biological networks. These naturally occurring control systems play a vital role in regulating the dynamics of these networks and thus controlling the behaviour of different biological processes. In this paper we investigate systematically the effect of both positive and negative regulation and their combination in irreversible chains of reaction networks. The dynamic behaviour of the resulting non-linear systems are studied using simulation, bifurcation analysis and analytical work. This provides important insights into the effect of individual and combined regulation in chains of networks. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Feedback control, Positive feedback, negative feedback, mixed feedback, irreversible.
Vol. 3. n. 1, pp. 45-52
Abstract - The Linear Observer Method was adopted in this paper to study the SSR damping characteristics with TCSC. The study system was modified from the IEEE Second benchmark model by changing a part of the fixed series capacitor to TCSC. It is tried to stable torsional modes of turbine – generator units and improve their damping by using optimal linear control, with an practical viewpoint. In some of genuine applications, measurement of all state variables is impossible and uneconomic. Therefore in this paper, a novel approach is proposed by using optimal state feedback, based on the reduced – order observer structure. It was shown also that the Linear Observer Method can mitigates Sub-synchronous Oscillations (SSO) in power systems. The proposed method is applied to the IEEE Second Benchmark system for SSR studies and the results are verified based on comparison with those obtained from digital computer simulation by MATLAB. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Sub-synchronous resonance, Sub-synchronous oscillations, Reduced-Order Observer, Torsional Modes, TCSC.
Vol. 3. n. 1, pp. 53-59
Abstract - In this
work we show that the variable speed drives are growing and varying. A
new FLC controller and its application to the speed control of an
induction motor drive is compared to the traditionally PI controller.
The PI controller has trouble meeting with parameter variations and load
disturbances. The proposed fuzzy controller is applied to solve these
problems. Computer simulations are provided to demonstrate the
robustness of the proposed fuzzy controller in presence of load
disturbances and parameters variations. The simulation results show the
validity and of the proposed technique. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Speed, Fuzzy Logic, Fuzzification, FLC, PI Controller, FOC, Intelligent Control.
Vol. 3. n. 1, pp. 60-65
Abstract - Mobile systems traveling through a complex environment, like underwater environments, present major difficulties in determining accurate dynamic models. Autonomous underwater vehicle motion in these conditions requires investigation of competent control solutions that guarantee robustness against external parameter uncertainty. In this paper, a microcontroller-based fuzzy logic controller is introduced to stabilize balancing the robot while it is moving forward. This approach is applied to one onboard microcontroller which is inside small AUV and the control system is able to meet the required robustness. The significance of this work is because of using a microcontroller with its limited amount of on-chip RAM rather than using commercial computer. It is implemented along with a fuzzy PI controller as the supervisor, and evaluated through experiments. It is shown that the characteristics of the fuzzy logic, such as flexibility of the I/O selection and saturation of the outputs, provide favorable performance to the control system for AUVs. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Autonomous underwater robot, AUV, Fuzzy logic controller, Pulse width modulation.
Vol. 3. n. 1, pp. 66-74
Abstract - The automatic maintenance of the optimal distance between automobiles is one of the applications that will certainly have a wide application on the streets of the future. Today there are few automobiles that have this facility, but her necessity is obvious in the relentless growing conditions of traffic. For speed regulation, the driver can operate at a comfortable speed until reaching a maximum speed limit, at which point a vibrotactile vest on the seat belt informs the driver what degree of braking is necessary to return to a safe operating speed. If the vehicle detects an unavoidable collision with an obstacle, the vest cues the driver to stop the vehicle immediately. In this paper we will treat the problem of using the distance sensors information in the way of finding an automatic method of keeping the optimal distance between a automobile and the automobile behind. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Regulator classic, Regulator fuzzy, Optimal control.
Vol. 3. n. 1, pp. 75-82
Abstract - In this paper two algorithms for sensorless control of induction machines, linear reduced-order observer and sliding mode observer will be discussed and compared. The linear reduced-order observer method is a third order disturbance observer which is very simple to design and execute, while the sliding mode observer is complicated. It will be shown by the simulation results that the estimated speed by the two methods are very well, but proposed reduced order observer is sensitive to the stator and rotor resistance parameters while the sliding mode observer is robust against parameter variation. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Induction Machine, Sensorless Control, Sliding Mode Observer.
Vol. 3. n. 1, pp. 83-87
Abstract - The
automatism represents an important gap in the command of new technical
systems. This function has become much practiced either by the designers
or by operators of technical systems. For this purpose, same older
systems have also become an application domain of the automatism. Indeed
the problem of an automation project resides in how to respond in a
clear manner the two essential questions following: Do what hardware use
for a project Automation given? What are the scenarios that must ensure
the project Automation? Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Automation, System approach, OOPP method, Printing system.
Vol. 3. n. 1, pp. 88-93
Abstract - This paper discusses an approach to tune the PID controller parameters using the optimization method. The method involves analytically calculating the gain of the controller (Kc), integral time (Ti) and the derivative time (Td) for PID controlled systems whose process is modeled in first order lag plus time delay (FOLPD) form. A mat lab program is used to find the optimum value of the PID controller parameters which can achieve most of the systems requirements such as reducing the overshoot, maintain a high system response, achieve a good load disturbances rejection and maintain robustness. The objective function is selected so as to minimize the integral of Time Absolute Error (ITAE) performance index. A comparison between the proposed tuning rules and the traditional tuning rules is done through the Matlab software to show the efficiency of the new tuning rule. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: ITAE criteria, AMIGO, Z-N tuning rule, PID Template.
Vol. 3. n. 1, pp. 94-99
Abstract - The problem of estimating the parameters of a noisy autoregressive (AR) signal is considered. We propose a new least-squares (LS) method for estimating AR parameters that uses both low-order and high-order Yule-Walker equations in a new way. This estimate is biased. We derive a new method for noise variance estimation to yield unbiased LS estimate of the AR parameters. To evaluate the performance of the proposed method, computer simulations are performed. Simulation results illustrate that the performance of the proposed method is much better than the other estimation methods. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Autoregressive signals, Least-squares method, Yule Walker equations.
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