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Issue 1, Volume 6,
January 2011
Title of the Paper: An Exploratory
Method for Effective Deployment of Programmable Logic Controllers (PLCs)
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Authors: Lucien
Ngalamou, Leary Myers
Abstract: This paper presents a preliminary study of an approach that models
programmable logic controllers (PLCs) for their effective deployment in
industrial control processes. A working model is developed for automatic
allocation of PLCs and also a formal verification of Ladder Diagram
representations of control processes using the Symbolic Model Verifier (SMV)
tool. Automatic resource allocation is achieved through the proposition of a
digraph model for any Ladder Diagram representation of a control process,
which is then translated into an XML (Extensible Mark Up Language) model. The
required PLC resources needed to implement a control process are extracted
from the XML model. These resources are then used by a selection engine to
determine, from a PLC database, the most appropriate PLCs or Embedded
Controllers (EBCs) that can satisfy the resource requirements. Additionally,
information extracted from the XML model is used to generate a formally
verifiable SMV code of the system. This paper focuses on the practical
implementation, testing, and verification of three conceptual modules applied
to a control process. These are, the XML model of the control process, the PLC
Database Automatic Resource Allocation, and the XML-to-SMV translator. This
work was significantly motivated by the ever increasing number of industries
who seek to increase their productivity by automating their processes.
Keywords: Automatic
Resource Allocation, XML Model, Programmable Logic Controllers (PLCs), PLC
Database, XML to SMV Translation, and Formal Verification
Title of the Paper: Robust Design for
Etching Process Parameters of Hard Disk Drive Slider Fabrication Using Data
Mining and Multi Response Optimization
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Authors: Pongsak
Holimchayachotikul, Komgrit Leksakul, Guido Guizzi
Abstract: This paper is to provide a proper insight into solving a
multi-response optimization problem using hybrid response surface methodology
(RSM) based on robust parameter design (RPD) concepts and data mining (DM) for
the multi-response optimization of a RIE process. Over the recent years in
many high precision manufacturing organizations, domain experience and
engineering judgment have been used to handle multiple response optimization
problems. These manners have led to the increase in uncertainty during the
decision-making process. This situation has also happened in the hard disk
drive fabrication based on reactive ion etching (RIE). This process is highly
complicated in setting the parameters using the slider to the right customer
specifications. Therefore, this paper presents a hybrid model to optimize the
concerning responses of this process in terms of mean and variance. The
silicon plates with a patterned wet film photo resistance as a base substrate
are used to demonstrate this research. To begin the proposed approach, design
of experiment (DOE), named central composite design (CCD), was employed to
accumulate the process records and to specify the significant parameters of
the process. Then, support vector regression (SVR) was brought into play to
institute the nonlinear multivariate relationships between process parameters
and responses. Data obtained from DOE were used in the training process. Last
but not least, the regression decision tree and domain engineering knowledge
were opted for the initial point of optimization algorithms as well. In
conclusion, the reduced gradient search algorithm, a hill-climbing procedure
and desirability function were adapted to the DOE model while grid search and
desirability function were adapted to the SVR model to find the optimum
parameter setting. SVR was found to be the technique with the highest
prominent accuracy performance, so it was selected to construct a RIE process
model. Consequently, the optimum condition from the final model has been
efficiently enabled to be applied in real production based on its experiment
confirmation.
Keywords: Reactive Ion
Etching (RIE), Response Surface Methodology (RSM), Support Vector Regression
(SVR) Multi-response Optimization, Robust Parameter Design (RPD), Data Mining
(DM)
Title of the Paper: Adaptive Wavelet
Neural Controller Design for a DC-DC Power Converter using an FPGA Chip
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Authors: Yu-Hsiung Lin,
Chun-Fei Hsu
Abstract: The DC-DC power converters are widely used; however, the controller
design for the DC-DC power converters cannot easily design if the load
dynamics vary widely. This paper proposes an adaptive wavelet neural control
(AWNC) system for a forward DC-DC power converter. The proposed AWNC system is
composed of a neural controller and a robust controller. The neural controller
uses a wavelet neural network to online mimic an ideal controller and the
robust controller is designed to cope with the approximation error between the
neural controller and the ideal controller. A proportional-integral (PI) type
parameter tuning mechanism is derived based on the Lyapunov stability theory;
thus not only the system stability can be guaranteed but also the convergence
of the tracking error can be speeded up. Finally, a comparison among the PI
controller, the fuzzy controller, the adaptive neural fuzzy control, the
adaptive neuro-wavelet control and the proposed AWNC is made. The experimental
results show that the proposed AWNC system is robust with regard to different
input voltages and load resistance variations.
Keywords: Adaptive
control; robust control; sliding-mode control, wavelet neural network; DC-DC
power converter
Issue 2, Volume 6,
February 2011
Title of the Paper: Subtractive Fuzzy
C-means Clustering Approach with Applications to Fuzzy Predictive Control
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Authors: Ji-Hang Zhu,
Hong-Guang Li
Abstract: To identify T-S models, this paper presents a so-called “subtractive
fuzzy C-means clustering” approach, in which the results of subtractive
clustering are applied to initialize clustering centers and the number of
rules in order to perform adaptive clustering. This method not only regulates
the division of fuzzy inference system input and output space and determines
the relative member function parameters, but also overcomes the impacts of
initial values on clustering performance. Additionally, the orthogonal least
square algorithm is employed to identify the parameters of consequents and
linearize the systems over every sample time, ultimately resulting in the
entire T-S fuzzy models. With this approach available, a fuzzy model
predictive control system is established, along with corresponding control
algorithms derived, as well as control system simulations carried out which
explicitly demonstrate the effectiveness of the proposed method.
Keywords: T-S mode
identification; subtractive clustering; fuzzy C-means clustering; Generalized
Predictive Control
Title of the Paper: Sliding Mode
Control Law for a Variable SpeedWind Turbine
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Authors: Oscar
Barambones, Jose Maria Gonzalez De Durana, Patxi Alkorta, Jose Antonio Ramos,
Manuel De La Sen
Abstract: Modern wind turbines are designed in order to work in variable speed
operations. To perform this task, wind turbines are provided with adjustable
speed generators, like the double feed induction generator. One of the main
advantage of adjustable speed generators is improving the system efficiency
compared to fixed speed generators, because turbine speed can be adjusted as a
function of wind speed in order to maximize the output power. However this
system requires a suitable speed controller in order to track the optimal
reference speed of the wind turbine. In this work, a sliding mode control for
variable speed wind turbines is proposed. An integral sliding surface is used,
because the integral term avoids the use of the acceleration signal, which
reduces the high frequency components in the sliding variable. The proposed
design also uses the vector oriented control theory in order to simplify the
generator dynamical equations. The stability analysis of the proposed
controller has been carried out under wind variations and parameter
uncertainties by using the Lyapunov stability theory. Finally simulated
results show, on the one hand that the proposed controller provides a
high-performance dynamic behavior, and on the other hand that this scheme is
robust with respect to parameter uncertainties and wind speed variations, that
usually appear in real systems.
Keywords: Wind Turbine
Control, Variable Structure Control, Modeling and Simulation
Title of the Paper: Hidden Oscillations
in Dynamical Systems
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Authors: G. A. Leonov,
N. V. Kuznetsov, O. A. Kuznetsova, S. M. Seledzhi, V. I. Vagaitsev
Abstract: The classical attractors of Lorenz, R¨ossler, Chua, Chen, and other
widely-known attractors are those excited from unstable equilibria. From
computational point of view this allows one to use standard numerical method,
in which after transient process a trajectory, started from a point of
unstable manifold in the neighborhood of equilibrium, reaches an attractor and
identifies it. However there are attractors of another type: hidden
attractors, a basin of attraction of which does not contain neighborhoods of
equilibria. Study of hidden oscillations and attractors requires the
development of new analytical and numerical methods which will be considered
in this paper.
Keywords: Hidden
oscillation, attractor localization, hidden attractor, harmonic balance,
describing function method, Aizerman conjecture, Kalman conjecture, Hilbert
16th problem
Issue 3, Volume 6,
March 2011
Title of the Paper: Unstable Systems -
Tracking and Disturbance Attenuation
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Authors: Roman Prokop,
Natalia Volkova, Zdenka Prokopova
Abstract: The paper is aimed to the design of linear continuous controllers
for unstable single input – output systems. The controller design is studied
in the ring of (Hurwitz) stable and proper rational functions RPS. All
stabilizing feedback controllers are given by a general solution of a
Diophantine equation in RPS. Then asymptotic tracking and disturbance
attenuation is obtained through the divisibility conditions in this ring. The
attention of the paper is focused on a class of unstable systems. Both, one
and two degree of freedom (1DOF, 2DOF) control structures are considered.
Control loops with a feedforward part significantly reduce overshoots in
control responses. The methodology brings a scalar parameter for tuning and
influencing of controller parameters. As a result, a class of PI, PID
controllers are developed but the approach generates also complex controllers.
Simulations and verification are performed in the Matlab+Simulink environment.
Keywords: Unstable
systems, Diophantine equation, asymptotic tracking, Disturbance attenuation
Title of the Paper: Root Locus Analysis
of a Retarded Quasipolynomial
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Authors: Libor Pekar
Abstract: Time delay systems (TDS), called hereditary or anisochronic as well,
can be frequently found in many engineering problems and they constitute a
widespread family of industrial plants. Modelling, identification, stability
analysis, stabilization, control, etc. of TDS are challenging and fascinating
tasks in modern systems and control theory as well as in academic and
industrial applications. One of their possible linear representations in the
form of the Laplace transform yields the transfer function expressed as a
fraction of quasipolynomials, instead of polynomials, with delay (exponential)
terms in denominators. In this contribution, detailed root location analysis
of a characteristic retarded quasipolynomial of degree one is presented, which
gives rise to the spectrum of a retarded TDS. The presented analysis
represents also a powerful tool for controller tuning in pole-placement
control algorithms for delayed systems. A simulation example clarifies the
results obtained vie proven propositions, lemmas and theorems.
Keywords: Time delay
systems, root locus, stability analysis, retarded quasipolynomials
Title of the Paper: Matlab & Simulink
Simulation with FPGA-Based Implementation Sliding Mode Control of a Permanent
Magnet Synchronous Machine Drive
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Authors: Badre Bossoufi,
Mohammed Karim, Silviu Ionila, Ahmed Lagrioui, Gabriel V. Iana
Abstract: This paper starts with an overview of FPGA technology development,
followed by a presentation of design methodologies, development tools and
relevant CAD environments, including the use of portable hardware description
languages and system level programming/design tools. In this paper, a new
contribution for the FPGA-Based implementation of controls electrical. This
approach is based on concept modularity and reusability. In this paper is
presents a detailed description of the structure by Indirect Sliding Mode of
Permanent Magnet Synchronous Machine PMSM. Experimental results carried from a
prototyping platform are given to illustrate the efficiency and the benefits
of the proposed approach and the various stages of implementation of this
structure in FPGA.
Keywords: Permanent Magnet
Synchronous Machine (PMSM), FPGA, Indirect Sliding Mode Control, Power System
Control, Systems Generator, Reusability, PWM
Issue 4, Volume 6,
April 2011
Title of the Paper: Land Mine Detecting
Robot Capable of Path Planning
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Authors: Muhammad
Zubair, Muhammad Ahmad Choudhry
Abstract: The purpose of Landmine detecting robot is to cover maximum possible
area, presentation of landmines and the left over area on a visual map with
accuracy in millimeters. This paper presents a prototype model of land mine
detecting robot that is powerful yet low cost, easy controllable, having the
required accuracy and is equipped with visual interface for landmines
plotting, PID tuning and cameras alignment. Emphasis is placed on the control
of the differential drive robot in auto mode, semi auto mode and the manual
mode. The image processing is used to find the accurate position of robot
which provides the live reckoning feedback to the dead reckoning servo control
of the robot. Balance Beat metal detector is the sensor used to detect
landmines. The use of graphical user interface for the remote terminal
computer to control the robot provides the user a simple but powerful control.
The overall aspiration of system is to provide the user a powerful, cost
effective and the same time intelligible to an average user.
Keywords: Land Mine
detection, robot path mapping, image processing, Graphical user interface, PIC
microcontroller
Title of the Paper: Interdisciplinarity
in Computer-Aided Analysis of Thermal Therapies
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Authors: Daniela
Carstea, Ion Carstea, Iulia Maria Carstea
Abstract: The interdisciplinarity in computer-aided analysis of the human body
is an attitude of high education and top research and our work is an
illustrative example in this area. The thermal therapies, thermal injury and
thermal comfort can be understood if the temperature distribution in space and
time in the living tissue can be estimated or predicted. But this objective
can be fulfilled by a team of different specialists as engineers, doctors,
mathematicians and programmers. The work tries to present some computational
aspects in numerical simulation of the thermal model in skin tissue and the
limits of the mathematical models used in this approach. The bioheat equation
is discussed in the context of some clinical applications as irradiated skin
tissue by laser or a fire pulse. A thermal model based on the finite element
method was used.
Keywords: Thermal therapy;
Numerical solution; Bioheat transfer equation; Interdisciplinarity
Title of the Paper: Solar Cell Emulator
and Solar Cell Characteristics Measurements in Dark and Illuminated Conditions
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Authors: Yousry Atia,
Mohamed Zahran, Abdullah Al-Hossain
Abstract: This paper describes a novel data acquisition system designed and
implemented with facilities for measuring and monitoring the characteristics
of a PV solar cell, module and/or system. The functioning of the equipment is
based on the so-called virtual instrumentation. This is a non-conventional
concept, however it does not have the many limitations in other systems.
Additionally, the whole equipment can be implemented at significantly lower
cost than the commercial one. The dark characteristics test facility, based on
LabVIEW software to design an easy handling Graphical User Interface (GUI) and
use a single chip microcontroller with a serial interface. The system is used
to acquire the measured data from the cell under test and transfer it to a
supervisory computer for monitoring and other signal processing. The
preliminary test we have made indicates that the equipment we propose here is
highly reliable, which allows measuring and monitoring variety of solar cell
characteristics with a good accuracy.
Keywords: LabVIEW, AVR
Microcontroller, Solar Cells & Solar Array, I-V Curve Measurements, Solar Cell
Emulator
Title of the Paper: A Study on RTD-A
Controller for Multiple Input Multiple Output System and an Application
Example
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Authors: Du Bin, Chu
Jizheng, Cao Xi
Abstract: RTD-A (Robustness Tracking Disturbance rejection-global
Aggressiveness) controller, proposed by Babatunde A. Ogunnaike, is suitable
for single input single output system (SISO). On the basis of it, a new RTD-A
controller for Multiple Input Multiple Output system (MIMO) is illustrated and
the global optimal control solution is also discussed in this paper.
Simulation results prove that compared with IMC-PID (Internal Model Control),
this new algorithm has good performances in set-point tracking, disturbance
rejection and robustness.
Keywords: IMC-PID, RTD-A
Controller, Multiple Input Multiple Output System (MIMO), Robustness
Issue 5, Volume 6,
May 2011
Title of the Paper: Hierarchical
Control of a Complex Conveyors Belt System
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Authors: Corina Maria
Dinis, Gabriel Nicolae Popa, Angela Iagar
Abstract: Using the software-oriented technologies which contain maximum of
integrated software resources in product, in this work has been developed the
software for the hierarchical control of a complex conveyors system. This
ensures hardware simpleness, implementing of some evolved control algorithms,
on-screen measuring devices, a friendly graphic interface, which makes that
the entire system to show high reliability and flexibility. It shows the
advantages of microcontroller installations comparatively with classical
control installations.
Keywords:
Software-oriented hierarchical control, belt conveyors system, microcontroller
Title of the Paper: Contact-Bounce
Control and Remote Monitoring Interface Implementation of a PM Contactor
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Authors: Chih-Yu Hung
Abstract: This paper aims at researching the relationship between the dynamic
stability of an electromagnetic contactor (abbreviated as EM contactor below)
and the magnetic energy stored in the contactor. Explored contactors are in
terms of an equivalent nonlinear and time-varying inductor and the basic
characteristics of the contactor. Some special feature during closing phase
and voltage sag events occurred through the definitions of passivity
conditions theorem are found. By means of magnetic circuit analyzing method, a
mathematic modeland its numerical computer program of a contactor are first
established in our laboratory. Some important experiments such as the dynamic
stability of contactor during closing process and voltage-sag events are
carried out by using this model. These simulation results are compared with
the experimental results forvalidating the correctness of this contactor
model. The final comparing results are in agreement with well. For purpose of
further to know the voltage sensitivity of the experimental contactor, the
CBEMA curves are used and obtained as well. Finally, the dynamic stability of
the contactor during closing process and voltage sags is examined in terms of
the energy stored by means of the simulation model to simulate and there are
some very valuable results are obtained.
Keywords: Electromagnetic
contactor, permanent magnet contactor, CBEMA curve, passivity energy, dynamic
stability 1 Introduction
Title of the Paper: Geometrical Model
of Plant Presented on a State Surface of a Complex Error
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Authors: Oleg N.
Agamalov
Abstract: In paper considered a geometric approach for presentation the
mathematical model of a control plant, based on calculation a complex error,
allowing define an optimal control law of a plant as an equation of the
geodesic curve on a state surface of a complex error.
Keywords: Control system,
Hilbert transform, complex error of control, state surface of a complex error,
geodesic curve
Title of the Paper: Modeling and
Simulation of a New Active Vibration Control System for Flexible Structures
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Authors: Alireza
Tavakolpour, Musa Mailah, Intan Z. M. Darus
Abstract: This paper investigates the feasibility of using active force
control (AFC) method for the problem of active vibration control (AVC) of a
flexible thin plate structure through simulation. The plate system was first
modeled and simulated using Finite Difference (FD) method. Then, the validity
of the obtained computational model was investigated through comparative
studies between the plate natural frequencies redicted by the model and the
exact values of resonance modes found in literature. The AFC algorithm was
then embedded within the FD simulation platform to study the performance of
the control scheme. An appropriate value of the mass gain in the AFC algorithm
was estimated to be 14 kg through crude approximation technique which was
later shown to be close to the real mass of the plate system. Different types
of disturbances were applied to excite the plate system at different
excitation points so that the robustnessof the proposed control algorithm can
be evaluated in terms of its performance in reducing the vibration at
observation point. Results of the study clearly demonstrated the effectiveness
of the proposed control strategy to attenuate the unwanted vibrations of the
flexible thin plate system.
Keywords: Active force
control, finite difference, flexible plate, vibrations
Issue 6, Volume 6,
June 2011
Title of the Paper: Evolutionary
Programming Versus Artificial Immune System in Evolving Neural Network for
Grid-connected Photovoltaic System Output Prediction
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Authors: Shahril Irwan
Sulaiman, Titik Khawa Abdul Rahman, Ismail Musirin, Sulaiman Shaari
Abstract: This paper presents the evolutionary neural networks for the
prediction of energy output from a grid-connected photovoltaic (GCPV) system.
Two evolutionary neural network (ENN) models have been proposed using
evolutionary programming and artificial immune system (AIS) respectively. The
artificial neural network (ANN) employed for these models utilized solar
radiation and ambient temperature as its input whereas the kilowatt-hour
energy of the GCPV system is the only targeted output. The evolution of ANN
involves the search of the optimal number of nodes, the learning rate, the
momentum rate, the transfer function and the learning algorithm of a
single-hidden layer multi-layer feedforward ANN. The results showed that
evolutionary programming-ANN (EPANN) outperformed artificial immune system-ANN
(AISANN) in terms of correlation coefficient, R as well as computation time.
In addition, EPANN had also produced better convergence of the evolving
parameters compared to the AISANN.
Keywords: Artificial
neural network (ANN), multi-layer feedforward neural network (MLFNN),
photovoltaic (PV), grid-connected photovoltaic system (GCPV), correlation
coefficient (R), evolutionary programming (EP), artificial immune system (AIS)
and prediction
Title of the Paper: A Novel Block
Matching Algorithm Based on Particle Swarm Optimization with Mutation Operator
and Simplex Method
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Authors: Zhang Ping, Wei
Ping, Yu Hongyang
Abstract: To improve the performance of motion estimation in video coding, we
propose a novel block matching algorithm, which utilize the global search
ability of particle swarm optimization (PSO) with mutation operator and the
local search ability of simplex method (SM).According to the center-biased and
temporal-spatial correlation feature of motion vector and the global
randomness of PSO, the fixed and random points are selected as the initial
individual. Then, block matching process is executed by the updating of the
position and velocity of individual. In order to accelerate the convergence of
PSO and improve the accuracy of local search, mutation operator and simplex
method are used. Meanwhile, based on the feature of static macro blocks, the
proposed algorithm intelligently uses early termination strategies.
Experimental results demonstrate that the proposed algorithm has better PSNR
values than conventional fast block matching algorithms especially for video
sequences with violent motion while the computational complexity of the
proposed algorithm has negligible increase.
Keywords: Motion
estimation, block matching algorithm, particle swarm optimization, mutation,
simplex method, early termination
Title of the Paper: Necessary
Conditions for Optimal Control Problems with and without State Constraints: A
Comparative Study
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Authors: Md. Haider Ali
Biswas
Abstract: It is commonly accepted that optimal control theory was born with
the publication of a seminal paper by Pontryagin and collaborates last
century, at the end of 50’s. Since then optimal control theory has played a
relevant role not only in the dynamic optimization but also in the control and
system engineering. Another crucial moment in this theory is closely related
with the development of nonsmooth analysis during the 70’s and 80’s. Nonsmooth
analysis has triggered a renew interest in optimal control problems and
brought new solutions to old problems. Nowadays optimal control theory is
essential to different areas like system engineering, economics and biology
since many problems are modelled as optimal control problems. A challenging
area of study in this theory remains that of state constraints. In this paper
we review the very basic notions of optimal control problems with and without
state constraints focussing on necessary conditions of optimality for state
constrained problems.
Keywords: Optimal control,
State constraints, Maximum principle, Nonsmooth analysis
Title of the Paper: Identification of
Coherent Generators for Large-Scale Power Systems Using Fuzzy Algorithm
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Authors: Mahdi M. M.
El-Arini, Ahmed Fathy
Abstract: This paper presents a new proposed method for identifying the
coherent groups of generators for any large power system, this is based on two
different techniques; the first one is based on applying two proposed
coherency criterions introduced by using time response of the linearized power
system model; the second one is based on the application of Fuzzy C-Means
clustering algorithm (FCM). Also a new technique of constructing the dynamic
equivalent of power system is presented in this work. The proposed method is
applied on two different power systems. The obtained results proved that the
proposed technique is highly effective in determining the coherent groups of
generators and in constructing the dynamic equivalent of power system with
high accuracy.
Keywords: Coherent groups
of generator, Fuzzy C-Means Clustering Algorithm, Dynamic equivalents, Network
reduction, Dynamic aggregation, Large-scale power system.
Issue 7, Volume 6,
July 2011
Title of the Paper: Effective
Optimization of the Control System for the Cement Raw Meal Mixing Process: I.
PID Tuning Based on Loop Shaping
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Authors: Dimitris
Tsamatsoulis
Abstract: The objective of the present study is to use a reliable model of the
raw meal mixing process dynamics in raw meal production installations, in
order to tune effectively PID controllers, thus regulating the product’s
quality. The system is described by a TITO process. The M - Constrained
Integral Gain Optimization (MIGO) loop shaping method is utilized to adjust
the controller parameters. Long term actual industrial data are used for this
purpose while the controller robustness is also investigated. Taking into
account the maximum sensitivity constraint and the model uncertainty the
controller is parameterized and implemented to industrial raw meal production
units by replacing previous controllers or manual regulation. The results
indicate remarkable enhancement of the raw meal homogeneity fed to the kiln.
Therefore the tuning methodology applied provides effective PID controllers,
able to attenuate the disturbances affecting the raw meal quality.
Keywords: Dynamics, Raw
meal, Quality, Mill, Model, Uncertainty, PID, Robustness, Sensitivity
Title of the Paper: On Plant Modeling
for the PIM Digital Redesign of a Power System Stabilizer
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Authors: G. Shabib
Abstract: This paper is concerned with the plant modeling for the digital
redesign of a continuous-time power system stabilizer PSS for the single
machine power system using the so-called Plant –Input-Mapping PIM method. The
traditional approach has been to use the bilinear transform (Tustin’s method),
but this gives numerical difficulties with large sampling intervals which are
now becoming usual with modern control hardware. The proposed technique
guarantees the stability for any sampling rate and takes the closed-loop
characteristics into account. The proposed technique is successfully applied
to the discretization of a continuous time PSS for single-machine power
system. For comparison studies the proposed technique is compared with
continuous-time PSS and Tustin’s PSS. The simulation results show that the
proposed digital redesign technique reflects the frequency and dynamic
responses of the system more accurately as the continuous-time PSS. Also, they
show that Tustin’s method falls when sampling interval becomes larger while
the proposed PIM method guarantees stability even with relatively slow
sampling rates.
Keywords: Digital
redesign, Discretization, Dynamic stability, Power systems, Sampled-data
system
Title of the Paper: Model Predictive
Control Approach Based Load Frequency Controller
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Authors: Ali Mohamed
Yousef
Abstract: The present paper investigates the design of Load-Frequency Control
( LFC) system for improving power system dynamic performance over a wide range
of operating conditions based on model predtictive control MPC technique. The
objectives of load frequency control (LFC) are to minimize the transient
deviations in area frequency and tie-line power interchange variables . Also
steady state error of the above variaables forced to be zeros. The two control
schems namely Fuzzy logic control and proposed model predictive control are
designed. Both the two controllers empoly the local frequency deviation signal
as input signal. The dynamic model of two-area power system under study is
estabilished . To validate the effectiveness of the proposed MPC controller,
two-area power system is simulated over a wide range of operating conditions.
Further, comparative studies between the fuzzy logic controller (FLC), and the
proposed MPC load frequency control are evaluated.
Keywords: Model predictive
control - Fuzzy logic controller, Load Frequency Control, Two area power
system
Title of the Paper: Effective
Optimization of the Control System for the Cement Raw Meal Mixing Process: II.
Optimizing Robust PID Controllers Using Real Process Simulators
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Authors: Dimitris
Tsamatsoulis
Abstract: The present study is aiming to develop a simulator of the mixing
process in production installations of raw meal comprising all the main
characteristics of the process and raw materials. The system is described by a
TITO process regarding the adjustment of the two main quality indicators of
the raw meal and regulated via PID controllers. The M - Constrained Integral
Gain Optimization (MIGO) method is used to tune the controller parameters.
Based on actual industrial data the simulator is implemented to determine the
optimum PID parameters according to the subsequent criteria: (a) specified
robustness constraint and (b) minimum variance of the raw mix chemical modules
in raw mill outlet and kiln feed. The simulator offers the possibility to
analyze the effect of the process parameters on the raw meal homogeneity.
Other digital PID implementations except the one utilized or other control
laws can be investigated as well.
Keywords: Dynamics, Raw
meal, Quality, Mill, Simulation, Uncertainty, PID, Robustness
Issue 8, Volume 6,
August 2011
Title of the Paper: Stability
Enhancement for a Superconducting Generator in Multimachine Power System Using
STATCOM
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Authors: R. A. Amer, G.
A. Morsy, H. A. Yassin
Abstract: This paper investigates the multi-machine power systems stability
enhancement by means of STATCOM-based stabilizers. To demonstrate the
influence of the introduction of the STATCOM to the power systems, a
comparative study is implemented by attaching a single SVC or a single STATCOM
to the studied power system. The under-study power system includes a
superconducting generator (SCG) and nine conventional units of different types
and ratings. In view of control, various types of control systems are used
such as Proportional Integral Derivative (PID) controller and power system
stabilizers (PSSs). The system’s nonlinear model is established by achieving a
satisfactory degree of accuracy and tested for various types of contingency.
The simulation results reveal that, the introduction of STATCOM is achieving
further enhancement of the system performance in terms of damping increase and
fast return of system variables to their nominal values under different
disturbances such as 3-phase short circuit, step increase in load, and line
outage compared to the SVC-based stabilizers.
Keywords: Multi-machine
power systems, Control systems, Superconducting generator, Static var
compensator, STATCOM, PID controller
Title of the Paper: Morphing Motion in
Modular Robots
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Authors: Fei Yanqiong,
Wang Yong
Abstract: Two kinds of basic modules are presented to set up the modular
robots. One is the cuboid module, the other is the cubic module. Four
connecting types of cuboid modules and two connecting types of cubic modules
are analyzed based on their geometric feature. For deriving the transformation
matrix of each connecting type, the concepts of basic group are proposed.
Then, the geometric relationships of each connecting type are derived with the
group theory. The basic motion of modules is presented. With the rotary motion
around the neighboring module, the morphing motion from a quadruped to two-leg
modular robot is shown and the kinematics of modular robots is generated with
product of matrix exponentials. Examples of kinematics on a quadruped and a
two-leg modular robot are given to demonstrate the applicability of the
proposed methods.
Keywords: Modules, Robot,
Kinematics, Morphing, Motion
Title of the Paper: DC Characteristic
Analysis of Three-Phase LC Filter- Uncontrollable Rectifier Using Circuit DQ
Transformation
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Authors: Xin Geng,
Xi-Jun Yang, Zhe-Min Zhang, Hou-Jun Tang, Liang-Yu Bai
Abstract: The three-phase uncontrollable rectifiers are still widely applied,
at present, in kinds of household appliances, because of its low cost, simple
structure and excellent applicability. There are no LC filters in some
simplified schematics. Sometimes, filter inductors are connected between
rectifiers and power grids. For some higher requirements the three-phase
passive power factor correction techniques with input LC filter are used in
getting a higher power factor, just as the high power inverter air
conditioners. Since the three-phase LC filter uncontrollable rectifier circuit
is a strong coupling nonlinear system, it is difficult to analyse, model and
select the parameters of LC filters. In this paper, circuit DQ transformation
method is adopted to analyse the circuit’s working principle better. It can
convert the nonlinear circuit into linear system, then propose the novel
concepts of the equivalent switching function, the control angle and the
overlapping angle of uncontrollable rectifier. From this way, it makes the
system controllable and discovers the controllability in three-phase LC filter
uncontrollable rectifier systems. Through the analysis of the system DC
characteristics, the expressions of output voltage, active power, passive
power and power factor are calculated, which are identical to those of other
controlled rectifiers. The relationship between the control angle and the load
resistance are obtained through the simulation analysis. Experimental results
on the rated output power 7.5kW three-phase rectifying system has proven the
above theoretical analysis and circuit DQ transformation method. It has also
proven the proposed concepts, which is practical to analyze the performances
of the uncontrollable rectifier systems.
Keywords: Three-phase
passive PFC, Uncontrollable rectifier, DQ transformation, Power factor
correction, Input LC filter, Equivalent switching function
Issue 9, Volume 6,
September 2011
Title of the Paper: SCG Stability
Enhancement Using STATCOM Based-ANN Controller
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Authors: R. A. Amer, G.
A. Morsy, H. A. Yassin
Abstract: Artificial neural network (ANN) control of static compensator
(STATCOM) to improve the damping of power systems is presented. The proposed
control strategy is applied on a STATCOM attached to a single machine-infinite
bus (SMIB) and a multi-machine power systems that include a superconducting
generator (SCG). The proposed control method, ANN-STATCOM is designed based on
proportional integral derivative (PID) by means of minimization of the
system’s deviations. The damping provided by the ANNSTATCOM controller is
compared with a fixed-parameter PID-STATCOM controller. In view of power
systems control, various conventional types of control systems are employed
such as PID controller for SCG and power system stabilizers (PSSs) for
conventional units. The simulation results demonstrate the effectiveness of
the proposed ANN-STATCOM controller in stabilizing the power systems
performance for various disturbances at multiple operating points.
Keywords: Power system
control, Superconducting generator, Static compensator, ANN control
Title of the Paper: Reliability and
Quality Improvement of Robotic Manipulation Systems
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Authors: Yaser Maddahi,
Ali Maddahi
Abstract: This paper reports the procedure of experimental evaluation and
objective/quantitative comparison, among different performance parameters, of
the Cartesian (3P) robots. Here, first by implementing the equations of
motion, the mechanical model of this type of robot is simulated using Working
Model software. Next, the initial model of robot is designed based on the
results concluded from the simulated model and the robot structure including
control unit, mechanical elements and operating procedure is described. Also,
some tests are applied on the prototype robot in order to verify the
analytical side of design procedure. The experiments consist of calibrating
the robot motion along all three axes (prismatic joints) and validation of
three performance indices, which are easy to measure via simple
experimentations namely accuracy, repeatability and maximum allowable load
carrying capacity. The acceptable values of the indices are predefined as
input of design process. The data derived from the experimental tests showed
that the robot satisfies the acceptable values. The main contribution of this
paper is to improve the robot design by exerting the changes obtained from
assessment of some defined statistical and mechanical indices.
Keywords: Design,
Cartesian robot, Performance index, Experimental test, Design improvement
Title of the Paper: Techniques for
Predictor Design in Multivariable Predictive Control
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Authors: Marek Kubalcik,
Vladimir Bobal
Abstract: Model Based Predictive Control (MBPC) or only Predictive Control is
one of the control methods which have developed considerably over a few past
years. It is mostly based on discrete models of controlled systems. Model of a
controlled system is used for computation of predictions of the systems output
on the basis of past inputs, outputs and states and designed sequence of
future control increments. This paper is focused in comparison of various
approaches to computation of multi–step–ahead predictions using a
multivariable input – output model. Computational aspects of derivation of
predictions can be limiting especially in adaptive predictive control. Many
processes are affected by external disturbances that can be measured.
Inclusion of measurable disturbances into prediction equations for different
approaches was also elaborated.
Keywords: Predictive
control, multivariable systems, multi-step-ahead prediction, Diophantine
equations, CARIMA model
Issue 10, Volume 6,
October 2011
Title of the Paper: The Torque Control
with Multi-Objective Performance for E-Bike Systems with Human Power
Assistance
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Authors: Pang-Chia Chen,
Chih-Ching Hsiao, Sun-Li Wu, Shyue-Bin Chang
Abstract: This paper proposes a velocity control approach for the light
electric bike with human power assistance. The velocity control signal is
composed of two signals. One is a velocity-dependent equilibratory torque to
compensate the wind resistance. Another is a deviation torque to achieve
desired multi-objective performance represented in terms of linear matrix
inequality (LMI) conditions. The formulated multi-objective performances
includes the invariant set of state variable under the magnitude bounded
disturbance, the magnitude bound on the regulated output, and the ?H
performance optimization for attenuation of various disturbance effects on the
regulated output. The disturbances include the deviations of tire resistance,
human assistant torque, and driver’s weight from nominal values. Based on the
parameters and specifications of the EL-168 electric bike produced by KENTFA
Advanced Technology, Taiwan, the design results are verified through
time-response simulations under both the flat and linear varying gradient road
conditions.
Keywords: Electric Bike,
Torque Control, LMI, Multi-Objective Control, Human Power Assistance
Title of the Paper: Hysteresis Model
Parameters Identification for the SAS Rotational MR Damper
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Authors: Yousef
Iskandarani, Hamid Reza Karimi
Abstract: Comfort, reliability, functionality performance which provide a
longer life cycle requires thourogh understanding and analysis of the
vibrations, this is a general rule for most of the static and dynamic when
studying the functionality performance of any application. Vibrations is an
extremely important issue to consider when designing various systems.The
hysteresis in the dampers is very important issue when characterizing the
damper used to suppress the vibrations, it is a very complex phenomena but
very important to understand and consider during the design phase. The
hysteresis equations of Bouc-Wen, Lugre, and Dahl have been modeled and
simulated in Matlab/Simulink. Afterward, the different parameters in the
models was manipulated and their effects on the outcome was analyzed. The
hysteresis models of Bouc-Wen, Dahl and LuGre have been analyzed and compared
analytically to really show the difference in the models. At last the Bouc-Wen
model was implemented together with the SAS(Semi Active Suspension) system.
The model parameters were tuned manually to try to fit the response of the
system. In this paper a predefined methodology has been applied for
determining the hysteresis loop parameters using the data collected for
vibration analysis under predefined test specifications. The following data
has been used later to regenerate the vibration signal, so on get as closer to
the real signal.In the coming work, advanced method will be used to determine
the exact parameters for the hysteresis loop as well as using the inverse
hysteresis to improve the of the vibration suspension in the Semi Active
Suspension system.The behavior of MR dampers can be presented with different
mathematical models. The Bouc-Wen model was found to be model to both
illustrate the MR damper and recreate the behavior of the SAS system.
Keywords: Bouc-Wen model,
Dahl model, Hysteresis, Lugre model, Magnetorheological damper,Parameters
identification, Semi-Active Suspension System
Title of the Paper: Robust Stability of
Linear Fractional Systems with Non Linear Uncertainties
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Authors: Ouadia El
Figuigui, Nourreddine El Alami
Abstract: Using the differentiation and integration of fractional order or
non-integer order in systems control is gaining more and more interest from
the systems control community. In the present document, we study the stability
of multivariable fractional systems using robust fractional controller. Some
important mathematical inequalities and particularly the Gronwall inequality
are employed to investigate the robust stability conditions which are based to
non linear bounded uncertainties.
Keywords: Fractional
system, robust stability, controller, Gronwall Bellman, inequality,
multivariable system
Issue 11, Volume 6,
November 2011
Title of the Paper: Fuzzy Tracking
Control Based on H? Performance for Nonlinear Systems
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Authors: Trihastuti
Agustinah, Achmad Jazidie, Mohammad Nuh
Abstract: This paper presents a fuzzy tracking control design based on H?
performance for nonlinear systems. The Takagi-Sugeno fuzzy model is employed
to approximate a nonlinear system. Based on the H? tracking performance, the
nonlinear system output is controlled to track a reference signal, and at the
same time the tracking performance is attenuated to a prescribed level. Linear
matrix inequalities (LMI) techniques are used to solve the fuzzy tracking
control problem. The proposed method has been applied to control of a
laboratory pendulum-cart system. Hence, the performance has been evaluated in
simulations as well as in real-time control.
Keywords: Fuzzy tracking
control, H? performance, LMI, Pendulum-cart system
Title of the Paper: On-Line Adaptive
Fuzzy Switching Controller for SCARA Robot
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Authors: Marwan A.,
Farrukh Nagi, Ksm Sahari, Hanim S., Fadi. I.
Abstract: This paper presents the design, development and implementation of a
new on-line adaptive MIMO switching controller (FSC) for real-time tracking
control of an industrial SCARA robot. Two link SCARA robot is a nonlinear
plant. The fuzzy control is based on the Takagi-Sugeno’s type fuzzy
architecture model with on-line self-tuning so that both the desired transient
and steady state responses can be achieved at different operation conditions.
The online real-time self-tuning is based on the gradient steepest descent
method, which tunes the inputs and outputs scaling factors of the proposed
fuzzy controller. This controller simplifies the Real-time control
implementation and improves the control performance. Real-time controller is
implemented in Matlab’s xPC Real-time workshop environment. SCARA robot system
identification was accomplished by using Auto Regression with external input
method (ARX) to determine the discrete time transfer function necessary for
the controller design. Comparison between the self-tuned fuzzy switching
controller and fixed fuzzy switching controller was made to evaluate the real
time tuning’s performance. The comparison is based on the tracking ability
subjected to large payload. Based on the real time results the performance of
fuzzy switching controller with this tuning strategy was found to be superior
and it matches favourably to the operating conditions.
Keywords: SCARA robot ,
two-link manipulators, fuzzy switching control, online self-tuning, xPC
Target, educational robotics
Title of the Paper: Stability Condition
for Discrete Systems with Multiple State Delays
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Authors: Sara Pakzad,
Mohammad Ali Pakzad
Abstract: Many natural systems have intrinsic delays, caused by input, output
or state variables. In an openloop system, input delay doesn’t affect the
stability but if feedback of the state is utilized for controlling the
systems, the delay is transferred to closed-loop state and would affect the
stability of the system. It is important to evaluate/examine the stability of
continuous and discrete delayed-systems. In continuous systems existence of
delay increases system dimension to infinity (number of poles is infinite). In
discrete systems, number of poles increases but it is finite. Due to the lack
of proper and powerful tools in discrete systems, the evaluations of stability
in these systems are very important. In this paper, an approach has been
proposed based on Lyapunov equation and frequency domain stability analysis
for systems which have delay in their states. In this approach, stability
conditions have been obtained for discrete systems with delay in a specific
interval. All previous works on discrete systems are often for single-delay in
state. The purpose of this paper is to extend the existence approaches for
systems that have multiple delays in their states. Performance of the proposed
method has been studied in several examples.
Keywords: Discrete-time
systems with delay, stability, Lyapunov equation, state delay
Issue 12, Volume 6,
December 2011
Title of the Paper: Wind Driven
Induction Generator Regulation Using Ant system Approach to Takagi Sugeno
Fuzzy PID Control
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Authors: A. H. Besheer
Abstract: This study introduces new tuning technique for the PID control
scheme and its application to regulate the voltage magnitude and the frequency
of wind energy conversion system (WECS). The developed technique is stem from
blending the ant system optimization method with Takagi Sugeno (T-S) fuzzy
system approach. The optimum relationship between the PID controller gains and
the parameters of T-S fuzzy modules is explored using Ant system algorithm. A
steady-state analysis for self excited slip ring induction generator is
performed. The calculated and the experimental results on 1.1 KW laboratory
machine enables the control characteristics to be deduced. Different
simulation examples are provided to illustrate the effectiveness of the
proposed technique. Finally, the response of a closed loop control scheme for
WECS using chopper controlled external rotor resistance and fixed capacitor
with thyristor controlled reactor shows that the proposed control approach
exhibits a superior performance to that of established traditional control
methods.
Keywords: T-S fuzzy
control, PID control, Ant system optimization, WECS
Title of the Paper: Gain Scheduled
Automatic Flight Control Systems Design for a Light Commercial Helicopter
Model
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Authors: Erkan
Abdulhamitbilal, Elbrous M. Jafarov
Abstract: In this paper, nonlinear rigid body dynamics for rotorcraft
mathematical model is studied. A linearization of helicopter flight dynamics
is evaluated. Automatic Flight Control System (AFCS) with gain scheduled LQ
optimal control is designed based on look-up tables. Stability analyses are
performed and results are illustrated graphically for open and closed-loop
systems. As seen from results, LQ optimal control system pushes eigenvalues to
left side of imaginary axis without excessive control inputs to maintain
stability of naturally unstable rotorcraft dynamics. Proposed AFCS is tested
by nonlinear flight dynamics model in Matlab- Simulink environment. Simulation
results illustrate effectiveness of evaluated method and techniques.
Keywords: helicopter,
flight dynamics, nonlinear model, simulation
Title of the Paper: Control Design for
Uncertain Singularly Perturbed Systems with Discrete Time Delay
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Authors: Bahador Makki,
Baharak Makki
Abstract: The problem of state-feedback control design for a class of
singularly perturbed systems with time delays and norm-bounded nonlinear
uncertainties is studied in this paper. The system under consideration
considers discrete delays in both slow and fast dynamics and norm-bounded
nonlinear uncertainties. It is shown that the control gains are obtained to
guarantee the stability of the closed-loop system for all perturbed parameters
in terms of linear matrix inequalities (LMIs). We present an illustrative
example to demonstrate the applicability of the proposed design approach.
Keywords: singularly
perturbed systems, time delay, control design, LMI
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