Iraqi Journal for Electrical And Electronic Engineering

Pre-processing is very useful in a variety of situations
since it helps to suppress information that is not related to the
exact image processing or analysis task. Mathematical
morphology is used for analysis, understanding and image
processing. It is an influential method in the geometric
morphological analysis and image understanding. It has befallen
a new theory in the digital image processing domain. Edges
detection and noise reduction are a crucial and very important
pre-processing step. The classical edge detection methods and
filtering are less accurate in detecting complex edge and filtering
various types of noise. This paper proposed some useful
mathematic morphological techniques to detect edge and to
filter noise in metal parts image. The experimental result
showed that the proposed algorithm helps to increase accuracy
of metal parts inspection system.

Analog filters constitute indispensible
component of analog circuits and still playing an
important part in interface with analog real world.
realizing filters with odd order is preferred because of its
time response . Therefore, this paper is conducted to
introduce a new generalized Chebyshev – like
approximation for analog filters. The analyses presented
to realize the filters with odd order. This proposed novel
approach offer good results in terms of flat delay and
time domain response. Also, the achieved results are
validated by comparison to normal Chebyshev filter via
investigation several examples

This paper examines the use of non-integer switching
frequency ratios in digitally controlled DC-DC converters. In
particular the execution of multiple control algorithms using a
Digital Signal Processor (DSP) for this application is analyzed.
The variation in delay from when the Analog to Digital
Converter (ADC) samples the output voltage to when the duty
cycle is updated is identified as a critical factor to be considered
when implementing the digital control system. Fixing the delay
to its maximum value is found to produce reasonable
performance using a conventional DSP. A modification of the
DSP’s interrupt control logic is proposed here that minimizes
the delay and thereby yields improved performance compared
with that given by a standard interrupt controller. Applying this
technique to a multi-rail power supply system provides the
designer with the flexibility to choose arbitrary switching
frequencies for individual converters, thereby allowing
optimization of the efficiency and performance of the individual
converters.

This paper present an adaptation mechanism for
fuzzy logic controller FLC in order to perfect the response
performance against small rotation angles of real D.C. motor
with unknown parameters. A supervisor fuzzy controller SFC is
designed to continuously adjust, on-line, the universe of
discourse UOD of the basic fuzzy controller BFC input variables
based on position error and change of position error.
Performance of the proposed adaptive fuzzy controller is
compared with corresponding conventional FLC in terms of
several performance measures such rise time, settling time, peak
overshoot, and steady state error. The system design and
implementation are carried out using LabVIEW 2009 with NI
PCI-6251 data acquisition DAQ card. The practical results
demonstrate using self tuning FLC scheme grant a better
performance as compared with conventional FLC which is
incapable of rotating a motor if the rotation angle is being small

Induction Motor (IM) speed control is an area of
research that has been in prominence for some time now. In this
paper, a nonlinear controller is presented for IM drives. The
nonlinear controller is designed based on input-output feedback
linearization control technique, combined with sliding mode
control (SMC) to obtain a robust, fast and precise control of IM
speed. The input-output feedback linearization control
decouples the flux control from the speed control and makes the
synthesis of linear controllers possible. To validate the
performances of the proposed control scheme, we provided a
series of simulation results and a comparative study between the
performances of the proposed control strategy and those of the
feedback linearization control (FLC) schemes. Simulation
results show that the proposed control strategy scheme shows
better performance than the FLC strategy in the face of system
parameters variation

It's not easy to implement the mixed /
optimal controller for high order system, since in the
conventional mixed / optimal feedback the
order of the controller is much than that of the plant.
This difficulty had been solved by using the structured
specified PID controller. The merit of PID controllers
comes from its simple structure, and can meets the
industry processes. Also it have some kind of
robustness. Even that it's hard to PID to cope the
complex control problems such as the uncertainty and
the disturbance effects. The present ideas suggests
combining some of model control theories with the
PID controller to achieve the complicated control
problems. One of these ideas is presented in this paper
by tuning the PID parameters to achieve the mixed
/ optimal performance by using Intelligent
Genetic Algorithm (IGA). A simple modification is
added to IGA in this paper to speed up the
optimization search process. Two MIMO example are
used during investigation in this paper. Each one of
them has different control problem

The paper dells with a modified experimental
prototype for pulse-width modulation (PWM) sliding mode
control (SMC) applied to a DC-to-DC-boost converter operated
in continuous conduction mode (CCM). Experimental results
show that the proposed control schme provides good voltage
regulation and is suitable for common DC-to-DC conversion
purposes. The prototype and its implementation are given in
detail. The static and dynamic performances of the The static
and dynamic performances of the experimental system are
recorded. Experimental results show that the proposed control
scheme provides good voltage regulation and is suitable for
common DC-to-DC conversion purposes.

Among all control methods for induction
motor drives, Direct Torque Control (DTC) seems
to be particularly interesting being independent of
machine rotor parameters and requiring no speed
or position sensors. The DTC scheme is
characterized by the absence of PI regulators,
coordinate transformations, current regulators and
PWM signals generators. In spite of its simplicity,
DTC allows a good torque control in steady state
and transient operating conditions to be obtained.
However, the presence of hysterics controllers for
flux and torque could determine torque and current
ripple and variable switching frequency operation
for the voltage source inverter. This paper is aimed
to analyze DTC principles, and the problems related
to its implementation, especially the torque ripple
and the possible improvements to reduce this torque
ripple by using a proposed fuzzy based duty cycle
controller. The effectiveness of the duty ratio
method was verified by simulation using
Matlab/Simulink software package. The results are
compared with that of the traditional DTC models.

This paper addresses the problem of pitch angle
regulation of floating wind turbines with the presence of
dynamic uncertainty and unknown disturbances usually
encountered in offshore wind turbines, where two control laws
are derived for two different cases to continuously achieve zero
pitch angle for the floating turbine. In the first case, the timevarying
unknown coefficients that characterize the turbine's
dynamics are assumed reasonably bounded by known functions,
where robust controller is designed in terms of these known
functions to achieve zero pitch angle for the turbine with
exponential rate of convergence. While in the second case, the
turbine's dynamics are considered to be characterized by
unknown coefficients of unknown bounds. In this case, a slidingmode
adaptive controller is constructed in terms of estimated
values for the unknown coefficients, where these values are
continuously updated by adaptive laws associated with the
proposed controller to ensure asymptotic convergence to zero
for the turbine's pitch angle. Simulations are performed to
demonstrate the validity of the proposed controllers to achieve
the required regulation objective.

This paper concerns with exploitation of renewable
energy sources for meeting energy requirements of remote
locations. It presents an investigation which is based on a
practical project that was executed in collaboration between
academia and industry. It involves design and installation of a
prototype integrated renewable energy system which consists of
two 15 kW wind turbines, electrolyser, fuel cell system (FCS)
and the associated control equipment. It was installed at the
furthest island of Shetland, North of Scotland, U.K. The
philosophy used in designing this system is summarised as
follows: During times of high wind, the electricity generated by
wind turbines is normally greater than that required by site
electrical load. The excessive amount of generated electricity is
stored into Hydrogen by utilising an electrolyser which is then
used to generate the deficient electric power by the FCS at times
of low wind.

In this paper we have proposed a nonlinear
mathematical model for a wind turbine. The
objective function maximizes the power of the wind
turbine and the constraints are related to the rotor
and tower costs. Rotor diameter and hub height are
the variables which affect on power of the wind
turbine, so we have considered them as decision
variable in our mathematical model. By increasing
rotor diameter and hub height the power of the
turbine will increase but the costs don’t let the
infinitive increase in rotor diameter and height. The
model applied for a typical case study and the results
of solving the model for it have shown in the paper.

solar power is environment friendly power source, but is characterized by being highly dependent on the irradiation level which is function of the sun position on the sky. to overcome this ssituation and extract maximum power from the sun, th PV array must be kept nearly perpendicular to the sun during the daytime.
in this paper, a smart relay based sun tracking system has been designed and implemented tp keep the PV array perpendicular to the sun during the day hours.

The ability to harvest energy from the environment
represents an important technology area that promises to
eliminate wires and battery maintenance for many important
applications and permits deploying self powered devices. This
paper suggests the use of a solar energy harvester to charge
mobile phone devices. In the beginning, a comprehensive
overview to the energy harvesting concept and technologies is
presented. Then the design procedure of our energy harvester
was detailed. Our prototype solar energy harvester proves its
efficiency to charge the aimed batteries under sunlight or an
indoor artificial light

A genetic algorithm is implemented to represent the
different shapes of Photonic Crystal Fiber (PCF) profile; this is
due to the fact that such fibers have special structure. A novel
approach is suggested which differs from the usual fibers. By
applying this new approach, more realistic representations of
their profiles are drawn and hence highly accurate results are
obtained including propagation and dispersion characteristics.

In this paper two theoretical models have been
considered for the prediction of path loss for two different
districts in Mosul city, using MATLAB 7.4 program. The
Walfisch-Ikegami (W-I) model for uniform heights and similar
buildings in the Karama district . The other model is
Okumura-Hata (OH) model applied for irregular and
dissimilar buildings in the Almajmoa'a district. The
information buildings heights are obtained from the civil Eng.
Depart. in Mosul university. In this paper it can be shown that
The effect of distance in regular area (karama) on path loss is
about 10 dB larger than irregular area (Almajmoa'a), and The
effect of varying antenna height in regular area (karama) on
path loss is about 7 dB greater than irregular area
(Almajmoa'a) for 40 meter variation.

The synchronization of chaos is a well-known topic
which attracted the attention of the scientific community in the
last two decades. However, the robustness of the synchronous
state has been not widely studied, especially considering real
cases in which the effects introduced by the physical channel
through which chaotic circuits interact, may deeply influence the
quality of synchronization and even the onset of it. In this paper,
the synchronization of two chaotic circuit coupled through a non–
ideal channel is investigated. In particular, the effects of channels
introducing a frequency–independent or frequency–dependent
time–delay are investigated. Furthermore, two different design
strategies to obtain a linear compensation block able to compensate
the considered channel effects are presented and the recovery
of the synchronous state is discussed.