Pusat Pengajian Kejuruteraaan Elektrik dan Elektronik - Tesis
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- PublicationIdentification Of Muscle Sound (MMG) In Human Body(1999-04)Khedher A. HmoodFrom the biomedical engineering study on muscle fibers, there are two types of signals: Electromyography (EMG) signal and muscle sound (MMG). The EMG signal is generated by the human muscle and is detected by using stainless steel electrodes but the muscle sound MMG is detected using vibration detection sensor such as piezoelectric sensor. In this thesis, a suitable sensor has been used to detect the muscle sound in order to analyze its characteristics.
- PublicationAn Efficient Surface Mapping Technique Using Laser Triangulation For Image Recontruction(2003-05)Tjio Hok HooAn image acquisition system, which is used to capture 2-D images of object/scene for 3-D image reconstruction, is developed based on triangulation technique. The system consists of three devices, i.e. B/W CCO camera, laser diode and rotary table. These devices are placed in such a way that a triangle is formed. A grating line, which has a width of one pixel, is mounted in front of the laser diode. The purpose of the grating line is to project a stripe line on the surface of the object/scene. In this research, the positions of the camera and the laser diode are fixed. In order to acquire sufficient information for 3-D image reconstruction, the object/scene is rotated 360° about the azimuth of the rotary table. At every 15°, the rotary table is paused and a reflected image of the object is captured by the camera. Therefore, 24 different images are recorded in one complete rotation.
- PublicationElectromagnetic Tomography For 2-D Mapping Of Moisture Content In Rice(2003-10)Lim, Meng ChunThis thesis deals with the development and application of electromagnetic tomography in food engineering applications, especially in moisture content profiling of cereals such as rice grain.
- PublicationDesign and development of an intelligent battery charger station(2009-03-01)Teoh, Wee WeeThis thesis presents the design and development of an intelligent battery charger for simultaneous charging of four NiMH batteries. It is designed to satisfy the demands of high current and fast charge applications such as electrical vehicles which use batteries as the electrical source energy. The purpose of this design is to provide an efficient charging algorithm using a microcontroller PIC16F877 in order to protect against overcharging and reduce the recharging time. This design includes the discharging function. In this design, the control and supervision of the whole charging process is entrusted to a microcontroller, which able to find out the initial battery state , decide the fit way to charge the battery (in order to ensure a long cycle-life) and determine when the charge process must be finished. The proposed design provides multiple charging current options with automated selection of optimum charging rate for the battery being charged. The charging algorithm is programmed in the PIC16F877 by using PIC Basic Pro. There are four basic charging algorithm used in this charger: slow (10%C), soft (20%C), fast (55%C) and trickle (4%C). The experimental results obtained show that the charger is functioning properly with the state defined in the microcontroller. The current regulation is successfully done by using PWM control. The accurate termination of fast charging cycle and safe charging of batteries demonstrate the reliable functioning of the proposed design. The charging and discharging curve obtained is almost the same as stated in the theoretical characteristic. The charging time to charge the battery from empty to full is almost two hours. The battery voltage at the end of charging cycle obtained is around 1.38V/battery. The fast charge cycle bring the battery to approximately 90% of the full charge condition. The implementation of design’s objective is fulfilled and is supported by experimental results.
- PublicationDevelopment of behaviour-based mobile robot for goal seeking and obstacle navigation(2009-03-01)Oo, Cheng HoeIn the field of robotic, there are some concerns that always grab the world attention which are the motion planning and control problem. Both of them will finally decide the collision-free trajectories for a robot in static or dynamic environments which may have many unknown obstacle around while seeking the goal. Thus this report describes the development of a behavior-based mobile robot for the obstacle navigation and goal seeking. The subsumption architecture will be utilized with the obstacle avoidance having higher priority over goal seeking. In fact, there are many possible obstacles that may keep the robot wandering around aimlessly seeking the goal. One of its main problems is local minimum problem which keep robot trapping in a corner. Owing to simplicity, wall following will be the better solution for that case. Beside that, a deadlock is also consideration in this paper. In the nutshell, the report will discuss all possible obstacles that may exist in the real world. However the goal seeking feature still has flaw when it is combined with the obstacle avoidance. Besides that, the designed robot will act as leader guiding the other robots which are the followers to avoid the obstacle around while searching the goal. This is called the leader-following.
- PublicationDesign and implementation of autonomous autopiloted aerial vehicle platform(2009-04-01)Mohamad, Ahmad AshrafThe control of a helicopter is complex, and includes the interaction of forces and the balancing of them. Although a stable condition can be achieved with sophisticated control system, good mechanical design can reduce the problem of instability of a helicopter. One of the designs is the coaxial types of blade system. Nevertheless, a good control system is still needed since a helicopter control involves many parameters. The PIC16F876A microcontroller has been used to measured the input from sensor, do the calculation and control the actuators (two DC motors and two servos). In this project, ultrasonic sensor is used to control the height of the platform. The implementation of a control system such as PID will increase the efficiency of the system. Implementation shows that the coaxial helicopter is able to fly in control condition but more adjustment needs to be made to make it more stable.
- PublicationControl strategy of permanent magnet brushlessdc motor using matlab / Simulink(2009-04-01)Manan, NoradzimThe Permanent Magnet Brushless DC motor (PMBLDC) has a permanentmagnet rotor, and the stator windings are wound such that the back electromotive force (BEMF) is trapezoidal. Therefore it requires rectangular shaped stator phase currents to produce constant torque. The trapezoidal back EMF implies that the mutual inductance between the stator and rotor is nonsinusoidal. The objective of this project is to develop a simulation of PMBLDC using Matlab / Simulink software. The result of this simulation is to show theperformance of the PMBLDC by referring its stator current, speed, torque and back electromotive force (BEMF). This result will be compare with the ideal waveform obtained from theory. In this simulation model, the PMBLDC is controlled by hysteresis current controller and PI controller for motor speed.
- PublicationImage super resolution using interpolation(2009-04-01)Lee, Siang HoeInterpolation is a method to enlarge an image. It collects information from an image and uses this information to predict the unknown information in the upgrade size of image. The information in an image will affect the image resolution. Low resolution image has least information or smaller image size, and high resolution image has more information and bigger image size. In this project, a low resolution image is interpolated by four different interpolation methods, and this interpolated image is filtered by four filtering methods. These four interpolation and four filtering methods are nearest neighbor interpolation, bilinear interpolation, bicubic interpolation, Lanczos interpolation, smoothing filter, Gaussian filter, sharpening filter and unsharp masking filter. The final image of each method is compared, and the difference with ground truth image is measured. Based on the results, it shows that magnification ratio is inversely proportional to output image. As magnification ratio increase, the output image quality is decreased. In up sampling an image, interpolation methods should be considered first then only filtering methods. This because interpolation methods affects output result the most rather than filtering methods. Bicubic interpolation gives 18.5513 of MSE value and Gaussian filter gives 17.3515 of MSE value which both are the lowest MSE value among others interpolation and filtering methods for magnification factor of two.
- PublicationModeling and simulation of thermal microactuator(2009-04-01)Ang, Beng SengThis thesis focuses on the modeling and simulation of a thermal bimorph microactuator. It involves the modeling of electrothermal, mechanical, electrical and geometrical characteristics of a thermal bimorph microactuator. Upon studying the principles of a thermal microactuator, the analytical modeling and simulation is achieved through CAD software, Coventorware®. For most materials, when they are heated, it causes an increase in size; and a decrease in size occurs with decreasing temperature. The amount of expansion is small when compared to the overall size of the device undergoing the expansion. Therefore, actuation by thermal expansion must be coupled with a way to amplify the motion or displacement. The best way to amplify the thermal expansion motion is by varying the length of the arm rather than changing the input voltage. For the same material properties of the thermal bimorph microactuator, changing the input voltage consume more electrical power than the one that changes with the length. Normally, the temperature in the thermal bimorph microactuator is only being changed when the applied voltage varies. The displacement of the thermal bimorph microactuator is not affected by the temperature change. The maximum temperature of the thermal bimorph microactuator appears at the middle of the hot arm. The parameters that influence the performance of the thermal bimorph microactuator are also discussed.
- PublicationHand tracking system as virtual input device(2009-04-01)New, Mung YinThe objective of this project is to develop a vision-based hand tracking system, which can be used as an input device for communicating with the computer. In this system, the only external device required is a webcam. There are two webcams being used throughout the project, each for one hand. In this report, a hand tracking algorithm has been presented using Simulink® to track and recognize hand gestures for interacting with a computer. This algorithm is based on five steps; which are image acquisition, hand detection, hand segmentation, feature extraction, and gesture recognition. In hand detection, accurate skin colour model is being built, and is used for hand segmentation to segment the hand from the background. Feature extraction is performed to extract useful information from images. In gesture recognition, extracted information is used for recognizing the hand movement. Besides, a graphical user interface (GUI) is created for presenting the results. The results show that the system can successfully track the hand, and integration of the algorithm into useful applications such as motion controlling. From the project, it can also be seen that vision-based hand tracking system can be realized, and it provides a convenient way for human-computer interface.
- PublicationExploring graph cut technique for mammography images(2009-04-01)Ding, Nik SiongBreast cancer is one of the most common diseases among woman nowadays. However, the presence of medical imaging tools such as mammography enables diagnosis of breast cancer to be conducted at beginning stage of breast cancer development. Mammogram is the image produced by mammography process. The presence of abnormal structures in mammograms will indicate that the woman is having a breast cancer. In this study, a new algorithm called graph cut was explored to evaluate its efficiency to detect the presence of abnormal structures in mammograms. Although graph cut technique is new but it has generated a lot interest among the researchers in the computer vision community. The primary reason for this rising popularity has been the successes of efficient graph cut algorithm in solving many low level vision problems such as image segmentation, object reconstruction, image restoration and disparity estimation. Masses and mircocalcifications are two most common abnormal structures in mammograms. In this study, a specific mammogram segmentation algorithm was developed based on the graph cut technique. This mammogram segmentation algorithm was used to test efficiency of the graph cut technique to segment the abnormal structures out of mammograms. The success rates of detecting these abnormal structures are high. For masses, graph cut technique able to detect the mass structures in all mammograms used to test this technique. Meanwhile, for microcalcifications, graph cut technique only can detect the microcalcification structures in mammograms which show low density breast. These segmentation results proved that graph cut technique is suitable to be used to detect the presence of abnormal structures in mammograms.
- PublicationArtificial neural network for gas-oil flow pattern recognition using capacitance tomography data(2009-04-01)Tan, Kim LengThe technique to recognize the oil and gas flow pattern in a pipe is needed in the oil and gas industry to monitoring the condition of the oil and gas pipe system. Any mistake or malfunction may lead to serious loss and endanger the workers and environments. Generally there are lots of flow pattern such as Empty, Full, Stratified, Bubble, Core and Annular. The Electrical Capacitance Tomography (ECT) technique is used to take the cross sectional data of the pipe. The Artificial Neural Networks (ANNs) is used to recognize the flow patterns. This project uses the Multilayer Perceptron (MLP) as the ANNs model. The MLP is trained, validated, and tested with the ECT data. The ECT data is divided into three groups, training, validation, and testing. The Matlab software is used to build the MLP architecture. The learning algorithms used for this project is the Levenberg-Marquardt algorithms and the Quasi-Newton algorithms. Result show that trained MLP is able to give a percentage of accuracy of 99.102% in oil and gas flow pattern recognition. This shows that the MLP is suitable to be used in the oil and gas flow pattern recognition.
- PublicationImplementation of motion estimation and motion compensation using block matching algorithms for video coding(2009-04-01)Tan, Sin PengA motion estimation and compensation algorithm for video compression is implemented using MATLAB software. In this project, two types of block matching algorithm (BMA) have been developed that is the Exhaustive Search (ES) and Three Step Search (TSS). In this approach, the current frame of a video sequence is divided into a matrix of macro blocks that are then compared with corresponding block and its adjacent neighbors in the previous frame to find the motion vector that stipulates the movement of a macro block from one location to another in the previous frame. This movement calculated for all the macro blocks comprising a frame, constitutes the motion estimated in the current frame. A motion compensated image for the current frame is then created that is built of blocks of image from the previous frame. The matching of one macro block with another is based on the output of a cost function. The macro block that results in the least cost is the one that matches the closest to current block. From thesimulation results obtained, ES has a better PSNR performance compared with the TSS. The average search point per macro block for ES is also computed and the value is almost 9 times of that of the TSS. TSS technique proved to be the better BMA since it has a significantly smaller computation time with its PSNR performance almost the same as the ES.
- PublicationAnalysis of harmonic current produced by ac-dc converters with various firing angles(2009-04-01)Nik Hassan, Nik Mohd FaridThe main propose of this project is to analyze harmonic input current produced by AC to DC converter by varying firing angle.Generally,the analysis of input current can be defined as changes to Total Harmonic Distorted. This overall project analyzes 2 variables to relate firing angle with thyristor by differences of the total harmonic distorted.The AC to DC converter that is used is single phase AC to DC converter and three phases AC to DC converter.The AC to DC one phase converter used 4 thyristor while 3 phase AC to DC converter used 6 thyristor as as switch.The resistance being assumed in this analysis is pure resistance.The values of capacitor and inductor resistance are not considered. The purpose of doing so is to neglect the value of Power Factor for the AC to DC circuit.In this Project,3 steps is taken to analyze the relationship of firing angle in thyristor to the total harmonic distorted.The first step is to use theories of input waveform current harmonic changes and this value is interpreted by Fourier Series.Based on the results obtained from the three methods,for single phase control rectifier,it can is observed that the firing angle is directly proportional to THD,and the range varying angle obeys the standard introduced by IEEE for THD,which is less than 20% for angles of 0° to 40°.For three phase control rectifier,it is observed that the firing angle increases with respect to THD,and no range firing angles obeys the standard of IEEE.This is because based on the experiment,3 phase controlled rectifier,when the varying angle of thyristor is 0°,the THD value is 26.7%,and exceeded the standard fixed by IEEE.
- PublicationDevelopement of a 500w inverter system(2009-04-01)Sabri, Ahmad YusrieThe goal of the project is to produce a high efficiency inverter system to convert a 12 V dc supply to a 240 V sinusoidal ac output with a 50 Hz frequency. It is aimed at first the project will be able to produced an inverter having an efficiency of 75% or greater. A PWM switching scheme will be used for the switching of a full bridge inverter. Full bridge inverter circuit is used to convert a DC input to AC output. Output will be step up using a 500 W transformer with a ratio of 12 V primary sides and 240 V secondary sides. Another important issue in designing inverter is how the harmonics is present and how to eliminate it. A second order LC filter is able to eliminate the unwanted harmonics that occur at the output of the system. The simulation result shows that the design able to produce a circuit of high efficiency (greater than 95%), however the practical implementation fails to yield a desired output.
- PublicationAutomation of voltage using analog voltage margining card(2009-04-01)Loh, Han YangIn this project, voltage automation scripts for Analog Voltage Margining Card (AVMC) are being developed. The AVMC card is a card used to support analog validation of a target test system. It supports margining of target voltage supplies through voltage and simulated current controls. AVMC is used to replace ADM1066 chip for the voltage margining due to its accuracy and flexibility. Voltage automation scripts are written using bash language because it is suited for automation tasks. For the scripts to work, an operating system called System Validation Operating System (SVOS) such that user can margin the voltage by entering a single command. The voltage margining scripts generated is being tested on two types of Intel board which are Pinetrail and Tigerhill. Seven Pinetrail and five Tigerhill boards are used for testing the voltage margining scripts. When running a script on a board, the output voltage on the board is being measured using a digital multimeter. The measurement is then compared to the actual or desired value of the user. Voltage margining had been carried out to each available board and it shows that the scripts work. Hence, the voltage margining scripts for AVMC had been successfully developed and is currently used for running test purposes in Intel.
- PublicationMicro and millimeter wave integrated circuit (mmwic) amplifier(2009-04-01)Ng, Xiang RhungThe aim of this project was to design low noise (LNA) and medium power amplifier (MPA) at 30GHz based on 0.15um GaAs Power Pseudomorphic High Electron Mobility Transistor pHEMT technology. The simulation was performed using ADS. The LNA and MPA in this project are using the same methodology that is define the device characteristic, biasing network, stability network, input and output matching network, cascading the single stage circuit and design layout. At a supply voltage of 3.0V and 30 GHz operating frequency, this two-stage LNA achieves an associated gain of 21.628 dB, noise figure (NF) of 2.509 dB and output referred 1dB compression point (P1dB) of -11.003dBm, the total power consumptions for the LNA is 174mW. At a supply voltage of 6.0V and 30 GHz operating frequency, a 2-stage MPA achieves a linear gain (S21) of 13.236 dB, P1dB of 22.455dBm, power gain of 11.055 dB and the PAE of 14.606% and the total power consumptions for the MPA is 1.122W. The 30GHz LNA and PA can be applied in direct broadcast satellite (DBS), automotive radar transmitter and receiver respectively.
- PublicationImage processing with artificial intelligence(2009-04-01)Kenny, Toh Kal VinDigital images acquired through many consumer electronics products are often corrupted by salt-and-pepper noise during image acquisition, recording and transmission due to a number of nonidealities encountered in image sensors, communication channels and external disturbance. In most image processing applications, it is of vital importance to remove the noise from the image data because the performance of subsequent image processing tasks such as edge detection, image segmentation and others. This includes the elimination of salt-and-pepper noise contained in the images and at the same time preserving the image integrity. Specifically for the removal of salt-and-pepper noise, the median-based filters have been chief in this regard. Besides, there is the class of fuzzy-inference ruled by else-action (FIRE) filters, employing soft computing techniques to filter salt-and-pepper noise. In this project, a new fuzzy switching median (FSM) filter utilizing fuzzy techniques in image processing is developed. The designed filter is able to remove salt-and-pepper noise in digital images while preserving image details and textures very well. By incorporating fuzzy reasoning in correcting the detected noisy pixel, the low complexity FSMfilter is able to outperform some well known existing salt-and-pepper noise fuzzy and classical filters.
- PublicationAnalysis of rf-to-voltage power detector for outdoor application(2009-04-01)Ng, Gua BinThis is a dissertation regarding the analysis of RF power detector for outdoor application. RF power detector is an apparatus provided for detection of the output power from an RF power amplifier for purposes of controlling the output power. It is important in wireless communication system since each system has a specific power regulation and strength. This leads to the need for selectivity and good control of the output signal’s level. This became a fundamental issue in the design of any communication system. Therefore, AGC circuits become an important system especially for any device or system where wide amplitude variations in the output signal could lead to a lost of information or to an unacceptable performance of the system. Since there are various types of power detector available in the market, logarithmic amplifier was utilized to be implemented in AGC circuit after considering some factors. Before implementing on practical environment, analysis on log amp and AGC circuit is done by using ADS software. After that, the AGC practical circuit is presented and analyzed on breadboard according to the simulation circuit. From the analysis, the performance of AGC practical circuit is better in between 500 kHz and 1 MHz frequency range with a 40dB dynamic range.
- PublicationHigh speed image processing using dsp card(2009-04-01)Tan, Chen YanThis project is about the development of a system to detect objects like circles in real-time processing. This system can be adapted to the automation industries to modify for defects detection and location upon objects detection. Objects will be setting onto the conveyor belt, passing through by scanning the targeted objects with the ‘robotic eye’, which is the CCD camera. High speed image processing will be conducted to ensure the detection upon purposes. In this project, detection of center of circles is highlighted. CHT will be implemented, mapping each possible edge into horizontal and vertical components into accumulator. The center of the circles can be then estimated by analyzing the accumulator. The data of the estimated center of circles will be sent to the robotic part through serial communication to act upon the data received, locating and pointing to the center of circles. The output of the processing can be shown on monitor as well if required.