Hussain A. Attia

Automatic control of agricultural pumps based on soil moisture sensing

In this paper, we investigate the design and simulation of an electronic system for automatic controlling of water pumps that are used for agricultural fields or plant watering based on the level of soil moisture sensing. The detected signal from the soil moisture sensor is processed by a conditional comparator circuit corresponding to different levels of actual soil moisture content. A logic circuit follows the conditional circuit with its output signals used to activate a system of relays that control the power circuit of the motors used for water pumping. The speed of the motor is varied according to the level of the soil moisture content; the motor is OFF during maximum wet and is running with HIGH speed during dry soil conditions respectively. The duration of water pumping is controlled by a timer circuit where the timer can be designed according to the desired watering time. The different stages of the overall electronic system are simulated and tested using NI MULTISM simulation software. The technique is useful to save human-power, enhances crop or plant productivity, saves water and provides proper water management to ensure efficient and viable farming industry especially in those places that receive less rain or mostly dry areas.

Novel Design and Implementation of Portable Charger through Low-Power PV Energy System

This paper proposes a novel design for a solar-powered charger for low-power devices. The level of the charging current is controllable and any residue power is saveable to a rechargeable 9V battery. Two power sources (AC and solar) are used, and two charging speeds are possible. Quick charging is 20% of the battery output current (almost 180mA/hr) so the current is limited to 34 mA. Two types of cellular batteries (5.7V and 3.7V) can be charged. Normal charging is 10% of the cellular battery output current (almost 1,000mA/hr), so the charging current is limited to 100mA. The design uses only a few components so the system is cost effective besides being highly portable. It was simulated on MultiSim Ver. 11 before being implemented practically to validate it. The results from the simulation and the experiment show the designs sufficient feasibility for practical implementation.

Design and Simulation of a High Performance Standalone Photovoltaic System

This paper proposes a full design with all included stages of a high performance standalone photovoltaic system based on discrete electronic components. The design proposes a solution to reduce or eliminate the fluctuation of the supplied DC voltage of solar panel due to weather variations. The proposed design includes DC–DC boost converter that produces a stable DC output voltage with a higher level, this is achieved by controlling the Duty cycle of the drive switching pulses during sensing the level of the solar panel voltage. The next stage is a modified unipolar Sinusoidal Pulse Width Modulation inverter with Zero Crossing Detector circuit that is designed with a modified higher power reference wave compared with traditional SPWM. The modified SPWM controls the Modulation Index to stabilize the fluctuation in the output AC voltage. The selected filter type LCL-Filter is designed to minimize the effect of harmonics on the load voltage. On the other hand, an accurate DC power supply is designed to provide the required stable DC voltages for all included electronic circuits; the solar panel voltage is an input to the designed DC power supply. Total Harmonic Distribution measurements, the stable output voltage level of the DC–DC converter, DC power supply, and the stabilization of the load voltage reflect the effectiveness of the proposed photovoltaic system. The overall electronic design works under wide range of solar panel voltage fluctuations. The satisfactory simulation results indicate that there is a promise to implement the proposed electronic design using discrete components as practical module.

Design of decentralized street LED light dimming system

To reduce power consumption due to street lighting, we propose replacing conventional power consuming High Pressure Sodium Lamps and metal Halide lamps with LED lamps which consume much less power. We also propose employing LED light dimming by modifying the light intensity based on the traffic conditions on the road. Most of the dimming systems currently deployed on the streets use computerized and remotely controlled wireless monitoring systems which suffer from complexity, high cost and a response that is dependent on the network data transfer speed. Unlike these systems, we propose, in this paper, a decentralized street LED light dimming system that is installed on each pole and whose dimming action is controlled by the dimming circuit of the pole itself. This yields faster and more reliable response. In addition, the proposed system does not need any additional infrastructure. It is scalable in the sense that it can be used in small or main streets with any number of poles, and flexible in system specifications based on the selection of the coverage distance of the designed motion detector. Simulations show the effectiveness of the proposed system and in saving energy.

Multi-classifier decision fusion for enhancing melanoma recognition accuracy

This paper proposes an automated non-invasive multi-classifier system for skin cancer (melanoma) detection. The proposed system fuses the results obtained from three classification systems to enhance the melanoma detection rate. All of the classification systems use Support Vector Machine classifier. However, the image feature sets used in each classification system are different. The features sets used are Wavelets and Color features, Curvelets features and Grey Level Co-occurrence Matrices features. The output class labels or class probabilities of the three classification systems are combined using Majority Voting or Averaging Fusion to obtain enhanced classification rates. The dataset used include digital images for benign and malignant skin lesions. Experimental results show that the proposed multi-classifier fusion method outperforms standalone Skin Lesion classification systems in terms of recognition accuracy. Consequently, this can increase the chances of non-invasive melanoma detection from digital images.

Automatic water level sensor and controller system

In this paper, we investigate the design of a water level sensor device that is able to detect and control the level of water in a certain water tank or a similar water storage system. The system firstly senses the amount of water available in the tank by the level detector part and then adjusts the state of the water pump in accordance to the water level information. This electronic design achieves automation through sequential logic implemented using a flip flop. A seven segment display and a relay-based motor pump driving circuit are part of this integrated design. The water pump automatically turns on and starts filling the tank when the water level is empty or level ONE and turned-off and stop filling the tank when water level reaches maximum-level NINE; furthermore, the water pump will remain in its standstill state from level EIGHT down to TWO when the level is decreasing due to water consumption.

Identification of dialed telephone numbers in touch tone telephone system based on frequency analysis

This work investigates identification of dialed numbers in a touch-tone telephone system based on Dual Tone Multi Frequency (DTMF) signaling technique. The tone of each dialed number is a sum of two carrier frequencies uniquely assigned to the number and any dialed number can be uniquely identified or decoded by analyzing and locating the pair of frequencies where there is maximum energy or amplitude in the spectrum of each tone. Frequency analysis is performed using Discrete Time Fourier Transform (DTFT) and simulation steps and results of the decoding technique are presented. Reliable DTMF decoding is essential as nowadays the use of DTMF signaling is prevalent not only for ordinary telephone signaling but also remote controlling of home, industrial and rural applications.

Evaluation of Selective Harmonic Elimination Pulse Width Modulation Technique for Unipolar Single-Phase H-Bridge Inverter: Comparative Study

This paper describes the method to control a hybrid robot whose main task is to climb a pole to place an object on the top of the pole. The hybrid pole-climbing robot considered in this paper uses 2 Planetary PG36 DC-motors as actuators and an external rotary encoder sensor to provide a feedback on the change in robot orientation during the climbing movement. The orientation control of the pole-climbing robot using self-tuning method has been realized by identifying the transfer function of the actuator system under consideration, being followed with the calculation of control parameters using the self-tuning pole-placement method, and furthermore being implemented on the external rotary encoder sensor. Self-tuning pole-placement method has been explored to control the parameters q 0 , q 1 , q 2 , and p 1 of the controller. The experiments were done on a movement path in a form of a cylindrical pole. The first experiment was done based one the change in rotation angle of the rotary sensor with the angle values greater than 50˚ in the positive direction, whereas the second experiment was done with the angle values greater than -50˚ in the negative direction. The experiment results show that the control of the robot under consideration could maintain its original position at the time of angle change disturbance and that the robot could climb in a straight direction within the specified tolerance of orientation angle change.

Fuzzy Logic Controller Effectiveness Evaluation through Comparative Memberships for Photovoltaic Maximum Power Point Tracking Function

Efficiency, reliability, high power quality and continuous operation are important aspects in electric vehicle attraction system. Therefore, quick fault detection, isolation and enhanced fault-tolerant control for open-switches faults in inverter driving systems become more and more required in this filed. However, fault detection and localization algorithms have been known to have many performance limitations due to speed variations such as wrong decision making of fault occurrence. Those weaknesses are investigated and solved in this paper using currents magnitudes fault indices, current direct component fault indices and a decision system. A simulation model and experimental setup are utilized to validate the proposed concept. Many simulation and experimental results are carried out to show the effectiveness of the proposed fault detection approach.The inverter with critical loads should be able to provide critical loads with a stable and seamless voltage during control mode change as well as clearing time. The indirect current control has been proposed for providing stable voltage with critical load during clearing time and seamless control mode transfer of inverters. However, the islanding detection is difficult since with the indirect current control the magnitude and frequency of voltage do not change when the islanding occurs. The conventional anti-islanding method based on the magnitude and frequency of voltage variation cannot apply to the indirect current control. This paper proposes an islanding detection method for the indirect current control. The proposed islanding detection method can detect the islanding using reactive power perturbation and observation when the frequency and magnitude of voltage don’t vary during clearing time. In order to verify the proposed anti-islanding method, the experimental results of a 600W three-phase inverter are provided.

Electronic monitoring and protection system for drunk driver based on breath sample testing

This paper focuses on the problem of drunk driver which is represent one of the major reasons for traffic accidents during the last decades. Alcohol negatively affects the drunk driver judgment abilities and driving skills. Many engineering solutions have been proposed to reduce the consequences of drunk driving. However, most of these solutions were based on a certain type of control units or though computerized protection systems including wirelessly monitoring facilities. This resulted in having systems with demerits of complexity, high cost and slow response in the case of remote monitoring and remote decision making. These solutions were mainly dependendent on one type of controlling unit as well. To avoid all the above mentioned disadvantages, this paper introduces a simple, cheap and highly responsive design. The proposed design is based on discrete electronic components with processing and decision made locally and does not involve wireless transmission to guarantee the required fast response.