Mohammad Ahmad Choudhry

Land Mine Detecting Robot Capable of Path Planning

The Landmine detecting robots are designed to cover maximum possible area of landmine field for detection of landmines. The detected landmines along with scanned and leftover area are represented 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 and easily controllable. A graphical user interface is developed for plotting the landmines, scanned & leftover area presentation, PID tuning and camera alignment. Emphasis is placed on the control of the differential drive robot in auto mode, semi-auto mode and the manual mode. Image processing technique is employed to find the accurate position of robot which provides the live reckoning feedback to the dead reckoning servo control of the robot. Metal detector is the sensor used to detect landmines. The graphical user interface for the remote terminal computer provides the effective control for the robot. The system is simple but powerful and intelligible to achieve the required results.

Dynamic modeling of the airship using analytical aerodynamic model

Buoyant vehicle concept provides the attractive solution to the many adverse problems. Basic objective is to operate the vehicle with a sufficient level of autonomy under extreme range of atmospheric conditions. In order to achieve these goals, a guidance and control system is needed which controls the airship attitude in the air. The accurate control system first requires an accurate model of the airship dynamics. In this paper, we discuss first some airship basic concepts. Based on six degree of freedom, airship dynamic model is presented next. Its aerodynamic part is based on analytical geometry instead of expansive wind tunnel test arrangement and the easily understandable MATLAB environment is used to simulate the results.

Investigating Smooth Power Flow Control for Dispersed Generator Working Parallel to the Grid System on the Load Side

This research work investigates development of a power flow control strategy so that power flowing from utility supply side to the common load bus can be controlled economically in the presence of DG. The control of power flow from Main/utility supply and DG source to common load bus will be such that, load will not sense any king of disturbance. The studies are performed based on well known software package MATLAB/Simpower tool box. The work proposes use of static/FACT device, Unified power flow controller (UPFQ) to control power flow at load bus by utility in coordination with DG source so that response time taken by DG source to share load with utility and transients that appears in initial seconds are reduced. The work shows that Reliable, Effective and Efficient operation of DG source in coordination with main utility network is achieved using static device. Hence, the consumer is optimally benefited

An efficient design of genetic algorithm based Adaptive Fuzzy Logic Controller for multivariable control of HVAC systems

In Heating, Ventilating and Air Conditioning (HVAC) systems, effective thermal management is required because energy and operation costs of buildings are directly influenced by how well an air-conditioning system performs. HVAC systems are typically nonlinear time varying with disturbances, where conventional PID controllers may trade-off between stability and rise time. To overcome this limitation, a Genetic Algorithm based Adaptive Fuzzy Logic Controller (AFLC) design has been proposed for the control of temperature and relative humidity of an experimental setup by manipulating valve positions to adjust the water and steam flow rates for Air Handling Unit (AHU). Modulating equal percentage Globe valves for chilled water and steam have been modeled according to exact flow rates of water and steam. A novel method for the adaptation of Fuzzy Logic Controller (FLC) by modifying Fuzzy Rule Matrix (FRM) based on Genetic Algorithm (GA) has been proposed. The proposed adaptive controller outperforms the existing fuzzy controller in terms of steady state error, rise time and settling time.

Multivariable adaptive Fuzzy logic controller design based on genetic algorithm applied to HVAC systems

In Heating, Ventilating and Air Conditioning (HVAC) systems, effective thermal management is required because energy and operation costs of buildings are directly influenced by how well an air-conditioning system performs. HVAC systems are typically nonlinear time varying with disturbances, where conventional PID controllers may trade-off between stability and rise time. To overcome this limitation, a Genetic Algorithm based Adaptive Fuzzy Logic Controller (AFLC) design has been proposed for the control of temperature and relative humidity of an experimental setup by manipulating valve positions to adjust the water and steam flow rates for Air Handling Unit (AHU). Modulating equal percentage Globe valves for chilled water and steam have been modeled according to exact flow rates of water and steam. A novel method for the adaptation of Fuzzy Logic Controller (FLC) by modifying Fuzzy Rule Matrix (FRM) based on Genetic Algorithm (GA) has been proposed. The proposed adaptive controller outperforms the existing fuzzy controller in terms of steady state error, rise time and settling time.

Application of State Estimation Technique for Impedance matching to optimize Static Transfer Switch operation

The performance of complementary feeders, running in parallel, is significantly improved by installing static transfer switch (STS) at critical locations. Normally STS control logic is designed such that both feeder voltages are considered in phase and the three phase (3-Phi) line reactance of both the feeders are assumed to be equal. However, the two different feeders have different parameters and hence the phase angle between both bus voltages at the receiving end of the STS terminals is different. Depending on phase angle difference and time of disturbance, cross current phenomena occurs during switching consequently transfer time is maximized. Results show improvement in the performance of STS when weighted-least square state estimation technique has been used to estimate the phase angle at the input terminals of STS. The impedances of both feeders have been matched and phase angle difference at the STS terminals has been eliminated by installing shunt capacitor of proper size. PSCAD/EMTDC software package has been used for simulation and analysis.

Performance Improvement In Distribution Feeder By Installing Distributed Generation At Strategic Locations

In the competitive deregulated environment, the interest in the distributed generation (DG) is world widely increasing. The installation of small generating units affects the operation of electric utility system and classical modeling and analyzing techniques must be revised. The increasing load demand may violate the consumers voltage permissible limits. This paper proposes the utilization of DG, a novel technique for feeder voltage drop mitigation at strategic locations. The results from the case study shows that DG can be practically applied to distribution feeder for eliminating voltage drop at customers premises. The proposed method helps to alleviate power quality problems for sensitive loads and improve the system reliability. The system has been simulated in PSCAD/EMTDC software

Reconfiguration of feeders using static transfer switch

Electricity customers often suffer from supply voltage interruptions/sags due to different types of faults. An effective way to improve power quality and reliability of sensitive customers is to use static transfer switch (STS). Most power quality problems are removed by transferring customers to alternate feeder using STS. In this paper, performance of STS and its control logic for feeder reconfiguration to handle power problems is evaluated. Two particular network feeders namely primary and secondary were selected for simulation studies. Both feeders belong to IESCO system (Islamabad Electric Supply Company, Pakistan). Different simulation cases were performed for optimum installation of STS to obtain the required voltage quality and the point of interest (PoI) was investigated. Different simulations are performed using the PSCAD/EMTDC package, to improve the voltage quality

Application of Static Transfer Switch for Feeder Reconfiguration to Improve Voltage at Critical Locations

The main objective of this work was to assess and evaluate the performance of static transfer switch (STS) for feeder reconfiguration. Two particular network feeders namely preferred and alternate were selected for simulation studies. Both feeders belong to IESCO system (Islamabad Electric Supply Company, Pakistan). The sensitive loads are fed by preferred feeder but in case of disturbances, the loads are transferred to alternate feeder. Different simulation cases were performed for optimum installation of STS to obtain the required voltage quality. The simulations are performed using the PSCAD/EMTDC package

Nonlinear auto-regressive neural network for mathematical modelling of an airship using experimental data

Autonomous flight of an aerial vehicle requires a sufficiently accurate mathematical model, which can capture system dynamics in the presence of external disturbances. Artificial neural network is known for ideal in capturing systems behaviour, where little knowledge about vehicle dynamics is available. In this paper, we explored this potential of artificial neural network for characterizing nonlinear dynamics of an unmanned airship. The flight experimentation data for an outdoor experimental airship are acquired through a series of pre-determined flight tests. The experimental data are subjected to a class of dynamic recurrent neural network model dubbed as nonlinear auto-regressive model with exogenous inputs for training. Sufficiently trained neural network model captured and demonstrated the longitudinal dynamics of the airship satisfactorily. We also demonstrated the usefulness of proposed technique for Lotte airship, wherein the performance of proposed model is validated and analysed for the Lotte airship flight test data.